From 018aca4eb1724a1196675b06b01a4bc4039ada35 Mon Sep 17 00:00:00 2001 From: boB Rudis Date: Sun, 4 Mar 2018 21:40:41 -0500 Subject: [PATCH] Travis run for pre-CRAN flight check --- DESCRIPTION | 5 +- NEWS.md | 8 + R/RcppExports.R | 12 +- R/ndjson.R | 6 +- README.Rmd | 18 +- README.md | 170 +- cran-comments.md | 12 +- src/RcppExports.cpp | 30 +- src/json.h | 24733 +++++++++++++++++++++++------------------ src/ndjson.cpp | 6 +- tests/testthat/test-ndjson.R | 9 +- 11 files changed, 13841 insertions(+), 11168 deletions(-) diff --git a/DESCRIPTION b/DESCRIPTION index 93e482c..71a89d5 100644 --- a/DESCRIPTION +++ b/DESCRIPTION @@ -2,7 +2,7 @@ Package: ndjson Type: Package Title: Wicked-Fast Streaming 'JSON' ('ndjson') Reader Version: 0.5.0 -Date: 2017-06-28 +Date: 2018-03-04 Author: Bob Rudis (bob@rud.is), Niels Lohmann (C++ json parser), Deepak Bandyopadhyay (C++ gzstream), Lutz Kettner (C++ gzstream) Maintainer: Bob Rudis @@ -18,6 +18,7 @@ BugReports: https://gitlab.com/hrbrmstr/ndjson/issues SystemRequirements: zlib, C++11 NeedsCompilation: yes License: AGPL +Encoding: UTF-8 Suggests: testthat Depends: @@ -28,4 +29,4 @@ Imports: dplyr, dtplyr LinkingTo: Rcpp -RoxygenNote: 6.0.1 +RoxygenNote: 6.0.1.9000 diff --git a/NEWS.md b/NEWS.md index 67779b6..5851e99 100644 --- a/NEWS.md +++ b/NEWS.md @@ -1,3 +1,11 @@ +0.6.0 +===================== +* Updated to nlohmann/json.hpp v3.1.1 (Ref: + ) +* Removed nlohmann/json.hpp #pragma's causing CRAN issues vis-a-vis the new + "Clutter up the console with unnecessary warnings" policy. +# Slightly modified tests + 0.5.0 ===================== * Updated core ndjson file to take care of some buffer overflow vulns diff --git a/R/RcppExports.R b/R/RcppExports.R index d08fa46..6548608 100644 --- a/R/RcppExports.R +++ b/R/RcppExports.R @@ -1,15 +1,15 @@ # Generated by using Rcpp::compileAttributes() -> do not edit by hand # Generator token: 10BE3573-1514-4C36-9D1C-5A225CD40393 -internal_flatten <- function(lines) { - .Call(ndjson_internal_flatten, lines) +flatten_int <- function(lines) { + .Call(`_ndjson_flatten_int`, lines) } -internal_stream_in <- function(path) { - .Call(ndjson_internal_stream_in, path) +stream_in_int <- function(path) { + .Call(`_ndjson_stream_in_int`, path) } -internal_validate <- function(path, verbose) { - .Call(ndjson_internal_validate, path, verbose) +validate_int <- function(path, verbose) { + .Call(`_ndjson_validate_int`, path, verbose) } diff --git a/R/ndjson.R b/R/ndjson.R index 8677d0a..3a8aa3d 100644 --- a/R/ndjson.R +++ b/R/ndjson.R @@ -19,7 +19,7 @@ #' nrow(stream_in(gzf)) stream_in <- function(path, cls = c("dt", "tbl")) { cls <- match.arg(cls, c("dt", "tbl")) - tmp <- .Call('ndjson_internal_stream_in', path.expand(path), PACKAGE='ndjson') + tmp <- stream_in_int(path.expand(path)) tmp <- dtplyr::tbl_dt(data.table::rbindlist(tmp, fill=TRUE)) if (cls == "tbl") dplyr::tbl_df(tmp) else tmp } @@ -43,7 +43,7 @@ stream_in <- function(path, cls = c("dt", "tbl")) { #' gzf <- system.file("extdata", "testgz.json.gz", package="ndjson") #' validate(gzf) validate <- function(path, verbose=FALSE) { - .Call('ndjson_internal_validate', path.expand(path), verbose, PACKAGE='ndjson') + validate_int(path.expand(path), verbose) } #' Flatten a character vector of individual JSON lines into a \code{tbl_dt} @@ -59,7 +59,7 @@ validate <- function(path, verbose=FALSE) { #' flatten('{"top":{"next":{"final":1,"end":true},"another":"yes"},"more":"no"}') flatten <- function(x, cls = c("dt", "tbl")) { cls <- match.arg(cls, c("dt", "tbl")) - tmp <- .Call('ndjson_internal_flatten', x, PACKAGE='ndjson') + tmp <- flatten_int(x) tmp <- dtplyr::tbl_dt(data.table::rbindlist(tmp, fill=TRUE)) if (cls == "tbl") dplyr::tbl_df(tmp) else tmp } diff --git a/README.Rmd b/README.Rmd index 99d8dac..c9327e8 100644 --- a/README.Rmd +++ b/README.Rmd @@ -5,7 +5,11 @@ output: rmarkdown::github_document [![CRAN_Status_Badge](http://www.r-pkg.org/badges/version/ndjson)](https://cran.r-project.org/package=ndjson) ![downloads](http://cranlogs.r-pkg.org/badges/grand-total/ndjson) -`ndjson` : Wicked-fast Streaming JSON ('ndjson') Reader +# `ndjson` + +Wicked-fast Streaming JSON ('ndjson') Reader + +## Description Rcpp/C++11 wrapper for @@ -26,7 +30,7 @@ The least painful way to do this is to install gcc >= 4.9 (and you should instal FC=ccache gfortran F77=ccache gfortran -### Why `ndjson` + Examples +## Why `ndjson` + Examples An example of such files are the output from Rapid7 internet-wide scans, such as their [HTTPS study](https://scans.io/study/sonar.https). A gzip'd extract of 100,000 of one of those scans weighs in abt about 171MB. The records sometimes contain heavily nested JSON elements depending on how comprehensive the certificate data and other fields were. A typical record will look like this: @@ -93,6 +97,8 @@ All of the certificate sub-field data elents have been expanded and we have a hi However, if you do end up trying to work with that scan data, it's highly recommended that you use `jq` to filter out the fields or records you want into a more compact ndjson file. +## What's inside the tin? + The following functions are implemented: - `stream_in`: Stream in ndjson from a file (handles `.gz` files) @@ -101,7 +107,7 @@ The following functions are implemented: There are no current plans for a `stream_out()` function since `jsonlite::stream_out()` does a great job tossing `data.frame`-like structures out to an ndjson file. -### Installation +## Installation ```{r eval=FALSE} devtools::install_git("https://gitlab.com/hrbrmstr/ndjson.git") @@ -111,7 +117,7 @@ devtools::install_git("https://gitlab.com/hrbrmstr/ndjson.git") options(width=120) ``` -### Usage +## Usage ```{r message=FALSE} library(ndjson) @@ -143,7 +149,7 @@ microbenchmark( ``` -### Test Results +## Test Results ```{r message=FALSE} library(ndjson) @@ -154,4 +160,6 @@ date() test_dir("tests/") ``` +## Code of Conduct + Please note that this project is released with a [Contributor Code of Conduct](CONDUCT.md). By participating in this project you agree to abide by its terms. \ No newline at end of file diff --git a/README.md b/README.md index 6ace6c6..3ee4995 100644 --- a/README.md +++ b/README.md @@ -1,17 +1,29 @@ -[![Travis-CI Build Status](https://travis-ci.org/hrbrmstr/ndjson.svg)](https://travis-ci.org/hrbrmstr/ndjson) [![CRAN\_Status\_Badge](http://www.r-pkg.org/badges/version/ndjson)](https://cran.r-project.org/package=ndjson) ![downloads](http://cranlogs.r-pkg.org/badges/grand-total/ndjson) +[![Travis-CI Build +Status](https://travis-ci.org/hrbrmstr/ndjson.svg)](https://travis-ci.org/hrbrmstr/ndjson) +[![CRAN\_Status\_Badge](http://www.r-pkg.org/badges/version/ndjson)](https://cran.r-project.org/package=ndjson) +![downloads](http://cranlogs.r-pkg.org/badges/grand-total/ndjson) -`ndjson` : Wicked-fast Streaming JSON ('ndjson') Reader +# `ndjson` + +Wicked-fast Streaming JSON (‘ndjson’) Reader + +## Description Rcpp/C++11 wrapper for -The goal is to create a completely "flat" `data.frame`-like structure from ndjson records in plain text ndjson files or gzip'd ndjson files. +The goal is to create a completely “flat” `data.frame`-like structure +from ndjson records in plain text ndjson files or gzip’d ndjson files. ### Installation guidance for Linux/BSD-ish systems -CRAN has binaries for Windows and macOS. To build this on UNIX-like systems, you need at least g++4.9 or clang++. This is a forced requirement by the ndjson library. +CRAN has binaries for Windows and macOS. To build this on UNIX-like +systems, you need at least g++4.9 or clang++. This is a forced +requirement by the ndjson library. -The least painful way to do this is to install gcc >= 4.9 (and you should install ccache while you're at it) and mmodfiy `~/.R/Makevars` thusly: +The least painful way to do this is to install gcc \>= 4.9 (and you +should install ccache while you’re at it) and mmodfiy `~/.R/Makevars` +thusly: # Use whatever version of (g++ >=4.9 or clang++) that you downloaded VER=-4.9 @@ -21,9 +33,14 @@ The least painful way to do this is to install gcc >= 4.9 (and you should ins FC=ccache gfortran F77=ccache gfortran -### Why `ndjson` + Examples +## Why `ndjson` + Examples -An example of such files are the output from Rapid7 internet-wide scans, such as their [HTTPS study](https://scans.io/study/sonar.https). A gzip'd extract of 100,000 of one of those scans weighs in abt about 171MB. The records sometimes contain heavily nested JSON elements depending on how comprehensive the certificate data and other fields were. A typical record will look like this: +An example of such files are the output from Rapid7 internet-wide scans, +such as their [HTTPS study](https://scans.io/study/sonar.https). A +gzip’d extract of 100,000 of one of those scans weighs in abt about +171MB. The records sometimes contain heavily nested JSON elements +depending on how comprehensive the certificate data and other fields +were. A typical record will look like this: { "vhost": "teamchat.buzzpoints.com", @@ -38,10 +55,13 @@ An example of such files are the output from Rapid7 internet-wide scans, such as A `system.time(df <- stream_in("https-extract.json.gz"))` results in: - user system elapsed - 14.822 0.224 15.189 +``` + user system elapsed + 14.822 0.224 15.189 +``` -on a 13" MacBook Pro and produces: +on a 13" MacBook Pro and + produces: Classes ‘tbl_dt’, ‘tbl’, ‘data.table’ and 'data.frame': 100000 obs. of 36 variables: $ certsubject.CN : chr "*.tio.ch" "*.starwoodhotels.com" "a.ssl.fastly.net" "a.ssl.fastly.net" ... @@ -82,27 +102,40 @@ on a 13" MacBook Pro and produces: $ certsubject.Mail : chr NA NA NA NA ... - attr(*, ".internal.selfref")= -All of the certificate sub-field data elents have been expanded and we have a highly performant `tbl_dt` to work with now either in `dplyr` syntax or `data.table` heiroglyphic syntax. Just go see what you have to do in `jsonlite` to get a similar output (and how long it will take). +All of the certificate sub-field data elents have been expanded and we +have a highly performant `tbl_dt` to work with now either in `dplyr` +syntax or `data.table` heiroglyphic syntax. Just go see what you have to +do in `jsonlite` to get a similar output (and how long it will take). -`pryr::object_size(df)` for that shows it's consuming `394 MB`, which means we can read in many more extracts comfortably on a reasonably configured system and most (if not all) of it on a well-configured AWS box. +`pryr::object_size(df)` for that shows it’s consuming `394 MB`, which +means we can read in many more extracts comfortably on a reasonably +configured system and most (if not all) of it on a well-configured AWS +box. -However, if you do end up trying to work with that scan data, it's highly recommended that you use `jq` to filter out the fields or records you want into a more compact ndjson file. +However, if you do end up trying to work with that scan data, it’s +highly recommended that you use `jq` to filter out the fields or records +you want into a more compact ndjson file. + +## What’s inside the tin? The following functions are implemented: -- `stream_in`: Stream in ndjson from a file (handles `.gz` files) -- `validate`: Validate JSON records in an ndjson file (handles `.gz` files) -- `flatten`: Flatten a character vector of individual JSON lines + - `stream_in`: Stream in ndjson from a file (handles `.gz` files) + - `validate`: Validate JSON records in an ndjson file (handles `.gz` + files) + - `flatten`: Flatten a character vector of individual JSON lines -There are no current plans for a `stream_out()` function since `jsonlite::stream_out()` does a great job tossing `data.frame`-like structures out to an ndjson file. +There are no current plans for a `stream_out()` function since +`jsonlite::stream_out()` does a great job tossing `data.frame`-like +structures out to an ndjson file. -### Installation +## Installation ``` r devtools::install_git("https://gitlab.com/hrbrmstr/ndjson.git") ``` -### Usage +## Usage ``` r library(ndjson) @@ -112,7 +145,7 @@ library(microbenchmark) packageVersion("ndjson") ``` - ## [1] '0.3.0.0' + ## [1] '0.5.1' ``` r flatten('{"top":{"next":{"final":1,"end":true},"another":"yes"},"more":"no"}') @@ -120,7 +153,7 @@ flatten('{"top":{"next":{"final":1,"end":true},"another":"yes"},"more":"no"}') ## Source: local data table [1 x 4] ## - ## # tbl_dt [1 × 4] + ## # A tibble: 1 x 4 ## more top.another top.next.end top.next.final ## ## 1 no yes TRUE 1 @@ -134,14 +167,14 @@ dplyr::glimpse(ndjson::stream_in(f)) ## Observations: 100 ## Variables: 8 - ## $ args NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA,... - ## $ headers.Accept "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*",... - ## $ headers.Accept-Encoding "identity", "identity", "identity", "identity", "identity", "identity", "identity",... - ## $ headers.Host "httpbin.org", "httpbin.org", "httpbin.org", "httpbin.org", "httpbin.org", "httpbin... - ## $ headers.User-Agent "Wget/1.18 (darwin15.5.0)", "Wget/1.18 (darwin15.5.0)", "Wget/1.18 (darwin15.5.0)",... - ## $ id 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 2... - ## $ origin "50.252.233.22", "50.252.233.22", "50.252.233.22", "50.252.233.22", "50.252.233.22"... - ## $ url "http://httpbin.org/stream/100", "http://httpbin.org/stream/100", "http://httpbin.o... + ## $ args NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, N... + ## $ headers.Accept "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*... + ## $ `headers.Accept-Encoding` "identity", "identity", "identity", "identity", "identity", "identity", "identity... + ## $ headers.Host "httpbin.org", "httpbin.org", "httpbin.org", "httpbin.org", "httpbin.org", "httpb... + ## $ `headers.User-Agent` "Wget/1.18 (darwin15.5.0)", "Wget/1.18 (darwin15.5.0)", "Wget/1.18 (darwin15.5.0)... + ## $ id 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,... + ## $ origin "50.252.233.22", "50.252.233.22", "50.252.233.22", "50.252.233.22", "50.252.233.2... + ## $ url "http://httpbin.org/stream/100", "http://httpbin.org/stream/100", "http://httpbin... ``` r dplyr::glimpse(ndjson::stream_in(gzf)) @@ -149,14 +182,14 @@ dplyr::glimpse(ndjson::stream_in(gzf)) ## Observations: 100 ## Variables: 8 - ## $ args NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA,... - ## $ headers.Accept "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*",... - ## $ headers.Accept-Encoding "identity", "identity", "identity", "identity", "identity", "identity", "identity",... - ## $ headers.Host "httpbin.org", "httpbin.org", "httpbin.org", "httpbin.org", "httpbin.org", "httpbin... - ## $ headers.User-Agent "Wget/1.18 (darwin15.5.0)", "Wget/1.18 (darwin15.5.0)", "Wget/1.18 (darwin15.5.0)",... - ## $ id 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 2... - ## $ origin "50.252.233.22", "50.252.233.22", "50.252.233.22", "50.252.233.22", "50.252.233.22"... - ## $ url "http://httpbin.org/stream/100", "http://httpbin.org/stream/100", "http://httpbin.o... + ## $ args NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, N... + ## $ headers.Accept "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*... + ## $ `headers.Accept-Encoding` "identity", "identity", "identity", "identity", "identity", "identity", "identity... + ## $ headers.Host "httpbin.org", "httpbin.org", "httpbin.org", "httpbin.org", "httpbin.org", "httpb... + ## $ `headers.User-Agent` "Wget/1.18 (darwin15.5.0)", "Wget/1.18 (darwin15.5.0)", "Wget/1.18 (darwin15.5.0)... + ## $ id 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,... + ## $ origin "50.252.233.22", "50.252.233.22", "50.252.233.22", "50.252.233.22", "50.252.233.2... + ## $ url "http://httpbin.org/stream/100", "http://httpbin.org/stream/100", "http://httpbin... ``` r dplyr::glimpse(jsonlite::stream_in(file(f), flatten=TRUE, verbose=FALSE)) @@ -164,13 +197,13 @@ dplyr::glimpse(jsonlite::stream_in(file(f), flatten=TRUE, verbose=FALSE)) ## Observations: 100 ## Variables: 7 - ## $ url "http://httpbin.org/stream/100", "http://httpbin.org/stream/100", "http://httpbin.o... - ## $ id 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 2... - ## $ origin "50.252.233.22", "50.252.233.22", "50.252.233.22", "50.252.233.22", "50.252.233.22"... - ## $ headers.Host "httpbin.org", "httpbin.org", "httpbin.org", "httpbin.org", "httpbin.org", "httpbin... - ## $ headers.Accept-Encoding "identity", "identity", "identity", "identity", "identity", "identity", "identity",... - ## $ headers.Accept "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*",... - ## $ headers.User-Agent "Wget/1.18 (darwin15.5.0)", "Wget/1.18 (darwin15.5.0)", "Wget/1.18 (darwin15.5.0)",... + ## $ url "http://httpbin.org/stream/100", "http://httpbin.org/stream/100", "http://httpbin... + ## $ id 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,... + ## $ origin "50.252.233.22", "50.252.233.22", "50.252.233.22", "50.252.233.22", "50.252.233.2... + ## $ headers.Host "httpbin.org", "httpbin.org", "httpbin.org", "httpbin.org", "httpbin.org", "httpb... + ## $ `headers.Accept-Encoding` "identity", "identity", "identity", "identity", "identity", "identity", "identity... + ## $ headers.Accept "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*... + ## $ `headers.User-Agent` "Wget/1.18 (darwin15.5.0)", "Wget/1.18 (darwin15.5.0)", "Wget/1.18 (darwin15.5.0)... ``` r dplyr::glimpse(jsonlite::stream_in(gzfile(gzf), flatten=TRUE, verbose=FALSE)) @@ -178,13 +211,13 @@ dplyr::glimpse(jsonlite::stream_in(gzfile(gzf), flatten=TRUE, verbose=FALSE)) ## Observations: 100 ## Variables: 7 - ## $ url "http://httpbin.org/stream/100", "http://httpbin.org/stream/100", "http://httpbin.o... - ## $ id 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 2... - ## $ origin "50.252.233.22", "50.252.233.22", "50.252.233.22", "50.252.233.22", "50.252.233.22"... - ## $ headers.Host "httpbin.org", "httpbin.org", "httpbin.org", "httpbin.org", "httpbin.org", "httpbin... - ## $ headers.Accept-Encoding "identity", "identity", "identity", "identity", "identity", "identity", "identity",... - ## $ headers.Accept "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*",... - ## $ headers.User-Agent "Wget/1.18 (darwin15.5.0)", "Wget/1.18 (darwin15.5.0)", "Wget/1.18 (darwin15.5.0)",... + ## $ url "http://httpbin.org/stream/100", "http://httpbin.org/stream/100", "http://httpbin... + ## $ id 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,... + ## $ origin "50.252.233.22", "50.252.233.22", "50.252.233.22", "50.252.233.22", "50.252.233.2... + ## $ headers.Host "httpbin.org", "httpbin.org", "httpbin.org", "httpbin.org", "httpbin.org", "httpb... + ## $ `headers.Accept-Encoding` "identity", "identity", "identity", "identity", "identity", "identity", "identity... + ## $ headers.Accept "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*", "*/*... + ## $ `headers.User-Agent` "Wget/1.18 (darwin15.5.0)", "Wget/1.18 (darwin15.5.0)", "Wget/1.18 (darwin15.5.0)... ``` r microbenchmark( @@ -194,9 +227,9 @@ microbenchmark( ``` ## Unit: milliseconds - ## expr min lq mean median uq max neval cld - ## ndjson 2.694575 2.883204 3.000030 2.956595 3.033864 4.319816 100 a - ## jsonlite 8.487524 9.011873 9.411114 9.151305 9.334732 12.523081 100 b + ## expr min lq mean median uq max neval cld + ## ndjson 1.785639 1.877190 1.970529 1.937276 2.057145 2.317575 100 a + ## jsonlite 3.924401 4.087739 4.378292 4.233847 4.445059 6.395232 100 b ``` r microbenchmark( @@ -206,11 +239,11 @@ microbenchmark( ``` ## Unit: milliseconds - ## expr min lq mean median uq max neval cld - ## ndjson 2.856464 2.957216 3.030433 3.005832 3.069114 3.436334 100 a - ## jsonlite 8.302337 8.631042 9.021032 8.795794 9.031557 12.158147 100 b + ## expr min lq mean median uq max neval cld + ## ndjson 1.966033 2.056828 2.176153 2.141381 2.277848 2.853242 100 a + ## jsonlite 3.173205 3.386831 3.736111 3.545374 3.951642 6.565099 100 b -### Test Results +## Test Results ``` r library(ndjson) @@ -219,15 +252,26 @@ library(testthat) date() ``` - ## [1] "Tue Sep 27 11:08:18 2016" + ## [1] "Sun Mar 4 21:37:48 2018" ``` r test_dir("tests/") ``` - ## testthat results ======================================================================================================== - ## OK: 4 SKIPPED: 0 FAILED: 0 + ## ✔ | OK F W S | Context + ## ══ testthat results ══════════════════════════════════════════════════════════ + ## OK: 8 SKIPPED: 0 FAILED: 0 + ## + ## ══ Results ════════════════════════════════════════════════════════════════════ + ## Duration: 0.3 s ## - ## DONE =================================================================================================================== + ## OK: 0 + ## Failed: 0 + ## Warnings: 0 + ## Skipped: 0 + +## Code of Conduct -Please note that this project is released with a [Contributor Code of Conduct](CONDUCT.md). By participating in this project you agree to abide by its terms. +Please note that this project is released with a [Contributor Code of +Conduct](CONDUCT.md). By participating in this project you agree to +abide by its terms. diff --git a/cran-comments.md b/cran-comments.md index 4472b60..442e44d 100644 --- a/cran-comments.md +++ b/cran-comments.md @@ -1,7 +1,8 @@ ## Test environments -* local OS X install, R 3.4.0 (clang) -* local ubuntu 16.04, R 3.4.0 (g++-7) -* win-builder (devel and release) https://win-builder.r-project.org/P5u60xh8LPrA/ +* local OS X install, R 3.4.3 (clang) +* local ubuntu 16.04, R 3.4.3 (g++-7) +* Travis-CI (linux) https://travis-ci.org/hrbrmstr/ndjson +* win-builder (devel and release) ## R CMD check results @@ -15,5 +16,6 @@ None ## General notes -- Fixed CRAN gcc 7 toolchain issues (linux) -- Update core C++ library the pkg uses +- Removed included-json library #pragmas causing CRAN issues due to new + "show all warnings" policy +- Update core C++ library the pkg uses to 3.1.1 diff --git a/src/RcppExports.cpp b/src/RcppExports.cpp index 6fc6793..4d05db4 100644 --- a/src/RcppExports.cpp +++ b/src/RcppExports.cpp @@ -5,45 +5,45 @@ using namespace Rcpp; -// internal_flatten -List internal_flatten(CharacterVector lines); -RcppExport SEXP ndjson_internal_flatten(SEXP linesSEXP) { +// flatten_int +List flatten_int(CharacterVector lines); +RcppExport SEXP _ndjson_flatten_int(SEXP linesSEXP) { BEGIN_RCPP Rcpp::RObject rcpp_result_gen; Rcpp::RNGScope rcpp_rngScope_gen; Rcpp::traits::input_parameter< CharacterVector >::type lines(linesSEXP); - rcpp_result_gen = Rcpp::wrap(internal_flatten(lines)); + rcpp_result_gen = Rcpp::wrap(flatten_int(lines)); return rcpp_result_gen; END_RCPP } -// internal_stream_in -List internal_stream_in(const std::string& path); -RcppExport SEXP ndjson_internal_stream_in(SEXP pathSEXP) { +// stream_in_int +List stream_in_int(const std::string& path); +RcppExport SEXP _ndjson_stream_in_int(SEXP pathSEXP) { BEGIN_RCPP Rcpp::RObject rcpp_result_gen; Rcpp::RNGScope rcpp_rngScope_gen; Rcpp::traits::input_parameter< const std::string& >::type path(pathSEXP); - rcpp_result_gen = Rcpp::wrap(internal_stream_in(path)); + rcpp_result_gen = Rcpp::wrap(stream_in_int(path)); return rcpp_result_gen; END_RCPP } -// internal_validate -bool internal_validate(std::string path, bool verbose); -RcppExport SEXP ndjson_internal_validate(SEXP pathSEXP, SEXP verboseSEXP) { +// validate_int +bool validate_int(std::string path, bool verbose); +RcppExport SEXP _ndjson_validate_int(SEXP pathSEXP, SEXP verboseSEXP) { BEGIN_RCPP Rcpp::RObject rcpp_result_gen; Rcpp::RNGScope rcpp_rngScope_gen; Rcpp::traits::input_parameter< std::string >::type path(pathSEXP); Rcpp::traits::input_parameter< bool >::type verbose(verboseSEXP); - rcpp_result_gen = Rcpp::wrap(internal_validate(path, verbose)); + rcpp_result_gen = Rcpp::wrap(validate_int(path, verbose)); return rcpp_result_gen; END_RCPP } static const R_CallMethodDef CallEntries[] = { - {"ndjson_internal_flatten", (DL_FUNC) &ndjson_internal_flatten, 1}, - {"ndjson_internal_stream_in", (DL_FUNC) &ndjson_internal_stream_in, 1}, - {"ndjson_internal_validate", (DL_FUNC) &ndjson_internal_validate, 2}, + {"_ndjson_flatten_int", (DL_FUNC) &_ndjson_flatten_int, 1}, + {"_ndjson_stream_in_int", (DL_FUNC) &_ndjson_stream_in_int, 1}, + {"_ndjson_validate_int", (DL_FUNC) &_ndjson_validate_int, 2}, {NULL, NULL, 0} }; diff --git a/src/json.h b/src/json.h index 30cdd3a..c0cc003 100644 --- a/src/json.h +++ b/src/json.h @@ -1,11 +1,11 @@ /* __ _____ _____ _____ __| | __| | | | JSON for Modern C++ -| | |__ | | | | | | version 2.1.1 +| | |__ | | | | | | version 3.1.1 |_____|_____|_____|_|___| https://github.com/nlohmann/json Licensed under the MIT License . -Copyright (c) 2013-2017 Niels Lohmann . +Copyright (c) 2013-2018 Niels Lohmann . Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal @@ -29,55 +29,116 @@ SOFTWARE. #ifndef NLOHMANN_JSON_HPP #define NLOHMANN_JSON_HPP -#include // all_of, copy, fill, find, for_each, none_of, remove, reverse, transform -#include // array +#define NLOHMANN_JSON_VERSION_MAJOR 3 +#define NLOHMANN_JSON_VERSION_MINOR 1 +#define NLOHMANN_JSON_VERSION_PATCH 1 + +#include // all_of, find, for_each #include // assert #include // and, not, or -#include // lconv, localeconv -#include // isfinite, labs, ldexp, signbit #include // nullptr_t, ptrdiff_t, size_t -#include // int64_t, uint64_t -#include // abort, strtod, strtof, strtold, strtoul, strtoll, strtoull -#include // memcpy, strlen -#include // forward_list -#include // function, hash, less +#include // hash, less #include // initializer_list -#include // hex -#include // istream, ostream -#include // advance, begin, back_inserter, bidirectional_iterator_tag, distance, end, inserter, iterator, iterator_traits, next, random_access_iterator_tag, reverse_iterator -#include // numeric_limits -#include // locale -#include // map -#include // addressof, allocator, allocator_traits, unique_ptr +#include // istream, ostream +#include // iterator_traits, random_access_iterator_tag #include // accumulate -#include // stringstream -#include // getline, stoi, string, to_string -#include // add_pointer, conditional, decay, enable_if, false_type, integral_constant, is_arithmetic, is_base_of, is_const, is_constructible, is_convertible, is_default_constructible, is_enum, is_floating_point, is_integral, is_nothrow_move_assignable, is_nothrow_move_constructible, is_pointer, is_reference, is_same, is_scalar, is_signed, remove_const, remove_cv, remove_pointer, remove_reference, true_type, underlying_type -#include // declval, forward, make_pair, move, pair, swap +#include // string, stoi, to_string +#include // declval, forward, move, pair, swap + +// #include +#ifndef NLOHMANN_JSON_FWD_HPP +#define NLOHMANN_JSON_FWD_HPP + +#include // int64_t, uint64_t +#include // map +#include // allocator +#include // string #include // vector +/*! +@brief namespace for Niels Lohmann +@see https://github.com/nlohmann +@since version 1.0.0 +*/ +namespace nlohmann +{ +/*! +@brief default JSONSerializer template argument + +This serializer ignores the template arguments and uses ADL +([argument-dependent lookup](http://en.cppreference.com/w/cpp/language/adl)) +for serialization. +*/ +template +struct adl_serializer; + +template class ObjectType = + std::map, + template class ArrayType = std::vector, + class StringType = std::string, class BooleanType = bool, + class NumberIntegerType = std::int64_t, + class NumberUnsignedType = std::uint64_t, + class NumberFloatType = double, + template class AllocatorType = std::allocator, + template class JSONSerializer = + adl_serializer> +class basic_json; + +/*! +@brief JSON Pointer + +A JSON pointer defines a string syntax for identifying a specific value +within a JSON document. It can be used with functions `at` and +`operator[]`. Furthermore, JSON pointers are the base for JSON patches. + +@sa [RFC 6901](https://tools.ietf.org/html/rfc6901) + +@since version 2.0.0 +*/ +template +class json_pointer; + +/*! +@brief default JSON class + +This type is the default specialization of the @ref basic_json class which +uses the standard template types. + +@since version 1.0.0 +*/ +using json = basic_json<>; +} + +#endif + +// #include + + +// This file contains all internal macro definitions +// You MUST include macro_unscope.hpp at the end of json.hpp to undef all of them + // exclude unsupported compilers #if defined(__clang__) #if (__clang_major__ * 10000 + __clang_minor__ * 100 + __clang_patchlevel__) < 30400 #error "unsupported Clang version - see https://github.com/nlohmann/json#supported-compilers" #endif -#elif defined(__GNUC__) +#elif defined(__GNUC__) && !(defined(__ICC) || defined(__INTEL_COMPILER)) #if (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) < 40900 #error "unsupported GCC version - see https://github.com/nlohmann/json#supported-compilers" #endif #endif // disable float-equal warnings on GCC/clang -#if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__) - #pragma GCC diagnostic push - #pragma GCC diagnostic ignored "-Wfloat-equal" -#endif +// #if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__) +// #pragma GCC diagnostic push +// #pragma GCC diagnostic ignored "-Wfloat-equal" +// #endif // disable documentation warnings on clang -#if defined(__clang__) - #pragma GCC diagnostic push - #pragma GCC diagnostic ignored "-Wdocumentation" -#endif +// #if defined(__clang__) +// #pragma GCC diagnostic push +// #pragma GCC diagnostic ignored "-Wdocumentation" +// #endif // allow for portable deprecation warnings #if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__) @@ -89,7 +150,7 @@ SOFTWARE. #endif // allow to disable exceptions -#if (defined(__cpp_exceptions) || defined(__EXCEPTIONS) || defined(_CPPUNWIND)) && not defined(JSON_NOEXCEPTION) +#if (defined(__cpp_exceptions) || defined(__EXCEPTIONS) || defined(_CPPUNWIND)) && !defined(JSON_NOEXCEPTION) #define JSON_THROW(exception) throw exception #define JSON_TRY try #define JSON_CATCH(exception) catch(exception) @@ -99,6 +160,20 @@ SOFTWARE. #define JSON_CATCH(exception) if(false) #endif +// override exception macros +#if defined(JSON_THROW_USER) + #undef JSON_THROW + #define JSON_THROW JSON_THROW_USER +#endif +#if defined(JSON_TRY_USER) + #undef JSON_TRY + #define JSON_TRY JSON_TRY_USER +#endif +#if defined(JSON_CATCH_USER) + #undef JSON_CATCH + #define JSON_CATCH JSON_CATCH_USER +#endif + // manual branch prediction #if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__) #define JSON_LIKELY(x) __builtin_expect(!!(x), 1) @@ -108,824 +183,754 @@ SOFTWARE. #define JSON_UNLIKELY(x) x #endif -/*! -@brief namespace for Niels Lohmann -@see https://github.com/nlohmann -@since version 1.0.0 -*/ -namespace nlohmann -{ +// C++ language standard detection +#if (defined(__cplusplus) && __cplusplus >= 201703L) || (defined(_HAS_CXX17) && _HAS_CXX17 == 1) // fix for issue #464 + #define JSON_HAS_CPP_17 + #define JSON_HAS_CPP_14 +#elif (defined(__cplusplus) && __cplusplus >= 201402L) || (defined(_HAS_CXX14) && _HAS_CXX14 == 1) + #define JSON_HAS_CPP_14 +#endif -/*! -@brief unnamed namespace with internal helper functions +// Ugly macros to avoid uglier copy-paste when specializing basic_json. They +// may be removed in the future once the class is split. -This namespace collects some functions that could not be defined inside the -@ref basic_json class. +#define NLOHMANN_BASIC_JSON_TPL_DECLARATION \ + template class ObjectType, \ + template class ArrayType, \ + class StringType, class BooleanType, class NumberIntegerType, \ + class NumberUnsignedType, class NumberFloatType, \ + template class AllocatorType, \ + template class JSONSerializer> -@since version 2.1.0 -*/ -namespace detail -{ -//////////////// -// exceptions // -//////////////// +#define NLOHMANN_BASIC_JSON_TPL \ + basic_json /*! -@brief general exception of the @ref basic_json class - -Extension of std::exception objects with a member @a id for exception ids. +@brief Helper to determine whether there's a key_type for T. -@note To have nothrow-copy-constructible exceptions, we internally use - std::runtime_error which can cope with arbitrary-length error messages. - Intermediate strings are built with static functions and then passed to - the actual constructor. +This helper is used to tell associative containers apart from other containers +such as sequence containers. For instance, `std::map` passes the test as it +contains a `mapped_type`, whereas `std::vector` fails the test. -@since version 3.0.0 +@sa http://stackoverflow.com/a/7728728/266378 +@since version 1.0.0, overworked in version 2.0.6 */ -class exception : public std::exception -{ - public: - /// returns the explanatory string - virtual const char* what() const noexcept override - { - return m.what(); +#define NLOHMANN_JSON_HAS_HELPER(type) \ + template struct has_##type { \ + private: \ + template \ + static int detect(U &&); \ + static void detect(...); \ + public: \ + static constexpr bool value = \ + std::is_integral()))>::value; \ } - /// the id of the exception - const int id; +// #include - protected: - exception(int id_, const char* what_arg) - : id(id_), m(what_arg) - {} - static std::string name(const std::string& ename, int id) - { - return "[json.exception." + ename + "." + std::to_string(id) + "] "; - } +#include // not +#include // size_t +#include // numeric_limits +#include // conditional, enable_if, false_type, integral_constant, is_constructible, is_integral, is_same, remove_cv, remove_reference, true_type +#include // declval + +// #include + +// #include - private: - /// an exception object as storage for error messages - std::runtime_error m; -}; +namespace nlohmann +{ /*! -@brief exception indicating a parse error +@brief detail namespace with internal helper functions -This excpetion is thrown by the library when a parse error occurs. Parse -errors can occur during the deserialization of JSON text as well as when -using JSON Patch. +This namespace collects functions that should not be exposed, +implementations of some @ref basic_json methods, and meta-programming helpers. -Member @a byte holds the byte index of the last read character in the input -file. +@since version 2.1.0 +*/ +namespace detail +{ +///////////// +// helpers // +///////////// -@note For an input with n bytes, 1 is the index of the first character - and n+1 is the index of the terminating null byte or the end of - file. This also holds true when reading a byte vector (CBOR or - MessagePack). +template struct is_basic_json : std::false_type {}; -Exceptions have ids 1xx. +NLOHMANN_BASIC_JSON_TPL_DECLARATION +struct is_basic_json : std::true_type {}; -name / id | example massage | description ------------------------------- | --------------- | ------------------------- -json.exception.parse_error.101 | parse error at 2: unexpected end of input; expected string literal | This error indicates a syntax error while deserializing a JSON text. The error message describes that an unexpected token (character) was encountered, and the member @a byte indicates the error position. -json.exception.parse_error.102 | parse error at 14: missing or wrong low surrogate | JSON uses the `\uxxxx` format to describe Unicode characters. Code points above above 0xFFFF are split into two `\uxxxx` entries ("surrogate pairs"). This error indicates that the surrogate pair is incomplete or contains an invalid code point. -json.exception.parse_error.103 | parse error: code points above 0x10FFFF are invalid | Unicode supports code points up to 0x10FFFF. Code points above 0x10FFFF are invalid. -json.exception.parse_error.104 | parse error: JSON patch must be an array of objects | [RFC 6902](https://tools.ietf.org/html/rfc6902) requires a JSON Patch document to be a JSON document that represents an array of objects. -json.exception.parse_error.105 | parse error: operation must have string member 'op' | An operation of a JSON Patch document must contain exactly one "op" member, whose value indicates the operation to perform. Its value must be one of "add", "remove", "replace", "move", "copy", or "test"; other values are errors. -json.exception.parse_error.106 | parse error: array index '01' must not begin with '0' | An array index in a JSON Pointer ([RFC 6901](https://tools.ietf.org/html/rfc6901)) may be `0` or any number wihtout a leading `0`. -json.exception.parse_error.107 | parse error: JSON pointer must be empty or begin with '/' - was: 'foo' | A JSON Pointer must be a Unicode string containing a sequence of zero or more reference tokens, each prefixed by a `/` character. -json.exception.parse_error.108 | parse error: escape character '~' must be followed with '0' or '1' | In a JSON Pointer, only `~0` and `~1` are valid escape sequences. -json.exception.parse_error.109 | parse error: array index 'one' is not a number | A JSON Pointer array index must be a number. -json.exception.parse_error.110 | parse error at 1: cannot read 2 bytes from vector | When parsing CBOR or MessagePack, the byte vector ends before the complete value has been read. -json.exception.parse_error.111 | parse error: bad input stream | Parsing CBOR or MessagePack from an input stream where the [`badbit` or `failbit`](http://en.cppreference.com/w/cpp/io/ios_base/iostate) is set. -json.exception.parse_error.112 | parse error at 1: error reading CBOR; last byte: 0xf8 | Not all types of CBOR or MessagePack are supported. This exception occurs if an unsupported byte was read. -json.exception.parse_error.113 | parse error at 2: expected a CBOR string; last byte: 0x98 | While parsing a map key, a value that is not a string has been read. +// alias templates to reduce boilerplate +template +using enable_if_t = typename std::enable_if::type; -@since version 3.0.0 -*/ -class parse_error : public exception +template +using uncvref_t = typename std::remove_cv::type>::type; + +// implementation of C++14 index_sequence and affiliates +// source: https://stackoverflow.com/a/32223343 +template +struct index_sequence { - public: - /*! - @brief create a parse error exception - @param[in] id the id of the exception - @param[in] byte_ the byte index where the error occured (or 0 if - the position cannot be determined) - @param[in] what_arg the explanatory string - @return parse_error object - */ - static parse_error create(int id, size_t byte_, const std::string& what_arg) + using type = index_sequence; + using value_type = std::size_t; + static constexpr std::size_t size() noexcept { - std::string w = exception::name("parse_error", id) + "parse error" + - (byte_ != 0 ? (" at " + std::to_string(byte_)) : "") + - ": " + what_arg; - return parse_error(id, byte_, w.c_str()); + return sizeof...(Ints); } +}; - /*! - @brief byte index of the parse error +template +struct merge_and_renumber; - The byte index of the last read character in the input file. +template +struct merge_and_renumber, index_sequence> + : index_sequence < I1..., (sizeof...(I1) + I2)... > {}; - @note For an input with n bytes, 1 is the index of the first character - and n+1 is the index of the terminating null byte or the end of - file. This also holds true when reading a byte vector (CBOR or - MessagePack). - */ - const size_t byte; +template +struct make_index_sequence + : merge_and_renumber < typename make_index_sequence < N / 2 >::type, + typename make_index_sequence < N - N / 2 >::type > {}; - private: - parse_error(int id_, size_t byte_, const char* what_arg) - : exception(id_, what_arg), byte(byte_) - {} -}; +template<> struct make_index_sequence<0> : index_sequence<> {}; +template<> struct make_index_sequence<1> : index_sequence<0> {}; -/*! -@brief exception indicating errors with iterators +template +using index_sequence_for = make_index_sequence; -Exceptions have ids 2xx. +/* +Implementation of two C++17 constructs: conjunction, negation. This is needed +to avoid evaluating all the traits in a condition -name / id | example massage | description ------------------------------------ | --------------- | ------------------------- -json.exception.invalid_iterator.201 | iterators are not compatible | The iterators passed to constructor @ref basic_json(InputIT first, InputIT last) are not compatible, meaning they do not belong to the same container. Therefore, the range (@a first, @a last) is invalid. -json.exception.invalid_iterator.202 | iterator does not fit current value | In an erase or insert function, the passed iterator @a pos does not belong to the JSON value for which the function was called. It hence does not define a valid position for the deletion/insertion. -json.exception.invalid_iterator.203 | iterators do not fit current value | Either iterator passed to function @ref erase(IteratorType first, IteratorType last) does not belong to the JSON value from which values shall be erased. It hence does not define a valid range to delete values from. -json.exception.invalid_iterator.204 | iterators out of range | When an iterator range for a primitive type (number, boolean, or string) is passed to a constructor or an erase function, this range has to be exactly (@ref begin(), @ref end()), because this is the only way the single stored value is expressed. All other ranges are invalid. -json.exception.invalid_iterator.205 | iterator out of range | When an iterator for a primitive type (number, boolean, or string) is passed to an erase function, the iterator has to be the @ref begin() iterator, because it is the only way to address the stored value. All other iterators are invalid. -json.exception.invalid_iterator.206 | cannot construct with iterators from null | The iterators passed to constructor @ref basic_json(InputIT first, InputIT last) belong to a JSON null value and hence to not define a valid range. -json.exception.invalid_iterator.207 | cannot use key() for non-object iterators | The key() member function can only be used on iterators belonging to a JSON object, because other types do not have a concept of a key. -json.exception.invalid_iterator.208 | cannot use operator[] for object iterators | The operator[] to specify a concrete offset cannot be used on iterators belonging to a JSON object, because JSON objects are unordered. -json.exception.invalid_iterator.209 | cannot use offsets with object iterators | The offset operators (+, -, +=, -=) cannot be used on iterators belonging to a JSON object, because JSON objects are unordered. -json.exception.invalid_iterator.210 | iterators do not fit | The iterator range passed to the insert function are not compatible, meaning they do not belong to the same container. Therefore, the range (@a first, @a last) is invalid. -json.exception.invalid_iterator.211 | passed iterators may not belong to container | The iterator range passed to the insert function must not be a subrange of the container to insert to. -json.exception.invalid_iterator.212 | cannot compare iterators of different containers | When two iterators are compared, they must belong to the same container. -json.exception.invalid_iterator.213 | cannot compare order of object iterators | The order of object iterators cannot be compated, because JSON objects are unordered. -json.exception.invalid_iterator.214 | cannot get value | Cannot get value for iterator: Either the iterator belongs to a null value or it is an iterator to a primitive type (number, boolean, or string), but the iterator is different to @ref begin(). +For example: not std::is_same::value and has_value_type::value +will not compile when T = void (on MSVC at least). Whereas +conjunction>, has_value_type>::value will +stop evaluating if negation<...>::value == false -@since version 3.0.0 +Please note that those constructs must be used with caution, since symbols can +become very long quickly (which can slow down compilation and cause MSVC +internal compiler errors). Only use it when you have to (see example ahead). */ -class invalid_iterator : public exception -{ - public: - static invalid_iterator create(int id, const std::string& what_arg) - { - std::string w = exception::name("invalid_iterator", id) + what_arg; - return invalid_iterator(id, w.c_str()); - } - - private: - invalid_iterator(int id_, const char* what_arg) - : exception(id_, what_arg) - {} -}; +template struct conjunction : std::true_type {}; +template struct conjunction : B1 {}; +template +struct conjunction : std::conditional, B1>::type {}; -/*! -@brief exception indicating executing a member function with a wrong type +template struct negation : std::integral_constant {}; -Exceptions have ids 3xx. +// dispatch utility (taken from ranges-v3) +template struct priority_tag : priority_tag < N - 1 > {}; +template<> struct priority_tag<0> {}; -name / id | example message | description ------------------------------ | --------------- | ------------------------- -json.exception.type_error.301 | cannot create object from initializer list | To create an object from an initializer list, the initializer list must consist only of a list of pairs whose first element is a string. When this constraint is violated, an array is created instead. -json.exception.type_error.302 | type must be object, but is array | During implicit or explicit value conversion, the JSON type must be compatible to the target type. For instance, a JSON string can only be converted into string types, but not into numbers or boolean types. -json.exception.type_error.303 | incompatible ReferenceType for get_ref, actual type is object | To retrieve a reference to a value stored in a @ref basic_json object with @ref get_ref, the type of the reference must match the value type. For instance, for a JSON array, the @a ReferenceType must be @ref array_t&. -json.exception.type_error.304 | cannot use at() with string | The @ref at() member functions can only be executed for certain JSON types. -json.exception.type_error.305 | cannot use operator[] with string | The @ref operator[] member functions can only be executed for certain JSON types. -json.exception.type_error.306 | cannot use value() with string | The @ref value() member functions can only be executed for certain JSON types. -json.exception.type_error.307 | cannot use erase() with string | The @ref erase() member functions can only be executed for certain JSON types. -json.exception.type_error.308 | cannot use push_back() with string | The @ref push_back() and @ref operator+= member functions can only be executed for certain JSON types. -json.exception.type_error.309 | cannot use insert() with | The @ref insert() member functions can only be executed for certain JSON types. -json.exception.type_error.310 | cannot use swap() with number | The @ref swap() member functions can only be executed for certain JSON types. -json.exception.type_error.311 | cannot use emplace_back() with string | The @ref emplace_back() member function can only be executed for certain JSON types. -json.exception.type_error.313 | invalid value to unflatten | The @ref unflatten function converts an object whose keys are JSON Pointers back into an arbitrary nested JSON value. The JSON Pointers must not overlap, because then the resulting value would not be well defined. -json.exception.type_error.314 | only objects can be unflattened | The @ref unflatten function only works for an object whose keys are JSON Pointers. -json.exception.type_error.315 | values in object must be primitive | The @ref unflatten function only works for an object whose keys are JSON Pointers and whose values are primitive. +//////////////////////// +// has_/is_ functions // +//////////////////////// -@since version 3.0.0 -*/ -class type_error : public exception -{ - public: - static type_error create(int id, const std::string& what_arg) - { - std::string w = exception::name("type_error", id) + what_arg; - return type_error(id, w.c_str()); - } +// source: https://stackoverflow.com/a/37193089/4116453 - private: - type_error(int id_, const char* what_arg) - : exception(id_, what_arg) - {} -}; +template +struct is_complete_type : std::false_type {}; -/*! -@brief exception indicating access out of the defined range +template +struct is_complete_type : std::true_type {}; -Exceptions have ids 4xx. +NLOHMANN_JSON_HAS_HELPER(mapped_type); +NLOHMANN_JSON_HAS_HELPER(key_type); +NLOHMANN_JSON_HAS_HELPER(value_type); +NLOHMANN_JSON_HAS_HELPER(iterator); -name / id | example message | description -------------------------------- | --------------- | ------------------------- -json.exception.out_of_range.401 | array index 3 is out of range | The provided array index @a i is larger than @a size-1. -json.exception.out_of_range.402 | array index '-' (3) is out of range | The special array index `-` in a JSON Pointer never describes a valid element of the array, but the index past the end. That is, it can only be used to add elements at this position, but not to read it. -json.exception.out_of_range.403 | key 'foo' not found | The provided key was not found in the JSON object. -json.exception.out_of_range.404 | unresolved reference token 'foo' | A reference token in a JSON Pointer could not be resolved. -json.exception.out_of_range.405 | JSON pointer has no parent | The JSON Patch operations 'remove' and 'add' can not be applied to the root element of the JSON value. -json.exception.out_of_range.406 | number overflow parsing '10E1000' | A parsed number could not be stored as without changing it to NaN or INF. +template +struct is_compatible_object_type_impl : std::false_type {}; -@since version 3.0.0 -*/ -class out_of_range : public exception +template +struct is_compatible_object_type_impl { - public: - static out_of_range create(int id, const std::string& what_arg) - { - std::string w = exception::name("out_of_range", id) + what_arg; - return out_of_range(id, w.c_str()); - } + static constexpr auto value = + std::is_constructible::value and + std::is_constructible::value; +}; - private: - out_of_range(int id_, const char* what_arg) - : exception(id_, what_arg) - {} +template +struct is_compatible_object_type +{ + static auto constexpr value = is_compatible_object_type_impl < + conjunction>, + has_mapped_type, + has_key_type>::value, + typename BasicJsonType::object_t, CompatibleObjectType >::value; }; -/*! -@brief exception indicating other errors +template +struct is_basic_json_nested_type +{ + static auto constexpr value = std::is_same::value or + std::is_same::value or + std::is_same::value or + std::is_same::value; +}; -Exceptions have ids 5xx. +template +struct is_compatible_array_type +{ + static auto constexpr value = + conjunction>, + negation>, + negation>, + negation>, + has_value_type, + has_iterator>::value; +}; -name / id | example message | description ------------------------------- | --------------- | ------------------------- -json.exception.other_error.501 | unsuccessful: {"op":"test","path":"/baz", "value":"bar"} | A JSON Patch operation 'test' failed. The unsuccessful operation is also printed. -json.exception.other_error.502 | invalid object size for conversion | Some conversions to user-defined types impose constraints on the object size (e.g. std::pair) +template +struct is_compatible_integer_type_impl : std::false_type {}; -@since version 3.0.0 -*/ -class other_error : public exception +template +struct is_compatible_integer_type_impl { - public: - static other_error create(int id, const std::string& what_arg) - { - std::string w = exception::name("other_error", id) + what_arg; - return other_error(id, w.c_str()); - } + // is there an assert somewhere on overflows? + using RealLimits = std::numeric_limits; + using CompatibleLimits = std::numeric_limits; - private: - other_error(int id_, const char* what_arg) - : exception(id_, what_arg) - {} + static constexpr auto value = + std::is_constructible::value and + CompatibleLimits::is_integer and + RealLimits::is_signed == CompatibleLimits::is_signed; }; +template +struct is_compatible_integer_type +{ + static constexpr auto value = + is_compatible_integer_type_impl < + std::is_integral::value and + not std::is_same::value, + RealIntegerType, CompatibleNumberIntegerType > ::value; +}; +// trait checking if JSONSerializer::from_json(json const&, udt&) exists +template +struct has_from_json +{ + private: + // also check the return type of from_json + template::from_json( + std::declval(), std::declval()))>::value>> + static int detect(U&&); + static void detect(...); -/////////////////////////// -// JSON type enumeration // -/////////////////////////// - -/*! -@brief the JSON type enumeration + public: + static constexpr bool value = std::is_integral>()))>::value; +}; -This enumeration collects the different JSON types. It is internally used to -distinguish the stored values, and the functions @ref basic_json::is_null(), -@ref basic_json::is_object(), @ref basic_json::is_array(), -@ref basic_json::is_string(), @ref basic_json::is_boolean(), -@ref basic_json::is_number() (with @ref basic_json::is_number_integer(), -@ref basic_json::is_number_unsigned(), and @ref basic_json::is_number_float()), -@ref basic_json::is_discarded(), @ref basic_json::is_primitive(), and -@ref basic_json::is_structured() rely on it. +// This trait checks if JSONSerializer::from_json(json const&) exists +// this overload is used for non-default-constructible user-defined-types +template +struct has_non_default_from_json +{ + private: + template < + typename U, + typename = enable_if_t::from_json(std::declval()))>::value >> + static int detect(U&&); + static void detect(...); -@note There are three enumeration entries (number_integer, number_unsigned, and -number_float), because the library distinguishes these three types for numbers: -@ref basic_json::number_unsigned_t is used for unsigned integers, -@ref basic_json::number_integer_t is used for signed integers, and -@ref basic_json::number_float_t is used for floating-point numbers or to -approximate integers which do not fit in the limits of their respective type. + public: + static constexpr bool value = std::is_integral>()))>::value; +}; -@sa @ref basic_json::basic_json(const value_t value_type) -- create a JSON -value with the default value for a given type +// This trait checks if BasicJsonType::json_serializer::to_json exists +template +struct has_to_json +{ + private: + template::to_json( + std::declval(), std::declval()))> + static int detect(U&&); + static void detect(...); -@since version 1.0.0 -*/ -enum class value_t : uint8_t -{ - null, ///< null value - object, ///< object (unordered set of name/value pairs) - array, ///< array (ordered collection of values) - string, ///< string value - boolean, ///< boolean value - number_integer, ///< number value (signed integer) - number_unsigned, ///< number value (unsigned integer) - number_float, ///< number value (floating-point) - discarded ///< discarded by the the parser callback function + public: + static constexpr bool value = std::is_integral>()))>::value; }; -/*! -@brief comparison operator for JSON types - -Returns an ordering that is similar to Python: -- order: null < boolean < number < object < array < string -- furthermore, each type is not smaller than itself +template +struct is_compatible_complete_type +{ + static constexpr bool value = + not std::is_base_of::value and + not std::is_same::value and + not is_basic_json_nested_type::value and + has_to_json::value; +}; -@since version 1.0.0 -*/ -inline bool operator<(const value_t lhs, const value_t rhs) noexcept +template +struct is_compatible_type + : conjunction, + is_compatible_complete_type> { - static constexpr std::array order = {{ - 0, // null - 3, // object - 4, // array - 5, // string - 1, // boolean - 2, // integer - 2, // unsigned - 2, // float - } - }; +}; - // discarded values are not comparable - if (lhs == value_t::discarded or rhs == value_t::discarded) - { - return false; - } +// taken from ranges-v3 +template +struct static_const +{ + static constexpr T value{}; +}; - return order[static_cast(lhs)] < - order[static_cast(rhs)]; +template +constexpr T static_const::value; +} } +// #include -///////////// -// helpers // -///////////// - -// alias templates to reduce boilerplate -template -using enable_if_t = typename std::enable_if::type; -template -using uncvref_t = typename std::remove_cv::type>::type; +#include // exception +#include // runtime_error +#include // to_string -// implementation of C++14 index_sequence and affiliates -// source: https://stackoverflow.com/a/32223343 -template -struct index_sequence +namespace nlohmann { - using type = index_sequence; - using value_type = std::size_t; - static constexpr std::size_t size() noexcept - { - return sizeof...(Ints); - } -}; - -template -struct merge_and_renumber; - -template -struct merge_and_renumber, index_sequence> - : index_sequence < I1..., (sizeof...(I1) + I2)... > - { }; +namespace detail +{ +//////////////// +// exceptions // +//////////////// -template -struct make_index_sequence - : merge_and_renumber < typename make_index_sequence < N / 2 >::type, - typename make_index_sequence < N - N / 2 >::type > -{ }; +/*! +@brief general exception of the @ref basic_json class -template<> struct make_index_sequence<0> : index_sequence<> { }; -template<> struct make_index_sequence<1> : index_sequence<0> { }; +This class is an extension of `std::exception` objects with a member @a id for +exception ids. It is used as the base class for all exceptions thrown by the +@ref basic_json class. This class can hence be used as "wildcard" to catch +exceptions. -template -using index_sequence_for = make_index_sequence; +Subclasses: +- @ref parse_error for exceptions indicating a parse error +- @ref invalid_iterator for exceptions indicating errors with iterators +- @ref type_error for exceptions indicating executing a member function with + a wrong type +- @ref out_of_range for exceptions indicating access out of the defined range +- @ref other_error for exceptions indicating other library errors -/* -Implementation of two C++17 constructs: conjunction, negation. This is needed -to avoid evaluating all the traits in a condition +@internal +@note To have nothrow-copy-constructible exceptions, we internally use + `std::runtime_error` which can cope with arbitrary-length error messages. + Intermediate strings are built with static functions and then passed to + the actual constructor. +@endinternal -For example: not std::is_same::value and has_value_type::value -will not compile when T = void (on MSVC at least). Whereas -conjunction>, has_value_type>::value will -stop evaluating if negation<...>::value == false +@liveexample{The following code shows how arbitrary library exceptions can be +caught.,exception} -Please note that those constructs must be used with caution, since symbols can -become very long quickly (which can slow down compilation and cause MSVC -internal compiler errors). Only use it when you have to (see example ahead). +@since version 3.0.0 */ -template struct conjunction : std::true_type {}; -template struct conjunction : B1 {}; -template -struct conjunction : std::conditional, B1>::type {}; +class exception : public std::exception +{ + public: + /// returns the explanatory string + const char* what() const noexcept override + { + return m.what(); + } -template struct negation : std::integral_constant < bool, !B::value > {}; + /// the id of the exception + const int id; -// dispatch utility (taken from ranges-v3) -template struct priority_tag : priority_tag < N - 1 > {}; -template<> struct priority_tag<0> {}; + protected: + exception(int id_, const char* what_arg) : id(id_), m(what_arg) {} + static std::string name(const std::string& ename, int id_) + { + return "[json.exception." + ename + "." + std::to_string(id_) + "] "; + } -////////////////// -// constructors // -////////////////// + private: + /// an exception object as storage for error messages + std::runtime_error m; +}; -template struct external_constructor; +/*! +@brief exception indicating a parse error -template<> -struct external_constructor -{ - template - static void construct(BasicJsonType& j, typename BasicJsonType::boolean_t b) noexcept - { - j.m_type = value_t::boolean; - j.m_value = b; - j.assert_invariant(); - } -}; +This exception is thrown by the library when a parse error occurs. Parse errors +can occur during the deserialization of JSON text, CBOR, MessagePack, as well +as when using JSON Patch. -template<> -struct external_constructor -{ - template - static void construct(BasicJsonType& j, const typename BasicJsonType::string_t& s) - { - j.m_type = value_t::string; - j.m_value = s; - j.assert_invariant(); - } -}; +Member @a byte holds the byte index of the last read character in the input +file. -template<> -struct external_constructor +Exceptions have ids 1xx. + +name / id | example message | description +------------------------------ | --------------- | ------------------------- +json.exception.parse_error.101 | parse error at 2: unexpected end of input; expected string literal | This error indicates a syntax error while deserializing a JSON text. The error message describes that an unexpected token (character) was encountered, and the member @a byte indicates the error position. +json.exception.parse_error.102 | parse error at 14: missing or wrong low surrogate | JSON uses the `\uxxxx` format to describe Unicode characters. Code points above above 0xFFFF are split into two `\uxxxx` entries ("surrogate pairs"). This error indicates that the surrogate pair is incomplete or contains an invalid code point. +json.exception.parse_error.103 | parse error: code points above 0x10FFFF are invalid | Unicode supports code points up to 0x10FFFF. Code points above 0x10FFFF are invalid. +json.exception.parse_error.104 | parse error: JSON patch must be an array of objects | [RFC 6902](https://tools.ietf.org/html/rfc6902) requires a JSON Patch document to be a JSON document that represents an array of objects. +json.exception.parse_error.105 | parse error: operation must have string member 'op' | An operation of a JSON Patch document must contain exactly one "op" member, whose value indicates the operation to perform. Its value must be one of "add", "remove", "replace", "move", "copy", or "test"; other values are errors. +json.exception.parse_error.106 | parse error: array index '01' must not begin with '0' | An array index in a JSON Pointer ([RFC 6901](https://tools.ietf.org/html/rfc6901)) may be `0` or any number without a leading `0`. +json.exception.parse_error.107 | parse error: JSON pointer must be empty or begin with '/' - was: 'foo' | A JSON Pointer must be a Unicode string containing a sequence of zero or more reference tokens, each prefixed by a `/` character. +json.exception.parse_error.108 | parse error: escape character '~' must be followed with '0' or '1' | In a JSON Pointer, only `~0` and `~1` are valid escape sequences. +json.exception.parse_error.109 | parse error: array index 'one' is not a number | A JSON Pointer array index must be a number. +json.exception.parse_error.110 | parse error at 1: cannot read 2 bytes from vector | When parsing CBOR or MessagePack, the byte vector ends before the complete value has been read. +json.exception.parse_error.112 | parse error at 1: error reading CBOR; last byte: 0xF8 | Not all types of CBOR or MessagePack are supported. This exception occurs if an unsupported byte was read. +json.exception.parse_error.113 | parse error at 2: expected a CBOR string; last byte: 0x98 | While parsing a map key, a value that is not a string has been read. + +@note For an input with n bytes, 1 is the index of the first character and n+1 + is the index of the terminating null byte or the end of file. This also + holds true when reading a byte vector (CBOR or MessagePack). + +@liveexample{The following code shows how a `parse_error` exception can be +caught.,parse_error} + +@sa @ref exception for the base class of the library exceptions +@sa @ref invalid_iterator for exceptions indicating errors with iterators +@sa @ref type_error for exceptions indicating executing a member function with + a wrong type +@sa @ref out_of_range for exceptions indicating access out of the defined range +@sa @ref other_error for exceptions indicating other library errors + +@since version 3.0.0 +*/ +class parse_error : public exception { - template - static void construct(BasicJsonType& j, typename BasicJsonType::number_float_t val) noexcept + public: + /*! + @brief create a parse error exception + @param[in] id_ the id of the exception + @param[in] byte_ the byte index where the error occurred (or 0 if the + position cannot be determined) + @param[in] what_arg the explanatory string + @return parse_error object + */ + static parse_error create(int id_, std::size_t byte_, const std::string& what_arg) { - j.m_type = value_t::number_float; - j.m_value = val; - j.assert_invariant(); + std::string w = exception::name("parse_error", id_) + "parse error" + + (byte_ != 0 ? (" at " + std::to_string(byte_)) : "") + + ": " + what_arg; + return parse_error(id_, byte_, w.c_str()); } + + /*! + @brief byte index of the parse error + + The byte index of the last read character in the input file. + + @note For an input with n bytes, 1 is the index of the first character and + n+1 is the index of the terminating null byte or the end of file. + This also holds true when reading a byte vector (CBOR or MessagePack). + */ + const std::size_t byte; + + private: + parse_error(int id_, std::size_t byte_, const char* what_arg) + : exception(id_, what_arg), byte(byte_) {} }; -template<> -struct external_constructor +/*! +@brief exception indicating errors with iterators + +This exception is thrown if iterators passed to a library function do not match +the expected semantics. + +Exceptions have ids 2xx. + +name / id | example message | description +----------------------------------- | --------------- | ------------------------- +json.exception.invalid_iterator.201 | iterators are not compatible | The iterators passed to constructor @ref basic_json(InputIT first, InputIT last) are not compatible, meaning they do not belong to the same container. Therefore, the range (@a first, @a last) is invalid. +json.exception.invalid_iterator.202 | iterator does not fit current value | In an erase or insert function, the passed iterator @a pos does not belong to the JSON value for which the function was called. It hence does not define a valid position for the deletion/insertion. +json.exception.invalid_iterator.203 | iterators do not fit current value | Either iterator passed to function @ref erase(IteratorType first, IteratorType last) does not belong to the JSON value from which values shall be erased. It hence does not define a valid range to delete values from. +json.exception.invalid_iterator.204 | iterators out of range | When an iterator range for a primitive type (number, boolean, or string) is passed to a constructor or an erase function, this range has to be exactly (@ref begin(), @ref end()), because this is the only way the single stored value is expressed. All other ranges are invalid. +json.exception.invalid_iterator.205 | iterator out of range | When an iterator for a primitive type (number, boolean, or string) is passed to an erase function, the iterator has to be the @ref begin() iterator, because it is the only way to address the stored value. All other iterators are invalid. +json.exception.invalid_iterator.206 | cannot construct with iterators from null | The iterators passed to constructor @ref basic_json(InputIT first, InputIT last) belong to a JSON null value and hence to not define a valid range. +json.exception.invalid_iterator.207 | cannot use key() for non-object iterators | The key() member function can only be used on iterators belonging to a JSON object, because other types do not have a concept of a key. +json.exception.invalid_iterator.208 | cannot use operator[] for object iterators | The operator[] to specify a concrete offset cannot be used on iterators belonging to a JSON object, because JSON objects are unordered. +json.exception.invalid_iterator.209 | cannot use offsets with object iterators | The offset operators (+, -, +=, -=) cannot be used on iterators belonging to a JSON object, because JSON objects are unordered. +json.exception.invalid_iterator.210 | iterators do not fit | The iterator range passed to the insert function are not compatible, meaning they do not belong to the same container. Therefore, the range (@a first, @a last) is invalid. +json.exception.invalid_iterator.211 | passed iterators may not belong to container | The iterator range passed to the insert function must not be a subrange of the container to insert to. +json.exception.invalid_iterator.212 | cannot compare iterators of different containers | When two iterators are compared, they must belong to the same container. +json.exception.invalid_iterator.213 | cannot compare order of object iterators | The order of object iterators cannot be compared, because JSON objects are unordered. +json.exception.invalid_iterator.214 | cannot get value | Cannot get value for iterator: Either the iterator belongs to a null value or it is an iterator to a primitive type (number, boolean, or string), but the iterator is different to @ref begin(). + +@liveexample{The following code shows how an `invalid_iterator` exception can be +caught.,invalid_iterator} + +@sa @ref exception for the base class of the library exceptions +@sa @ref parse_error for exceptions indicating a parse error +@sa @ref type_error for exceptions indicating executing a member function with + a wrong type +@sa @ref out_of_range for exceptions indicating access out of the defined range +@sa @ref other_error for exceptions indicating other library errors + +@since version 3.0.0 +*/ +class invalid_iterator : public exception { - template - static void construct(BasicJsonType& j, typename BasicJsonType::number_unsigned_t val) noexcept + public: + static invalid_iterator create(int id_, const std::string& what_arg) { - j.m_type = value_t::number_unsigned; - j.m_value = val; - j.assert_invariant(); + std::string w = exception::name("invalid_iterator", id_) + what_arg; + return invalid_iterator(id_, w.c_str()); } + + private: + invalid_iterator(int id_, const char* what_arg) + : exception(id_, what_arg) {} }; -template<> -struct external_constructor +/*! +@brief exception indicating executing a member function with a wrong type + +This exception is thrown in case of a type error; that is, a library function is +executed on a JSON value whose type does not match the expected semantics. + +Exceptions have ids 3xx. + +name / id | example message | description +----------------------------- | --------------- | ------------------------- +json.exception.type_error.301 | cannot create object from initializer list | To create an object from an initializer list, the initializer list must consist only of a list of pairs whose first element is a string. When this constraint is violated, an array is created instead. +json.exception.type_error.302 | type must be object, but is array | During implicit or explicit value conversion, the JSON type must be compatible to the target type. For instance, a JSON string can only be converted into string types, but not into numbers or boolean types. +json.exception.type_error.303 | incompatible ReferenceType for get_ref, actual type is object | To retrieve a reference to a value stored in a @ref basic_json object with @ref get_ref, the type of the reference must match the value type. For instance, for a JSON array, the @a ReferenceType must be @ref array_t&. +json.exception.type_error.304 | cannot use at() with string | The @ref at() member functions can only be executed for certain JSON types. +json.exception.type_error.305 | cannot use operator[] with string | The @ref operator[] member functions can only be executed for certain JSON types. +json.exception.type_error.306 | cannot use value() with string | The @ref value() member functions can only be executed for certain JSON types. +json.exception.type_error.307 | cannot use erase() with string | The @ref erase() member functions can only be executed for certain JSON types. +json.exception.type_error.308 | cannot use push_back() with string | The @ref push_back() and @ref operator+= member functions can only be executed for certain JSON types. +json.exception.type_error.309 | cannot use insert() with | The @ref insert() member functions can only be executed for certain JSON types. +json.exception.type_error.310 | cannot use swap() with number | The @ref swap() member functions can only be executed for certain JSON types. +json.exception.type_error.311 | cannot use emplace_back() with string | The @ref emplace_back() member function can only be executed for certain JSON types. +json.exception.type_error.312 | cannot use update() with string | The @ref update() member functions can only be executed for certain JSON types. +json.exception.type_error.313 | invalid value to unflatten | The @ref unflatten function converts an object whose keys are JSON Pointers back into an arbitrary nested JSON value. The JSON Pointers must not overlap, because then the resulting value would not be well defined. +json.exception.type_error.314 | only objects can be unflattened | The @ref unflatten function only works for an object whose keys are JSON Pointers. +json.exception.type_error.315 | values in object must be primitive | The @ref unflatten function only works for an object whose keys are JSON Pointers and whose values are primitive. +json.exception.type_error.316 | invalid UTF-8 byte at index 10: 0x7E | The @ref dump function only works with UTF-8 encoded strings; that is, if you assign a `std::string` to a JSON value, make sure it is UTF-8 encoded. | + +@liveexample{The following code shows how a `type_error` exception can be +caught.,type_error} + +@sa @ref exception for the base class of the library exceptions +@sa @ref parse_error for exceptions indicating a parse error +@sa @ref invalid_iterator for exceptions indicating errors with iterators +@sa @ref out_of_range for exceptions indicating access out of the defined range +@sa @ref other_error for exceptions indicating other library errors + +@since version 3.0.0 +*/ +class type_error : public exception { - template - static void construct(BasicJsonType& j, typename BasicJsonType::number_integer_t val) noexcept + public: + static type_error create(int id_, const std::string& what_arg) { - j.m_type = value_t::number_integer; - j.m_value = val; - j.assert_invariant(); + std::string w = exception::name("type_error", id_) + what_arg; + return type_error(id_, w.c_str()); } + + private: + type_error(int id_, const char* what_arg) : exception(id_, what_arg) {} }; -template<> -struct external_constructor -{ - template - static void construct(BasicJsonType& j, const typename BasicJsonType::array_t& arr) - { - j.m_type = value_t::array; - j.m_value = arr; - j.assert_invariant(); - } +/*! +@brief exception indicating access out of the defined range - template::value, - int> = 0> - static void construct(BasicJsonType& j, const CompatibleArrayType& arr) - { - using std::begin; - using std::end; - j.m_type = value_t::array; - j.m_value.array = j.template create(begin(arr), end(arr)); - j.assert_invariant(); - } +This exception is thrown in case a library function is called on an input +parameter that exceeds the expected range, for instance in case of array +indices or nonexisting object keys. - template - static void construct(BasicJsonType& j, const std::vector& arr) - { - j.m_type = value_t::array; - j.m_value = value_t::array; - j.m_value.array->reserve(arr.size()); - for (bool x : arr) - { - j.m_value.array->push_back(x); - } - j.assert_invariant(); - } -}; +Exceptions have ids 4xx. -template<> -struct external_constructor +name / id | example message | description +------------------------------- | --------------- | ------------------------- +json.exception.out_of_range.401 | array index 3 is out of range | The provided array index @a i is larger than @a size-1. +json.exception.out_of_range.402 | array index '-' (3) is out of range | The special array index `-` in a JSON Pointer never describes a valid element of the array, but the index past the end. That is, it can only be used to add elements at this position, but not to read it. +json.exception.out_of_range.403 | key 'foo' not found | The provided key was not found in the JSON object. +json.exception.out_of_range.404 | unresolved reference token 'foo' | A reference token in a JSON Pointer could not be resolved. +json.exception.out_of_range.405 | JSON pointer has no parent | The JSON Patch operations 'remove' and 'add' can not be applied to the root element of the JSON value. +json.exception.out_of_range.406 | number overflow parsing '10E1000' | A parsed number could not be stored as without changing it to NaN or INF. +json.exception.out_of_range.407 | number overflow serializing '9223372036854775808' | UBJSON only supports integers numbers up to 9223372036854775807. | +json.exception.out_of_range.408 | excessive array size: 8658170730974374167 | The size (following `#`) of an UBJSON array or object exceeds the maximal capacity. | + +@liveexample{The following code shows how an `out_of_range` exception can be +caught.,out_of_range} + +@sa @ref exception for the base class of the library exceptions +@sa @ref parse_error for exceptions indicating a parse error +@sa @ref invalid_iterator for exceptions indicating errors with iterators +@sa @ref type_error for exceptions indicating executing a member function with + a wrong type +@sa @ref other_error for exceptions indicating other library errors + +@since version 3.0.0 +*/ +class out_of_range : public exception { - template - static void construct(BasicJsonType& j, const typename BasicJsonType::object_t& obj) + public: + static out_of_range create(int id_, const std::string& what_arg) { - j.m_type = value_t::object; - j.m_value = obj; - j.assert_invariant(); + std::string w = exception::name("out_of_range", id_) + what_arg; + return out_of_range(id_, w.c_str()); } - template::value, - int> = 0> - static void construct(BasicJsonType& j, const CompatibleObjectType& obj) - { - using std::begin; - using std::end; - - j.m_type = value_t::object; - j.m_value.object = j.template create(begin(obj), end(obj)); - j.assert_invariant(); - } + private: + out_of_range(int id_, const char* what_arg) : exception(id_, what_arg) {} }; +/*! +@brief exception indicating other library errors -//////////////////////// -// has_/is_ functions // -//////////////////////// +This exception is thrown in case of errors that cannot be classified with the +other exception types. -/*! -@brief Helper to determine whether there's a key_type for T. +Exceptions have ids 5xx. -This helper is used to tell associative containers apart from other containers -such as sequence containers. For instance, `std::map` passes the test as it -contains a `mapped_type`, whereas `std::vector` fails the test. +name / id | example message | description +------------------------------ | --------------- | ------------------------- +json.exception.other_error.501 | unsuccessful: {"op":"test","path":"/baz", "value":"bar"} | A JSON Patch operation 'test' failed. The unsuccessful operation is also printed. -@sa http://stackoverflow.com/a/7728728/266378 -@since version 1.0.0, overworked in version 2.0.6 +@sa @ref exception for the base class of the library exceptions +@sa @ref parse_error for exceptions indicating a parse error +@sa @ref invalid_iterator for exceptions indicating errors with iterators +@sa @ref type_error for exceptions indicating executing a member function with + a wrong type +@sa @ref out_of_range for exceptions indicating access out of the defined range + +@liveexample{The following code shows how an `other_error` exception can be +caught.,other_error} + +@since version 3.0.0 */ -#define NLOHMANN_JSON_HAS_HELPER(type) \ - template struct has_##type { \ - private: \ - template \ - static int detect(U &&); \ - static void detect(...); \ - public: \ - static constexpr bool value = \ - std::is_integral()))>::value; \ +class other_error : public exception +{ + public: + static other_error create(int id_, const std::string& what_arg) + { + std::string w = exception::name("other_error", id_) + what_arg; + return other_error(id_, w.c_str()); } -NLOHMANN_JSON_HAS_HELPER(mapped_type); -NLOHMANN_JSON_HAS_HELPER(key_type); -NLOHMANN_JSON_HAS_HELPER(value_type); -NLOHMANN_JSON_HAS_HELPER(iterator); + private: + other_error(int id_, const char* what_arg) : exception(id_, what_arg) {} +}; +} +} -#undef NLOHMANN_JSON_HAS_HELPER +// #include -template -struct is_compatible_object_type_impl : std::false_type {}; - -template -struct is_compatible_object_type_impl -{ - static constexpr auto value = - std::is_constructible::value and - std::is_constructible::value; -}; - -template -struct is_compatible_object_type -{ - static auto constexpr value = is_compatible_object_type_impl < - conjunction>, - has_mapped_type, - has_key_type>::value, - typename BasicJsonType::object_t, CompatibleObjectType >::value; -}; +#include // array +#include // and +#include // size_t +#include // uint8_t -template -struct is_basic_json_nested_type +namespace nlohmann { - static auto constexpr value = std::is_same::value or - std::is_same::value or - std::is_same::value or - std::is_same::value or - std::is_same::value; -}; - -template -struct is_compatible_array_type +namespace detail { - static auto constexpr value = - conjunction>, - negation>, - negation>, - negation>, - has_value_type, - has_iterator>::value; -}; - -template -struct is_compatible_integer_type_impl : std::false_type {}; +/////////////////////////// +// JSON type enumeration // +/////////////////////////// -template -struct is_compatible_integer_type_impl -{ - // is there an assert somewhere on overflows? - using RealLimits = std::numeric_limits; - using CompatibleLimits = std::numeric_limits; +/*! +@brief the JSON type enumeration - static constexpr auto value = - std::is_constructible::value and - CompatibleLimits::is_integer and - RealLimits::is_signed == CompatibleLimits::is_signed; -}; +This enumeration collects the different JSON types. It is internally used to +distinguish the stored values, and the functions @ref basic_json::is_null(), +@ref basic_json::is_object(), @ref basic_json::is_array(), +@ref basic_json::is_string(), @ref basic_json::is_boolean(), +@ref basic_json::is_number() (with @ref basic_json::is_number_integer(), +@ref basic_json::is_number_unsigned(), and @ref basic_json::is_number_float()), +@ref basic_json::is_discarded(), @ref basic_json::is_primitive(), and +@ref basic_json::is_structured() rely on it. -template -struct is_compatible_integer_type -{ - static constexpr auto value = - is_compatible_integer_type_impl < - std::is_integral::value and - not std::is_same::value, - RealIntegerType, CompatibleNumberIntegerType > ::value; -}; +@note There are three enumeration entries (number_integer, number_unsigned, and +number_float), because the library distinguishes these three types for numbers: +@ref basic_json::number_unsigned_t is used for unsigned integers, +@ref basic_json::number_integer_t is used for signed integers, and +@ref basic_json::number_float_t is used for floating-point numbers or to +approximate integers which do not fit in the limits of their respective type. +@sa @ref basic_json::basic_json(const value_t value_type) -- create a JSON +value with the default value for a given type -// trait checking if JSONSerializer::from_json(json const&, udt&) exists -template -struct has_from_json +@since version 1.0.0 +*/ +enum class value_t : std::uint8_t { - private: - // also check the return type of from_json - template::from_json( - std::declval(), std::declval()))>::value>> - static int detect(U&&); - static void detect(...); - - public: - static constexpr bool value = std::is_integral>()))>::value; + null, ///< null value + object, ///< object (unordered set of name/value pairs) + array, ///< array (ordered collection of values) + string, ///< string value + boolean, ///< boolean value + number_integer, ///< number value (signed integer) + number_unsigned, ///< number value (unsigned integer) + number_float, ///< number value (floating-point) + discarded ///< discarded by the the parser callback function }; -// This trait checks if JSONSerializer::from_json(json const&) exists -// this overload is used for non-default-constructible user-defined-types -template -struct has_non_default_from_json -{ - private: - template < - typename U, - typename = enable_if_t::from_json(std::declval()))>::value >> - static int detect(U&&); - static void detect(...); +/*! +@brief comparison operator for JSON types - public: - static constexpr bool value = std::is_integral>()))>::value; -}; +Returns an ordering that is similar to Python: +- order: null < boolean < number < object < array < string +- furthermore, each type is not smaller than itself +- discarded values are not comparable -// This trait checks if BasicJsonType::json_serializer::to_json exists -template -struct has_to_json +@since version 1.0.0 +*/ +inline bool operator<(const value_t lhs, const value_t rhs) noexcept { - private: - template::to_json( - std::declval(), std::declval()))> - static int detect(U&&); - static void detect(...); - - public: - static constexpr bool value = std::is_integral>()))>::value; -}; - - -///////////// -// to_json // -///////////// + static constexpr std::array order = {{ + 0 /* null */, 3 /* object */, 4 /* array */, 5 /* string */, + 1 /* boolean */, 2 /* integer */, 2 /* unsigned */, 2 /* float */ + } + }; -template::value, int> = 0> -void to_json(BasicJsonType& j, T b) noexcept -{ - external_constructor::construct(j, b); + const auto l_index = static_cast(lhs); + const auto r_index = static_cast(rhs); + return l_index < order.size() and r_index < order.size() and order[l_index] < order[r_index]; } - -template::value, int> = 0> -void to_json(BasicJsonType& j, const CompatibleString& s) -{ - external_constructor::construct(j, s); } - -template::value, int> = 0> -void to_json(BasicJsonType& j, FloatType val) noexcept -{ - external_constructor::construct(j, static_cast(val)); } -template < - typename BasicJsonType, typename CompatibleNumberUnsignedType, - enable_if_t::value, int> = 0 > -void to_json(BasicJsonType& j, CompatibleNumberUnsignedType val) noexcept -{ - external_constructor::construct(j, static_cast(val)); -} +// #include -template < - typename BasicJsonType, typename CompatibleNumberIntegerType, - enable_if_t::value, int> = 0 > -void to_json(BasicJsonType& j, CompatibleNumberIntegerType val) noexcept -{ - external_constructor::construct(j, static_cast(val)); -} -template::value, int> = 0> -void to_json(BasicJsonType& j, EnumType e) noexcept -{ - using underlying_type = typename std::underlying_type::type; - external_constructor::construct(j, static_cast(e)); -} +#include // transform +#include // array +#include // and, not +#include // forward_list +#include // inserter, front_inserter, end +#include // string +#include // tuple, make_tuple +#include // is_arithmetic, is_same, is_enum, underlying_type, is_convertible +#include // pair, declval +#include // valarray -template -void to_json(BasicJsonType& j, const std::vector& e) -{ - external_constructor::construct(j, e); -} +// #include -template < - typename BasicJsonType, typename CompatibleArrayType, - enable_if_t < - is_compatible_array_type::value or - std::is_same::value, - int > = 0 > -void to_json(BasicJsonType& j, const CompatibleArrayType& arr) -{ - external_constructor::construct(j, arr); -} +// #include -template < - typename BasicJsonType, typename CompatibleObjectType, - enable_if_t::value, - int> = 0 > -void to_json(BasicJsonType& j, const CompatibleObjectType& arr) -{ - external_constructor::construct(j, arr); -} +// #include -template ::value, - int> = 0> -void to_json(BasicJsonType& j, T (&arr)[N]) -{ - external_constructor::construct(j, arr); -} +// #include -template -void to_json(BasicJsonType& j, const std::pair& p) -{ - j = {p.first, p.second}; -} -template -void to_json_tuple_impl(BasicJsonType& j, const Tuple& t, index_sequence) +namespace nlohmann { - j = {std::get(t)...}; -} - -template -void to_json(BasicJsonType& j, const std::tuple& t) +namespace detail { - to_json_tuple_impl(j, t, index_sequence_for {}); -} - -/////////////// -// from_json // -/////////////// - // overloads for basic_json template parameters template::value and - not std::is_same::value, + not std::is_same::value, int> = 0> void get_arithmetic_value(const BasicJsonType& j, ArithmeticType& val) { @@ -933,35 +938,31 @@ void get_arithmetic_value(const BasicJsonType& j, ArithmeticType& val) { case value_t::number_unsigned: { - val = static_cast( - *j.template get_ptr()); + val = static_cast(*j.template get_ptr()); break; } case value_t::number_integer: { - val = static_cast( - *j.template get_ptr()); + val = static_cast(*j.template get_ptr()); break; } case value_t::number_float: { - val = static_cast( - *j.template get_ptr()); + val = static_cast(*j.template get_ptr()); break; } + default: - { - JSON_THROW(type_error::create(302, "type must be number, but is " + j.type_name())); - } + JSON_THROW(type_error::create(302, "type must be number, but is " + std::string(j.type_name()))); } } template void from_json(const BasicJsonType& j, typename BasicJsonType::boolean_t& b) { - if (not j.is_boolean()) + if (JSON_UNLIKELY(not j.is_boolean())) { - JSON_THROW(type_error::create(302, "type must be boolean, but is " + j.type_name())); + JSON_THROW(type_error::create(302, "type must be boolean, but is " + std::string(j.type_name()))); } b = *j.template get_ptr(); } @@ -969,9 +970,9 @@ void from_json(const BasicJsonType& j, typename BasicJsonType::boolean_t& b) template void from_json(const BasicJsonType& j, typename BasicJsonType::string_t& s) { - if (not j.is_string()) + if (JSON_UNLIKELY(not j.is_string())) { - JSON_THROW(type_error::create(302, "type must be string, but is " + j.type_name())); + JSON_THROW(type_error::create(302, "type must be string, but is " + std::string(j.type_name()))); } s = *j.template get_ptr(); } @@ -1006,9 +1007,9 @@ void from_json(const BasicJsonType& j, EnumType& e) template void from_json(const BasicJsonType& j, typename BasicJsonType::array_t& arr) { - if (not j.is_array()) + if (JSON_UNLIKELY(not j.is_array())) { - JSON_THROW(type_error::create(302, "type must be array, but is " + j.type_name())); + JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name()))); } arr = *j.template get_ptr(); } @@ -1018,21 +1019,33 @@ template::value, int> = 0> void from_json(const BasicJsonType& j, std::forward_list& l) { - if (not j.is_array()) + if (JSON_UNLIKELY(not j.is_array())) { - JSON_THROW(type_error::create(302, "type must be array, but is " + j.type_name())); + JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name()))); } + std::transform(j.rbegin(), j.rend(), + std::front_inserter(l), [](const BasicJsonType & i) + { + return i.template get(); + }); +} - for (auto it = j.rbegin(), end = j.rend(); it != end; ++it) +// valarray doesn't have an insert method +template::value, int> = 0> +void from_json(const BasicJsonType& j, std::valarray& l) +{ + if (JSON_UNLIKELY(not j.is_array())) { - l.push_front(it->template get()); + JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name()))); } + l.resize(j.size()); + std::copy(j.m_value.array->begin(), j.m_value.array->end(), std::begin(l)); } template -void from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr, priority_tag<0>) +void from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr, priority_tag<0> /*unused*/) { - using std::begin; using std::end; std::transform(j.begin(), j.end(), @@ -1045,12 +1058,11 @@ void from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr, prio } template -auto from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr, priority_tag<1>) +auto from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr, priority_tag<1> /*unused*/) -> decltype( arr.reserve(std::declval()), void()) { - using std::begin; using std::end; arr.reserve(j.size()); @@ -1063,8 +1075,8 @@ auto from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr, prio }); } -template -void from_json_array_impl(const BasicJsonType& j, std::array& arr, priority_tag<2>) +template +void from_json_array_impl(const BasicJsonType& j, std::array& arr, priority_tag<2> /*unused*/) { for (std::size_t i = 0; i < N; ++i) { @@ -1072,15 +1084,21 @@ void from_json_array_impl(const BasicJsonType& j, std::array& arr, priorit } } -template::value and - std::is_convertible::value and - not std::is_same::value, int> = 0> +template < + typename BasicJsonType, typename CompatibleArrayType, + enable_if_t < + is_compatible_array_type::value and + not std::is_same::value and + std::is_constructible < + BasicJsonType, typename CompatibleArrayType::value_type >::value, + int > = 0 > void from_json(const BasicJsonType& j, CompatibleArrayType& arr) { - if (not j.is_array()) + if (JSON_UNLIKELY(not j.is_array())) { - JSON_THROW(type_error::create(302, "type must be array, but is " + j.type_name())); + JSON_THROW(type_error::create(302, "type must be array, but is " + + std::string(j.type_name()))); } from_json_array_impl(j, arr, priority_tag<2> {}); @@ -1090,24 +1108,19 @@ template::value, int> = 0> void from_json(const BasicJsonType& j, CompatibleObjectType& obj) { - if (not j.is_object()) + if (JSON_UNLIKELY(not j.is_object())) { - JSON_THROW(type_error::create(302, "type must be object, but is " + j.type_name())); + JSON_THROW(type_error::create(302, "type must be object, but is " + std::string(j.type_name()))); } auto inner_object = j.template get_ptr(); - using std::begin; - using std::end; using value_type = typename CompatibleObjectType::value_type; std::transform( inner_object->begin(), inner_object->end(), std::inserter(obj, obj.begin()), [](typename BasicJsonType::object_t::value_type const & p) { - return value_type( - p.first, - p.second - .template get()); + return value_type(p.first, p.second.template get()); }); } @@ -1147,62 +1160,35 @@ void from_json(const BasicJsonType& j, ArithmeticType& val) val = static_cast(*j.template get_ptr()); break; } + default: - { - JSON_THROW(type_error::create(302, "type must be number, but is " + j.type_name())); - } + JSON_THROW(type_error::create(302, "type must be number, but is " + std::string(j.type_name()))); } } -template -void from_json(const BasicJsonType& j, std::pair& p) +template +void from_json(const BasicJsonType& j, std::pair& p) { - p = {j.at(0), j.at(1)}; + p = {j.at(0).template get(), j.at(1).template get()}; } -template +template void from_json_tuple_impl(const BasicJsonType& j, Tuple& t, index_sequence) { - t = std::make_tuple(j.at(Idx)...); + t = std::make_tuple(j.at(Idx).template get::type>()...); } -template +template void from_json(const BasicJsonType& j, std::tuple& t) { from_json_tuple_impl(j, t, index_sequence_for {}); } -struct to_json_fn -{ - private: - template - auto call(BasicJsonType& j, T&& val, priority_tag<1>) const noexcept(noexcept(to_json(j, std::forward(val)))) - -> decltype(to_json(j, std::forward(val)), void()) - { - return to_json(j, std::forward(val)); - } - - template - void call(BasicJsonType&, T&&, priority_tag<0>) const noexcept - { - static_assert(sizeof(BasicJsonType) == 0, - "could not find to_json() method in T's namespace"); - } - - public: - template - void operator()(BasicJsonType& j, T&& val) const - noexcept(noexcept(std::declval().call(j, std::forward(val), priority_tag<1> {}))) - { - return call(j, std::forward(val), priority_tag<1> {}); - } -}; - struct from_json_fn { private: template - auto call(const BasicJsonType& j, T& val, priority_tag<1>) const + auto call(const BasicJsonType& j, T& val, priority_tag<1> /*unused*/) const noexcept(noexcept(from_json(j, val))) -> decltype(from_json(j, val), void()) { @@ -1210,10 +1196,16 @@ struct from_json_fn } template - void call(const BasicJsonType&, T&, priority_tag<0>) const noexcept + void call(const BasicJsonType& /*unused*/, T& /*unused*/, priority_tag<0> /*unused*/) const noexcept { static_assert(sizeof(BasicJsonType) == 0, "could not find from_json() method in T's namespace"); +#ifdef _MSC_VER + // MSVC does not show a stacktrace for the above assert + using decayed = uncvref_t; + static_assert(sizeof(typename decayed::force_msvc_stacktrace) == 0, + "forcing MSVC stacktrace to show which T we're talking about."); +#endif } public: @@ -1224,953 +1216,1949 @@ struct from_json_fn return call(j, val, priority_tag<1> {}); } }; +} -// taken from ranges-v3 -template -struct static_const -{ - static constexpr T value{}; -}; - -template -constexpr T static_const::value; -} // namespace detail - - -/// namespace to hold default `to_json` / `from_json` functions +/// namespace to hold default `from_json` function +/// to see why this is required: +/// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4381.html namespace { -constexpr const auto& to_json = detail::static_const::value; constexpr const auto& from_json = detail::static_const::value; } +} +// #include -/*! -@brief default JSONSerializer template argument -This serializer ignores the template arguments and uses ADL -([argument-dependent lookup](http://en.cppreference.com/w/cpp/language/adl)) -for serialization. -*/ -template -struct adl_serializer +#include // or, and, not +#include // begin, end +#include // tuple, get +#include // is_same, is_constructible, is_floating_point, is_enum, underlying_type +#include // move, forward, declval, pair +#include // valarray +#include // vector + +// #include + +// #include + + +namespace nlohmann { - /*! - @brief convert a JSON value to any value type +namespace detail +{ +////////////////// +// constructors // +////////////////// - This function is usually called by the `get()` function of the - @ref basic_json class (either explicit or via conversion operators). +template struct external_constructor; - @param[in] j JSON value to read from - @param[in,out] val value to write to - */ - template - static void from_json(BasicJsonType&& j, ValueType& val) noexcept( - noexcept(::nlohmann::from_json(std::forward(j), val))) +template<> +struct external_constructor +{ + template + static void construct(BasicJsonType& j, typename BasicJsonType::boolean_t b) noexcept { - ::nlohmann::from_json(std::forward(j), val); + j.m_type = value_t::boolean; + j.m_value = b; + j.assert_invariant(); } +}; - /*! - @brief convert any value type to a JSON value - - This function is usually called by the constructors of the @ref basic_json - class. +template<> +struct external_constructor +{ + template + static void construct(BasicJsonType& j, const typename BasicJsonType::string_t& s) + { + j.m_type = value_t::string; + j.m_value = s; + j.assert_invariant(); + } - @param[in,out] j JSON value to write to - @param[in] val value to read from - */ - template - static void to_json(BasicJsonType& j, ValueType&& val) noexcept( - noexcept(::nlohmann::to_json(j, std::forward(val)))) + template + static void construct(BasicJsonType& j, typename BasicJsonType::string_t&& s) { - ::nlohmann::to_json(j, std::forward(val)); + j.m_type = value_t::string; + j.m_value = std::move(s); + j.assert_invariant(); } }; +template<> +struct external_constructor +{ + template + static void construct(BasicJsonType& j, typename BasicJsonType::number_float_t val) noexcept + { + j.m_type = value_t::number_float; + j.m_value = val; + j.assert_invariant(); + } +}; -/*! -@brief a class to store JSON values +template<> +struct external_constructor +{ + template + static void construct(BasicJsonType& j, typename BasicJsonType::number_unsigned_t val) noexcept + { + j.m_type = value_t::number_unsigned; + j.m_value = val; + j.assert_invariant(); + } +}; -@tparam ObjectType type for JSON objects (`std::map` by default; will be used -in @ref object_t) -@tparam ArrayType type for JSON arrays (`std::vector` by default; will be used -in @ref array_t) -@tparam StringType type for JSON strings and object keys (`std::string` by -default; will be used in @ref string_t) -@tparam BooleanType type for JSON booleans (`bool` by default; will be used -in @ref boolean_t) -@tparam NumberIntegerType type for JSON integer numbers (`int64_t` by -default; will be used in @ref number_integer_t) -@tparam NumberUnsignedType type for JSON unsigned integer numbers (@c -`uint64_t` by default; will be used in @ref number_unsigned_t) -@tparam NumberFloatType type for JSON floating-point numbers (`double` by -default; will be used in @ref number_float_t) -@tparam AllocatorType type of the allocator to use (`std::allocator` by -default) -@tparam JSONSerializer the serializer to resolve internal calls to `to_json()` -and `from_json()` (@ref adl_serializer by default) +template<> +struct external_constructor +{ + template + static void construct(BasicJsonType& j, typename BasicJsonType::number_integer_t val) noexcept + { + j.m_type = value_t::number_integer; + j.m_value = val; + j.assert_invariant(); + } +}; -@requirement The class satisfies the following concept requirements: -- Basic - - [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible): - JSON values can be default constructed. The result will be a JSON null - value. - - [MoveConstructible](http://en.cppreference.com/w/cpp/concept/MoveConstructible): - A JSON value can be constructed from an rvalue argument. - - [CopyConstructible](http://en.cppreference.com/w/cpp/concept/CopyConstructible): - A JSON value can be copy-constructed from an lvalue expression. - - [MoveAssignable](http://en.cppreference.com/w/cpp/concept/MoveAssignable): - A JSON value van be assigned from an rvalue argument. - - [CopyAssignable](http://en.cppreference.com/w/cpp/concept/CopyAssignable): - A JSON value can be copy-assigned from an lvalue expression. - - [Destructible](http://en.cppreference.com/w/cpp/concept/Destructible): - JSON values can be destructed. -- Layout - - [StandardLayoutType](http://en.cppreference.com/w/cpp/concept/StandardLayoutType): - JSON values have - [standard layout](http://en.cppreference.com/w/cpp/language/data_members#Standard_layout): - All non-static data members are private and standard layout types, the - class has no virtual functions or (virtual) base classes. -- Library-wide - - [EqualityComparable](http://en.cppreference.com/w/cpp/concept/EqualityComparable): - JSON values can be compared with `==`, see @ref - operator==(const_reference,const_reference). - - [LessThanComparable](http://en.cppreference.com/w/cpp/concept/LessThanComparable): - JSON values can be compared with `<`, see @ref - operator<(const_reference,const_reference). - - [Swappable](http://en.cppreference.com/w/cpp/concept/Swappable): - Any JSON lvalue or rvalue of can be swapped with any lvalue or rvalue of - other compatible types, using unqualified function call @ref swap(). - - [NullablePointer](http://en.cppreference.com/w/cpp/concept/NullablePointer): - JSON values can be compared against `std::nullptr_t` objects which are used - to model the `null` value. -- Container - - [Container](http://en.cppreference.com/w/cpp/concept/Container): - JSON values can be used like STL containers and provide iterator access. - - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer); - JSON values can be used like STL containers and provide reverse iterator - access. +template<> +struct external_constructor +{ + template + static void construct(BasicJsonType& j, const typename BasicJsonType::array_t& arr) + { + j.m_type = value_t::array; + j.m_value = arr; + j.assert_invariant(); + } -@invariant The member variables @a m_value and @a m_type have the following -relationship: -- If `m_type == value_t::object`, then `m_value.object != nullptr`. -- If `m_type == value_t::array`, then `m_value.array != nullptr`. -- If `m_type == value_t::string`, then `m_value.string != nullptr`. -The invariants are checked by member function assert_invariant(). + template + static void construct(BasicJsonType& j, typename BasicJsonType::array_t&& arr) + { + j.m_type = value_t::array; + j.m_value = std::move(arr); + j.assert_invariant(); + } -@internal -@note ObjectType trick from http://stackoverflow.com/a/9860911 -@endinternal + template::value, + int> = 0> + static void construct(BasicJsonType& j, const CompatibleArrayType& arr) + { + using std::begin; + using std::end; + j.m_type = value_t::array; + j.m_value.array = j.template create(begin(arr), end(arr)); + j.assert_invariant(); + } -@see [RFC 7159: The JavaScript Object Notation (JSON) Data Interchange -Format](http://rfc7159.net/rfc7159) + template + static void construct(BasicJsonType& j, const std::vector& arr) + { + j.m_type = value_t::array; + j.m_value = value_t::array; + j.m_value.array->reserve(arr.size()); + for (const bool x : arr) + { + j.m_value.array->push_back(x); + } + j.assert_invariant(); + } -@since version 1.0.0 + template::value, int> = 0> + static void construct(BasicJsonType& j, const std::valarray& arr) + { + j.m_type = value_t::array; + j.m_value = value_t::array; + j.m_value.array->resize(arr.size()); + std::copy(std::begin(arr), std::end(arr), j.m_value.array->begin()); + j.assert_invariant(); + } +}; -@nosubgrouping -*/ -template < - template class ObjectType = std::map, - template class ArrayType = std::vector, - class StringType = std::string, - class BooleanType = bool, - class NumberIntegerType = std::int64_t, - class NumberUnsignedType = std::uint64_t, - class NumberFloatType = double, - template class AllocatorType = std::allocator, - template class JSONSerializer = adl_serializer - > -class basic_json +template<> +struct external_constructor { - private: - template friend struct detail::external_constructor; - /// workaround type for MSVC - using basic_json_t = basic_json; + template + static void construct(BasicJsonType& j, const typename BasicJsonType::object_t& obj) + { + j.m_type = value_t::object; + j.m_value = obj; + j.assert_invariant(); + } - public: - using value_t = detail::value_t; - // forward declarations - template class iter_impl; - template class json_reverse_iterator; - class json_pointer; - template - using json_serializer = JSONSerializer; + template + static void construct(BasicJsonType& j, typename BasicJsonType::object_t&& obj) + { + j.m_type = value_t::object; + j.m_value = std::move(obj); + j.assert_invariant(); + } + template::value, int> = 0> + static void construct(BasicJsonType& j, const CompatibleObjectType& obj) + { + using std::begin; + using std::end; - //////////////// - // exceptions // - //////////////// - - /// @name exceptions - /// Classes to implement user-defined exceptions. - /// @{ - - /// @copydoc detail::exception - using exception = detail::exception; - /// @copydoc detail::parse_error - using parse_error = detail::parse_error; - /// @copydoc detail::invalid_iterator - using invalid_iterator = detail::invalid_iterator; - /// @copydoc detail::type_error - using type_error = detail::type_error; - /// @copydoc detail::out_of_range - using out_of_range = detail::out_of_range; - /// @copydoc detail::other_error - using other_error = detail::other_error; + j.m_type = value_t::object; + j.m_value.object = j.template create(begin(obj), end(obj)); + j.assert_invariant(); + } +}; - /// @} +///////////// +// to_json // +///////////// +template::value, int> = 0> +void to_json(BasicJsonType& j, T b) noexcept +{ + external_constructor::construct(j, b); +} - ///////////////////// - // container types // - ///////////////////// +template::value, int> = 0> +void to_json(BasicJsonType& j, const CompatibleString& s) +{ + external_constructor::construct(j, s); +} - /// @name container types - /// The canonic container types to use @ref basic_json like any other STL - /// container. - /// @{ +template +void to_json(BasicJsonType& j, typename BasicJsonType::string_t&& s) +{ + external_constructor::construct(j, std::move(s)); +} - /// the type of elements in a basic_json container - using value_type = basic_json; +template::value, int> = 0> +void to_json(BasicJsonType& j, FloatType val) noexcept +{ + external_constructor::construct(j, static_cast(val)); +} - /// the type of an element reference - using reference = value_type&; - /// the type of an element const reference - using const_reference = const value_type&; +template::value, int> = 0> +void to_json(BasicJsonType& j, CompatibleNumberUnsignedType val) noexcept +{ + external_constructor::construct(j, static_cast(val)); +} - /// a type to represent differences between iterators - using difference_type = std::ptrdiff_t; - /// a type to represent container sizes - using size_type = std::size_t; +template::value, int> = 0> +void to_json(BasicJsonType& j, CompatibleNumberIntegerType val) noexcept +{ + external_constructor::construct(j, static_cast(val)); +} - /// the allocator type - using allocator_type = AllocatorType; +template::value, int> = 0> +void to_json(BasicJsonType& j, EnumType e) noexcept +{ + using underlying_type = typename std::underlying_type::type; + external_constructor::construct(j, static_cast(e)); +} - /// the type of an element pointer - using pointer = typename std::allocator_traits::pointer; - /// the type of an element const pointer - using const_pointer = typename std::allocator_traits::const_pointer; +template +void to_json(BasicJsonType& j, const std::vector& e) +{ + external_constructor::construct(j, e); +} - /// an iterator for a basic_json container - using iterator = iter_impl; - /// a const iterator for a basic_json container - using const_iterator = iter_impl; - /// a reverse iterator for a basic_json container - using reverse_iterator = json_reverse_iterator; - /// a const reverse iterator for a basic_json container - using const_reverse_iterator = json_reverse_iterator; +template::value or + std::is_same::value, + int> = 0> +void to_json(BasicJsonType& j, const CompatibleArrayType& arr) +{ + external_constructor::construct(j, arr); +} - /// @} +template::value, int> = 0> +void to_json(BasicJsonType& j, std::valarray arr) +{ + external_constructor::construct(j, std::move(arr)); +} +template +void to_json(BasicJsonType& j, typename BasicJsonType::array_t&& arr) +{ + external_constructor::construct(j, std::move(arr)); +} - /*! - @brief returns the allocator associated with the container - */ - static allocator_type get_allocator() - { - return allocator_type(); - } +template::value, int> = 0> +void to_json(BasicJsonType& j, const CompatibleObjectType& obj) +{ + external_constructor::construct(j, obj); +} - /*! - @brief returns version information on the library +template +void to_json(BasicJsonType& j, typename BasicJsonType::object_t&& obj) +{ + external_constructor::construct(j, std::move(obj)); +} - This function returns a JSON object with information about the library, - including the version number and information on the platform and compiler. +template::value, int> = 0> +void to_json(BasicJsonType& j, T (&arr)[N]) +{ + external_constructor::construct(j, arr); +} - @return JSON object holding version information - key | description - ----------- | --------------- - `compiler` | Information on the used compiler. It is an object with the following keys: `c++` (the used C++ standard), `family` (the compiler family; possible values are `clang`, `icc`, `gcc`, `ilecpp`, `msvc`, `pgcpp`, `sunpro`, and `unknown`), and `version` (the compiler version). - `copyright` | The copyright line for the library as string. - `name` | The name of the library as string. - `platform` | The used platform as string. Possible values are `win32`, `linux`, `apple`, `unix`, and `unknown`. - `url` | The URL of the project as string. - `version` | The version of the library. It is an object with the following keys: `major`, `minor`, and `patch` as defined by [Semantic Versioning](http://semver.org), and `string` (the version string). +template +void to_json(BasicJsonType& j, const std::pair& p) +{ + j = {p.first, p.second}; +} - @liveexample{The following code shows an example output of the `meta()` - function.,meta} +template +void to_json_tuple_impl(BasicJsonType& j, const Tuple& t, index_sequence) +{ + j = {std::get(t)...}; +} - @complexity Constant. +template +void to_json(BasicJsonType& j, const std::tuple& t) +{ + to_json_tuple_impl(j, t, index_sequence_for {}); +} - @since 2.1.0 - */ - static basic_json meta() +struct to_json_fn +{ + private: + template + auto call(BasicJsonType& j, T&& val, priority_tag<1> /*unused*/) const noexcept(noexcept(to_json(j, std::forward(val)))) + -> decltype(to_json(j, std::forward(val)), void()) { - basic_json result; - - result["copyright"] = "(C) 2013-2017 Niels Lohmann"; - result["name"] = "JSON for Modern C++"; - result["url"] = "https://github.com/nlohmann/json"; - result["version"] = - { - {"string", "2.1.1"}, {"major", 2}, {"minor", 1}, {"patch", 1} - }; - -#ifdef _WIN32 - result["platform"] = "win32"; -#elif defined __linux__ - result["platform"] = "linux"; -#elif defined __APPLE__ - result["platform"] = "apple"; -#elif defined __unix__ - result["platform"] = "unix"; -#else - result["platform"] = "unknown"; -#endif + return to_json(j, std::forward(val)); + } -#if defined(__clang__) - result["compiler"] = {{"family", "clang"}, {"version", __clang_version__}}; -#elif defined(__ICC) || defined(__INTEL_COMPILER) - result["compiler"] = {{"family", "icc"}, {"version", __INTEL_COMPILER}}; -#elif defined(__GNUC__) || defined(__GNUG__) - result["compiler"] = {{"family", "gcc"}, {"version", std::to_string(__GNUC__) + "." + std::to_string(__GNUC_MINOR__) + "." + std::to_string(__GNUC_PATCHLEVEL__)}}; -#elif defined(__HP_cc) || defined(__HP_aCC) - result["compiler"] = "hp" -#elif defined(__IBMCPP__) - result["compiler"] = {{"family", "ilecpp"}, {"version", __IBMCPP__}}; -#elif defined(_MSC_VER) - result["compiler"] = {{"family", "msvc"}, {"version", _MSC_VER}}; -#elif defined(__PGI) - result["compiler"] = {{"family", "pgcpp"}, {"version", __PGI}}; -#elif defined(__SUNPRO_CC) - result["compiler"] = {{"family", "sunpro"}, {"version", __SUNPRO_CC}}; -#else - result["compiler"] = {{"family", "unknown"}, {"version", "unknown"}}; -#endif + template + void call(BasicJsonType& /*unused*/, T&& /*unused*/, priority_tag<0> /*unused*/) const noexcept + { + static_assert(sizeof(BasicJsonType) == 0, + "could not find to_json() method in T's namespace"); -#ifdef __cplusplus - result["compiler"]["c++"] = std::to_string(__cplusplus); -#else - result["compiler"]["c++"] = "unknown"; +#ifdef _MSC_VER + // MSVC does not show a stacktrace for the above assert + using decayed = uncvref_t; + static_assert(sizeof(typename decayed::force_msvc_stacktrace) == 0, + "forcing MSVC stacktrace to show which T we're talking about."); #endif - return result; } + public: + template + void operator()(BasicJsonType& j, T&& val) const + noexcept(noexcept(std::declval().call(j, std::forward(val), priority_tag<1> {}))) + { + return call(j, std::forward(val), priority_tag<1> {}); + } +}; +} - /////////////////////////// - // JSON value data types // - /////////////////////////// +/// namespace to hold default `to_json` function +namespace +{ +constexpr const auto& to_json = detail::static_const::value; +} +} - /// @name JSON value data types - /// The data types to store a JSON value. These types are derived from - /// the template arguments passed to class @ref basic_json. - /// @{ +// #include - /*! - @brief a type for an object - [RFC 7159](http://rfc7159.net/rfc7159) describes JSON objects as follows: - > An object is an unordered collection of zero or more name/value pairs, - > where a name is a string and a value is a string, number, boolean, null, - > object, or array. +#include // min +#include // array +#include // assert +#include // size_t +#include // strlen +#include // streamsize, streamoff, streampos +#include // istream +#include // begin, end, iterator_traits, random_access_iterator_tag, distance, next +#include // shared_ptr, make_shared, addressof +#include // accumulate +#include // string, char_traits +#include // enable_if, is_base_of, is_pointer, is_integral, remove_pointer +#include // pair, declval - To store objects in C++, a type is defined by the template parameters - described below. +// #include - @tparam ObjectType the container to store objects (e.g., `std::map` or - `std::unordered_map`) - @tparam StringType the type of the keys or names (e.g., `std::string`). - The comparison function `std::less` is used to order elements - inside the container. - @tparam AllocatorType the allocator to use for objects (e.g., - `std::allocator`) - #### Default type +namespace nlohmann +{ +namespace detail +{ +//////////////////// +// input adapters // +//////////////////// - With the default values for @a ObjectType (`std::map`), @a StringType - (`std::string`), and @a AllocatorType (`std::allocator`), the default - value for @a object_t is: +/*! +@brief abstract input adapter interface + +Produces a stream of std::char_traits::int_type characters from a +std::istream, a buffer, or some other input type. Accepts the return of exactly +one non-EOF character for future input. The int_type characters returned +consist of all valid char values as positive values (typically unsigned char), +plus an EOF value outside that range, specified by the value of the function +std::char_traits::eof(). This value is typically -1, but could be any +arbitrary value which is not a valid char value. +*/ +struct input_adapter_protocol +{ + /// get a character [0,255] or std::char_traits::eof(). + virtual std::char_traits::int_type get_character() = 0; + /// restore the last non-eof() character to input + virtual void unget_character() = 0; + virtual ~input_adapter_protocol() = default; +}; - @code {.cpp} - std::map< - std::string, // key_type - basic_json, // value_type - std::less, // key_compare - std::allocator> // allocator_type - > - @endcode +/// a type to simplify interfaces +using input_adapter_t = std::shared_ptr; - #### Behavior +/*! +Input adapter for a (caching) istream. Ignores a UFT Byte Order Mark at +beginning of input. Does not support changing the underlying std::streambuf +in mid-input. Maintains underlying std::istream and std::streambuf to support +subsequent use of standard std::istream operations to process any input +characters following those used in parsing the JSON input. Clears the +std::istream flags; any input errors (e.g., EOF) will be detected by the first +subsequent call for input from the std::istream. +*/ +class input_stream_adapter : public input_adapter_protocol +{ + public: + ~input_stream_adapter() override + { + // clear stream flags; we use underlying streambuf I/O, do not + // maintain ifstream flags + is.clear(); + } - The choice of @a object_t influences the behavior of the JSON class. With - the default type, objects have the following behavior: + explicit input_stream_adapter(std::istream& i) + : is(i), sb(*i.rdbuf()) + { + // skip byte order mark + std::char_traits::int_type c; + if ((c = get_character()) == 0xEF) + { + if ((c = get_character()) == 0xBB) + { + if ((c = get_character()) == 0xBF) + { + return; // Ignore BOM + } + else if (c != std::char_traits::eof()) + { + is.unget(); + } + is.putback('\xBB'); + } + else if (c != std::char_traits::eof()) + { + is.unget(); + } + is.putback('\xEF'); + } + else if (c != std::char_traits::eof()) + { + is.unget(); // no byte order mark; process as usual + } + } - - When all names are unique, objects will be interoperable in the sense - that all software implementations receiving that object will agree on - the name-value mappings. - - When the names within an object are not unique, later stored name/value - pairs overwrite previously stored name/value pairs, leaving the used - names unique. For instance, `{"key": 1}` and `{"key": 2, "key": 1}` will - be treated as equal and both stored as `{"key": 1}`. - - Internally, name/value pairs are stored in lexicographical order of the - names. Objects will also be serialized (see @ref dump) in this order. - For instance, `{"b": 1, "a": 2}` and `{"a": 2, "b": 1}` will be stored - and serialized as `{"a": 2, "b": 1}`. - - When comparing objects, the order of the name/value pairs is irrelevant. - This makes objects interoperable in the sense that they will not be - affected by these differences. For instance, `{"b": 1, "a": 2}` and - `{"a": 2, "b": 1}` will be treated as equal. + // delete because of pointer members + input_stream_adapter(const input_stream_adapter&) = delete; + input_stream_adapter& operator=(input_stream_adapter&) = delete; - #### Limits + // std::istream/std::streambuf use std::char_traits::to_int_type, to + // ensure that std::char_traits::eof() and the character 0xFF do not + // end up as the same value, eg. 0xFFFFFFFF. + std::char_traits::int_type get_character() override + { + return sb.sbumpc(); + } - [RFC 7159](http://rfc7159.net/rfc7159) specifies: - > An implementation may set limits on the maximum depth of nesting. + void unget_character() override + { + sb.sungetc(); // is.unget() avoided for performance + } - In this class, the object's limit of nesting is not constraint explicitly. - However, a maximum depth of nesting may be introduced by the compiler or - runtime environment. A theoretical limit can be queried by calling the - @ref max_size function of a JSON object. + private: + /// the associated input stream + std::istream& is; + std::streambuf& sb; +}; - #### Storage +/// input adapter for buffer input +class input_buffer_adapter : public input_adapter_protocol +{ + public: + input_buffer_adapter(const char* b, const std::size_t l) + : cursor(b), limit(b + l), start(b) + { + // skip byte order mark + if (l >= 3 and b[0] == '\xEF' and b[1] == '\xBB' and b[2] == '\xBF') + { + cursor += 3; + } + } - Objects are stored as pointers in a @ref basic_json type. That is, for any - access to object values, a pointer of type `object_t*` must be - dereferenced. + // delete because of pointer members + input_buffer_adapter(const input_buffer_adapter&) = delete; + input_buffer_adapter& operator=(input_buffer_adapter&) = delete; - @sa @ref array_t -- type for an array value + std::char_traits::int_type get_character() noexcept override + { + if (JSON_LIKELY(cursor < limit)) + { + return std::char_traits::to_int_type(*(cursor++)); + } - @since version 1.0.0 + return std::char_traits::eof(); + } - @note The order name/value pairs are added to the object is *not* - preserved by the library. Therefore, iterating an object may return - name/value pairs in a different order than they were originally stored. In - fact, keys will be traversed in alphabetical order as `std::map` with - `std::less` is used by default. Please note this behavior conforms to [RFC - 7159](http://rfc7159.net/rfc7159), because any order implements the - specified "unordered" nature of JSON objects. - */ - using object_t = ObjectType, - AllocatorType>>; + void unget_character() noexcept override + { + if (JSON_LIKELY(cursor > start)) + { + --cursor; + } + } - /*! - @brief a type for an array + private: + /// pointer to the current character + const char* cursor; + /// pointer past the last character + const char* limit; + /// pointer to the first character + const char* start; +}; - [RFC 7159](http://rfc7159.net/rfc7159) describes JSON arrays as follows: - > An array is an ordered sequence of zero or more values. +class input_adapter +{ + public: + // native support - To store objects in C++, a type is defined by the template parameters - explained below. + /// input adapter for input stream + input_adapter(std::istream& i) + : ia(std::make_shared(i)) {} - @tparam ArrayType container type to store arrays (e.g., `std::vector` or - `std::list`) - @tparam AllocatorType allocator to use for arrays (e.g., `std::allocator`) + /// input adapter for input stream + input_adapter(std::istream&& i) + : ia(std::make_shared(i)) {} - #### Default type + /// input adapter for buffer + template::value and + std::is_integral::type>::value and + sizeof(typename std::remove_pointer::type) == 1, + int>::type = 0> + input_adapter(CharT b, std::size_t l) + : ia(std::make_shared(reinterpret_cast(b), l)) {} - With the default values for @a ArrayType (`std::vector`) and @a - AllocatorType (`std::allocator`), the default value for @a array_t is: + // derived support - @code {.cpp} - std::vector< - basic_json, // value_type - std::allocator // allocator_type - > - @endcode + /// input adapter for string literal + template::value and + std::is_integral::type>::value and + sizeof(typename std::remove_pointer::type) == 1, + int>::type = 0> + input_adapter(CharT b) + : input_adapter(reinterpret_cast(b), + std::strlen(reinterpret_cast(b))) {} + + /// input adapter for iterator range with contiguous storage + template::iterator_category, std::random_access_iterator_tag>::value, + int>::type = 0> + input_adapter(IteratorType first, IteratorType last) + { + // assertion to check that the iterator range is indeed contiguous, + // see http://stackoverflow.com/a/35008842/266378 for more discussion + assert(std::accumulate( + first, last, std::pair(true, 0), + [&first](std::pair res, decltype(*first) val) + { + res.first &= (val == *(std::next(std::addressof(*first), res.second++))); + return res; + }).first); - #### Limits + // assertion to check that each element is 1 byte long + static_assert( + sizeof(typename std::iterator_traits::value_type) == 1, + "each element in the iterator range must have the size of 1 byte"); - [RFC 7159](http://rfc7159.net/rfc7159) specifies: - > An implementation may set limits on the maximum depth of nesting. + const auto len = static_cast(std::distance(first, last)); + if (JSON_LIKELY(len > 0)) + { + // there is at least one element: use the address of first + ia = std::make_shared(reinterpret_cast(&(*first)), len); + } + else + { + // the address of first cannot be used: use nullptr + ia = std::make_shared(nullptr, len); + } + } - In this class, the array's limit of nesting is not constraint explicitly. - However, a maximum depth of nesting may be introduced by the compiler or - runtime environment. A theoretical limit can be queried by calling the - @ref max_size function of a JSON array. + /// input adapter for array + template + input_adapter(T (&array)[N]) + : input_adapter(std::begin(array), std::end(array)) {} + + /// input adapter for contiguous container + template::value and + std::is_base_of()))>::iterator_category>::value, + int>::type = 0> + input_adapter(const ContiguousContainer& c) + : input_adapter(std::begin(c), std::end(c)) {} + + operator input_adapter_t() + { + return ia; + } - #### Storage + private: + /// the actual adapter + input_adapter_t ia = nullptr; +}; +} +} - Arrays are stored as pointers in a @ref basic_json type. That is, for any - access to array values, a pointer of type `array_t*` must be dereferenced. +// #include - @sa @ref object_t -- type for an object value - @since version 1.0.0 - */ - using array_t = ArrayType>; +#include // localeconv +#include // size_t +#include // strtof, strtod, strtold, strtoll, strtoull +#include // initializer_list +#include // hex, uppercase +#include // setw, setfill +#include // stringstream +#include // char_traits, string +#include // vector - /*! - @brief a type for a string +// #include - [RFC 7159](http://rfc7159.net/rfc7159) describes JSON strings as follows: - > A string is a sequence of zero or more Unicode characters. +// #include - To store objects in C++, a type is defined by the template parameter - described below. Unicode values are split by the JSON class into - byte-sized characters during deserialization. - @tparam StringType the container to store strings (e.g., `std::string`). - Note this container is used for keys/names in objects, see @ref object_t. +namespace nlohmann +{ +namespace detail +{ +/////////// +// lexer // +/////////// - #### Default type +/*! +@brief lexical analysis - With the default values for @a StringType (`std::string`), the default - value for @a string_t is: +This class organizes the lexical analysis during JSON deserialization. +*/ +template +class lexer +{ + using number_integer_t = typename BasicJsonType::number_integer_t; + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + using number_float_t = typename BasicJsonType::number_float_t; - @code {.cpp} - std::string - @endcode + public: + /// token types for the parser + enum class token_type + { + uninitialized, ///< indicating the scanner is uninitialized + literal_true, ///< the `true` literal + literal_false, ///< the `false` literal + literal_null, ///< the `null` literal + value_string, ///< a string -- use get_string() for actual value + value_unsigned, ///< an unsigned integer -- use get_number_unsigned() for actual value + value_integer, ///< a signed integer -- use get_number_integer() for actual value + value_float, ///< an floating point number -- use get_number_float() for actual value + begin_array, ///< the character for array begin `[` + begin_object, ///< the character for object begin `{` + end_array, ///< the character for array end `]` + end_object, ///< the character for object end `}` + name_separator, ///< the name separator `:` + value_separator, ///< the value separator `,` + parse_error, ///< indicating a parse error + end_of_input, ///< indicating the end of the input buffer + literal_or_value ///< a literal or the begin of a value (only for diagnostics) + }; - #### Encoding + /// return name of values of type token_type (only used for errors) + static const char* token_type_name(const token_type t) noexcept + { + switch (t) + { + case token_type::uninitialized: + return ""; + case token_type::literal_true: + return "true literal"; + case token_type::literal_false: + return "false literal"; + case token_type::literal_null: + return "null literal"; + case token_type::value_string: + return "string literal"; + case lexer::token_type::value_unsigned: + case lexer::token_type::value_integer: + case lexer::token_type::value_float: + return "number literal"; + case token_type::begin_array: + return "'['"; + case token_type::begin_object: + return "'{'"; + case token_type::end_array: + return "']'"; + case token_type::end_object: + return "'}'"; + case token_type::name_separator: + return "':'"; + case token_type::value_separator: + return "','"; + case token_type::parse_error: + return ""; + case token_type::end_of_input: + return "end of input"; + case token_type::literal_or_value: + return "'[', '{', or a literal"; + default: // catch non-enum values + return "unknown token"; // LCOV_EXCL_LINE + } + } - Strings are stored in UTF-8 encoding. Therefore, functions like - `std::string::size()` or `std::string::length()` return the number of - bytes in the string rather than the number of characters or glyphs. + explicit lexer(detail::input_adapter_t adapter) + : ia(std::move(adapter)), decimal_point_char(get_decimal_point()) {} - #### String comparison + // delete because of pointer members + lexer(const lexer&) = delete; + lexer& operator=(lexer&) = delete; - [RFC 7159](http://rfc7159.net/rfc7159) states: - > Software implementations are typically required to test names of object - > members for equality. Implementations that transform the textual - > representation into sequences of Unicode code units and then perform the - > comparison numerically, code unit by code unit, are interoperable in the - > sense that implementations will agree in all cases on equality or - > inequality of two strings. For example, implementations that compare - > strings with escaped characters unconverted may incorrectly find that - > `"a\\b"` and `"a\u005Cb"` are not equal. + private: + ///////////////////// + // locales + ///////////////////// - This implementation is interoperable as it does compare strings code unit - by code unit. + /// return the locale-dependent decimal point + static char get_decimal_point() noexcept + { + const auto loc = localeconv(); + assert(loc != nullptr); + return (loc->decimal_point == nullptr) ? '.' : *(loc->decimal_point); + } - #### Storage + ///////////////////// + // scan functions + ///////////////////// - String values are stored as pointers in a @ref basic_json type. That is, - for any access to string values, a pointer of type `string_t*` must be - dereferenced. + /*! + @brief get codepoint from 4 hex characters following `\u` - @since version 1.0.0 - */ - using string_t = StringType; + For input "\u c1 c2 c3 c4" the codepoint is: + (c1 * 0x1000) + (c2 * 0x0100) + (c3 * 0x0010) + c4 + = (c1 << 12) + (c2 << 8) + (c3 << 4) + (c4 << 0) - /*! - @brief a type for a boolean + Furthermore, the possible characters '0'..'9', 'A'..'F', and 'a'..'f' + must be converted to the integers 0x0..0x9, 0xA..0xF, 0xA..0xF, resp. The + conversion is done by subtracting the offset (0x30, 0x37, and 0x57) + between the ASCII value of the character and the desired integer value. - [RFC 7159](http://rfc7159.net/rfc7159) implicitly describes a boolean as a - type which differentiates the two literals `true` and `false`. + @return codepoint (0x0000..0xFFFF) or -1 in case of an error (e.g. EOF or + non-hex character) + */ + int get_codepoint() + { + // this function only makes sense after reading `\u` + assert(current == 'u'); + int codepoint = 0; - To store objects in C++, a type is defined by the template parameter @a - BooleanType which chooses the type to use. + const auto factors = { 12, 8, 4, 0 }; + for (const auto factor : factors) + { + get(); - #### Default type + if (current >= '0' and current <= '9') + { + codepoint += ((current - 0x30) << factor); + } + else if (current >= 'A' and current <= 'F') + { + codepoint += ((current - 0x37) << factor); + } + else if (current >= 'a' and current <= 'f') + { + codepoint += ((current - 0x57) << factor); + } + else + { + return -1; + } + } - With the default values for @a BooleanType (`bool`), the default value for - @a boolean_t is: + assert(0x0000 <= codepoint and codepoint <= 0xFFFF); + return codepoint; + } - @code {.cpp} - bool - @endcode + /*! + @brief check if the next byte(s) are inside a given range - #### Storage + Adds the current byte and, for each passed range, reads a new byte and + checks if it is inside the range. If a violation was detected, set up an + error message and return false. Otherwise, return true. - Boolean values are stored directly inside a @ref basic_json type. + @param[in] ranges list of integers; interpreted as list of pairs of + inclusive lower and upper bound, respectively - @since version 1.0.0 + @pre The passed list @a ranges must have 2, 4, or 6 elements; that is, + 1, 2, or 3 pairs. This precondition is enforced by an assertion. + + @return true if and only if no range violation was detected */ - using boolean_t = BooleanType; + bool next_byte_in_range(std::initializer_list ranges) + { + assert(ranges.size() == 2 or ranges.size() == 4 or ranges.size() == 6); + add(current); + + for (auto range = ranges.begin(); range != ranges.end(); ++range) + { + get(); + if (JSON_LIKELY(*range <= current and current <= *(++range))) + { + add(current); + } + else + { + error_message = "invalid string: ill-formed UTF-8 byte"; + return false; + } + } + + return true; + } /*! - @brief a type for a number (integer) + @brief scan a string literal - [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows: - > The representation of numbers is similar to that used in most - > programming languages. A number is represented in base 10 using decimal - > digits. It contains an integer component that may be prefixed with an - > optional minus sign, which may be followed by a fraction part and/or an - > exponent part. Leading zeros are not allowed. (...) Numeric values that - > cannot be represented in the grammar below (such as Infinity and NaN) - > are not permitted. + This function scans a string according to Sect. 7 of RFC 7159. While + scanning, bytes are escaped and copied into buffer token_buffer. Then the + function returns successfully, token_buffer is *not* null-terminated (as it + may contain \0 bytes), and token_buffer.size() is the number of bytes in the + string. - This description includes both integer and floating-point numbers. - However, C++ allows more precise storage if it is known whether the number - is a signed integer, an unsigned integer or a floating-point number. - Therefore, three different types, @ref number_integer_t, @ref - number_unsigned_t and @ref number_float_t are used. + @return token_type::value_string if string could be successfully scanned, + token_type::parse_error otherwise - To store integer numbers in C++, a type is defined by the template - parameter @a NumberIntegerType which chooses the type to use. + @note In case of errors, variable error_message contains a textual + description. + */ + token_type scan_string() + { + // reset token_buffer (ignore opening quote) + reset(); - #### Default type + // we entered the function by reading an open quote + assert(current == '\"'); - With the default values for @a NumberIntegerType (`int64_t`), the default - value for @a number_integer_t is: + while (true) + { + // get next character + switch (get()) + { + // end of file while parsing string + case std::char_traits::eof(): + { + error_message = "invalid string: missing closing quote"; + return token_type::parse_error; + } - @code {.cpp} - int64_t - @endcode + // closing quote + case '\"': + { + return token_type::value_string; + } - #### Default behavior + // escapes + case '\\': + { + switch (get()) + { + // quotation mark + case '\"': + add('\"'); + break; + // reverse solidus + case '\\': + add('\\'); + break; + // solidus + case '/': + add('/'); + break; + // backspace + case 'b': + add('\b'); + break; + // form feed + case 'f': + add('\f'); + break; + // line feed + case 'n': + add('\n'); + break; + // carriage return + case 'r': + add('\r'); + break; + // tab + case 't': + add('\t'); + break; + + // unicode escapes + case 'u': + { + const int codepoint1 = get_codepoint(); + int codepoint = codepoint1; // start with codepoint1 - - The restrictions about leading zeros is not enforced in C++. Instead, - leading zeros in integer literals lead to an interpretation as octal - number. Internally, the value will be stored as decimal number. For - instance, the C++ integer literal `010` will be serialized to `8`. - During deserialization, leading zeros yield an error. - - Not-a-number (NaN) values will be serialized to `null`. + if (JSON_UNLIKELY(codepoint1 == -1)) + { + error_message = "invalid string: '\\u' must be followed by 4 hex digits"; + return token_type::parse_error; + } - #### Limits + // check if code point is a high surrogate + if (0xD800 <= codepoint1 and codepoint1 <= 0xDBFF) + { + // expect next \uxxxx entry + if (JSON_LIKELY(get() == '\\' and get() == 'u')) + { + const int codepoint2 = get_codepoint(); - [RFC 7159](http://rfc7159.net/rfc7159) specifies: - > An implementation may set limits on the range and precision of numbers. + if (JSON_UNLIKELY(codepoint2 == -1)) + { + error_message = "invalid string: '\\u' must be followed by 4 hex digits"; + return token_type::parse_error; + } - When the default type is used, the maximal integer number that can be - stored is `9223372036854775807` (INT64_MAX) and the minimal integer number - that can be stored is `-9223372036854775808` (INT64_MIN). Integer numbers - that are out of range will yield over/underflow when used in a - constructor. During deserialization, too large or small integer numbers - will be automatically be stored as @ref number_unsigned_t or @ref - number_float_t. + // check if codepoint2 is a low surrogate + if (JSON_LIKELY(0xDC00 <= codepoint2 and codepoint2 <= 0xDFFF)) + { + // overwrite codepoint + codepoint = + // high surrogate occupies the most significant 22 bits + (codepoint1 << 10) + // low surrogate occupies the least significant 15 bits + + codepoint2 + // there is still the 0xD800, 0xDC00 and 0x10000 noise + // in the result so we have to subtract with: + // (0xD800 << 10) + DC00 - 0x10000 = 0x35FDC00 + - 0x35FDC00; + } + else + { + error_message = "invalid string: surrogate U+DC00..U+DFFF must be followed by U+DC00..U+DFFF"; + return token_type::parse_error; + } + } + else + { + error_message = "invalid string: surrogate U+DC00..U+DFFF must be followed by U+DC00..U+DFFF"; + return token_type::parse_error; + } + } + else + { + if (JSON_UNLIKELY(0xDC00 <= codepoint1 and codepoint1 <= 0xDFFF)) + { + error_message = "invalid string: surrogate U+DC00..U+DFFF must follow U+D800..U+DBFF"; + return token_type::parse_error; + } + } - [RFC 7159](http://rfc7159.net/rfc7159) further states: - > Note that when such software is used, numbers that are integers and are - > in the range \f$[-2^{53}+1, 2^{53}-1]\f$ are interoperable in the sense - > that implementations will agree exactly on their numeric values. + // result of the above calculation yields a proper codepoint + assert(0x00 <= codepoint and codepoint <= 0x10FFFF); - As this range is a subrange of the exactly supported range [INT64_MIN, - INT64_MAX], this class's integer type is interoperable. + // translate codepoint into bytes + if (codepoint < 0x80) + { + // 1-byte characters: 0xxxxxxx (ASCII) + add(codepoint); + } + else if (codepoint <= 0x7FF) + { + // 2-byte characters: 110xxxxx 10xxxxxx + add(0xC0 | (codepoint >> 6)); + add(0x80 | (codepoint & 0x3F)); + } + else if (codepoint <= 0xFFFF) + { + // 3-byte characters: 1110xxxx 10xxxxxx 10xxxxxx + add(0xE0 | (codepoint >> 12)); + add(0x80 | ((codepoint >> 6) & 0x3F)); + add(0x80 | (codepoint & 0x3F)); + } + else + { + // 4-byte characters: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx + add(0xF0 | (codepoint >> 18)); + add(0x80 | ((codepoint >> 12) & 0x3F)); + add(0x80 | ((codepoint >> 6) & 0x3F)); + add(0x80 | (codepoint & 0x3F)); + } - #### Storage + break; + } - Integer number values are stored directly inside a @ref basic_json type. + // other characters after escape + default: + error_message = "invalid string: forbidden character after backslash"; + return token_type::parse_error; + } - @sa @ref number_float_t -- type for number values (floating-point) + break; + } - @sa @ref number_unsigned_t -- type for number values (unsigned integer) + // invalid control characters + case 0x00: + case 0x01: + case 0x02: + case 0x03: + case 0x04: + case 0x05: + case 0x06: + case 0x07: + case 0x08: + case 0x09: + case 0x0A: + case 0x0B: + case 0x0C: + case 0x0D: + case 0x0E: + case 0x0F: + case 0x10: + case 0x11: + case 0x12: + case 0x13: + case 0x14: + case 0x15: + case 0x16: + case 0x17: + case 0x18: + case 0x19: + case 0x1A: + case 0x1B: + case 0x1C: + case 0x1D: + case 0x1E: + case 0x1F: + { + error_message = "invalid string: control character must be escaped"; + return token_type::parse_error; + } - @since version 1.0.0 - */ - using number_integer_t = NumberIntegerType; + // U+0020..U+007F (except U+0022 (quote) and U+005C (backspace)) + case 0x20: + case 0x21: + case 0x23: + case 0x24: + case 0x25: + case 0x26: + case 0x27: + case 0x28: + case 0x29: + case 0x2A: + case 0x2B: + case 0x2C: + case 0x2D: + case 0x2E: + case 0x2F: + case 0x30: + case 0x31: + case 0x32: + case 0x33: + case 0x34: + case 0x35: + case 0x36: + case 0x37: + case 0x38: + case 0x39: + case 0x3A: + case 0x3B: + case 0x3C: + case 0x3D: + case 0x3E: + case 0x3F: + case 0x40: + case 0x41: + case 0x42: + case 0x43: + case 0x44: + case 0x45: + case 0x46: + case 0x47: + case 0x48: + case 0x49: + case 0x4A: + case 0x4B: + case 0x4C: + case 0x4D: + case 0x4E: + case 0x4F: + case 0x50: + case 0x51: + case 0x52: + case 0x53: + case 0x54: + case 0x55: + case 0x56: + case 0x57: + case 0x58: + case 0x59: + case 0x5A: + case 0x5B: + case 0x5D: + case 0x5E: + case 0x5F: + case 0x60: + case 0x61: + case 0x62: + case 0x63: + case 0x64: + case 0x65: + case 0x66: + case 0x67: + case 0x68: + case 0x69: + case 0x6A: + case 0x6B: + case 0x6C: + case 0x6D: + case 0x6E: + case 0x6F: + case 0x70: + case 0x71: + case 0x72: + case 0x73: + case 0x74: + case 0x75: + case 0x76: + case 0x77: + case 0x78: + case 0x79: + case 0x7A: + case 0x7B: + case 0x7C: + case 0x7D: + case 0x7E: + case 0x7F: + { + add(current); + break; + } - /*! - @brief a type for a number (unsigned) + // U+0080..U+07FF: bytes C2..DF 80..BF + case 0xC2: + case 0xC3: + case 0xC4: + case 0xC5: + case 0xC6: + case 0xC7: + case 0xC8: + case 0xC9: + case 0xCA: + case 0xCB: + case 0xCC: + case 0xCD: + case 0xCE: + case 0xCF: + case 0xD0: + case 0xD1: + case 0xD2: + case 0xD3: + case 0xD4: + case 0xD5: + case 0xD6: + case 0xD7: + case 0xD8: + case 0xD9: + case 0xDA: + case 0xDB: + case 0xDC: + case 0xDD: + case 0xDE: + case 0xDF: + { + if (JSON_UNLIKELY(not next_byte_in_range({0x80, 0xBF}))) + { + return token_type::parse_error; + } + break; + } - [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows: - > The representation of numbers is similar to that used in most - > programming languages. A number is represented in base 10 using decimal - > digits. It contains an integer component that may be prefixed with an - > optional minus sign, which may be followed by a fraction part and/or an - > exponent part. Leading zeros are not allowed. (...) Numeric values that - > cannot be represented in the grammar below (such as Infinity and NaN) - > are not permitted. + // U+0800..U+0FFF: bytes E0 A0..BF 80..BF + case 0xE0: + { + if (JSON_UNLIKELY(not (next_byte_in_range({0xA0, 0xBF, 0x80, 0xBF})))) + { + return token_type::parse_error; + } + break; + } - This description includes both integer and floating-point numbers. - However, C++ allows more precise storage if it is known whether the number - is a signed integer, an unsigned integer or a floating-point number. - Therefore, three different types, @ref number_integer_t, @ref - number_unsigned_t and @ref number_float_t are used. + // U+1000..U+CFFF: bytes E1..EC 80..BF 80..BF + // U+E000..U+FFFF: bytes EE..EF 80..BF 80..BF + case 0xE1: + case 0xE2: + case 0xE3: + case 0xE4: + case 0xE5: + case 0xE6: + case 0xE7: + case 0xE8: + case 0xE9: + case 0xEA: + case 0xEB: + case 0xEC: + case 0xEE: + case 0xEF: + { + if (JSON_UNLIKELY(not (next_byte_in_range({0x80, 0xBF, 0x80, 0xBF})))) + { + return token_type::parse_error; + } + break; + } - To store unsigned integer numbers in C++, a type is defined by the - template parameter @a NumberUnsignedType which chooses the type to use. + // U+D000..U+D7FF: bytes ED 80..9F 80..BF + case 0xED: + { + if (JSON_UNLIKELY(not (next_byte_in_range({0x80, 0x9F, 0x80, 0xBF})))) + { + return token_type::parse_error; + } + break; + } - #### Default type + // U+10000..U+3FFFF F0 90..BF 80..BF 80..BF + case 0xF0: + { + if (JSON_UNLIKELY(not (next_byte_in_range({0x90, 0xBF, 0x80, 0xBF, 0x80, 0xBF})))) + { + return token_type::parse_error; + } + break; + } - With the default values for @a NumberUnsignedType (`uint64_t`), the - default value for @a number_unsigned_t is: + // U+40000..U+FFFFF F1..F3 80..BF 80..BF 80..BF + case 0xF1: + case 0xF2: + case 0xF3: + { + if (JSON_UNLIKELY(not (next_byte_in_range({0x80, 0xBF, 0x80, 0xBF, 0x80, 0xBF})))) + { + return token_type::parse_error; + } + break; + } - @code {.cpp} - uint64_t - @endcode + // U+100000..U+10FFFF F4 80..8F 80..BF 80..BF + case 0xF4: + { + if (JSON_UNLIKELY(not (next_byte_in_range({0x80, 0x8F, 0x80, 0xBF, 0x80, 0xBF})))) + { + return token_type::parse_error; + } + break; + } - #### Default behavior - - - The restrictions about leading zeros is not enforced in C++. Instead, - leading zeros in integer literals lead to an interpretation as octal - number. Internally, the value will be stored as decimal number. For - instance, the C++ integer literal `010` will be serialized to `8`. - During deserialization, leading zeros yield an error. - - Not-a-number (NaN) values will be serialized to `null`. + // remaining bytes (80..C1 and F5..FF) are ill-formed + default: + { + error_message = "invalid string: ill-formed UTF-8 byte"; + return token_type::parse_error; + } + } + } + } - #### Limits + static void strtof(float& f, const char* str, char** endptr) noexcept + { + f = std::strtof(str, endptr); + } - [RFC 7159](http://rfc7159.net/rfc7159) specifies: - > An implementation may set limits on the range and precision of numbers. + static void strtof(double& f, const char* str, char** endptr) noexcept + { + f = std::strtod(str, endptr); + } - When the default type is used, the maximal integer number that can be - stored is `18446744073709551615` (UINT64_MAX) and the minimal integer - number that can be stored is `0`. Integer numbers that are out of range - will yield over/underflow when used in a constructor. During - deserialization, too large or small integer numbers will be automatically - be stored as @ref number_integer_t or @ref number_float_t. + static void strtof(long double& f, const char* str, char** endptr) noexcept + { + f = std::strtold(str, endptr); + } - [RFC 7159](http://rfc7159.net/rfc7159) further states: - > Note that when such software is used, numbers that are integers and are - > in the range \f$[-2^{53}+1, 2^{53}-1]\f$ are interoperable in the sense - > that implementations will agree exactly on their numeric values. + /*! + @brief scan a number literal + + This function scans a string according to Sect. 6 of RFC 7159. + + The function is realized with a deterministic finite state machine derived + from the grammar described in RFC 7159. Starting in state "init", the + input is read and used to determined the next state. Only state "done" + accepts the number. State "error" is a trap state to model errors. In the + table below, "anything" means any character but the ones listed before. + + state | 0 | 1-9 | e E | + | - | . | anything + ---------|----------|----------|----------|---------|---------|----------|----------- + init | zero | any1 | [error] | [error] | minus | [error] | [error] + minus | zero | any1 | [error] | [error] | [error] | [error] | [error] + zero | done | done | exponent | done | done | decimal1 | done + any1 | any1 | any1 | exponent | done | done | decimal1 | done + decimal1 | decimal2 | [error] | [error] | [error] | [error] | [error] | [error] + decimal2 | decimal2 | decimal2 | exponent | done | done | done | done + exponent | any2 | any2 | [error] | sign | sign | [error] | [error] + sign | any2 | any2 | [error] | [error] | [error] | [error] | [error] + any2 | any2 | any2 | done | done | done | done | done + + The state machine is realized with one label per state (prefixed with + "scan_number_") and `goto` statements between them. The state machine + contains cycles, but any cycle can be left when EOF is read. Therefore, + the function is guaranteed to terminate. + + During scanning, the read bytes are stored in token_buffer. This string is + then converted to a signed integer, an unsigned integer, or a + floating-point number. + + @return token_type::value_unsigned, token_type::value_integer, or + token_type::value_float if number could be successfully scanned, + token_type::parse_error otherwise + + @note The scanner is independent of the current locale. Internally, the + locale's decimal point is used instead of `.` to work with the + locale-dependent converters. + */ + token_type scan_number() + { + // reset token_buffer to store the number's bytes + reset(); - As this range is a subrange (when considered in conjunction with the - number_integer_t type) of the exactly supported range [0, UINT64_MAX], - this class's integer type is interoperable. + // the type of the parsed number; initially set to unsigned; will be + // changed if minus sign, decimal point or exponent is read + token_type number_type = token_type::value_unsigned; - #### Storage + // state (init): we just found out we need to scan a number + switch (current) + { + case '-': + { + add(current); + goto scan_number_minus; + } - Integer number values are stored directly inside a @ref basic_json type. + case '0': + { + add(current); + goto scan_number_zero; + } - @sa @ref number_float_t -- type for number values (floating-point) - @sa @ref number_integer_t -- type for number values (integer) + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_any1; + } - @since version 2.0.0 - */ - using number_unsigned_t = NumberUnsignedType; + default: + { + // all other characters are rejected outside scan_number() + assert(false); // LCOV_EXCL_LINE + } + } - /*! - @brief a type for a number (floating-point) +scan_number_minus: + // state: we just parsed a leading minus sign + number_type = token_type::value_integer; + switch (get()) + { + case '0': + { + add(current); + goto scan_number_zero; + } - [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows: - > The representation of numbers is similar to that used in most - > programming languages. A number is represented in base 10 using decimal - > digits. It contains an integer component that may be prefixed with an - > optional minus sign, which may be followed by a fraction part and/or an - > exponent part. Leading zeros are not allowed. (...) Numeric values that - > cannot be represented in the grammar below (such as Infinity and NaN) - > are not permitted. + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_any1; + } - This description includes both integer and floating-point numbers. - However, C++ allows more precise storage if it is known whether the number - is a signed integer, an unsigned integer or a floating-point number. - Therefore, three different types, @ref number_integer_t, @ref - number_unsigned_t and @ref number_float_t are used. + default: + { + error_message = "invalid number; expected digit after '-'"; + return token_type::parse_error; + } + } - To store floating-point numbers in C++, a type is defined by the template - parameter @a NumberFloatType which chooses the type to use. +scan_number_zero: + // state: we just parse a zero (maybe with a leading minus sign) + switch (get()) + { + case '.': + { + add(decimal_point_char); + goto scan_number_decimal1; + } - #### Default type + case 'e': + case 'E': + { + add(current); + goto scan_number_exponent; + } - With the default values for @a NumberFloatType (`double`), the default - value for @a number_float_t is: + default: + goto scan_number_done; + } - @code {.cpp} - double - @endcode +scan_number_any1: + // state: we just parsed a number 0-9 (maybe with a leading minus sign) + switch (get()) + { + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_any1; + } - #### Default behavior + case '.': + { + add(decimal_point_char); + goto scan_number_decimal1; + } - - The restrictions about leading zeros is not enforced in C++. Instead, - leading zeros in floating-point literals will be ignored. Internally, - the value will be stored as decimal number. For instance, the C++ - floating-point literal `01.2` will be serialized to `1.2`. During - deserialization, leading zeros yield an error. - - Not-a-number (NaN) values will be serialized to `null`. + case 'e': + case 'E': + { + add(current); + goto scan_number_exponent; + } - #### Limits + default: + goto scan_number_done; + } - [RFC 7159](http://rfc7159.net/rfc7159) states: - > This specification allows implementations to set limits on the range and - > precision of numbers accepted. Since software that implements IEEE - > 754-2008 binary64 (double precision) numbers is generally available and - > widely used, good interoperability can be achieved by implementations - > that expect no more precision or range than these provide, in the sense - > that implementations will approximate JSON numbers within the expected - > precision. +scan_number_decimal1: + // state: we just parsed a decimal point + number_type = token_type::value_float; + switch (get()) + { + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_decimal2; + } - This implementation does exactly follow this approach, as it uses double - precision floating-point numbers. Note values smaller than - `-1.79769313486232e+308` and values greater than `1.79769313486232e+308` - will be stored as NaN internally and be serialized to `null`. + default: + { + error_message = "invalid number; expected digit after '.'"; + return token_type::parse_error; + } + } - #### Storage +scan_number_decimal2: + // we just parsed at least one number after a decimal point + switch (get()) + { + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_decimal2; + } - Floating-point number values are stored directly inside a @ref basic_json - type. + case 'e': + case 'E': + { + add(current); + goto scan_number_exponent; + } - @sa @ref number_integer_t -- type for number values (integer) + default: + goto scan_number_done; + } - @sa @ref number_unsigned_t -- type for number values (unsigned integer) +scan_number_exponent: + // we just parsed an exponent + number_type = token_type::value_float; + switch (get()) + { + case '+': + case '-': + { + add(current); + goto scan_number_sign; + } - @since version 1.0.0 - */ - using number_float_t = NumberFloatType; + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_any2; + } - /// @} + default: + { + error_message = + "invalid number; expected '+', '-', or digit after exponent"; + return token_type::parse_error; + } + } - private: +scan_number_sign: + // we just parsed an exponent sign + switch (get()) + { + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_any2; + } - /// helper for exception-safe object creation - template - static T* create(Args&& ... args) - { - AllocatorType alloc; - auto deleter = [&](T * object) - { - alloc.deallocate(object, 1); - }; - std::unique_ptr object(alloc.allocate(1), deleter); - alloc.construct(object.get(), std::forward(args)...); - assert(object != nullptr); - return object.release(); - } + default: + { + error_message = "invalid number; expected digit after exponent sign"; + return token_type::parse_error; + } + } - //////////////////////// - // JSON value storage // - //////////////////////// +scan_number_any2: + // we just parsed a number after the exponent or exponent sign + switch (get()) + { + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_any2; + } - /*! - @brief a JSON value + default: + goto scan_number_done; + } - The actual storage for a JSON value of the @ref basic_json class. This - union combines the different storage types for the JSON value types - defined in @ref value_t. +scan_number_done: + // unget the character after the number (we only read it to know that + // we are done scanning a number) + unget(); - JSON type | value_t type | used type - --------- | --------------- | ------------------------ - object | object | pointer to @ref object_t - array | array | pointer to @ref array_t - string | string | pointer to @ref string_t - boolean | boolean | @ref boolean_t - number | number_integer | @ref number_integer_t - number | number_unsigned | @ref number_unsigned_t - number | number_float | @ref number_float_t - null | null | *no value is stored* + char* endptr = nullptr; + errno = 0; - @note Variable-length types (objects, arrays, and strings) are stored as - pointers. The size of the union should not exceed 64 bits if the default - value types are used. + // try to parse integers first and fall back to floats + if (number_type == token_type::value_unsigned) + { + const auto x = std::strtoull(token_buffer.data(), &endptr, 10); - @since version 1.0.0 - */ - union json_value - { - /// object (stored with pointer to save storage) - object_t* object; - /// array (stored with pointer to save storage) - array_t* array; - /// string (stored with pointer to save storage) - string_t* string; - /// boolean - boolean_t boolean; - /// number (integer) - number_integer_t number_integer; - /// number (unsigned integer) - number_unsigned_t number_unsigned; - /// number (floating-point) - number_float_t number_float; + // we checked the number format before + assert(endptr == token_buffer.data() + token_buffer.size()); - /// default constructor (for null values) - json_value() = default; - /// constructor for booleans - json_value(boolean_t v) noexcept : boolean(v) {} - /// constructor for numbers (integer) - json_value(number_integer_t v) noexcept : number_integer(v) {} - /// constructor for numbers (unsigned) - json_value(number_unsigned_t v) noexcept : number_unsigned(v) {} - /// constructor for numbers (floating-point) - json_value(number_float_t v) noexcept : number_float(v) {} - /// constructor for empty values of a given type - json_value(value_t t) - { - switch (t) + if (errno == 0) { - case value_t::object: + value_unsigned = static_cast(x); + if (value_unsigned == x) { - object = create(); - break; + return token_type::value_unsigned; } + } + } + else if (number_type == token_type::value_integer) + { + const auto x = std::strtoll(token_buffer.data(), &endptr, 10); - case value_t::array: - { - array = create(); - break; - } + // we checked the number format before + assert(endptr == token_buffer.data() + token_buffer.size()); - case value_t::string: + if (errno == 0) + { + value_integer = static_cast(x); + if (value_integer == x) { - string = create(""); - break; + return token_type::value_integer; } + } + } - case value_t::boolean: - { - boolean = boolean_t(false); - break; - } - - case value_t::number_integer: - { - number_integer = number_integer_t(0); - break; - } - - case value_t::number_unsigned: - { - number_unsigned = number_unsigned_t(0); - break; - } + // this code is reached if we parse a floating-point number or if an + // integer conversion above failed + strtof(value_float, token_buffer.data(), &endptr); - case value_t::number_float: - { - number_float = number_float_t(0.0); - break; - } + // we checked the number format before + assert(endptr == token_buffer.data() + token_buffer.size()); - case value_t::null: - { - break; - } + return token_type::value_float; + } - default: - { - if (JSON_UNLIKELY(t == value_t::null)) - { - JSON_THROW(other_error::create(500, "961c151d2e87f2686a955a9be24d316f1362bf21 2.1.1")); // LCOV_EXCL_LINE - } - break; - } + /*! + @param[in] literal_text the literal text to expect + @param[in] length the length of the passed literal text + @param[in] return_type the token type to return on success + */ + token_type scan_literal(const char* literal_text, const std::size_t length, + token_type return_type) + { + assert(current == literal_text[0]); + for (std::size_t i = 1; i < length; ++i) + { + if (JSON_UNLIKELY(get() != literal_text[i])) + { + error_message = "invalid literal"; + return token_type::parse_error; } } + return return_type; + } - /// constructor for strings - json_value(const string_t& value) + ///////////////////// + // input management + ///////////////////// + + /// reset token_buffer; current character is beginning of token + void reset() noexcept + { + token_buffer.clear(); + token_string.clear(); + token_string.push_back(std::char_traits::to_char_type(current)); + } + + /* + @brief get next character from the input + + This function provides the interface to the used input adapter. It does + not throw in case the input reached EOF, but returns a + `std::char_traits::eof()` in that case. Stores the scanned characters + for use in error messages. + + @return character read from the input + */ + std::char_traits::int_type get() + { + ++chars_read; + current = ia->get_character(); + if (JSON_LIKELY(current != std::char_traits::eof())) { - string = create(value); + token_string.push_back(std::char_traits::to_char_type(current)); } + return current; + } - /// constructor for objects - json_value(const object_t& value) + /// unget current character (return it again on next get) + void unget() + { + --chars_read; + if (JSON_LIKELY(current != std::char_traits::eof())) { - object = create(value); + ia->unget_character(); + assert(token_string.size() != 0); + token_string.pop_back(); } + } - /// constructor for arrays - json_value(const array_t& value) + /// add a character to token_buffer + void add(int c) + { + token_buffer.push_back(std::char_traits::to_char_type(c)); + } + + public: + ///////////////////// + // value getters + ///////////////////// + + /// return integer value + constexpr number_integer_t get_number_integer() const noexcept + { + return value_integer; + } + + /// return unsigned integer value + constexpr number_unsigned_t get_number_unsigned() const noexcept + { + return value_unsigned; + } + + /// return floating-point value + constexpr number_float_t get_number_float() const noexcept + { + return value_float; + } + + /// return current string value (implicitly resets the token; useful only once) + std::string move_string() + { + return std::move(token_buffer); + } + + ///////////////////// + // diagnostics + ///////////////////// + + /// return position of last read token + constexpr std::size_t get_position() const noexcept + { + return chars_read; + } + + /// return the last read token (for errors only). Will never contain EOF + /// (an arbitrary value that is not a valid char value, often -1), because + /// 255 may legitimately occur. May contain NUL, which should be escaped. + std::string get_token_string() const + { + // escape control characters + std::string result; + for (const auto c : token_string) { - array = create(value); + if ('\x00' <= c and c <= '\x1F') + { + // escape control characters + std::stringstream ss; + ss << "(c) << ">"; + result += ss.str(); + } + else + { + // add character as is + result.push_back(c); + } } - }; - /*! - @brief checks the class invariants + return result; + } - This function asserts the class invariants. It needs to be called at the - end of every constructor to make sure that created objects respect the - invariant. Furthermore, it has to be called each time the type of a JSON - value is changed, because the invariant expresses a relationship between - @a m_type and @a m_value. - */ - void assert_invariant() const + /// return syntax error message + constexpr const char* get_error_message() const noexcept { - assert(m_type != value_t::object or m_value.object != nullptr); - assert(m_type != value_t::array or m_value.array != nullptr); - assert(m_type != value_t::string or m_value.string != nullptr); + return error_message; } - public: - ////////////////////////// - // JSON parser callback // - ////////////////////////// + ///////////////////// + // actual scanner + ///////////////////// - /*! - @brief JSON callback events + token_type scan() + { + // read next character and ignore whitespace + do + { + get(); + } + while (current == ' ' or current == '\t' or current == '\n' or current == '\r'); + + switch (current) + { + // structural characters + case '[': + return token_type::begin_array; + case ']': + return token_type::end_array; + case '{': + return token_type::begin_object; + case '}': + return token_type::end_object; + case ':': + return token_type::name_separator; + case ',': + return token_type::value_separator; + + // literals + case 't': + return scan_literal("true", 4, token_type::literal_true); + case 'f': + return scan_literal("false", 5, token_type::literal_false); + case 'n': + return scan_literal("null", 4, token_type::literal_null); + + // string + case '\"': + return scan_string(); + + // number + case '-': + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + return scan_number(); + + // end of input (the null byte is needed when parsing from + // string literals) + case '\0': + case std::char_traits::eof(): + return token_type::end_of_input; + + // error + default: + error_message = "invalid literal"; + return token_type::parse_error; + } + } - This enumeration lists the parser events that can trigger calling a - callback function of type @ref parser_callback_t during parsing. + private: + /// input adapter + detail::input_adapter_t ia = nullptr; - @image html callback_events.png "Example when certain parse events are triggered" + /// the current character + std::char_traits::int_type current = std::char_traits::eof(); - @since version 1.0.0 - */ + /// the number of characters read + std::size_t chars_read = 0; + + /// raw input token string (for error messages) + std::vector token_string {}; + + /// buffer for variable-length tokens (numbers, strings) + std::string token_buffer {}; + + /// a description of occurred lexer errors + const char* error_message = ""; + + // number values + number_integer_t value_integer = 0; + number_unsigned_t value_unsigned = 0; + number_float_t value_float = 0; + + /// the decimal point + const char decimal_point_char = '.'; +}; +} +} + +// #include + + +#include // assert +#include // isfinite +#include // uint8_t +#include // function +#include // string +#include // move + +// #include + +// #include + +// #include + +// #include + +// #include + + +namespace nlohmann +{ +namespace detail +{ +//////////// +// parser // +//////////// + +/*! +@brief syntax analysis + +This class implements a recursive decent parser. +*/ +template +class parser +{ + using number_integer_t = typename BasicJsonType::number_integer_t; + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + using number_float_t = typename BasicJsonType::number_float_t; + using lexer_t = lexer; + using token_type = typename lexer_t::token_type; + + public: enum class parse_event_t : uint8_t { /// the parser read `{` and started to process a JSON object @@ -2187,11576 +3175,13115 @@ class basic_json value }; - /*! - @brief per-element parser callback type - - With a parser callback function, the result of parsing a JSON text can be - influenced. When passed to @ref parse(std::istream&, const - parser_callback_t) or @ref parse(const CharT, const parser_callback_t), - it is called on certain events (passed as @ref parse_event_t via parameter - @a event) with a set recursion depth @a depth and context JSON value - @a parsed. The return value of the callback function is a boolean - indicating whether the element that emitted the callback shall be kept or - not. - - We distinguish six scenarios (determined by the event type) in which the - callback function can be called. The following table describes the values - of the parameters @a depth, @a event, and @a parsed. + using parser_callback_t = + std::function; - parameter @a event | description | parameter @a depth | parameter @a parsed - ------------------ | ----------- | ------------------ | ------------------- - parse_event_t::object_start | the parser read `{` and started to process a JSON object | depth of the parent of the JSON object | a JSON value with type discarded - parse_event_t::key | the parser read a key of a value in an object | depth of the currently parsed JSON object | a JSON string containing the key - parse_event_t::object_end | the parser read `}` and finished processing a JSON object | depth of the parent of the JSON object | the parsed JSON object - parse_event_t::array_start | the parser read `[` and started to process a JSON array | depth of the parent of the JSON array | a JSON value with type discarded - parse_event_t::array_end | the parser read `]` and finished processing a JSON array | depth of the parent of the JSON array | the parsed JSON array - parse_event_t::value | the parser finished reading a JSON value | depth of the value | the parsed JSON value + /// a parser reading from an input adapter + explicit parser(detail::input_adapter_t adapter, + const parser_callback_t cb = nullptr, + const bool allow_exceptions_ = true) + : callback(cb), m_lexer(adapter), allow_exceptions(allow_exceptions_) + {} - @image html callback_events.png "Example when certain parse events are triggered" + /*! + @brief public parser interface - Discarding a value (i.e., returning `false`) has different effects - depending on the context in which function was called: + @param[in] strict whether to expect the last token to be EOF + @param[in,out] result parsed JSON value - - Discarded values in structured types are skipped. That is, the parser - will behave as if the discarded value was never read. - - In case a value outside a structured type is skipped, it is replaced - with `null`. This case happens if the top-level element is skipped. + @throw parse_error.101 in case of an unexpected token + @throw parse_error.102 if to_unicode fails or surrogate error + @throw parse_error.103 if to_unicode fails + */ + void parse(const bool strict, BasicJsonType& result) + { + // read first token + get_token(); - @param[in] depth the depth of the recursion during parsing + parse_internal(true, result); + result.assert_invariant(); - @param[in] event an event of type parse_event_t indicating the context in - the callback function has been called + // in strict mode, input must be completely read + if (strict) + { + get_token(); + expect(token_type::end_of_input); + } - @param[in,out] parsed the current intermediate parse result; note that - writing to this value has no effect for parse_event_t::key events + // in case of an error, return discarded value + if (errored) + { + result = value_t::discarded; + return; + } - @return Whether the JSON value which called the function during parsing - should be kept (`true`) or not (`false`). In the latter case, it is either - skipped completely or replaced by an empty discarded object. + // set top-level value to null if it was discarded by the callback + // function + if (result.is_discarded()) + { + result = nullptr; + } + } - @sa @ref parse(std::istream&, parser_callback_t) or - @ref parse(const CharT, const parser_callback_t) for examples + /*! + @brief public accept interface - @since version 1.0.0 + @param[in] strict whether to expect the last token to be EOF + @return whether the input is a proper JSON text */ - using parser_callback_t = std::function; - + bool accept(const bool strict = true) + { + // read first token + get_token(); - ////////////////// - // constructors // - ////////////////// + if (not accept_internal()) + { + return false; + } - /// @name constructors and destructors - /// Constructors of class @ref basic_json, copy/move constructor, copy - /// assignment, static functions creating objects, and the destructor. - /// @{ + // strict => last token must be EOF + return not strict or (get_token() == token_type::end_of_input); + } + private: /*! - @brief create an empty value with a given type + @brief the actual parser + @throw parse_error.101 in case of an unexpected token + @throw parse_error.102 if to_unicode fails or surrogate error + @throw parse_error.103 if to_unicode fails + */ + void parse_internal(bool keep, BasicJsonType& result) + { + // never parse after a parse error was detected + assert(not errored); - Create an empty JSON value with a given type. The value will be default - initialized with an empty value which depends on the type: + // start with a discarded value + if (not result.is_discarded()) + { + result.m_value.destroy(result.m_type); + result.m_type = value_t::discarded; + } - Value type | initial value - ----------- | ------------- - null | `null` - boolean | `false` - string | `""` - number | `0` - object | `{}` - array | `[]` + switch (last_token) + { + case token_type::begin_object: + { + if (keep) + { + if (callback) + { + keep = callback(depth++, parse_event_t::object_start, result); + } - @param[in] value_type the type of the value to create + if (not callback or keep) + { + // explicitly set result to object to cope with {} + result.m_type = value_t::object; + result.m_value = value_t::object; + } + } - @complexity Constant. + // read next token + get_token(); - @liveexample{The following code shows the constructor for different @ref - value_t values,basic_json__value_t} + // closing } -> we are done + if (last_token == token_type::end_object) + { + if (keep and callback and not callback(--depth, parse_event_t::object_end, result)) + { + result.m_value.destroy(result.m_type); + result.m_type = value_t::discarded; + } + break; + } - @since version 1.0.0 - */ - basic_json(const value_t value_type) - : m_type(value_type), m_value(value_type) - { - assert_invariant(); - } - - /*! - @brief create a null object - - Create a `null` JSON value. It either takes a null pointer as parameter - (explicitly creating `null`) or no parameter (implicitly creating `null`). - The passed null pointer itself is not read -- it is only used to choose - the right constructor. - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this constructor never throws - exceptions. - - @liveexample{The following code shows the constructor with and without a - null pointer parameter.,basic_json__nullptr_t} - - @since version 1.0.0 - */ - basic_json(std::nullptr_t = nullptr) noexcept - : basic_json(value_t::null) - { - assert_invariant(); - } - - /*! - @brief create a JSON value + // parse values + std::string key; + BasicJsonType value; + while (true) + { + // store key + if (not expect(token_type::value_string)) + { + return; + } + key = m_lexer.move_string(); - This is a "catch all" constructor for all compatible JSON types; that is, - types for which a `to_json()` method exsits. The constructor forwards the - parameter @a val to that method (to `json_serializer::to_json` method - with `U = uncvref_t`, to be exact). + bool keep_tag = false; + if (keep) + { + if (callback) + { + BasicJsonType k(key); + keep_tag = callback(depth, parse_event_t::key, k); + } + else + { + keep_tag = true; + } + } - Template type @a CompatibleType includes, but is not limited to, the - following types: - - **arrays**: @ref array_t and all kinds of compatible containers such as - `std::vector`, `std::deque`, `std::list`, `std::forward_list`, - `std::array`, `std::set`, `std::unordered_set`, `std::multiset`, and - `unordered_multiset` with a `value_type` from which a @ref basic_json - value can be constructed. - - **objects**: @ref object_t and all kinds of compatible associative - containers such as `std::map`, `std::unordered_map`, `std::multimap`, - and `std::unordered_multimap` with a `key_type` compatible to - @ref string_t and a `value_type` from which a @ref basic_json value can - be constructed. - - **strings**: @ref string_t, string literals, and all compatible string - containers can be used. - - **numbers**: @ref number_integer_t, @ref number_unsigned_t, - @ref number_float_t, and all convertible number types such as `int`, - `size_t`, `int64_t`, `float` or `double` can be used. - - **boolean**: @ref boolean_t / `bool` can be used. + // parse separator (:) + get_token(); + if (not expect(token_type::name_separator)) + { + return; + } - See the examples below. + // parse and add value + get_token(); + value.m_value.destroy(value.m_type); + value.m_type = value_t::discarded; + parse_internal(keep, value); - @tparam CompatibleType a type such that: - - @a CompatibleType is not derived from `std::istream`, - - @a CompatibleType is not @ref basic_json (to avoid hijacking copy/move - constructors), - - @a CompatibleType is not a @ref basic_json nested type (e.g., - @ref json_pointer, @ref iterator, etc ...) - - @ref @ref json_serializer has a - `to_json(basic_json_t&, CompatibleType&&)` method + if (JSON_UNLIKELY(errored)) + { + return; + } - @tparam U = `uncvref_t` + if (keep and keep_tag and not value.is_discarded()) + { + result.m_value.object->emplace(std::move(key), std::move(value)); + } - @param[in] val the value to be forwarded + // comma -> next value + get_token(); + if (last_token == token_type::value_separator) + { + get_token(); + continue; + } - @complexity Usually linear in the size of the passed @a val, also - depending on the implementation of the called `to_json()` - method. + // closing } + if (not expect(token_type::end_object)) + { + return; + } + break; + } - @throw what `json_serializer::to_json()` throws + if (keep and callback and not callback(--depth, parse_event_t::object_end, result)) + { + result.m_value.destroy(result.m_type); + result.m_type = value_t::discarded; + } + break; + } - @liveexample{The following code shows the constructor with several - compatible types.,basic_json__CompatibleType} + case token_type::begin_array: + { + if (keep) + { + if (callback) + { + keep = callback(depth++, parse_event_t::array_start, result); + } - @since version 2.1.0 - */ - template, - detail::enable_if_t::value and - not std::is_same::value and - not detail::is_basic_json_nested_type< - basic_json_t, U>::value and - detail::has_to_json::value, - int> = 0> - basic_json(CompatibleType && val) noexcept(noexcept(JSONSerializer::to_json( - std::declval(), std::forward(val)))) - { - JSONSerializer::to_json(*this, std::forward(val)); - assert_invariant(); - } + if (not callback or keep) + { + // explicitly set result to array to cope with [] + result.m_type = value_t::array; + result.m_value = value_t::array; + } + } - /*! - @brief create a container (array or object) from an initializer list + // read next token + get_token(); - Creates a JSON value of type array or object from the passed initializer - list @a init. In case @a type_deduction is `true` (default), the type of - the JSON value to be created is deducted from the initializer list @a init - according to the following rules: + // closing ] -> we are done + if (last_token == token_type::end_array) + { + if (callback and not callback(--depth, parse_event_t::array_end, result)) + { + result.m_value.destroy(result.m_type); + result.m_type = value_t::discarded; + } + break; + } - 1. If the list is empty, an empty JSON object value `{}` is created. - 2. If the list consists of pairs whose first element is a string, a JSON - object value is created where the first elements of the pairs are - treated as keys and the second elements are as values. - 3. In all other cases, an array is created. + // parse values + BasicJsonType value; + while (true) + { + // parse value + value.m_value.destroy(value.m_type); + value.m_type = value_t::discarded; + parse_internal(keep, value); - The rules aim to create the best fit between a C++ initializer list and - JSON values. The rationale is as follows: + if (JSON_UNLIKELY(errored)) + { + return; + } - 1. The empty initializer list is written as `{}` which is exactly an empty - JSON object. - 2. C++ has now way of describing mapped types other than to list a list of - pairs. As JSON requires that keys must be of type string, rule 2 is the - weakest constraint one can pose on initializer lists to interpret them - as an object. - 3. In all other cases, the initializer list could not be interpreted as - JSON object type, so interpreting it as JSON array type is safe. + if (keep and not value.is_discarded()) + { + result.m_value.array->push_back(std::move(value)); + } - With the rules described above, the following JSON values cannot be - expressed by an initializer list: + // comma -> next value + get_token(); + if (last_token == token_type::value_separator) + { + get_token(); + continue; + } - - the empty array (`[]`): use @ref array(std::initializer_list) - with an empty initializer list in this case - - arrays whose elements satisfy rule 2: use @ref - array(std::initializer_list) with the same initializer list - in this case + // closing ] + if (not expect(token_type::end_array)) + { + return; + } + break; + } - @note When used without parentheses around an empty initializer list, @ref - basic_json() is called instead of this function, yielding the JSON null - value. + if (keep and callback and not callback(--depth, parse_event_t::array_end, result)) + { + result.m_value.destroy(result.m_type); + result.m_type = value_t::discarded; + } + break; + } - @param[in] init initializer list with JSON values + case token_type::literal_null: + { + result.m_type = value_t::null; + break; + } - @param[in] type_deduction internal parameter; when set to `true`, the type - of the JSON value is deducted from the initializer list @a init; when set - to `false`, the type provided via @a manual_type is forced. This mode is - used by the functions @ref array(std::initializer_list) and - @ref object(std::initializer_list). + case token_type::value_string: + { + result.m_type = value_t::string; + result.m_value = m_lexer.move_string(); + break; + } - @param[in] manual_type internal parameter; when @a type_deduction is set - to `false`, the created JSON value will use the provided type (only @ref - value_t::array and @ref value_t::object are valid); when @a type_deduction - is set to `true`, this parameter has no effect + case token_type::literal_true: + { + result.m_type = value_t::boolean; + result.m_value = true; + break; + } - @throw type_error.301 if @a type_deduction is `false`, @a manual_type is - `value_t::object`, but @a init contains an element which is not a pair - whose first element is a string. In this case, the constructor could not - create an object. If @a type_deduction would have be `true`, an array - would have been created. See @ref object(std::initializer_list) - for an example. + case token_type::literal_false: + { + result.m_type = value_t::boolean; + result.m_value = false; + break; + } - @complexity Linear in the size of the initializer list @a init. + case token_type::value_unsigned: + { + result.m_type = value_t::number_unsigned; + result.m_value = m_lexer.get_number_unsigned(); + break; + } - @liveexample{The example below shows how JSON values are created from - initializer lists.,basic_json__list_init_t} + case token_type::value_integer: + { + result.m_type = value_t::number_integer; + result.m_value = m_lexer.get_number_integer(); + break; + } - @sa @ref array(std::initializer_list) -- create a JSON array - value from an initializer list - @sa @ref object(std::initializer_list) -- create a JSON object - value from an initializer list + case token_type::value_float: + { + result.m_type = value_t::number_float; + result.m_value = m_lexer.get_number_float(); - @since version 1.0.0 - */ - basic_json(std::initializer_list init, - bool type_deduction = true, - value_t manual_type = value_t::array) - { - // check if each element is an array with two elements whose first - // element is a string - bool is_an_object = std::all_of(init.begin(), init.end(), - [](const basic_json & element) - { - return element.is_array() and element.size() == 2 and element[0].is_string(); - }); + // throw in case of infinity or NAN + if (JSON_UNLIKELY(not std::isfinite(result.m_value.number_float))) + { + if (allow_exceptions) + { + JSON_THROW(out_of_range::create(406, "number overflow parsing '" + + m_lexer.get_token_string() + "'")); + } + expect(token_type::uninitialized); + } + break; + } - // adjust type if type deduction is not wanted - if (not type_deduction) - { - // if array is wanted, do not create an object though possible - if (manual_type == value_t::array) + case token_type::parse_error: { - is_an_object = false; + // using "uninitialized" to avoid "expected" message + if (not expect(token_type::uninitialized)) + { + return; + } + break; // LCOV_EXCL_LINE } - // if object is wanted but impossible, throw an exception - if (manual_type == value_t::object and not is_an_object) + default: { - JSON_THROW(type_error::create(301, "cannot create object from initializer list")); + // the last token was unexpected; we expected a value + if (not expect(token_type::literal_or_value)) + { + return; + } + break; // LCOV_EXCL_LINE } } - if (is_an_object) - { - // the initializer list is a list of pairs -> create object - m_type = value_t::object; - m_value = value_t::object; - - std::for_each(init.begin(), init.end(), [this](const basic_json & element) - { - m_value.object->emplace(*(element[0].m_value.string), element[1]); - }); - } - else + if (keep and callback and not callback(depth, parse_event_t::value, result)) { - // the initializer list describes an array -> create array - m_type = value_t::array; - m_value.array = create(init); + result.m_type = value_t::discarded; } - - assert_invariant(); } /*! - @brief explicitly create an array from an initializer list + @brief the actual acceptor - Creates a JSON array value from a given initializer list. That is, given a - list of values `a, b, c`, creates the JSON value `[a, b, c]`. If the - initializer list is empty, the empty array `[]` is created. + @invariant 1. The last token is not yet processed. Therefore, the caller + of this function must make sure a token has been read. + 2. When this function returns, the last token is processed. + That is, the last read character was already considered. - @note This function is only needed to express two edge cases that cannot - be realized with the initializer list constructor (@ref - basic_json(std::initializer_list, bool, value_t)). These cases - are: - 1. creating an array whose elements are all pairs whose first element is a - string -- in this case, the initializer list constructor would create an - object, taking the first elements as keys - 2. creating an empty array -- passing the empty initializer list to the - initializer list constructor yields an empty object + This invariant makes sure that no token needs to be "unput". + */ + bool accept_internal() + { + switch (last_token) + { + case token_type::begin_object: + { + // read next token + get_token(); - @param[in] init initializer list with JSON values to create an array from - (optional) + // closing } -> we are done + if (last_token == token_type::end_object) + { + return true; + } - @return JSON array value + // parse values + while (true) + { + // parse key + if (last_token != token_type::value_string) + { + return false; + } - @complexity Linear in the size of @a init. + // parse separator (:) + get_token(); + if (last_token != token_type::name_separator) + { + return false; + } - @liveexample{The following code shows an example for the `array` - function.,array} + // parse value + get_token(); + if (not accept_internal()) + { + return false; + } - @sa @ref basic_json(std::initializer_list, bool, value_t) -- - create a JSON value from an initializer list - @sa @ref object(std::initializer_list) -- create a JSON object - value from an initializer list + // comma -> next value + get_token(); + if (last_token == token_type::value_separator) + { + get_token(); + continue; + } - @since version 1.0.0 - */ - static basic_json array(std::initializer_list init = - std::initializer_list()) - { - return basic_json(init, false, value_t::array); - } + // closing } + return (last_token == token_type::end_object); + } + } - /*! - @brief explicitly create an object from an initializer list + case token_type::begin_array: + { + // read next token + get_token(); - Creates a JSON object value from a given initializer list. The initializer - lists elements must be pairs, and their first elements must be strings. If - the initializer list is empty, the empty object `{}` is created. + // closing ] -> we are done + if (last_token == token_type::end_array) + { + return true; + } - @note This function is only added for symmetry reasons. In contrast to the - related function @ref array(std::initializer_list), there are - no cases which can only be expressed by this function. That is, any - initializer list @a init can also be passed to the initializer list - constructor @ref basic_json(std::initializer_list, bool, value_t). + // parse values + while (true) + { + // parse value + if (not accept_internal()) + { + return false; + } - @param[in] init initializer list to create an object from (optional) + // comma -> next value + get_token(); + if (last_token == token_type::value_separator) + { + get_token(); + continue; + } - @return JSON object value + // closing ] + return (last_token == token_type::end_array); + } + } - @throw type_error.301 if @a init is not a list of pairs whose first - elements are strings. In this case, no object can be created. When such a - value is passed to @ref basic_json(std::initializer_list, bool, value_t), - an array would have been created from the passed initializer list @a init. - See example below. + case token_type::value_float: + { + // reject infinity or NAN + return std::isfinite(m_lexer.get_number_float()); + } - @complexity Linear in the size of @a init. + case token_type::literal_false: + case token_type::literal_null: + case token_type::literal_true: + case token_type::value_integer: + case token_type::value_string: + case token_type::value_unsigned: + return true; - @liveexample{The following code shows an example for the `object` - function.,object} + default: // the last token was unexpected + return false; + } + } - @sa @ref basic_json(std::initializer_list, bool, value_t) -- - create a JSON value from an initializer list - @sa @ref array(std::initializer_list) -- create a JSON array - value from an initializer list + /// get next token from lexer + token_type get_token() + { + return (last_token = m_lexer.scan()); + } - @since version 1.0.0 + /*! + @throw parse_error.101 if expected token did not occur */ - static basic_json object(std::initializer_list init = - std::initializer_list()) + bool expect(token_type t) { - return basic_json(init, false, value_t::object); + if (JSON_UNLIKELY(t != last_token)) + { + errored = true; + expected = t; + if (allow_exceptions) + { + throw_exception(); + } + else + { + return false; + } + } + + return true; } - /*! - @brief construct an array with count copies of given value + [[noreturn]] void throw_exception() const + { + std::string error_msg = "syntax error - "; + if (last_token == token_type::parse_error) + { + error_msg += std::string(m_lexer.get_error_message()) + "; last read: '" + + m_lexer.get_token_string() + "'"; + } + else + { + error_msg += "unexpected " + std::string(lexer_t::token_type_name(last_token)); + } - Constructs a JSON array value by creating @a cnt copies of a passed value. - In case @a cnt is `0`, an empty array is created. As postcondition, - `std::distance(begin(),end()) == cnt` holds. + if (expected != token_type::uninitialized) + { + error_msg += "; expected " + std::string(lexer_t::token_type_name(expected)); + } - @param[in] cnt the number of JSON copies of @a val to create - @param[in] val the JSON value to copy + JSON_THROW(parse_error::create(101, m_lexer.get_position(), error_msg)); + } - @complexity Linear in @a cnt. + private: + /// current level of recursion + int depth = 0; + /// callback function + const parser_callback_t callback = nullptr; + /// the type of the last read token + token_type last_token = token_type::uninitialized; + /// the lexer + lexer_t m_lexer; + /// whether a syntax error occurred + bool errored = false; + /// possible reason for the syntax error + token_type expected = token_type::uninitialized; + /// whether to throw exceptions in case of errors + const bool allow_exceptions = true; +}; +} +} - @liveexample{The following code shows examples for the @ref - basic_json(size_type\, const basic_json&) - constructor.,basic_json__size_type_basic_json} +// #include - @since version 1.0.0 - */ - basic_json(size_type cnt, const basic_json& val) - : m_type(value_t::array) + +#include // ptrdiff_t +#include // numeric_limits + +namespace nlohmann +{ +namespace detail +{ +/* +@brief an iterator for primitive JSON types + +This class models an iterator for primitive JSON types (boolean, number, +string). It's only purpose is to allow the iterator/const_iterator classes +to "iterate" over primitive values. Internally, the iterator is modeled by +a `difference_type` variable. Value begin_value (`0`) models the begin, +end_value (`1`) models past the end. +*/ +class primitive_iterator_t +{ + private: + using difference_type = std::ptrdiff_t; + static constexpr difference_type begin_value = 0; + static constexpr difference_type end_value = begin_value + 1; + + /// iterator as signed integer type + difference_type m_it = (std::numeric_limits::min)(); + + public: + constexpr difference_type get_value() const noexcept { - m_value.array = create(cnt, val); - assert_invariant(); + return m_it; } - /*! - @brief construct a JSON container given an iterator range + /// set iterator to a defined beginning + void set_begin() noexcept + { + m_it = begin_value; + } - Constructs the JSON value with the contents of the range `[first, last)`. - The semantics depends on the different types a JSON value can have: - - In case of primitive types (number, boolean, or string), @a first must - be `begin()` and @a last must be `end()`. In this case, the value is - copied. Otherwise, invalid_iterator.204 is thrown. - - In case of structured types (array, object), the constructor behaves as - similar versions for `std::vector`. - - In case of a null type, invalid_iterator.206 is thrown. + /// set iterator to a defined past the end + void set_end() noexcept + { + m_it = end_value; + } - @tparam InputIT an input iterator type (@ref iterator or @ref - const_iterator) + /// return whether the iterator can be dereferenced + constexpr bool is_begin() const noexcept + { + return m_it == begin_value; + } - @param[in] first begin of the range to copy from (included) - @param[in] last end of the range to copy from (excluded) + /// return whether the iterator is at end + constexpr bool is_end() const noexcept + { + return m_it == end_value; + } - @pre Iterators @a first and @a last must be initialized. **This - precondition is enforced with an assertion.** + friend constexpr bool operator==(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept + { + return lhs.m_it == rhs.m_it; + } - @pre Range `[first, last)` is valid. Usually, this precondition cannot be - checked efficiently. Only certain edge cases are detected; see the - description of the exceptions below. + friend constexpr bool operator<(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept + { + return lhs.m_it < rhs.m_it; + } - @throw invalid_iterator.201 if iterators @a first and @a last are not - compatible (i.e., do not belong to the same JSON value). In this case, - the range `[first, last)` is undefined. - @throw invalid_iterator.204 if iterators @a first and @a last belong to a - primitive type (number, boolean, or string), but @a first does not point - to the first element any more. In this case, the range `[first, last)` is - undefined. See example code below. - @throw invalid_iterator.206 if iterators @a first and @a last belong to a - null value. In this case, the range `[first, last)` is undefined. + primitive_iterator_t operator+(difference_type n) noexcept + { + auto result = *this; + result += n; + return result; + } - @complexity Linear in distance between @a first and @a last. + friend constexpr difference_type operator-(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept + { + return lhs.m_it - rhs.m_it; + } - @liveexample{The example below shows several ways to create JSON values by - specifying a subrange with iterators.,basic_json__InputIt_InputIt} + primitive_iterator_t& operator++() noexcept + { + ++m_it; + return *this; + } - @since version 1.0.0 - */ - template::value or - std::is_same::value, int>::type = 0> - basic_json(InputIT first, InputIT last) + primitive_iterator_t const operator++(int) noexcept { - assert(first.m_object != nullptr); - assert(last.m_object != nullptr); + auto result = *this; + m_it++; + return result; + } - // make sure iterator fits the current value - if (first.m_object != last.m_object) - { - JSON_THROW(invalid_iterator::create(201, "iterators are not compatible")); - } + primitive_iterator_t& operator--() noexcept + { + --m_it; + return *this; + } - // copy type from first iterator - m_type = first.m_object->m_type; + primitive_iterator_t const operator--(int) noexcept + { + auto result = *this; + m_it--; + return result; + } - // check if iterator range is complete for primitive values - switch (m_type) - { - case value_t::boolean: - case value_t::number_float: - case value_t::number_integer: - case value_t::number_unsigned: - case value_t::string: - { - if (not first.m_it.primitive_iterator.is_begin() or not last.m_it.primitive_iterator.is_end()) - { - JSON_THROW(invalid_iterator::create(204, "iterators out of range")); - } - break; - } + primitive_iterator_t& operator+=(difference_type n) noexcept + { + m_it += n; + return *this; + } - default: - { - break; - } - } + primitive_iterator_t& operator-=(difference_type n) noexcept + { + m_it -= n; + return *this; + } +}; +} +} - switch (m_type) - { - case value_t::number_integer: - { - m_value.number_integer = first.m_object->m_value.number_integer; - break; - } +// #include - case value_t::number_unsigned: - { - m_value.number_unsigned = first.m_object->m_value.number_unsigned; - break; - } - case value_t::number_float: - { - m_value.number_float = first.m_object->m_value.number_float; - break; - } +// #include - case value_t::boolean: - { - m_value.boolean = first.m_object->m_value.boolean; - break; - } - case value_t::string: - { - m_value = *first.m_object->m_value.string; - break; - } +namespace nlohmann +{ +namespace detail +{ +/*! +@brief an iterator value + +@note This structure could easily be a union, but MSVC currently does not allow +unions members with complex constructors, see https://github.com/nlohmann/json/pull/105. +*/ +template struct internal_iterator +{ + /// iterator for JSON objects + typename BasicJsonType::object_t::iterator object_iterator {}; + /// iterator for JSON arrays + typename BasicJsonType::array_t::iterator array_iterator {}; + /// generic iterator for all other types + primitive_iterator_t primitive_iterator {}; +}; +} +} + +// #include + + +#include // not +#include // iterator, random_access_iterator_tag, bidirectional_iterator_tag, advance, next +#include // conditional, is_const, remove_const + +// #include + +// #include + +// #include + +// #include + +// #include + +// #include + + +namespace nlohmann +{ +namespace detail +{ +// forward declare, to be able to friend it later on +template class iteration_proxy; + +/*! +@brief a template for a bidirectional iterator for the @ref basic_json class + +This class implements a both iterators (iterator and const_iterator) for the +@ref basic_json class. + +@note An iterator is called *initialized* when a pointer to a JSON value has + been set (e.g., by a constructor or a copy assignment). If the iterator is + default-constructed, it is *uninitialized* and most methods are undefined. + **The library uses assertions to detect calls on uninitialized iterators.** + +@requirement The class satisfies the following concept requirements: +- +[BidirectionalIterator](http://en.cppreference.com/w/cpp/concept/BidirectionalIterator): + The iterator that can be moved can be moved in both directions (i.e. + incremented and decremented). + +@since version 1.0.0, simplified in version 2.0.9, change to bidirectional + iterators in version 3.0.0 (see https://github.com/nlohmann/json/issues/593) +*/ +template +class iter_impl +{ + /// allow basic_json to access private members + friend iter_impl::value, typename std::remove_const::type, const BasicJsonType>::type>; + friend BasicJsonType; + friend iteration_proxy; + + using object_t = typename BasicJsonType::object_t; + using array_t = typename BasicJsonType::array_t; + // make sure BasicJsonType is basic_json or const basic_json + static_assert(is_basic_json::type>::value, + "iter_impl only accepts (const) basic_json"); + + public: + + /// The std::iterator class template (used as a base class to provide typedefs) is deprecated in C++17. + /// The C++ Standard has never required user-defined iterators to derive from std::iterator. + /// A user-defined iterator should provide publicly accessible typedefs named + /// iterator_category, value_type, difference_type, pointer, and reference. + /// Note that value_type is required to be non-const, even for constant iterators. + using iterator_category = std::bidirectional_iterator_tag; + + /// the type of the values when the iterator is dereferenced + using value_type = typename BasicJsonType::value_type; + /// a type to represent differences between iterators + using difference_type = typename BasicJsonType::difference_type; + /// defines a pointer to the type iterated over (value_type) + using pointer = typename std::conditional::value, + typename BasicJsonType::const_pointer, + typename BasicJsonType::pointer>::type; + /// defines a reference to the type iterated over (value_type) + using reference = + typename std::conditional::value, + typename BasicJsonType::const_reference, + typename BasicJsonType::reference>::type; + + /// default constructor + iter_impl() = default; + /*! + @brief constructor for a given JSON instance + @param[in] object pointer to a JSON object for this iterator + @pre object != nullptr + @post The iterator is initialized; i.e. `m_object != nullptr`. + */ + explicit iter_impl(pointer object) noexcept : m_object(object) + { + assert(m_object != nullptr); + + switch (m_object->m_type) + { case value_t::object: { - m_value.object = create(first.m_it.object_iterator, - last.m_it.object_iterator); + m_it.object_iterator = typename object_t::iterator(); break; } case value_t::array: { - m_value.array = create(first.m_it.array_iterator, - last.m_it.array_iterator); + m_it.array_iterator = typename array_t::iterator(); break; } default: { - JSON_THROW(invalid_iterator::create(206, "cannot construct with iterators from " + - first.m_object->type_name())); + m_it.primitive_iterator = primitive_iterator_t(); + break; } } - - assert_invariant(); } - - /////////////////////////////////////// - // other constructors and destructor // - /////////////////////////////////////// - /*! - @brief copy constructor - - Creates a copy of a given JSON value. - - @param[in] other the JSON value to copy - - @complexity Linear in the size of @a other. + @note The conventional copy constructor and copy assignment are implicitly + defined. Combined with the following converting constructor and + assignment, they support: (1) copy from iterator to iterator, (2) + copy from const iterator to const iterator, and (3) conversion from + iterator to const iterator. However conversion from const iterator + to iterator is not defined. + */ - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is linear. - - As postcondition, it holds: `other == basic_json(other)`. + /*! + @brief converting constructor + @param[in] other non-const iterator to copy from + @note It is not checked whether @a other is initialized. + */ + iter_impl(const iter_impl::type>& other) noexcept + : m_object(other.m_object), m_it(other.m_it) {} - @liveexample{The following code shows an example for the copy - constructor.,basic_json__basic_json} + /*! + @brief converting assignment + @param[in,out] other non-const iterator to copy from + @return const/non-const iterator + @note It is not checked whether @a other is initialized. + */ + iter_impl& operator=(const iter_impl::type>& other) noexcept + { + m_object = other.m_object; + m_it = other.m_it; + return *this; + } - @since version 1.0.0 + private: + /*! + @brief set the iterator to the first value + @pre The iterator is initialized; i.e. `m_object != nullptr`. */ - basic_json(const basic_json& other) - : m_type(other.m_type) + void set_begin() noexcept { - // check of passed value is valid - other.assert_invariant(); + assert(m_object != nullptr); - switch (m_type) + switch (m_object->m_type) { case value_t::object: { - m_value = *other.m_value.object; + m_it.object_iterator = m_object->m_value.object->begin(); break; } case value_t::array: { - m_value = *other.m_value.array; + m_it.array_iterator = m_object->m_value.array->begin(); break; } - case value_t::string: + case value_t::null: { - m_value = *other.m_value.string; + // set to end so begin()==end() is true: null is empty + m_it.primitive_iterator.set_end(); break; } - case value_t::boolean: + default: { - m_value = other.m_value.boolean; + m_it.primitive_iterator.set_begin(); break; } + } + } - case value_t::number_integer: - { - m_value = other.m_value.number_integer; - break; - } + /*! + @brief set the iterator past the last value + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + void set_end() noexcept + { + assert(m_object != nullptr); - case value_t::number_unsigned: + switch (m_object->m_type) + { + case value_t::object: { - m_value = other.m_value.number_unsigned; + m_it.object_iterator = m_object->m_value.object->end(); break; } - case value_t::number_float: + case value_t::array: { - m_value = other.m_value.number_float; + m_it.array_iterator = m_object->m_value.array->end(); break; } default: { + m_it.primitive_iterator.set_end(); break; } } - - assert_invariant(); } + public: /*! - @brief move constructor + @brief return a reference to the value pointed to by the iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + reference operator*() const + { + assert(m_object != nullptr); - Move constructor. Constructs a JSON value with the contents of the given - value @a other using move semantics. It "steals" the resources from @a - other and leaves it as JSON null value. + switch (m_object->m_type) + { + case value_t::object: + { + assert(m_it.object_iterator != m_object->m_value.object->end()); + return m_it.object_iterator->second; + } - @param[in,out] other value to move to this object + case value_t::array: + { + assert(m_it.array_iterator != m_object->m_value.array->end()); + return *m_it.array_iterator; + } - @post @a other is a JSON null value + case value_t::null: + JSON_THROW(invalid_iterator::create(214, "cannot get value")); - @complexity Constant. + default: + { + if (JSON_LIKELY(m_it.primitive_iterator.is_begin())) + { + return *m_object; + } - @liveexample{The code below shows the move constructor explicitly called - via std::move.,basic_json__moveconstructor} + JSON_THROW(invalid_iterator::create(214, "cannot get value")); + } + } + } - @since version 1.0.0 + /*! + @brief dereference the iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. */ - basic_json(basic_json&& other) noexcept - : m_type(std::move(other.m_type)), - m_value(std::move(other.m_value)) + pointer operator->() const { - // check that passed value is valid - other.assert_invariant(); + assert(m_object != nullptr); - // invalidate payload - other.m_type = value_t::null; - other.m_value = {}; + switch (m_object->m_type) + { + case value_t::object: + { + assert(m_it.object_iterator != m_object->m_value.object->end()); + return &(m_it.object_iterator->second); + } - assert_invariant(); + case value_t::array: + { + assert(m_it.array_iterator != m_object->m_value.array->end()); + return &*m_it.array_iterator; + } + + default: + { + if (JSON_LIKELY(m_it.primitive_iterator.is_begin())) + { + return m_object; + } + + JSON_THROW(invalid_iterator::create(214, "cannot get value")); + } + } } /*! - @brief copy assignment + @brief post-increment (it++) + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + iter_impl const operator++(int) + { + auto result = *this; + ++(*this); + return result; + } - Copy assignment operator. Copies a JSON value via the "copy and swap" - strategy: It is expressed in terms of the copy constructor, destructor, - and the swap() member function. + /*! + @brief pre-increment (++it) + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + iter_impl& operator++() + { + assert(m_object != nullptr); - @param[in] other value to copy from + switch (m_object->m_type) + { + case value_t::object: + { + std::advance(m_it.object_iterator, 1); + break; + } - @complexity Linear. + case value_t::array: + { + std::advance(m_it.array_iterator, 1); + break; + } - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is linear. + default: + { + ++m_it.primitive_iterator; + break; + } + } - @liveexample{The code below shows and example for the copy assignment. It - creates a copy of value `a` which is then swapped with `b`. Finally\, the - copy of `a` (which is the null value after the swap) is - destroyed.,basic_json__copyassignment} + return *this; + } - @since version 1.0.0 + /*! + @brief post-decrement (it--) + @pre The iterator is initialized; i.e. `m_object != nullptr`. */ - reference& operator=(basic_json other) noexcept ( - std::is_nothrow_move_constructible::value and - std::is_nothrow_move_assignable::value and - std::is_nothrow_move_constructible::value and - std::is_nothrow_move_assignable::value - ) + iter_impl const operator--(int) { - // check that passed value is valid - other.assert_invariant(); - - using std::swap; - swap(m_type, other.m_type); - swap(m_value, other.m_value); - - assert_invariant(); - return *this; + auto result = *this; + --(*this); + return result; } /*! - @brief destructor - - Destroys the JSON value and frees all allocated memory. - - @complexity Linear. - - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is linear. - - All stored elements are destroyed and all memory is freed. - - @since version 1.0.0 + @brief pre-decrement (--it) + @pre The iterator is initialized; i.e. `m_object != nullptr`. */ - ~basic_json() + iter_impl& operator--() { - assert_invariant(); + assert(m_object != nullptr); - switch (m_type) + switch (m_object->m_type) { case value_t::object: { - AllocatorType alloc; - alloc.destroy(m_value.object); - alloc.deallocate(m_value.object, 1); + std::advance(m_it.object_iterator, -1); break; } case value_t::array: { - AllocatorType alloc; - alloc.destroy(m_value.array); - alloc.deallocate(m_value.array, 1); - break; - } - - case value_t::string: - { - AllocatorType alloc; - alloc.destroy(m_value.string); - alloc.deallocate(m_value.string, 1); + std::advance(m_it.array_iterator, -1); break; } default: { - // all other types need no specific destructor + --m_it.primitive_iterator; break; } } - } - /// @} - - public: - /////////////////////// - // object inspection // - /////////////////////// - - /// @name object inspection - /// Functions to inspect the type of a JSON value. - /// @{ + return *this; + } /*! - @brief serialization - - Serialization function for JSON values. The function tries to mimic - Python's `json.dumps()` function, and currently supports its @a indent - parameter. - - @param[in] indent If indent is nonnegative, then array elements and object - members will be pretty-printed with that indent level. An indent level of - `0` will only insert newlines. `-1` (the default) selects the most compact - representation. - @param[in] indent_char The character to use for indentation of @a indent is - greate than `0`. The default is ` ` (space). + @brief comparison: equal + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + bool operator==(const iter_impl& other) const + { + // if objects are not the same, the comparison is undefined + if (JSON_UNLIKELY(m_object != other.m_object)) + { + JSON_THROW(invalid_iterator::create(212, "cannot compare iterators of different containers")); + } - @return string containing the serialization of the JSON value + assert(m_object != nullptr); - @complexity Linear. + switch (m_object->m_type) + { + case value_t::object: + return (m_it.object_iterator == other.m_it.object_iterator); - @liveexample{The following example shows the effect of different @a indent - parameters to the result of the serialization.,dump} + case value_t::array: + return (m_it.array_iterator == other.m_it.array_iterator); - @see https://docs.python.org/2/library/json.html#json.dump + default: + return (m_it.primitive_iterator == other.m_it.primitive_iterator); + } + } - @since version 1.0.0; indentaction character added in version 3.0.0 + /*! + @brief comparison: not equal + @pre The iterator is initialized; i.e. `m_object != nullptr`. */ - string_t dump(const int indent = -1, const char indent_char = ' ') const + bool operator!=(const iter_impl& other) const { - string_t result; - serializer s(output_adapter::create(result), indent_char); + return not operator==(other); + } - if (indent >= 0) + /*! + @brief comparison: smaller + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + bool operator<(const iter_impl& other) const + { + // if objects are not the same, the comparison is undefined + if (JSON_UNLIKELY(m_object != other.m_object)) { - s.dump(*this, true, static_cast(indent)); + JSON_THROW(invalid_iterator::create(212, "cannot compare iterators of different containers")); } - else + + assert(m_object != nullptr); + + switch (m_object->m_type) { - s.dump(*this, false, 0); + case value_t::object: + JSON_THROW(invalid_iterator::create(213, "cannot compare order of object iterators")); + + case value_t::array: + return (m_it.array_iterator < other.m_it.array_iterator); + + default: + return (m_it.primitive_iterator < other.m_it.primitive_iterator); } + } - return result; + /*! + @brief comparison: less than or equal + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + bool operator<=(const iter_impl& other) const + { + return not other.operator < (*this); } /*! - @brief return the type of the JSON value (explicit) + @brief comparison: greater than + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + bool operator>(const iter_impl& other) const + { + return not operator<=(other); + } - Return the type of the JSON value as a value from the @ref value_t - enumeration. + /*! + @brief comparison: greater than or equal + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + bool operator>=(const iter_impl& other) const + { + return not operator<(other); + } - @return the type of the JSON value + /*! + @brief add to iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + iter_impl& operator+=(difference_type i) + { + assert(m_object != nullptr); - @complexity Constant. + switch (m_object->m_type) + { + case value_t::object: + JSON_THROW(invalid_iterator::create(209, "cannot use offsets with object iterators")); - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + case value_t::array: + { + std::advance(m_it.array_iterator, i); + break; + } - @liveexample{The following code exemplifies `type()` for all JSON - types.,type} + default: + { + m_it.primitive_iterator += i; + break; + } + } - @since version 1.0.0 + return *this; + } + + /*! + @brief subtract from iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. */ - constexpr value_t type() const noexcept + iter_impl& operator-=(difference_type i) { - return m_type; + return operator+=(-i); } /*! - @brief return whether type is primitive + @brief add to iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + iter_impl operator+(difference_type i) const + { + auto result = *this; + result += i; + return result; + } - This function returns true iff the JSON type is primitive (string, number, - boolean, or null). + /*! + @brief addition of distance and iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + friend iter_impl operator+(difference_type i, const iter_impl& it) + { + auto result = it; + result += i; + return result; + } - @return `true` if type is primitive (string, number, boolean, or null), - `false` otherwise. + /*! + @brief subtract from iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + iter_impl operator-(difference_type i) const + { + auto result = *this; + result -= i; + return result; + } - @complexity Constant. + /*! + @brief return difference + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + difference_type operator-(const iter_impl& other) const + { + assert(m_object != nullptr); - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + switch (m_object->m_type) + { + case value_t::object: + JSON_THROW(invalid_iterator::create(209, "cannot use offsets with object iterators")); - @liveexample{The following code exemplifies `is_primitive()` for all JSON - types.,is_primitive} + case value_t::array: + return m_it.array_iterator - other.m_it.array_iterator; - @sa @ref is_structured() -- returns whether JSON value is structured - @sa @ref is_null() -- returns whether JSON value is `null` - @sa @ref is_string() -- returns whether JSON value is a string - @sa @ref is_boolean() -- returns whether JSON value is a boolean - @sa @ref is_number() -- returns whether JSON value is a number + default: + return m_it.primitive_iterator - other.m_it.primitive_iterator; + } + } - @since version 1.0.0 + /*! + @brief access to successor + @pre The iterator is initialized; i.e. `m_object != nullptr`. */ - constexpr bool is_primitive() const noexcept + reference operator[](difference_type n) const { - return is_null() or is_string() or is_boolean() or is_number(); - } + assert(m_object != nullptr); - /*! - @brief return whether type is structured + switch (m_object->m_type) + { + case value_t::object: + JSON_THROW(invalid_iterator::create(208, "cannot use operator[] for object iterators")); - This function returns true iff the JSON type is structured (array or - object). + case value_t::array: + return *std::next(m_it.array_iterator, n); - @return `true` if type is structured (array or object), `false` otherwise. + case value_t::null: + JSON_THROW(invalid_iterator::create(214, "cannot get value")); - @complexity Constant. + default: + { + if (JSON_LIKELY(m_it.primitive_iterator.get_value() == -n)) + { + return *m_object; + } - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + JSON_THROW(invalid_iterator::create(214, "cannot get value")); + } + } + } - @liveexample{The following code exemplifies `is_structured()` for all JSON - types.,is_structured} + /*! + @brief return the key of an object iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + typename object_t::key_type key() const + { + assert(m_object != nullptr); - @sa @ref is_primitive() -- returns whether value is primitive - @sa @ref is_array() -- returns whether value is an array - @sa @ref is_object() -- returns whether value is an object + if (JSON_LIKELY(m_object->is_object())) + { + return m_it.object_iterator->first; + } - @since version 1.0.0 + JSON_THROW(invalid_iterator::create(207, "cannot use key() for non-object iterators")); + } + + /*! + @brief return the value of an iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. */ - constexpr bool is_structured() const noexcept + reference value() const { - return is_array() or is_object(); + return operator*(); } - /*! - @brief return whether value is null + private: + /// associated JSON instance + pointer m_object = nullptr; + /// the actual iterator of the associated instance + internal_iterator::type> m_it; +}; +} +} - This function returns true iff the JSON value is null. +// #include - @return `true` if type is null, `false` otherwise. - @complexity Constant. +#include // size_t +#include // string, to_string - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. +// #include - @liveexample{The following code exemplifies `is_null()` for all JSON - types.,is_null} - @since version 1.0.0 - */ - constexpr bool is_null() const noexcept +namespace nlohmann +{ +namespace detail +{ +/// proxy class for the items() function +template class iteration_proxy +{ + private: + /// helper class for iteration + class iteration_proxy_internal { - return m_type == value_t::null; - } - - /*! - @brief return whether value is a boolean + private: + /// the iterator + IteratorType anchor; + /// an index for arrays (used to create key names) + std::size_t array_index = 0; - This function returns true iff the JSON value is a boolean. + public: + explicit iteration_proxy_internal(IteratorType it) noexcept : anchor(it) {} - @return `true` if type is boolean, `false` otherwise. + /// dereference operator (needed for range-based for) + iteration_proxy_internal& operator*() + { + return *this; + } - @complexity Constant. + /// increment operator (needed for range-based for) + iteration_proxy_internal& operator++() + { + ++anchor; + ++array_index; - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + return *this; + } - @liveexample{The following code exemplifies `is_boolean()` for all JSON - types.,is_boolean} + /// inequality operator (needed for range-based for) + bool operator!=(const iteration_proxy_internal& o) const noexcept + { + return anchor != o.anchor; + } - @since version 1.0.0 - */ - constexpr bool is_boolean() const noexcept - { - return m_type == value_t::boolean; - } + /// return key of the iterator + std::string key() const + { + assert(anchor.m_object != nullptr); - /*! - @brief return whether value is a number + switch (anchor.m_object->type()) + { + // use integer array index as key + case value_t::array: + return std::to_string(array_index); - This function returns true iff the JSON value is a number. This includes - both integer and floating-point values. + // use key from the object + case value_t::object: + return anchor.key(); - @return `true` if type is number (regardless whether integer, unsigned - integer or floating-type), `false` otherwise. + // use an empty key for all primitive types + default: + return ""; + } + } - @complexity Constant. + /// return value of the iterator + typename IteratorType::reference value() const + { + return anchor.value(); + } + }; - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + /// the container to iterate + typename IteratorType::reference container; - @liveexample{The following code exemplifies `is_number()` for all JSON - types.,is_number} + public: + /// construct iteration proxy from a container + explicit iteration_proxy(typename IteratorType::reference cont) noexcept + : container(cont) {} - @sa @ref is_number_integer() -- check if value is an integer or unsigned - integer number - @sa @ref is_number_unsigned() -- check if value is an unsigned integer - number - @sa @ref is_number_float() -- check if value is a floating-point number + /// return iterator begin (needed for range-based for) + iteration_proxy_internal begin() noexcept + { + return iteration_proxy_internal(container.begin()); + } - @since version 1.0.0 - */ - constexpr bool is_number() const noexcept + /// return iterator end (needed for range-based for) + iteration_proxy_internal end() noexcept { - return is_number_integer() or is_number_float(); + return iteration_proxy_internal(container.end()); } +}; +} +} - /*! - @brief return whether value is an integer number +// #include - This function returns true iff the JSON value is an integer or unsigned - integer number. This excludes floating-point values. - @return `true` if type is an integer or unsigned integer number, `false` - otherwise. +#include // ptrdiff_t +#include // reverse_iterator +#include // declval - @complexity Constant. +namespace nlohmann +{ +namespace detail +{ +////////////////////// +// reverse_iterator // +////////////////////// - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. +/*! +@brief a template for a reverse iterator class - @liveexample{The following code exemplifies `is_number_integer()` for all - JSON types.,is_number_integer} +@tparam Base the base iterator type to reverse. Valid types are @ref +iterator (to create @ref reverse_iterator) and @ref const_iterator (to +create @ref const_reverse_iterator). - @sa @ref is_number() -- check if value is a number - @sa @ref is_number_unsigned() -- check if value is an unsigned integer - number - @sa @ref is_number_float() -- check if value is a floating-point number - - @since version 1.0.0 - */ - constexpr bool is_number_integer() const noexcept - { - return m_type == value_t::number_integer or m_type == value_t::number_unsigned; - } - - /*! - @brief return whether value is an unsigned integer number - - This function returns true iff the JSON value is an unsigned integer - number. This excludes floating-point and (signed) integer values. +@requirement The class satisfies the following concept requirements: +- +[BidirectionalIterator](http://en.cppreference.com/w/cpp/concept/BidirectionalIterator): + The iterator that can be moved can be moved in both directions (i.e. + incremented and decremented). +- [OutputIterator](http://en.cppreference.com/w/cpp/concept/OutputIterator): + It is possible to write to the pointed-to element (only if @a Base is + @ref iterator). - @return `true` if type is an unsigned integer number, `false` otherwise. +@since version 1.0.0 +*/ +template +class json_reverse_iterator : public std::reverse_iterator +{ + public: + using difference_type = std::ptrdiff_t; + /// shortcut to the reverse iterator adapter + using base_iterator = std::reverse_iterator; + /// the reference type for the pointed-to element + using reference = typename Base::reference; - @complexity Constant. + /// create reverse iterator from iterator + json_reverse_iterator(const typename base_iterator::iterator_type& it) noexcept + : base_iterator(it) {} - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + /// create reverse iterator from base class + json_reverse_iterator(const base_iterator& it) noexcept : base_iterator(it) {} - @liveexample{The following code exemplifies `is_number_unsigned()` for all - JSON types.,is_number_unsigned} + /// post-increment (it++) + json_reverse_iterator const operator++(int) + { + return static_cast(base_iterator::operator++(1)); + } - @sa @ref is_number() -- check if value is a number - @sa @ref is_number_integer() -- check if value is an integer or unsigned - integer number - @sa @ref is_number_float() -- check if value is a floating-point number + /// pre-increment (++it) + json_reverse_iterator& operator++() + { + return static_cast(base_iterator::operator++()); + } - @since version 2.0.0 - */ - constexpr bool is_number_unsigned() const noexcept + /// post-decrement (it--) + json_reverse_iterator const operator--(int) { - return m_type == value_t::number_unsigned; + return static_cast(base_iterator::operator--(1)); } - /*! - @brief return whether value is a floating-point number + /// pre-decrement (--it) + json_reverse_iterator& operator--() + { + return static_cast(base_iterator::operator--()); + } - This function returns true iff the JSON value is a floating-point number. - This excludes integer and unsigned integer values. + /// add to iterator + json_reverse_iterator& operator+=(difference_type i) + { + return static_cast(base_iterator::operator+=(i)); + } - @return `true` if type is a floating-point number, `false` otherwise. + /// add to iterator + json_reverse_iterator operator+(difference_type i) const + { + return static_cast(base_iterator::operator+(i)); + } - @complexity Constant. + /// subtract from iterator + json_reverse_iterator operator-(difference_type i) const + { + return static_cast(base_iterator::operator-(i)); + } - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + /// return difference + difference_type operator-(const json_reverse_iterator& other) const + { + return base_iterator(*this) - base_iterator(other); + } - @liveexample{The following code exemplifies `is_number_float()` for all - JSON types.,is_number_float} + /// access to successor + reference operator[](difference_type n) const + { + return *(this->operator+(n)); + } - @sa @ref is_number() -- check if value is number - @sa @ref is_number_integer() -- check if value is an integer number - @sa @ref is_number_unsigned() -- check if value is an unsigned integer - number + /// return the key of an object iterator + auto key() const -> decltype(std::declval().key()) + { + auto it = --this->base(); + return it.key(); + } - @since version 1.0.0 - */ - constexpr bool is_number_float() const noexcept + /// return the value of an iterator + reference value() const { - return m_type == value_t::number_float; + auto it = --this->base(); + return it.operator * (); } +}; +} +} - /*! - @brief return whether value is an object +// #include - This function returns true iff the JSON value is an object. - @return `true` if type is object, `false` otherwise. +#include // copy +#include // size_t +#include // streamsize +#include // back_inserter +#include // shared_ptr, make_shared +#include // basic_ostream +#include // basic_string +#include // vector - @complexity Constant. +namespace nlohmann +{ +namespace detail +{ +/// abstract output adapter interface +template struct output_adapter_protocol +{ + virtual void write_character(CharType c) = 0; + virtual void write_characters(const CharType* s, std::size_t length) = 0; + virtual ~output_adapter_protocol() = default; +}; - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. +/// a type to simplify interfaces +template +using output_adapter_t = std::shared_ptr>; - @liveexample{The following code exemplifies `is_object()` for all JSON - types.,is_object} +/// output adapter for byte vectors +template +class output_vector_adapter : public output_adapter_protocol +{ + public: + explicit output_vector_adapter(std::vector& vec) : v(vec) {} - @since version 1.0.0 - */ - constexpr bool is_object() const noexcept + void write_character(CharType c) override { - return m_type == value_t::object; + v.push_back(c); } - /*! - @brief return whether value is an array + void write_characters(const CharType* s, std::size_t length) override + { + std::copy(s, s + length, std::back_inserter(v)); + } - This function returns true iff the JSON value is an array. + private: + std::vector& v; +}; - @return `true` if type is array, `false` otherwise. +/// output adapter for output streams +template +class output_stream_adapter : public output_adapter_protocol +{ + public: + explicit output_stream_adapter(std::basic_ostream& s) : stream(s) {} - @complexity Constant. + void write_character(CharType c) override + { + stream.put(c); + } - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + void write_characters(const CharType* s, std::size_t length) override + { + stream.write(s, static_cast(length)); + } - @liveexample{The following code exemplifies `is_array()` for all JSON - types.,is_array} + private: + std::basic_ostream& stream; +}; - @since version 1.0.0 - */ - constexpr bool is_array() const noexcept +/// output adapter for basic_string +template +class output_string_adapter : public output_adapter_protocol +{ + public: + explicit output_string_adapter(std::basic_string& s) : str(s) {} + + void write_character(CharType c) override { - return m_type == value_t::array; + str.push_back(c); } - /*! - @brief return whether value is a string - - This function returns true iff the JSON value is a string. + void write_characters(const CharType* s, std::size_t length) override + { + str.append(s, length); + } - @return `true` if type is string, `false` otherwise. + private: + std::basic_string& str; +}; - @complexity Constant. +template +class output_adapter +{ + public: + output_adapter(std::vector& vec) + : oa(std::make_shared>(vec)) {} - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + output_adapter(std::basic_ostream& s) + : oa(std::make_shared>(s)) {} - @liveexample{The following code exemplifies `is_string()` for all JSON - types.,is_string} + output_adapter(std::basic_string& s) + : oa(std::make_shared>(s)) {} - @since version 1.0.0 - */ - constexpr bool is_string() const noexcept + operator output_adapter_t() { - return m_type == value_t::string; + return oa; } - /*! - @brief return whether value is discarded - - This function returns true iff the JSON value was discarded during parsing - with a callback function (see @ref parser_callback_t). - - @note This function will always be `false` for JSON values after parsing. - That is, discarded values can only occur during parsing, but will be - removed when inside a structured value or replaced by null in other cases. + private: + output_adapter_t oa = nullptr; +}; +} +} - @return `true` if type is discarded, `false` otherwise. +// #include - @complexity Constant. - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. +#include // generate_n +#include // array +#include // assert +#include // ldexp +#include // size_t +#include // uint8_t, uint16_t, uint32_t, uint64_t +#include // memcpy +#include // setw, setfill +#include // hex +#include // back_inserter +#include // numeric_limits +#include // stringstream +#include // char_traits, string +#include // make_pair, move - @liveexample{The following code exemplifies `is_discarded()` for all JSON - types.,is_discarded} +// #include - @since version 1.0.0 - */ - constexpr bool is_discarded() const noexcept - { - return m_type == value_t::discarded; - } +// #include - /*! - @brief return the type of the JSON value (implicit) +// #include - Implicitly return the type of the JSON value as a value from the @ref - value_t enumeration. +// #include - @return the type of the JSON value - @complexity Constant. +namespace nlohmann +{ +namespace detail +{ +/////////////////// +// binary reader // +/////////////////// - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. +/*! +@brief deserialization of CBOR and MessagePack values +*/ +template +class binary_reader +{ + using number_integer_t = typename BasicJsonType::number_integer_t; + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + using string_t = typename BasicJsonType::string_t; - @liveexample{The following code exemplifies the @ref value_t operator for - all JSON types.,operator__value_t} + public: + /*! + @brief create a binary reader - @since version 1.0.0 + @param[in] adapter input adapter to read from */ - constexpr operator value_t() const noexcept + explicit binary_reader(input_adapter_t adapter) : ia(std::move(adapter)) { - return m_type; + assert(ia); } - /// @} + /*! + @brief create a JSON value from CBOR input - private: - ////////////////// - // value access // - ////////////////// + @param[in] strict whether to expect the input to be consumed completed + @return JSON value created from CBOR input - /// get a boolean (explicit) - boolean_t get_impl(boolean_t* /*unused*/) const + @throw parse_error.110 if input ended unexpectedly or the end of file was + not reached when @a strict was set to true + @throw parse_error.112 if unsupported byte was read + */ + BasicJsonType parse_cbor(const bool strict) { - if (is_boolean()) + const auto res = parse_cbor_internal(); + if (strict) { - return m_value.boolean; + get(); + expect_eof(); } - - JSON_THROW(type_error::create(302, "type must be boolean, but is " + type_name())); + return res; } - /// get a pointer to the value (object) - object_t* get_impl_ptr(object_t* /*unused*/) noexcept - { - return is_object() ? m_value.object : nullptr; - } + /*! + @brief create a JSON value from MessagePack input - /// get a pointer to the value (object) - constexpr const object_t* get_impl_ptr(const object_t* /*unused*/) const noexcept - { - return is_object() ? m_value.object : nullptr; - } + @param[in] strict whether to expect the input to be consumed completed + @return JSON value created from MessagePack input - /// get a pointer to the value (array) - array_t* get_impl_ptr(array_t* /*unused*/) noexcept + @throw parse_error.110 if input ended unexpectedly or the end of file was + not reached when @a strict was set to true + @throw parse_error.112 if unsupported byte was read + */ + BasicJsonType parse_msgpack(const bool strict) { - return is_array() ? m_value.array : nullptr; + const auto res = parse_msgpack_internal(); + if (strict) + { + get(); + expect_eof(); + } + return res; } - /// get a pointer to the value (array) - constexpr const array_t* get_impl_ptr(const array_t* /*unused*/) const noexcept - { - return is_array() ? m_value.array : nullptr; - } + /*! + @brief create a JSON value from UBJSON input - /// get a pointer to the value (string) - string_t* get_impl_ptr(string_t* /*unused*/) noexcept - { - return is_string() ? m_value.string : nullptr; - } + @param[in] strict whether to expect the input to be consumed completed + @return JSON value created from UBJSON input - /// get a pointer to the value (string) - constexpr const string_t* get_impl_ptr(const string_t* /*unused*/) const noexcept + @throw parse_error.110 if input ended unexpectedly or the end of file was + not reached when @a strict was set to true + @throw parse_error.112 if unsupported byte was read + */ + BasicJsonType parse_ubjson(const bool strict) { - return is_string() ? m_value.string : nullptr; + const auto res = parse_ubjson_internal(); + if (strict) + { + get_ignore_noop(); + expect_eof(); + } + return res; } - /// get a pointer to the value (boolean) - boolean_t* get_impl_ptr(boolean_t* /*unused*/) noexcept - { - return is_boolean() ? &m_value.boolean : nullptr; - } + /*! + @brief determine system byte order - /// get a pointer to the value (boolean) - constexpr const boolean_t* get_impl_ptr(const boolean_t* /*unused*/) const noexcept - { - return is_boolean() ? &m_value.boolean : nullptr; - } + @return true if and only if system's byte order is little endian - /// get a pointer to the value (integer number) - number_integer_t* get_impl_ptr(number_integer_t* /*unused*/) noexcept + @note from http://stackoverflow.com/a/1001328/266378 + */ + static constexpr bool little_endianess(int num = 1) noexcept { - return is_number_integer() ? &m_value.number_integer : nullptr; + return (*reinterpret_cast(&num) == 1); } - /// get a pointer to the value (integer number) - constexpr const number_integer_t* get_impl_ptr(const number_integer_t* /*unused*/) const noexcept + private: + /*! + @param[in] get_char whether a new character should be retrieved from the + input (true, default) or whether the last read + character should be considered instead + */ + BasicJsonType parse_cbor_internal(const bool get_char = true) { - return is_number_integer() ? &m_value.number_integer : nullptr; - } + switch (get_char ? get() : current) + { + // EOF + case std::char_traits::eof(): + JSON_THROW(parse_error::create(110, chars_read, "unexpected end of input")); - /// get a pointer to the value (unsigned number) - number_unsigned_t* get_impl_ptr(number_unsigned_t* /*unused*/) noexcept - { - return is_number_unsigned() ? &m_value.number_unsigned : nullptr; - } + // Integer 0x00..0x17 (0..23) + case 0x00: + case 0x01: + case 0x02: + case 0x03: + case 0x04: + case 0x05: + case 0x06: + case 0x07: + case 0x08: + case 0x09: + case 0x0A: + case 0x0B: + case 0x0C: + case 0x0D: + case 0x0E: + case 0x0F: + case 0x10: + case 0x11: + case 0x12: + case 0x13: + case 0x14: + case 0x15: + case 0x16: + case 0x17: + return static_cast(current); + + case 0x18: // Unsigned integer (one-byte uint8_t follows) + return get_number(); + + case 0x19: // Unsigned integer (two-byte uint16_t follows) + return get_number(); + + case 0x1A: // Unsigned integer (four-byte uint32_t follows) + return get_number(); + + case 0x1B: // Unsigned integer (eight-byte uint64_t follows) + return get_number(); + + // Negative integer -1-0x00..-1-0x17 (-1..-24) + case 0x20: + case 0x21: + case 0x22: + case 0x23: + case 0x24: + case 0x25: + case 0x26: + case 0x27: + case 0x28: + case 0x29: + case 0x2A: + case 0x2B: + case 0x2C: + case 0x2D: + case 0x2E: + case 0x2F: + case 0x30: + case 0x31: + case 0x32: + case 0x33: + case 0x34: + case 0x35: + case 0x36: + case 0x37: + return static_cast(0x20 - 1 - current); + + case 0x38: // Negative integer (one-byte uint8_t follows) + { + return static_cast(-1) - get_number(); + } - /// get a pointer to the value (unsigned number) - constexpr const number_unsigned_t* get_impl_ptr(const number_unsigned_t* /*unused*/) const noexcept - { - return is_number_unsigned() ? &m_value.number_unsigned : nullptr; - } + case 0x39: // Negative integer -1-n (two-byte uint16_t follows) + { + return static_cast(-1) - get_number(); + } - /// get a pointer to the value (floating-point number) - number_float_t* get_impl_ptr(number_float_t* /*unused*/) noexcept - { - return is_number_float() ? &m_value.number_float : nullptr; - } + case 0x3A: // Negative integer -1-n (four-byte uint32_t follows) + { + return static_cast(-1) - get_number(); + } - /// get a pointer to the value (floating-point number) - constexpr const number_float_t* get_impl_ptr(const number_float_t* /*unused*/) const noexcept - { - return is_number_float() ? &m_value.number_float : nullptr; - } + case 0x3B: // Negative integer -1-n (eight-byte uint64_t follows) + { + return static_cast(-1) - + static_cast(get_number()); + } - /*! - @brief helper function to implement get_ref() + // UTF-8 string (0x00..0x17 bytes follow) + case 0x60: + case 0x61: + case 0x62: + case 0x63: + case 0x64: + case 0x65: + case 0x66: + case 0x67: + case 0x68: + case 0x69: + case 0x6A: + case 0x6B: + case 0x6C: + case 0x6D: + case 0x6E: + case 0x6F: + case 0x70: + case 0x71: + case 0x72: + case 0x73: + case 0x74: + case 0x75: + case 0x76: + case 0x77: + case 0x78: // UTF-8 string (one-byte uint8_t for n follows) + case 0x79: // UTF-8 string (two-byte uint16_t for n follow) + case 0x7A: // UTF-8 string (four-byte uint32_t for n follow) + case 0x7B: // UTF-8 string (eight-byte uint64_t for n follow) + case 0x7F: // UTF-8 string (indefinite length) + { + return get_cbor_string(); + } - This funcion helps to implement get_ref() without code duplication for - const and non-const overloads + // array (0x00..0x17 data items follow) + case 0x80: + case 0x81: + case 0x82: + case 0x83: + case 0x84: + case 0x85: + case 0x86: + case 0x87: + case 0x88: + case 0x89: + case 0x8A: + case 0x8B: + case 0x8C: + case 0x8D: + case 0x8E: + case 0x8F: + case 0x90: + case 0x91: + case 0x92: + case 0x93: + case 0x94: + case 0x95: + case 0x96: + case 0x97: + { + return get_cbor_array(current & 0x1F); + } - @tparam ThisType will be deduced as `basic_json` or `const basic_json` + case 0x98: // array (one-byte uint8_t for n follows) + { + return get_cbor_array(get_number()); + } - @throw type_error.303 if ReferenceType does not match underlying value - type of the current JSON - */ - template - static ReferenceType get_ref_impl(ThisType& obj) - { - // helper type - using PointerType = typename std::add_pointer::type; + case 0x99: // array (two-byte uint16_t for n follow) + { + return get_cbor_array(get_number()); + } - // delegate the call to get_ptr<>() - auto ptr = obj.template get_ptr(); + case 0x9A: // array (four-byte uint32_t for n follow) + { + return get_cbor_array(get_number()); + } - if (ptr != nullptr) - { - return *ptr; - } + case 0x9B: // array (eight-byte uint64_t for n follow) + { + return get_cbor_array(get_number()); + } - JSON_THROW(type_error::create(303, "incompatible ReferenceType for get_ref, actual type is " + obj.type_name())); - } + case 0x9F: // array (indefinite length) + { + BasicJsonType result = value_t::array; + while (get() != 0xFF) + { + result.push_back(parse_cbor_internal(false)); + } + return result; + } - public: - /// @name value access - /// Direct access to the stored value of a JSON value. - /// @{ + // map (0x00..0x17 pairs of data items follow) + case 0xA0: + case 0xA1: + case 0xA2: + case 0xA3: + case 0xA4: + case 0xA5: + case 0xA6: + case 0xA7: + case 0xA8: + case 0xA9: + case 0xAA: + case 0xAB: + case 0xAC: + case 0xAD: + case 0xAE: + case 0xAF: + case 0xB0: + case 0xB1: + case 0xB2: + case 0xB3: + case 0xB4: + case 0xB5: + case 0xB6: + case 0xB7: + { + return get_cbor_object(current & 0x1F); + } - /*! - @brief get special-case overload + case 0xB8: // map (one-byte uint8_t for n follows) + { + return get_cbor_object(get_number()); + } - This overloads avoids a lot of template boilerplate, it can be seen as the - identity method + case 0xB9: // map (two-byte uint16_t for n follow) + { + return get_cbor_object(get_number()); + } - @tparam BasicJsonType == @ref basic_json + case 0xBA: // map (four-byte uint32_t for n follow) + { + return get_cbor_object(get_number()); + } - @return a copy of *this + case 0xBB: // map (eight-byte uint64_t for n follow) + { + return get_cbor_object(get_number()); + } - @complexity Constant. + case 0xBF: // map (indefinite length) + { + BasicJsonType result = value_t::object; + while (get() != 0xFF) + { + auto key = get_cbor_string(); + result[key] = parse_cbor_internal(); + } + return result; + } - @since version 2.1.0 - */ - template < - typename BasicJsonType, - detail::enable_if_t::type, - basic_json_t>::value, - int> = 0 > - basic_json get() const - { - return *this; - } + case 0xF4: // false + { + return false; + } - /*! - @brief get a value (explicit) + case 0xF5: // true + { + return true; + } - Explicit type conversion between the JSON value and a compatible value - which is [CopyConstructible](http://en.cppreference.com/w/cpp/concept/CopyConstructible) - and [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible). - The value is converted by calling the @ref json_serializer - `from_json()` method. + case 0xF6: // null + { + return value_t::null; + } - The function is equivalent to executing - @code {.cpp} - ValueType ret; - JSONSerializer::from_json(*this, ret); - return ret; - @endcode + case 0xF9: // Half-Precision Float (two-byte IEEE 754) + { + const int byte1 = get(); + unexpect_eof(); + const int byte2 = get(); + unexpect_eof(); + + // code from RFC 7049, Appendix D, Figure 3: + // As half-precision floating-point numbers were only added + // to IEEE 754 in 2008, today's programming platforms often + // still only have limited support for them. It is very + // easy to include at least decoding support for them even + // without such support. An example of a small decoder for + // half-precision floating-point numbers in the C language + // is shown in Fig. 3. + const int half = (byte1 << 8) + byte2; + const int exp = (half >> 10) & 0x1F; + const int mant = half & 0x3FF; + double val; + if (exp == 0) + { + val = std::ldexp(mant, -24); + } + else if (exp != 31) + { + val = std::ldexp(mant + 1024, exp - 25); + } + else + { + val = (mant == 0) ? std::numeric_limits::infinity() + : std::numeric_limits::quiet_NaN(); + } + return (half & 0x8000) != 0 ? -val : val; + } - This overloads is chosen if: - - @a ValueType is not @ref basic_json, - - @ref json_serializer has a `from_json()` method of the form - `void from_json(const basic_json&, ValueType&)`, and - - @ref json_serializer does not have a `from_json()` method of - the form `ValueType from_json(const basic_json&)` + case 0xFA: // Single-Precision Float (four-byte IEEE 754) + { + return get_number(); + } - @tparam ValueTypeCV the provided value type - @tparam ValueType the returned value type + case 0xFB: // Double-Precision Float (eight-byte IEEE 754) + { + return get_number(); + } - @return copy of the JSON value, converted to @a ValueType + default: // anything else (0xFF is handled inside the other types) + { + std::stringstream ss; + ss << std::setw(2) << std::uppercase << std::setfill('0') << std::hex << current; + JSON_THROW(parse_error::create(112, chars_read, "error reading CBOR; last byte: 0x" + ss.str())); + } + } + } - @throw what @ref json_serializer `from_json()` method throws + BasicJsonType parse_msgpack_internal() + { + switch (get()) + { + // EOF + case std::char_traits::eof(): + JSON_THROW(parse_error::create(110, chars_read, "unexpected end of input")); - @liveexample{The example below shows several conversions from JSON values - to other types. There a few things to note: (1) Floating-point numbers can - be converted to integers\, (2) A JSON array can be converted to a standard - `std::vector`\, (3) A JSON object can be converted to C++ - associative containers such as `std::unordered_map`.,get__ValueType_const} + // positive fixint + case 0x00: + case 0x01: + case 0x02: + case 0x03: + case 0x04: + case 0x05: + case 0x06: + case 0x07: + case 0x08: + case 0x09: + case 0x0A: + case 0x0B: + case 0x0C: + case 0x0D: + case 0x0E: + case 0x0F: + case 0x10: + case 0x11: + case 0x12: + case 0x13: + case 0x14: + case 0x15: + case 0x16: + case 0x17: + case 0x18: + case 0x19: + case 0x1A: + case 0x1B: + case 0x1C: + case 0x1D: + case 0x1E: + case 0x1F: + case 0x20: + case 0x21: + case 0x22: + case 0x23: + case 0x24: + case 0x25: + case 0x26: + case 0x27: + case 0x28: + case 0x29: + case 0x2A: + case 0x2B: + case 0x2C: + case 0x2D: + case 0x2E: + case 0x2F: + case 0x30: + case 0x31: + case 0x32: + case 0x33: + case 0x34: + case 0x35: + case 0x36: + case 0x37: + case 0x38: + case 0x39: + case 0x3A: + case 0x3B: + case 0x3C: + case 0x3D: + case 0x3E: + case 0x3F: + case 0x40: + case 0x41: + case 0x42: + case 0x43: + case 0x44: + case 0x45: + case 0x46: + case 0x47: + case 0x48: + case 0x49: + case 0x4A: + case 0x4B: + case 0x4C: + case 0x4D: + case 0x4E: + case 0x4F: + case 0x50: + case 0x51: + case 0x52: + case 0x53: + case 0x54: + case 0x55: + case 0x56: + case 0x57: + case 0x58: + case 0x59: + case 0x5A: + case 0x5B: + case 0x5C: + case 0x5D: + case 0x5E: + case 0x5F: + case 0x60: + case 0x61: + case 0x62: + case 0x63: + case 0x64: + case 0x65: + case 0x66: + case 0x67: + case 0x68: + case 0x69: + case 0x6A: + case 0x6B: + case 0x6C: + case 0x6D: + case 0x6E: + case 0x6F: + case 0x70: + case 0x71: + case 0x72: + case 0x73: + case 0x74: + case 0x75: + case 0x76: + case 0x77: + case 0x78: + case 0x79: + case 0x7A: + case 0x7B: + case 0x7C: + case 0x7D: + case 0x7E: + case 0x7F: + return static_cast(current); + + // fixmap + case 0x80: + case 0x81: + case 0x82: + case 0x83: + case 0x84: + case 0x85: + case 0x86: + case 0x87: + case 0x88: + case 0x89: + case 0x8A: + case 0x8B: + case 0x8C: + case 0x8D: + case 0x8E: + case 0x8F: + { + return get_msgpack_object(current & 0x0F); + } - @since version 2.1.0 - */ - template < - typename ValueTypeCV, - typename ValueType = detail::uncvref_t, - detail::enable_if_t < - not std::is_same::value and - detail::has_from_json::value and - not detail::has_non_default_from_json::value, - int > = 0 > - ValueType get() const noexcept(noexcept( - JSONSerializer::from_json(std::declval(), std::declval()))) - { - // we cannot static_assert on ValueTypeCV being non-const, because - // there is support for get(), which is why we - // still need the uncvref - static_assert(not std::is_reference::value, - "get() cannot be used with reference types, you might want to use get_ref()"); - static_assert(std::is_default_constructible::value, - "types must be DefaultConstructible when used with get()"); + // fixarray + case 0x90: + case 0x91: + case 0x92: + case 0x93: + case 0x94: + case 0x95: + case 0x96: + case 0x97: + case 0x98: + case 0x99: + case 0x9A: + case 0x9B: + case 0x9C: + case 0x9D: + case 0x9E: + case 0x9F: + { + return get_msgpack_array(current & 0x0F); + } - ValueType ret; - JSONSerializer::from_json(*this, ret); - return ret; - } + // fixstr + case 0xA0: + case 0xA1: + case 0xA2: + case 0xA3: + case 0xA4: + case 0xA5: + case 0xA6: + case 0xA7: + case 0xA8: + case 0xA9: + case 0xAA: + case 0xAB: + case 0xAC: + case 0xAD: + case 0xAE: + case 0xAF: + case 0xB0: + case 0xB1: + case 0xB2: + case 0xB3: + case 0xB4: + case 0xB5: + case 0xB6: + case 0xB7: + case 0xB8: + case 0xB9: + case 0xBA: + case 0xBB: + case 0xBC: + case 0xBD: + case 0xBE: + case 0xBF: + return get_msgpack_string(); + + case 0xC0: // nil + return value_t::null; + + case 0xC2: // false + return false; - /*! - @brief get a value (explicit); special case + case 0xC3: // true + return true; - Explicit type conversion between the JSON value and a compatible value - which is **not** [CopyConstructible](http://en.cppreference.com/w/cpp/concept/CopyConstructible) - and **not** [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible). - The value is converted by calling the @ref json_serializer - `from_json()` method. + case 0xCA: // float 32 + return get_number(); - The function is equivalent to executing - @code {.cpp} - return JSONSerializer::from_json(*this); - @endcode + case 0xCB: // float 64 + return get_number(); - This overloads is chosen if: - - @a ValueType is not @ref basic_json and - - @ref json_serializer has a `from_json()` method of the form - `ValueType from_json(const basic_json&)` + case 0xCC: // uint 8 + return get_number(); - @note If @ref json_serializer has both overloads of - `from_json()`, this one is chosen. + case 0xCD: // uint 16 + return get_number(); - @tparam ValueTypeCV the provided value type - @tparam ValueType the returned value type + case 0xCE: // uint 32 + return get_number(); - @return copy of the JSON value, converted to @a ValueType + case 0xCF: // uint 64 + return get_number(); - @throw what @ref json_serializer `from_json()` method throws + case 0xD0: // int 8 + return get_number(); - @since version 2.1.0 - */ - template < - typename ValueTypeCV, - typename ValueType = detail::uncvref_t, - detail::enable_if_t::value and - detail::has_non_default_from_json::value, int> = 0 > - ValueType get() const noexcept(noexcept( - JSONSerializer::from_json(std::declval()))) - { - static_assert(not std::is_reference::value, - "get() cannot be used with reference types, you might want to use get_ref()"); - return JSONSerializer::from_json(*this); - } + case 0xD1: // int 16 + return get_number(); - /*! - @brief get a pointer value (explicit) + case 0xD2: // int 32 + return get_number(); - Explicit pointer access to the internally stored JSON value. No copies are - made. + case 0xD3: // int 64 + return get_number(); - @warning The pointer becomes invalid if the underlying JSON object - changes. + case 0xD9: // str 8 + case 0xDA: // str 16 + case 0xDB: // str 32 + return get_msgpack_string(); - @tparam PointerType pointer type; must be a pointer to @ref array_t, @ref - object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, - @ref number_unsigned_t, or @ref number_float_t. + case 0xDC: // array 16 + { + return get_msgpack_array(get_number()); + } - @return pointer to the internally stored JSON value if the requested - pointer type @a PointerType fits to the JSON value; `nullptr` otherwise + case 0xDD: // array 32 + { + return get_msgpack_array(get_number()); + } - @complexity Constant. + case 0xDE: // map 16 + { + return get_msgpack_object(get_number()); + } - @liveexample{The example below shows how pointers to internal values of a - JSON value can be requested. Note that no type conversions are made and a - `nullptr` is returned if the value and the requested pointer type does not - match.,get__PointerType} + case 0xDF: // map 32 + { + return get_msgpack_object(get_number()); + } - @sa @ref get_ptr() for explicit pointer-member access + // positive fixint + case 0xE0: + case 0xE1: + case 0xE2: + case 0xE3: + case 0xE4: + case 0xE5: + case 0xE6: + case 0xE7: + case 0xE8: + case 0xE9: + case 0xEA: + case 0xEB: + case 0xEC: + case 0xED: + case 0xEE: + case 0xEF: + case 0xF0: + case 0xF1: + case 0xF2: + case 0xF3: + case 0xF4: + case 0xF5: + case 0xF6: + case 0xF7: + case 0xF8: + case 0xF9: + case 0xFA: + case 0xFB: + case 0xFC: + case 0xFD: + case 0xFE: + case 0xFF: + return static_cast(current); + + default: // anything else + { + std::stringstream ss; + ss << std::setw(2) << std::uppercase << std::setfill('0') << std::hex << current; + JSON_THROW(parse_error::create(112, chars_read, + "error reading MessagePack; last byte: 0x" + ss.str())); + } + } + } - @since version 1.0.0 + /*! + @param[in] get_char whether a new character should be retrieved from the + input (true, default) or whether the last read + character should be considered instead */ - template::value, int>::type = 0> - PointerType get() noexcept + BasicJsonType parse_ubjson_internal(const bool get_char = true) { - // delegate the call to get_ptr - return get_ptr(); + return get_ubjson_value(get_char ? get_ignore_noop() : current); } /*! - @brief get a pointer value (explicit) - @copydoc get() + @brief get next character from the input + + This function provides the interface to the used input adapter. It does + not throw in case the input reached EOF, but returns a -'ve valued + `std::char_traits::eof()` in that case. + + @return character read from the input */ - template::value, int>::type = 0> - constexpr const PointerType get() const noexcept + int get() { - // delegate the call to get_ptr - return get_ptr(); + ++chars_read; + return (current = ia->get_character()); } /*! - @brief get a pointer value (implicit) + @return character read from the input after ignoring all 'N' entries + */ + int get_ignore_noop() + { + do + { + get(); + } + while (current == 'N'); - Implicit pointer access to the internally stored JSON value. No copies are - made. + return current; + } - @warning Writing data to the pointee of the result yields an undefined - state. + /* + @brief read a number from the input - @tparam PointerType pointer type; must be a pointer to @ref array_t, @ref - object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, - @ref number_unsigned_t, or @ref number_float_t. Enforced by a static - assertion. + @tparam NumberType the type of the number - @return pointer to the internally stored JSON value if the requested - pointer type @a PointerType fits to the JSON value; `nullptr` otherwise - - @complexity Constant. + @return number of type @a NumberType - @liveexample{The example below shows how pointers to internal values of a - JSON value can be requested. Note that no type conversions are made and a - `nullptr` is returned if the value and the requested pointer type does not - match.,get_ptr} + @note This function needs to respect the system's endianess, because + bytes in CBOR and MessagePack are stored in network order (big + endian) and therefore need reordering on little endian systems. - @since version 1.0.0 + @throw parse_error.110 if input has less than `sizeof(NumberType)` bytes */ - template::value, int>::type = 0> - PointerType get_ptr() noexcept + template NumberType get_number() { - // get the type of the PointerType (remove pointer and const) - using pointee_t = typename std::remove_const::type>::type>::type; - // make sure the type matches the allowed types - static_assert( - std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - , "incompatible pointer type"); + // step 1: read input into array with system's byte order + std::array vec; + for (std::size_t i = 0; i < sizeof(NumberType); ++i) + { + get(); + unexpect_eof(); - // delegate the call to get_impl_ptr<>() - return get_impl_ptr(static_cast(nullptr)); + // reverse byte order prior to conversion if necessary + if (is_little_endian) + { + vec[sizeof(NumberType) - i - 1] = static_cast(current); + } + else + { + vec[i] = static_cast(current); // LCOV_EXCL_LINE + } + } + + // step 2: convert array into number of type T and return + NumberType result; + std::memcpy(&result, vec.data(), sizeof(NumberType)); + return result; } /*! - @brief get a pointer value (implicit) - @copydoc get_ptr() + @brief create a string by reading characters from the input + + @param[in] len number of bytes to read + + @note We can not reserve @a len bytes for the result, because @a len + may be too large. Usually, @ref unexpect_eof() detects the end of + the input before we run out of string memory. + + @return string created by reading @a len bytes + + @throw parse_error.110 if input has less than @a len bytes */ - template::value and - std::is_const::type>::value, int>::type = 0> - constexpr const PointerType get_ptr() const noexcept + template + string_t get_string(const NumberType len) { - // get the type of the PointerType (remove pointer and const) - using pointee_t = typename std::remove_const::type>::type>::type; - // make sure the type matches the allowed types - static_assert( - std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - , "incompatible pointer type"); - - // delegate the call to get_impl_ptr<>() const - return get_impl_ptr(static_cast(nullptr)); + string_t result; + std::generate_n(std::back_inserter(result), len, [this]() + { + get(); + unexpect_eof(); + return static_cast(current); + }); + return result; } /*! - @brief get a reference value (implicit) + @brief reads a CBOR string - Implicit reference access to the internally stored JSON value. No copies - are made. + This function first reads starting bytes to determine the expected + string length and then copies this number of bytes into a string. + Additionally, CBOR's strings with indefinite lengths are supported. - @warning Writing data to the referee of the result yields an undefined - state. + @return string - @tparam ReferenceType reference type; must be a reference to @ref array_t, - @ref object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, or - @ref number_float_t. Enforced by static assertion. + @throw parse_error.110 if input ended + @throw parse_error.113 if an unexpected byte is read + */ + string_t get_cbor_string() + { + unexpect_eof(); + + switch (current) + { + // UTF-8 string (0x00..0x17 bytes follow) + case 0x60: + case 0x61: + case 0x62: + case 0x63: + case 0x64: + case 0x65: + case 0x66: + case 0x67: + case 0x68: + case 0x69: + case 0x6A: + case 0x6B: + case 0x6C: + case 0x6D: + case 0x6E: + case 0x6F: + case 0x70: + case 0x71: + case 0x72: + case 0x73: + case 0x74: + case 0x75: + case 0x76: + case 0x77: + { + return get_string(current & 0x1F); + } - @return reference to the internally stored JSON value if the requested - reference type @a ReferenceType fits to the JSON value; throws - type_error.303 otherwise + case 0x78: // UTF-8 string (one-byte uint8_t for n follows) + { + return get_string(get_number()); + } - @throw type_error.303 in case passed type @a ReferenceType is incompatible - with the stored JSON value; see example below + case 0x79: // UTF-8 string (two-byte uint16_t for n follow) + { + return get_string(get_number()); + } - @complexity Constant. + case 0x7A: // UTF-8 string (four-byte uint32_t for n follow) + { + return get_string(get_number()); + } - @liveexample{The example shows several calls to `get_ref()`.,get_ref} + case 0x7B: // UTF-8 string (eight-byte uint64_t for n follow) + { + return get_string(get_number()); + } - @since version 1.1.0 - */ - template::value, int>::type = 0> - ReferenceType get_ref() + case 0x7F: // UTF-8 string (indefinite length) + { + string_t result; + while (get() != 0xFF) + { + result.append(get_cbor_string()); + } + return result; + } + + default: + { + std::stringstream ss; + ss << std::setw(2) << std::uppercase << std::setfill('0') << std::hex << current; + JSON_THROW(parse_error::create(113, chars_read, "expected a CBOR string; last byte: 0x" + ss.str())); + } + } + } + + template + BasicJsonType get_cbor_array(const NumberType len) { - // delegate call to get_ref_impl - return get_ref_impl(*this); + BasicJsonType result = value_t::array; + std::generate_n(std::back_inserter(*result.m_value.array), len, [this]() + { + return parse_cbor_internal(); + }); + return result; } - /*! - @brief get a reference value (implicit) - @copydoc get_ref() - */ - template::value and - std::is_const::type>::value, int>::type = 0> - ReferenceType get_ref() const + template + BasicJsonType get_cbor_object(const NumberType len) { - // delegate call to get_ref_impl - return get_ref_impl(*this); + BasicJsonType result = value_t::object; + std::generate_n(std::inserter(*result.m_value.object, + result.m_value.object->end()), + len, [this]() + { + get(); + auto key = get_cbor_string(); + auto val = parse_cbor_internal(); + return std::make_pair(std::move(key), std::move(val)); + }); + return result; } /*! - @brief get a value (implicit) + @brief reads a MessagePack string - Implicit type conversion between the JSON value and a compatible value. - The call is realized by calling @ref get() const. + This function first reads starting bytes to determine the expected + string length and then copies this number of bytes into a string. - @tparam ValueType non-pointer type compatible to the JSON value, for - instance `int` for JSON integer numbers, `bool` for JSON booleans, or - `std::vector` types for JSON arrays. The character type of @ref string_t - as well as an initializer list of this type is excluded to avoid - ambiguities as these types implicitly convert to `std::string`. + @return string - @return copy of the JSON value, converted to type @a ValueType + @throw parse_error.110 if input ended + @throw parse_error.113 if an unexpected byte is read + */ + string_t get_msgpack_string() + { + unexpect_eof(); + + switch (current) + { + // fixstr + case 0xA0: + case 0xA1: + case 0xA2: + case 0xA3: + case 0xA4: + case 0xA5: + case 0xA6: + case 0xA7: + case 0xA8: + case 0xA9: + case 0xAA: + case 0xAB: + case 0xAC: + case 0xAD: + case 0xAE: + case 0xAF: + case 0xB0: + case 0xB1: + case 0xB2: + case 0xB3: + case 0xB4: + case 0xB5: + case 0xB6: + case 0xB7: + case 0xB8: + case 0xB9: + case 0xBA: + case 0xBB: + case 0xBC: + case 0xBD: + case 0xBE: + case 0xBF: + { + return get_string(current & 0x1F); + } - @throw type_error.302 in case passed type @a ValueType is incompatible - to the JSON value type (e.g., the JSON value is of type boolean, but a - string is requested); see example below + case 0xD9: // str 8 + { + return get_string(get_number()); + } - @complexity Linear in the size of the JSON value. + case 0xDA: // str 16 + { + return get_string(get_number()); + } - @liveexample{The example below shows several conversions from JSON values - to other types. There a few things to note: (1) Floating-point numbers can - be converted to integers\, (2) A JSON array can be converted to a standard - `std::vector`\, (3) A JSON object can be converted to C++ - associative containers such as `std::unordered_map`.,operator__ValueType} + case 0xDB: // str 32 + { + return get_string(get_number()); + } - @since version 1.0.0 - */ - template < typename ValueType, typename std::enable_if < - not std::is_pointer::value and - not std::is_same::value -#ifndef _MSC_VER // fix for issue #167 operator<< ambiguity under VS2015 - and not std::is_same>::value -#endif -#if (defined(__cplusplus) && __cplusplus >= 201703L) || (defined(_MSC_VER) && _MSC_VER >1900 && defined(_HAS_CXX17) && _HAS_CXX17 == 1) // fix for issue #464 - and not std::is_same::value -#endif - , int >::type = 0 > - operator ValueType() const - { - // delegate the call to get<>() const - return get(); + default: + { + std::stringstream ss; + ss << std::setw(2) << std::uppercase << std::setfill('0') << std::hex << current; + JSON_THROW(parse_error::create(113, chars_read, + "expected a MessagePack string; last byte: 0x" + ss.str())); + } + } } - /// @} - - - //////////////////// - // element access // - //////////////////// + template + BasicJsonType get_msgpack_array(const NumberType len) + { + BasicJsonType result = value_t::array; + std::generate_n(std::back_inserter(*result.m_value.array), len, [this]() + { + return parse_msgpack_internal(); + }); + return result; + } - /// @name element access - /// Access to the JSON value. - /// @{ + template + BasicJsonType get_msgpack_object(const NumberType len) + { + BasicJsonType result = value_t::object; + std::generate_n(std::inserter(*result.m_value.object, + result.m_value.object->end()), + len, [this]() + { + get(); + auto key = get_msgpack_string(); + auto val = parse_msgpack_internal(); + return std::make_pair(std::move(key), std::move(val)); + }); + return result; + } /*! - @brief access specified array element with bounds checking + @brief reads a UBJSON string - Returns a reference to the element at specified location @a idx, with - bounds checking. + This function is either called after reading the 'S' byte explicitly + indicating a string, or in case of an object key where the 'S' byte can be + left out. - @param[in] idx index of the element to access + @param[in] get_char whether a new character should be retrieved from the + input (true, default) or whether the last read + character should be considered instead - @return reference to the element at index @a idx + @return string - @throw type_error.304 if the JSON value is not an array; in this case, - calling `at` with an index makes no sense. See example below. - @throw out_of_range.401 if the index @a idx is out of range of the array; - that is, `idx >= size()`. See example below. + @throw parse_error.110 if input ended + @throw parse_error.113 if an unexpected byte is read + */ + string_t get_ubjson_string(const bool get_char = true) + { + if (get_char) + { + get(); // TODO: may we ignore N here? + } - @exceptionsafety Strong guarantee: if an exception is thrown, there are no - changes in the JSON value. + unexpect_eof(); - @complexity Constant. + switch (current) + { + case 'U': + return get_string(get_number()); + case 'i': + return get_string(get_number()); + case 'I': + return get_string(get_number()); + case 'l': + return get_string(get_number()); + case 'L': + return get_string(get_number()); + default: + std::stringstream ss; + ss << std::setw(2) << std::uppercase << std::setfill('0') << std::hex << current; + JSON_THROW(parse_error::create(113, chars_read, + "expected a UBJSON string; last byte: 0x" + ss.str())); + } + } - @since version 1.0.0 + /*! + @brief determine the type and size for a container - @liveexample{The example below shows how array elements can be read and - written using `at()`. It also demonstrates the different exceptions that - can be thrown.,at__size_type} + In the optimized UBJSON format, a type and a size can be provided to allow + for a more compact representation. + + @return pair of the size and the type */ - reference at(size_type idx) + std::pair get_ubjson_size_type() { - // at only works for arrays - if (is_array()) + std::size_t sz = string_t::npos; + int tc = 0; + + get_ignore_noop(); + + if (current == '$') { - JSON_TRY - { - return m_value.array->at(idx); - } - JSON_CATCH (std::out_of_range&) + tc = get(); // must not ignore 'N', because 'N' maybe the type + unexpect_eof(); + + get_ignore_noop(); + if (current != '#') { - // create better exception explanation - JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range")); + std::stringstream ss; + ss << std::setw(2) << std::uppercase << std::setfill('0') << std::hex << current; + JSON_THROW(parse_error::create(112, chars_read, + "expected '#' after UBJSON type information; last byte: 0x" + ss.str())); } + sz = parse_ubjson_internal(); } - else + else if (current == '#') { - JSON_THROW(type_error::create(304, "cannot use at() with " + type_name())); + sz = parse_ubjson_internal(); } + + return std::make_pair(sz, tc); } - /*! - @brief access specified array element with bounds checking + BasicJsonType get_ubjson_value(const int prefix) + { + switch (prefix) + { + case std::char_traits::eof(): // EOF + JSON_THROW(parse_error::create(110, chars_read, "unexpected end of input")); - Returns a const reference to the element at specified location @a idx, - with bounds checking. + case 'T': // true + return true; + case 'F': // false + return false; - @param[in] idx index of the element to access + case 'Z': // null + return nullptr; + + case 'U': + return get_number(); + case 'i': + return get_number(); + case 'I': + return get_number(); + case 'l': + return get_number(); + case 'L': + return get_number(); + case 'd': + return get_number(); + case 'D': + return get_number(); + + case 'C': // char + { + get(); + unexpect_eof(); + if (JSON_UNLIKELY(current > 127)) + { + std::stringstream ss; + ss << std::setw(2) << std::uppercase << std::setfill('0') << std::hex << current; + JSON_THROW(parse_error::create(113, chars_read, + "byte after 'C' must be in range 0x00..0x7F; last byte: 0x" + ss.str())); + } + return string_t(1, static_cast(current)); + } - @return const reference to the element at index @a idx + case 'S': // string + return get_ubjson_string(); - @throw type_error.304 if the JSON value is not an array; in this case, - calling `at` with an index makes no sense. See example below. - @throw out_of_range.401 if the index @a idx is out of range of the array; - that is, `idx >= size()`. See example below. + case '[': // array + return get_ubjson_array(); - @exceptionsafety Strong guarantee: if an exception is thrown, there are no - changes in the JSON value. + case '{': // object + return get_ubjson_object(); - @complexity Constant. - - @since version 1.0.0 + default: // anything else + std::stringstream ss; + ss << std::setw(2) << std::uppercase << std::setfill('0') << std::hex << current; + JSON_THROW(parse_error::create(112, chars_read, + "error reading UBJSON; last byte: 0x" + ss.str())); + } + } - @liveexample{The example below shows how array elements can be read using - `at()`. It also demonstrates the different exceptions that can be thrown., - at__size_type_const} - */ - const_reference at(size_type idx) const + BasicJsonType get_ubjson_array() { - // at only works for arrays - if (is_array()) + BasicJsonType result = value_t::array; + const auto size_and_type = get_ubjson_size_type(); + + if (size_and_type.first != string_t::npos) { - JSON_TRY - { - return m_value.array->at(idx); - } - JSON_CATCH (std::out_of_range&) + if (JSON_UNLIKELY(size_and_type.first > result.max_size())) { - // create better exception explanation - JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range")); + JSON_THROW(out_of_range::create(408, + "excessive array size: " + std::to_string(size_and_type.first))); } - } - else - { - JSON_THROW(type_error::create(304, "cannot use at() with " + type_name())); - } - } - - /*! - @brief access specified object element with bounds checking - - Returns a reference to the element at with specified key @a key, with - bounds checking. - - @param[in] key key of the element to access - @return reference to the element at key @a key - - @throw type_error.304 if the JSON value is not an object; in this case, - calling `at` with a key makes no sense. See example below. - @throw out_of_range.403 if the key @a key is is not stored in the object; - that is, `find(key) == end()`. See example below. - - @exceptionsafety Strong guarantee: if an exception is thrown, there are no - changes in the JSON value. - - @complexity Logarithmic in the size of the container. - - @sa @ref operator[](const typename object_t::key_type&) for unchecked - access by reference - @sa @ref value() for access by value with a default value - - @since version 1.0.0 - - @liveexample{The example below shows how object elements can be read and - written using `at()`. It also demonstrates the different exceptions that - can be thrown.,at__object_t_key_type} - */ - reference at(const typename object_t::key_type& key) - { - // at only works for objects - if (is_object()) - { - JSON_TRY + if (size_and_type.second != 0) { - return m_value.object->at(key); + if (size_and_type.second != 'N') + { + std::generate_n(std::back_inserter(*result.m_value.array), + size_and_type.first, [this, size_and_type]() + { + return get_ubjson_value(size_and_type.second); + }); + } } - JSON_CATCH (std::out_of_range&) + else { - // create better exception explanation - JSON_THROW(out_of_range::create(403, "key '" + key + "' not found")); + std::generate_n(std::back_inserter(*result.m_value.array), + size_and_type.first, [this]() + { + return parse_ubjson_internal(); + }); } } else { - JSON_THROW(type_error::create(304, "cannot use at() with " + type_name())); + while (current != ']') + { + result.push_back(parse_ubjson_internal(false)); + get_ignore_noop(); + } } - } - - /*! - @brief access specified object element with bounds checking - - Returns a const reference to the element at with specified key @a key, - with bounds checking. - - @param[in] key key of the element to access - - @return const reference to the element at key @a key - - @throw type_error.304 if the JSON value is not an object; in this case, - calling `at` with a key makes no sense. See example below. - @throw out_of_range.403 if the key @a key is is not stored in the object; - that is, `find(key) == end()`. See example below. - - @exceptionsafety Strong guarantee: if an exception is thrown, there are no - changes in the JSON value. - - @complexity Logarithmic in the size of the container. - - @sa @ref operator[](const typename object_t::key_type&) for unchecked - access by reference - @sa @ref value() for access by value with a default value - @since version 1.0.0 + return result; + } - @liveexample{The example below shows how object elements can be read using - `at()`. It also demonstrates the different exceptions that can be thrown., - at__object_t_key_type_const} - */ - const_reference at(const typename object_t::key_type& key) const + BasicJsonType get_ubjson_object() { - // at only works for objects - if (is_object()) + BasicJsonType result = value_t::object; + const auto size_and_type = get_ubjson_size_type(); + + if (size_and_type.first != string_t::npos) { - JSON_TRY + if (JSON_UNLIKELY(size_and_type.first > result.max_size())) { - return m_value.object->at(key); + JSON_THROW(out_of_range::create(408, + "excessive object size: " + std::to_string(size_and_type.first))); } - JSON_CATCH (std::out_of_range&) + + if (size_and_type.second != 0) { - // create better exception explanation - JSON_THROW(out_of_range::create(403, "key '" + key + "' not found")); + std::generate_n(std::inserter(*result.m_value.object, + result.m_value.object->end()), + size_and_type.first, [this, size_and_type]() + { + auto key = get_ubjson_string(); + auto val = get_ubjson_value(size_and_type.second); + return std::make_pair(std::move(key), std::move(val)); + }); + } + else + { + std::generate_n(std::inserter(*result.m_value.object, + result.m_value.object->end()), + size_and_type.first, [this]() + { + auto key = get_ubjson_string(); + auto val = parse_ubjson_internal(); + return std::make_pair(std::move(key), std::move(val)); + }); } } else { - JSON_THROW(type_error::create(304, "cannot use at() with " + type_name())); + while (current != '}') + { + auto key = get_ubjson_string(false); + result[std::move(key)] = parse_ubjson_internal(); + get_ignore_noop(); + } } + + return result; } /*! - @brief access specified array element - - Returns a reference to the element at specified location @a idx. - - @note If @a idx is beyond the range of the array (i.e., `idx >= size()`), - then the array is silently filled up with `null` values to make `idx` a - valid reference to the last stored element. - - @param[in] idx index of the element to access - - @return reference to the element at index @a idx - - @throw type_error.305 if the JSON value is not an array or null; in that - cases, using the [] operator with an index makes no sense. - - @complexity Constant if @a idx is in the range of the array. Otherwise - linear in `idx - size()`. - - @liveexample{The example below shows how array elements can be read and - written using `[]` operator. Note the addition of `null` - values.,operatorarray__size_type} - - @since version 1.0.0 + @brief throw if end of input is not reached + @throw parse_error.110 if input not ended */ - reference operator[](size_type idx) + void expect_eof() const { - // implicitly convert null value to an empty array - if (is_null()) - { - m_type = value_t::array; - m_value.array = create(); - assert_invariant(); - } - - // operator[] only works for arrays - if (is_array()) + if (JSON_UNLIKELY(current != std::char_traits::eof())) { - // fill up array with null values if given idx is outside range - if (idx >= m_value.array->size()) - { - m_value.array->insert(m_value.array->end(), - idx - m_value.array->size() + 1, - basic_json()); - } - - return m_value.array->operator[](idx); + JSON_THROW(parse_error::create(110, chars_read, "expected end of input")); } - - JSON_THROW(type_error::create(305, "cannot use operator[] with " + type_name())); } /*! - @brief access specified array element - - Returns a const reference to the element at specified location @a idx. - - @param[in] idx index of the element to access - - @return const reference to the element at index @a idx - - @throw type_error.305 if the JSON value is not an array; in that cases, - using the [] operator with an index makes no sense. - - @complexity Constant. - - @liveexample{The example below shows how array elements can be read using - the `[]` operator.,operatorarray__size_type_const} - - @since version 1.0.0 + @briefthrow if end of input is reached + @throw parse_error.110 if input ended */ - const_reference operator[](size_type idx) const + void unexpect_eof() const { - // const operator[] only works for arrays - if (is_array()) + if (JSON_UNLIKELY(current == std::char_traits::eof())) { - return m_value.array->operator[](idx); + JSON_THROW(parse_error::create(110, chars_read, "unexpected end of input")); } - - JSON_THROW(type_error::create(305, "cannot use operator[] with " + type_name())); } - /*! - @brief access specified object element - - Returns a reference to the element at with specified key @a key. + private: + /// input adapter + input_adapter_t ia = nullptr; - @note If @a key is not found in the object, then it is silently added to - the object and filled with a `null` value to make `key` a valid reference. - In case the value was `null` before, it is converted to an object. + /// the current character + int current = std::char_traits::eof(); - @param[in] key key of the element to access + /// the number of characters read + std::size_t chars_read = 0; - @return reference to the element at key @a key + /// whether we can assume little endianess + const bool is_little_endian = little_endianess(); +}; +} +} - @throw type_error.305 if the JSON value is not an object or null; in that - cases, using the [] operator with a key makes no sense. +// #include - @complexity Logarithmic in the size of the container. - @liveexample{The example below shows how object elements can be read and - written using the `[]` operator.,operatorarray__key_type} +#include // reverse +#include // array +#include // uint8_t, uint16_t, uint32_t, uint64_t +#include // memcpy +#include // numeric_limits - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value +// #include - @since version 1.0.0 - */ - reference operator[](const typename object_t::key_type& key) - { - // implicitly convert null value to an empty object - if (is_null()) - { - m_type = value_t::object; - m_value.object = create(); - assert_invariant(); - } +// #include - // operator[] only works for objects - if (is_object()) - { - return m_value.object->operator[](key); - } - JSON_THROW(type_error::create(305, "cannot use operator[] with " + type_name())); - } +namespace nlohmann +{ +namespace detail +{ +/////////////////// +// binary writer // +/////////////////// +/*! +@brief serialization to CBOR and MessagePack values +*/ +template +class binary_writer +{ + public: /*! - @brief read-only access specified object element + @brief create a binary writer - Returns a const reference to the element at with specified key @a key. No - bounds checking is performed. + @param[in] adapter output adapter to write to + */ + explicit binary_writer(output_adapter_t adapter) : oa(adapter) + { + assert(oa); + } - @warning If the element with key @a key does not exist, the behavior is - undefined. + /*! + @brief[in] j JSON value to serialize + */ + void write_cbor(const BasicJsonType& j) + { + switch (j.type()) + { + case value_t::null: + { + oa->write_character(static_cast(0xF6)); + break; + } - @param[in] key key of the element to access + case value_t::boolean: + { + oa->write_character(j.m_value.boolean + ? static_cast(0xF5) + : static_cast(0xF4)); + break; + } - @return const reference to the element at key @a key + case value_t::number_integer: + { + if (j.m_value.number_integer >= 0) + { + // CBOR does not differentiate between positive signed + // integers and unsigned integers. Therefore, we used the + // code from the value_t::number_unsigned case here. + if (j.m_value.number_integer <= 0x17) + { + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_integer <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x18)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_integer <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x19)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_integer <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x1A)); + write_number(static_cast(j.m_value.number_integer)); + } + else + { + oa->write_character(static_cast(0x1B)); + write_number(static_cast(j.m_value.number_integer)); + } + } + else + { + // The conversions below encode the sign in the first + // byte, and the value is converted to a positive number. + const auto positive_number = -1 - j.m_value.number_integer; + if (j.m_value.number_integer >= -24) + { + write_number(static_cast(0x20 + positive_number)); + } + else if (positive_number <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x38)); + write_number(static_cast(positive_number)); + } + else if (positive_number <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x39)); + write_number(static_cast(positive_number)); + } + else if (positive_number <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x3A)); + write_number(static_cast(positive_number)); + } + else + { + oa->write_character(static_cast(0x3B)); + write_number(static_cast(positive_number)); + } + } + break; + } - @pre The element with key @a key must exist. **This precondition is - enforced with an assertion.** + case value_t::number_unsigned: + { + if (j.m_value.number_unsigned <= 0x17) + { + write_number(static_cast(j.m_value.number_unsigned)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x18)); + write_number(static_cast(j.m_value.number_unsigned)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x19)); + write_number(static_cast(j.m_value.number_unsigned)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x1A)); + write_number(static_cast(j.m_value.number_unsigned)); + } + else + { + oa->write_character(static_cast(0x1B)); + write_number(static_cast(j.m_value.number_unsigned)); + } + break; + } - @throw type_error.305 if the JSON value is not an object; in that cases, - using the [] operator with a key makes no sense. + case value_t::number_float: // Double-Precision Float + { + oa->write_character(static_cast(0xFB)); + write_number(j.m_value.number_float); + break; + } - @complexity Logarithmic in the size of the container. + case value_t::string: + { + // step 1: write control byte and the string length + const auto N = j.m_value.string->size(); + if (N <= 0x17) + { + write_number(static_cast(0x60 + N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x78)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x79)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x7A)); + write_number(static_cast(N)); + } + // LCOV_EXCL_START + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x7B)); + write_number(static_cast(N)); + } + // LCOV_EXCL_STOP - @liveexample{The example below shows how object elements can be read using - the `[]` operator.,operatorarray__key_type_const} + // step 2: write the string + oa->write_characters( + reinterpret_cast(j.m_value.string->c_str()), + j.m_value.string->size()); + break; + } - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value + case value_t::array: + { + // step 1: write control byte and the array size + const auto N = j.m_value.array->size(); + if (N <= 0x17) + { + write_number(static_cast(0x80 + N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x98)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x99)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x9A)); + write_number(static_cast(N)); + } + // LCOV_EXCL_START + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x9B)); + write_number(static_cast(N)); + } + // LCOV_EXCL_STOP - @since version 1.0.0 + // step 2: write each element + for (const auto& el : *j.m_value.array) + { + write_cbor(el); + } + break; + } + + case value_t::object: + { + // step 1: write control byte and the object size + const auto N = j.m_value.object->size(); + if (N <= 0x17) + { + write_number(static_cast(0xA0 + N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0xB8)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0xB9)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0xBA)); + write_number(static_cast(N)); + } + // LCOV_EXCL_START + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0xBB)); + write_number(static_cast(N)); + } + // LCOV_EXCL_STOP + + // step 2: write each element + for (const auto& el : *j.m_value.object) + { + write_cbor(el.first); + write_cbor(el.second); + } + break; + } + + default: + break; + } + } + + /*! + @brief[in] j JSON value to serialize */ - const_reference operator[](const typename object_t::key_type& key) const + void write_msgpack(const BasicJsonType& j) { - // const operator[] only works for objects - if (is_object()) + switch (j.type()) { - assert(m_value.object->find(key) != m_value.object->end()); - return m_value.object->find(key)->second; - } + case value_t::null: // nil + { + oa->write_character(static_cast(0xC0)); + break; + } - JSON_THROW(type_error::create(305, "cannot use operator[] with " + type_name())); - } + case value_t::boolean: // true and false + { + oa->write_character(j.m_value.boolean + ? static_cast(0xC3) + : static_cast(0xC2)); + break; + } - /*! - @brief access specified object element + case value_t::number_integer: + { + if (j.m_value.number_integer >= 0) + { + // MessagePack does not differentiate between positive + // signed integers and unsigned integers. Therefore, we used + // the code from the value_t::number_unsigned case here. + if (j.m_value.number_unsigned < 128) + { + // positive fixnum + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 8 + oa->write_character(static_cast(0xCC)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 16 + oa->write_character(static_cast(0xCD)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 32 + oa->write_character(static_cast(0xCE)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 64 + oa->write_character(static_cast(0xCF)); + write_number(static_cast(j.m_value.number_integer)); + } + } + else + { + if (j.m_value.number_integer >= -32) + { + // negative fixnum + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_integer >= (std::numeric_limits::min)() and + j.m_value.number_integer <= (std::numeric_limits::max)()) + { + // int 8 + oa->write_character(static_cast(0xD0)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_integer >= (std::numeric_limits::min)() and + j.m_value.number_integer <= (std::numeric_limits::max)()) + { + // int 16 + oa->write_character(static_cast(0xD1)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_integer >= (std::numeric_limits::min)() and + j.m_value.number_integer <= (std::numeric_limits::max)()) + { + // int 32 + oa->write_character(static_cast(0xD2)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_integer >= (std::numeric_limits::min)() and + j.m_value.number_integer <= (std::numeric_limits::max)()) + { + // int 64 + oa->write_character(static_cast(0xD3)); + write_number(static_cast(j.m_value.number_integer)); + } + } + break; + } - Returns a reference to the element at with specified key @a key. + case value_t::number_unsigned: + { + if (j.m_value.number_unsigned < 128) + { + // positive fixnum + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 8 + oa->write_character(static_cast(0xCC)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 16 + oa->write_character(static_cast(0xCD)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 32 + oa->write_character(static_cast(0xCE)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 64 + oa->write_character(static_cast(0xCF)); + write_number(static_cast(j.m_value.number_integer)); + } + break; + } - @note If @a key is not found in the object, then it is silently added to - the object and filled with a `null` value to make `key` a valid reference. - In case the value was `null` before, it is converted to an object. + case value_t::number_float: // float 64 + { + oa->write_character(static_cast(0xCB)); + write_number(j.m_value.number_float); + break; + } - @param[in] key key of the element to access + case value_t::string: + { + // step 1: write control byte and the string length + const auto N = j.m_value.string->size(); + if (N <= 31) + { + // fixstr + write_number(static_cast(0xA0 | N)); + } + else if (N <= (std::numeric_limits::max)()) + { + // str 8 + oa->write_character(static_cast(0xD9)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + // str 16 + oa->write_character(static_cast(0xDA)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + // str 32 + oa->write_character(static_cast(0xDB)); + write_number(static_cast(N)); + } - @return reference to the element at key @a key + // step 2: write the string + oa->write_characters( + reinterpret_cast(j.m_value.string->c_str()), + j.m_value.string->size()); + break; + } - @throw type_error.305 if the JSON value is not an object or null; in that - cases, using the [] operator with a key makes no sense. + case value_t::array: + { + // step 1: write control byte and the array size + const auto N = j.m_value.array->size(); + if (N <= 15) + { + // fixarray + write_number(static_cast(0x90 | N)); + } + else if (N <= (std::numeric_limits::max)()) + { + // array 16 + oa->write_character(static_cast(0xDC)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + // array 32 + oa->write_character(static_cast(0xDD)); + write_number(static_cast(N)); + } - @complexity Logarithmic in the size of the container. + // step 2: write each element + for (const auto& el : *j.m_value.array) + { + write_msgpack(el); + } + break; + } - @liveexample{The example below shows how object elements can be read and - written using the `[]` operator.,operatorarray__key_type} + case value_t::object: + { + // step 1: write control byte and the object size + const auto N = j.m_value.object->size(); + if (N <= 15) + { + // fixmap + write_number(static_cast(0x80 | (N & 0xF))); + } + else if (N <= (std::numeric_limits::max)()) + { + // map 16 + oa->write_character(static_cast(0xDE)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + // map 32 + oa->write_character(static_cast(0xDF)); + write_number(static_cast(N)); + } - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value + // step 2: write each element + for (const auto& el : *j.m_value.object) + { + write_msgpack(el.first); + write_msgpack(el.second); + } + break; + } - @since version 1.0.0 - */ - template - reference operator[](T * (&key)[n]) - { - return operator[](static_cast(key)); + default: + break; + } } /*! - @brief read-only access specified object element - - Returns a const reference to the element at with specified key @a key. No - bounds checking is performed. - - @warning If the element with key @a key does not exist, the behavior is - undefined. - - @note This function is required for compatibility reasons with Clang. - - @param[in] key key of the element to access - - @return const reference to the element at key @a key - - @throw type_error.305 if the JSON value is not an object; in that cases, - using the [] operator with a key makes no sense. - - @complexity Logarithmic in the size of the container. - - @liveexample{The example below shows how object elements can be read using - the `[]` operator.,operatorarray__key_type_const} - - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value - - @since version 1.0.0 + @param[in] j JSON value to serialize + @param[in] use_count whether to use '#' prefixes (optimized format) + @param[in] use_type whether to use '$' prefixes (optimized format) + @param[in] add_prefix whether prefixes need to be used for this value */ - template - const_reference operator[](T * (&key)[n]) const + void write_ubjson(const BasicJsonType& j, const bool use_count, + const bool use_type, const bool add_prefix = true) { - return operator[](static_cast(key)); - } + switch (j.type()) + { + case value_t::null: + { + if (add_prefix) + { + oa->write_character(static_cast('Z')); + } + break; + } - /*! - @brief access specified object element + case value_t::boolean: + { + if (add_prefix) + oa->write_character(j.m_value.boolean + ? static_cast('T') + : static_cast('F')); + break; + } - Returns a reference to the element at with specified key @a key. + case value_t::number_integer: + { + write_number_with_ubjson_prefix(j.m_value.number_integer, add_prefix); + break; + } - @note If @a key is not found in the object, then it is silently added to - the object and filled with a `null` value to make `key` a valid reference. - In case the value was `null` before, it is converted to an object. + case value_t::number_unsigned: + { + write_number_with_ubjson_prefix(j.m_value.number_unsigned, add_prefix); + break; + } - @param[in] key key of the element to access + case value_t::number_float: + { + write_number_with_ubjson_prefix(j.m_value.number_float, add_prefix); + break; + } - @return reference to the element at key @a key + case value_t::string: + { + if (add_prefix) + { + oa->write_character(static_cast('S')); + } + write_number_with_ubjson_prefix(j.m_value.string->size(), true); + oa->write_characters( + reinterpret_cast(j.m_value.string->c_str()), + j.m_value.string->size()); + break; + } - @throw type_error.305 if the JSON value is not an object or null; in that - cases, using the [] operator with a key makes no sense. + case value_t::array: + { + if (add_prefix) + { + oa->write_character(static_cast('[')); + } - @complexity Logarithmic in the size of the container. + bool prefix_required = true; + if (use_type and not j.m_value.array->empty()) + { + assert(use_count); + const char first_prefix = ubjson_prefix(j.front()); + const bool same_prefix = std::all_of(j.begin() + 1, j.end(), + [this, first_prefix](const BasicJsonType & v) + { + return ubjson_prefix(v) == first_prefix; + }); - @liveexample{The example below shows how object elements can be read and - written using the `[]` operator.,operatorarray__key_type} + if (same_prefix) + { + prefix_required = false; + oa->write_character(static_cast('$')); + oa->write_character(static_cast(first_prefix)); + } + } - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value + if (use_count) + { + oa->write_character(static_cast('#')); + write_number_with_ubjson_prefix(j.m_value.array->size(), true); + } - @since version 1.1.0 - */ - template - reference operator[](T* key) - { - // implicitly convert null to object - if (is_null()) - { - m_type = value_t::object; - m_value = value_t::object; - assert_invariant(); - } + for (const auto& el : *j.m_value.array) + { + write_ubjson(el, use_count, use_type, prefix_required); + } - // at only works for objects - if (is_object()) - { - return m_value.object->operator[](key); - } + if (not use_count) + { + oa->write_character(static_cast(']')); + } - JSON_THROW(type_error::create(305, "cannot use operator[] with " + type_name())); - } + break; + } - /*! - @brief read-only access specified object element + case value_t::object: + { + if (add_prefix) + { + oa->write_character(static_cast('{')); + } - Returns a const reference to the element at with specified key @a key. No - bounds checking is performed. + bool prefix_required = true; + if (use_type and not j.m_value.object->empty()) + { + assert(use_count); + const char first_prefix = ubjson_prefix(j.front()); + const bool same_prefix = std::all_of(j.begin(), j.end(), + [this, first_prefix](const BasicJsonType & v) + { + return ubjson_prefix(v) == first_prefix; + }); - @warning If the element with key @a key does not exist, the behavior is - undefined. + if (same_prefix) + { + prefix_required = false; + oa->write_character(static_cast('$')); + oa->write_character(static_cast(first_prefix)); + } + } - @param[in] key key of the element to access + if (use_count) + { + oa->write_character(static_cast('#')); + write_number_with_ubjson_prefix(j.m_value.object->size(), true); + } - @return const reference to the element at key @a key + for (const auto& el : *j.m_value.object) + { + write_number_with_ubjson_prefix(el.first.size(), true); + oa->write_characters( + reinterpret_cast(el.first.c_str()), + el.first.size()); + write_ubjson(el.second, use_count, use_type, prefix_required); + } - @pre The element with key @a key must exist. **This precondition is - enforced with an assertion.** + if (not use_count) + { + oa->write_character(static_cast('}')); + } - @throw type_error.305 if the JSON value is not an object; in that cases, - using the [] operator with a key makes no sense. + break; + } - @complexity Logarithmic in the size of the container. + default: + break; + } + } - @liveexample{The example below shows how object elements can be read using - the `[]` operator.,operatorarray__key_type_const} + private: + /* + @brief write a number to output input - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value + @param[in] n number of type @a NumberType + @tparam NumberType the type of the number - @since version 1.1.0 + @note This function needs to respect the system's endianess, because bytes + in CBOR, MessagePack, and UBJSON are stored in network order (big + endian) and therefore need reordering on little endian systems. */ - template - const_reference operator[](T* key) const + template + void write_number(const NumberType n) { - // at only works for objects - if (is_object()) + // step 1: write number to array of length NumberType + std::array vec; + std::memcpy(vec.data(), &n, sizeof(NumberType)); + + // step 2: write array to output (with possible reordering) + if (is_little_endian) { - assert(m_value.object->find(key) != m_value.object->end()); - return m_value.object->find(key)->second; + // reverse byte order prior to conversion if necessary + std::reverse(vec.begin(), vec.end()); } - JSON_THROW(type_error::create(305, "cannot use operator[] with " + type_name())); - } - - /*! - @brief access specified object element with default value - - Returns either a copy of an object's element at the specified key @a key - or a given default value if no element with key @a key exists. - - The function is basically equivalent to executing - @code {.cpp} - try { - return at(key); - } catch(out_of_range) { - return default_value; + oa->write_characters(vec.data(), sizeof(NumberType)); } - @endcode - - @note Unlike @ref at(const typename object_t::key_type&), this function - does not throw if the given key @a key was not found. - - @note Unlike @ref operator[](const typename object_t::key_type& key), this - function does not implicitly add an element to the position defined by @a - key. This function is furthermore also applicable to const objects. - - @param[in] key key of the element to access - @param[in] default_value the value to return if @a key is not found - - @tparam ValueType type compatible to JSON values, for instance `int` for - JSON integer numbers, `bool` for JSON booleans, or `std::vector` types for - JSON arrays. Note the type of the expected value at @a key and the default - value @a default_value must be compatible. - - @return copy of the element at key @a key or @a default_value if @a key - is not found - - @throw type_error.306 if the JSON value is not an objec; in that cases, - using `value()` with a key makes no sense. - - @complexity Logarithmic in the size of the container. - - @liveexample{The example below shows how object elements can be queried - with a default value.,basic_json__value} - - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref operator[](const typename object_t::key_type&) for unchecked - access by reference - @since version 1.0.0 - */ - template::value, int>::type = 0> - ValueType value(const typename object_t::key_type& key, ValueType default_value) const + template + void write_number_with_ubjson_prefix(const NumberType n, + const bool add_prefix) { - // at only works for objects - if (is_object()) + if (std::is_floating_point::value) { - // if key is found, return value and given default value otherwise - const auto it = find(key); - if (it != end()) + if (add_prefix) { - return *it; + oa->write_character(static_cast('D')); // float64 + } + write_number(n); + } + else if (std::is_unsigned::value) + { + if (n <= (std::numeric_limits::max)()) + { + if (add_prefix) + { + oa->write_character(static_cast('i')); // int8 + } + write_number(static_cast(n)); + } + else if (n <= (std::numeric_limits::max)()) + { + if (add_prefix) + { + oa->write_character(static_cast('U')); // uint8 + } + write_number(static_cast(n)); + } + else if (n <= (std::numeric_limits::max)()) + { + if (add_prefix) + { + oa->write_character(static_cast('I')); // int16 + } + write_number(static_cast(n)); + } + else if (n <= (std::numeric_limits::max)()) + { + if (add_prefix) + { + oa->write_character(static_cast('l')); // int32 + } + write_number(static_cast(n)); + } + else if (n <= (std::numeric_limits::max)()) + { + if (add_prefix) + { + oa->write_character(static_cast('L')); // int64 + } + write_number(static_cast(n)); + } + else + { + JSON_THROW(out_of_range::create(407, "number overflow serializing " + std::to_string(n))); } - - return default_value; } else { - JSON_THROW(type_error::create(306, "cannot use value() with " + type_name())); + if ((std::numeric_limits::min)() <= n and n <= (std::numeric_limits::max)()) + { + if (add_prefix) + { + oa->write_character(static_cast('i')); // int8 + } + write_number(static_cast(n)); + } + else if ((std::numeric_limits::min)() <= n and n <= (std::numeric_limits::max)()) + { + if (add_prefix) + { + oa->write_character(static_cast('U')); // uint8 + } + write_number(static_cast(n)); + } + else if ((std::numeric_limits::min)() <= n and n <= (std::numeric_limits::max)()) + { + if (add_prefix) + { + oa->write_character(static_cast('I')); // int16 + } + write_number(static_cast(n)); + } + else if ((std::numeric_limits::min)() <= n and n <= (std::numeric_limits::max)()) + { + if (add_prefix) + { + oa->write_character(static_cast('l')); // int32 + } + write_number(static_cast(n)); + } + else if ((std::numeric_limits::min)() <= n and n <= (std::numeric_limits::max)()) + { + if (add_prefix) + { + oa->write_character(static_cast('L')); // int64 + } + write_number(static_cast(n)); + } + // LCOV_EXCL_START + else + { + JSON_THROW(out_of_range::create(407, "number overflow serializing " + std::to_string(n))); + } + // LCOV_EXCL_STOP } } /*! - @brief overload for a default value of type const char* - @copydoc basic_json::value(const typename object_t::key_type&, ValueType) const + @brief determine the type prefix of container values + + @note This function does not need to be 100% accurate when it comes to + integer limits. In case a number exceeds the limits of int64_t, + this will be detected by a later call to function + write_number_with_ubjson_prefix. Therefore, we return 'L' for any + value that does not fit the previous limits. */ - string_t value(const typename object_t::key_type& key, const char* default_value) const + char ubjson_prefix(const BasicJsonType& j) const noexcept { - return value(key, string_t(default_value)); - } - - /*! - @brief access specified object element via JSON Pointer with default value - - Returns either a copy of an object's element at the specified key @a key - or a given default value if no element with key @a key exists. - - The function is basically equivalent to executing - @code {.cpp} - try { - return at(ptr); - } catch(out_of_range) { - return default_value; - } - @endcode - - @note Unlike @ref at(const json_pointer&), this function does not throw - if the given key @a key was not found. + switch (j.type()) + { + case value_t::null: + return 'Z'; - @param[in] ptr a JSON pointer to the element to access - @param[in] default_value the value to return if @a ptr found no value + case value_t::boolean: + return j.m_value.boolean ? 'T' : 'F'; - @tparam ValueType type compatible to JSON values, for instance `int` for - JSON integer numbers, `bool` for JSON booleans, or `std::vector` types for - JSON arrays. Note the type of the expected value at @a key and the default - value @a default_value must be compatible. + case value_t::number_integer: + { + if ((std::numeric_limits::min)() <= j.m_value.number_integer and j.m_value.number_integer <= (std::numeric_limits::max)()) + { + return 'i'; + } + else if ((std::numeric_limits::min)() <= j.m_value.number_integer and j.m_value.number_integer <= (std::numeric_limits::max)()) + { + return 'U'; + } + else if ((std::numeric_limits::min)() <= j.m_value.number_integer and j.m_value.number_integer <= (std::numeric_limits::max)()) + { + return 'I'; + } + else if ((std::numeric_limits::min)() <= j.m_value.number_integer and j.m_value.number_integer <= (std::numeric_limits::max)()) + { + return 'l'; + } + else // no check and assume int64_t (see note above) + { + return 'L'; + } + } - @return copy of the element at key @a key or @a default_value if @a key - is not found + case value_t::number_unsigned: + { + if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + return 'i'; + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + return 'U'; + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + return 'I'; + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + return 'l'; + } + else // no check and assume int64_t (see note above) + { + return 'L'; + } + } - @throw type_error.306 if the JSON value is not an objec; in that cases, - using `value()` with a key makes no sense. + case value_t::number_float: + return 'D'; - @complexity Logarithmic in the size of the container. + case value_t::string: + return 'S'; - @liveexample{The example below shows how object elements can be queried - with a default value.,basic_json__value_ptr} + case value_t::array: + return '['; - @sa @ref operator[](const json_pointer&) for unchecked access by reference + case value_t::object: + return '{'; - @since version 2.0.2 - */ - template::value, int>::type = 0> - ValueType value(const json_pointer& ptr, ValueType default_value) const - { - // at only works for objects - if (is_object()) - { - // if pointer resolves a value, return it or use default value - JSON_TRY - { - return ptr.get_checked(this); - } - JSON_CATCH (out_of_range&) - { - return default_value; - } + default: // discarded values + return 'N'; } - - JSON_THROW(type_error::create(306, "cannot use value() with " + type_name())); } - /*! - @brief overload for a default value of type const char* - @copydoc basic_json::value(const json_pointer&, ValueType) const - */ - string_t value(const json_pointer& ptr, const char* default_value) const - { - return value(ptr, string_t(default_value)); - } + private: + /// whether we can assume little endianess + const bool is_little_endian = binary_reader::little_endianess(); - /*! - @brief access the first element + /// the output + output_adapter_t oa = nullptr; +}; +} +} - Returns a reference to the first element in the container. For a JSON - container `c`, the expression `c.front()` is equivalent to `*c.begin()`. +// #include - @return In case of a structured type (array or object), a reference to the - first element is returned. In case of number, string, or boolean values, a - reference to the value is returned. - @complexity Constant. +#include // reverse, remove, fill, find, none_of +#include // array +#include // assert +#include // and, or +#include // localeconv, lconv +#include // labs, isfinite, isnan, signbit +#include // size_t, ptrdiff_t +#include // uint8_t +#include // snprintf +#include // setfill +#include // next +#include // numeric_limits +#include // string +#include // stringstream +#include // is_same - @pre The JSON value must not be `null` (would throw `std::out_of_range`) - or an empty array or object (undefined behavior, **guarded by - assertions**). - @post The JSON value remains unchanged. +// #include - @throw invalid_iterator.214 when called on `null` value +// #include - @liveexample{The following code shows an example for `front()`.,front} - @sa @ref back() -- access the last element +#include // assert +#include // or, and, not +#include // signbit, isfinite +#include // intN_t, uintN_t +#include // memcpy, memmove - @since version 1.0.0 - */ - reference front() - { - return *begin(); - } +namespace nlohmann +{ +namespace detail +{ - /*! - @copydoc basic_json::front() - */ - const_reference front() const - { - return *cbegin(); - } +/*! +@brief implements the Grisu2 algorithm for binary to decimal floating-point +conversion. - /*! - @brief access the last element +This implementation is a slightly modified version of the reference +implementation which may be obtained from +http://florian.loitsch.com/publications (bench.tar.gz). - Returns a reference to the last element in the container. For a JSON - container `c`, the expression `c.back()` is equivalent to - @code {.cpp} - auto tmp = c.end(); - --tmp; - return *tmp; - @endcode +The code is distributed under the MIT license, Copyright (c) 2009 Florian Loitsch. - @return In case of a structured type (array or object), a reference to the - last element is returned. In case of number, string, or boolean values, a - reference to the value is returned. +For a detailed description of the algorithm see: - @complexity Constant. +[1] Loitsch, "Printing Floating-Point Numbers Quickly and Accurately with + Integers", Proceedings of the ACM SIGPLAN 2010 Conference on Programming + Language Design and Implementation, PLDI 2010 +[2] Burger, Dybvig, "Printing Floating-Point Numbers Quickly and Accurately", + Proceedings of the ACM SIGPLAN 1996 Conference on Programming Language + Design and Implementation, PLDI 1996 +*/ +namespace dtoa_impl +{ - @pre The JSON value must not be `null` (would throw `std::out_of_range`) - or an empty array or object (undefined behavior, **guarded by - assertions**). - @post The JSON value remains unchanged. +template +Target reinterpret_bits(const Source source) +{ + static_assert(sizeof(Target) == sizeof(Source), "size mismatch"); - @throw invalid_iterator.214 when called on a `null` value. See example - below. + Target target; + std::memcpy(&target, &source, sizeof(Source)); + return target; +} - @liveexample{The following code shows an example for `back()`.,back} +struct diyfp // f * 2^e +{ + static constexpr int kPrecision = 64; // = q - @sa @ref front() -- access the first element + uint64_t f; + int e; - @since version 1.0.0 + constexpr diyfp() noexcept : f(0), e(0) {} + constexpr diyfp(uint64_t f_, int e_) noexcept : f(f_), e(e_) {} + + /*! + @brief returns x - y + @pre x.e == y.e and x.f >= y.f */ - reference back() + static diyfp sub(const diyfp& x, const diyfp& y) noexcept { - auto tmp = end(); - --tmp; - return *tmp; + assert(x.e == y.e); + assert(x.f >= y.f); + + return diyfp(x.f - y.f, x.e); } /*! - @copydoc basic_json::back() + @brief returns x * y + @note The result is rounded. (Only the upper q bits are returned.) */ - const_reference back() const + static diyfp mul(const diyfp& x, const diyfp& y) noexcept { - auto tmp = cend(); - --tmp; - return *tmp; + static_assert(kPrecision == 64, "internal error"); + + // Computes: + // f = round((x.f * y.f) / 2^q) + // e = x.e + y.e + q + + // Emulate the 64-bit * 64-bit multiplication: + // + // p = u * v + // = (u_lo + 2^32 u_hi) (v_lo + 2^32 v_hi) + // = (u_lo v_lo ) + 2^32 ((u_lo v_hi ) + (u_hi v_lo )) + 2^64 (u_hi v_hi ) + // = (p0 ) + 2^32 ((p1 ) + (p2 )) + 2^64 (p3 ) + // = (p0_lo + 2^32 p0_hi) + 2^32 ((p1_lo + 2^32 p1_hi) + (p2_lo + 2^32 p2_hi)) + 2^64 (p3 ) + // = (p0_lo ) + 2^32 (p0_hi + p1_lo + p2_lo ) + 2^64 (p1_hi + p2_hi + p3) + // = (p0_lo ) + 2^32 (Q ) + 2^64 (H ) + // = (p0_lo ) + 2^32 (Q_lo + 2^32 Q_hi ) + 2^64 (H ) + // + // (Since Q might be larger than 2^32 - 1) + // + // = (p0_lo + 2^32 Q_lo) + 2^64 (Q_hi + H) + // + // (Q_hi + H does not overflow a 64-bit int) + // + // = p_lo + 2^64 p_hi + + const uint64_t u_lo = x.f & 0xFFFFFFFF; + const uint64_t u_hi = x.f >> 32; + const uint64_t v_lo = y.f & 0xFFFFFFFF; + const uint64_t v_hi = y.f >> 32; + + const uint64_t p0 = u_lo * v_lo; + const uint64_t p1 = u_lo * v_hi; + const uint64_t p2 = u_hi * v_lo; + const uint64_t p3 = u_hi * v_hi; + + const uint64_t p0_hi = p0 >> 32; + const uint64_t p1_lo = p1 & 0xFFFFFFFF; + const uint64_t p1_hi = p1 >> 32; + const uint64_t p2_lo = p2 & 0xFFFFFFFF; + const uint64_t p2_hi = p2 >> 32; + + uint64_t Q = p0_hi + p1_lo + p2_lo; + + // The full product might now be computed as + // + // p_hi = p3 + p2_hi + p1_hi + (Q >> 32) + // p_lo = p0_lo + (Q << 32) + // + // But in this particular case here, the full p_lo is not required. + // Effectively we only need to add the highest bit in p_lo to p_hi (and + // Q_hi + 1 does not overflow). + + Q += uint64_t{1} << (64 - 32 - 1); // round, ties up + + const uint64_t h = p3 + p2_hi + p1_hi + (Q >> 32); + + return diyfp(h, x.e + y.e + 64); } /*! - @brief remove element given an iterator + @brief normalize x such that the significand is >= 2^(q-1) + @pre x.f != 0 + */ + static diyfp normalize(diyfp x) noexcept + { + assert(x.f != 0); - Removes the element specified by iterator @a pos. The iterator @a pos must - be valid and dereferenceable. Thus the `end()` iterator (which is valid, - but is not dereferenceable) cannot be used as a value for @a pos. + while ((x.f >> 63) == 0) + { + x.f <<= 1; + x.e--; + } - If called on a primitive type other than `null`, the resulting JSON value - will be `null`. + return x; + } - @param[in] pos iterator to the element to remove - @return Iterator following the last removed element. If the iterator @a - pos refers to the last element, the `end()` iterator is returned. + /*! + @brief normalize x such that the result has the exponent E + @pre e >= x.e and the upper e - x.e bits of x.f must be zero. + */ + static diyfp normalize_to(const diyfp& x, const int target_exponent) noexcept + { + const int delta = x.e - target_exponent; - @tparam IteratorType an @ref iterator or @ref const_iterator + assert(delta >= 0); + assert(((x.f << delta) >> delta) == x.f); - @post Invalidates iterators and references at or after the point of the - erase, including the `end()` iterator. + return diyfp(x.f << delta, target_exponent); + } +}; - @throw type_error.307 if called on a `null` value; example: `"cannot use - erase() with null"` - @throw invalid_iterator.202 if called on an iterator which does not belong - to the current JSON value; example: `"iterator does not fit current - value"` - @throw invalid_iterator.205 if called on a primitive type with invalid - iterator (i.e., any iterator which is not `begin()`); example: `"iterator - out of range"` +struct boundaries +{ + diyfp w; + diyfp minus; + diyfp plus; +}; - @complexity The complexity depends on the type: - - objects: amortized constant - - arrays: linear in distance between @a pos and the end of the container - - strings: linear in the length of the string - - other types: constant +/*! +Compute the (normalized) diyfp representing the input number 'value' and its +boundaries. - @liveexample{The example shows the result of `erase()` for different JSON - types.,erase__IteratorType} +@pre value must be finite and positive +*/ +template +boundaries compute_boundaries(FloatType value) +{ + assert(std::isfinite(value)); + assert(value > 0); + + // Convert the IEEE representation into a diyfp. + // + // If v is denormal: + // value = 0.F * 2^(1 - bias) = ( F) * 2^(1 - bias - (p-1)) + // If v is normalized: + // value = 1.F * 2^(E - bias) = (2^(p-1) + F) * 2^(E - bias - (p-1)) + + static_assert(std::numeric_limits::is_iec559, + "internal error: dtoa_short requires an IEEE-754 floating-point implementation"); + + constexpr int kPrecision = std::numeric_limits::digits; // = p (includes the hidden bit) + constexpr int kBias = std::numeric_limits::max_exponent - 1 + (kPrecision - 1); + constexpr int kMinExp = 1 - kBias; + constexpr uint64_t kHiddenBit = uint64_t{1} << (kPrecision - 1); // = 2^(p-1) + + using bits_type = typename std::conditional< kPrecision == 24, uint32_t, uint64_t >::type; + + const uint64_t bits = reinterpret_bits(value); + const uint64_t E = bits >> (kPrecision - 1); + const uint64_t F = bits & (kHiddenBit - 1); + + const bool is_denormal = (E == 0); + const diyfp v = is_denormal + ? diyfp(F, kMinExp) + : diyfp(F + kHiddenBit, static_cast(E) - kBias); + + // Compute the boundaries m- and m+ of the floating-point value + // v = f * 2^e. + // + // Determine v- and v+, the floating-point predecessor and successor if v, + // respectively. + // + // v- = v - 2^e if f != 2^(p-1) or e == e_min (A) + // = v - 2^(e-1) if f == 2^(p-1) and e > e_min (B) + // + // v+ = v + 2^e + // + // Let m- = (v- + v) / 2 and m+ = (v + v+) / 2. All real numbers _strictly_ + // between m- and m+ round to v, regardless of how the input rounding + // algorithm breaks ties. + // + // ---+-------------+-------------+-------------+-------------+--- (A) + // v- m- v m+ v+ + // + // -----------------+------+------+-------------+-------------+--- (B) + // v- m- v m+ v+ + + const bool lower_boundary_is_closer = (F == 0 and E > 1); + const diyfp m_plus = diyfp(2 * v.f + 1, v.e - 1); + const diyfp m_minus = lower_boundary_is_closer + ? diyfp(4 * v.f - 1, v.e - 2) // (B) + : diyfp(2 * v.f - 1, v.e - 1); // (A) + + // Determine the normalized w+ = m+. + const diyfp w_plus = diyfp::normalize(m_plus); + + // Determine w- = m- such that e_(w-) = e_(w+). + const diyfp w_minus = diyfp::normalize_to(m_minus, w_plus.e); + + return {diyfp::normalize(v), w_minus, w_plus}; +} - @sa @ref erase(IteratorType, IteratorType) -- removes the elements in - the given range - @sa @ref erase(const typename object_t::key_type&) -- removes the element - from an object at the given key - @sa @ref erase(const size_type) -- removes the element from an array at - the given index +// Given normalized diyfp w, Grisu needs to find a (normalized) cached +// power-of-ten c, such that the exponent of the product c * w = f * 2^e lies +// within a certain range [alpha, gamma] (Definition 3.2 from [1]) +// +// alpha <= e = e_c + e_w + q <= gamma +// +// or +// +// f_c * f_w * 2^alpha <= f_c 2^(e_c) * f_w 2^(e_w) * 2^q +// <= f_c * f_w * 2^gamma +// +// Since c and w are normalized, i.e. 2^(q-1) <= f < 2^q, this implies +// +// 2^(q-1) * 2^(q-1) * 2^alpha <= c * w * 2^q < 2^q * 2^q * 2^gamma +// +// or +// +// 2^(q - 2 + alpha) <= c * w < 2^(q + gamma) +// +// The choice of (alpha,gamma) determines the size of the table and the form of +// the digit generation procedure. Using (alpha,gamma)=(-60,-32) works out well +// in practice: +// +// The idea is to cut the number c * w = f * 2^e into two parts, which can be +// processed independently: An integral part p1, and a fractional part p2: +// +// f * 2^e = ( (f div 2^-e) * 2^-e + (f mod 2^-e) ) * 2^e +// = (f div 2^-e) + (f mod 2^-e) * 2^e +// = p1 + p2 * 2^e +// +// The conversion of p1 into decimal form requires a series of divisions and +// modulos by (a power of) 10. These operations are faster for 32-bit than for +// 64-bit integers, so p1 should ideally fit into a 32-bit integer. This can be +// achieved by choosing +// +// -e >= 32 or e <= -32 := gamma +// +// In order to convert the fractional part +// +// p2 * 2^e = p2 / 2^-e = d[-1] / 10^1 + d[-2] / 10^2 + ... +// +// into decimal form, the fraction is repeatedly multiplied by 10 and the digits +// d[-i] are extracted in order: +// +// (10 * p2) div 2^-e = d[-1] +// (10 * p2) mod 2^-e = d[-2] / 10^1 + ... +// +// The multiplication by 10 must not overflow. It is sufficient to choose +// +// 10 * p2 < 16 * p2 = 2^4 * p2 <= 2^64. +// +// Since p2 = f mod 2^-e < 2^-e, +// +// -e <= 60 or e >= -60 := alpha + +constexpr int kAlpha = -60; +constexpr int kGamma = -32; + +struct cached_power // c = f * 2^e ~= 10^k +{ + uint64_t f; + int e; + int k; +}; - @since version 1.0.0 - */ - template::value or - std::is_same::value, int>::type - = 0> - IteratorType erase(IteratorType pos) +/*! +For a normalized diyfp w = f * 2^e, this function returns a (normalized) cached +power-of-ten c = f_c * 2^e_c, such that the exponent of the product w * c +satisfies (Definition 3.2 from [1]) + + alpha <= e_c + e + q <= gamma. +*/ +inline cached_power get_cached_power_for_binary_exponent(int e) +{ + // Now + // + // alpha <= e_c + e + q <= gamma (1) + // ==> f_c * 2^alpha <= c * 2^e * 2^q + // + // and since the c's are normalized, 2^(q-1) <= f_c, + // + // ==> 2^(q - 1 + alpha) <= c * 2^(e + q) + // ==> 2^(alpha - e - 1) <= c + // + // If c were an exakt power of ten, i.e. c = 10^k, one may determine k as + // + // k = ceil( log_10( 2^(alpha - e - 1) ) ) + // = ceil( (alpha - e - 1) * log_10(2) ) + // + // From the paper: + // "In theory the result of the procedure could be wrong since c is rounded, + // and the computation itself is approximated [...]. In practice, however, + // this simple function is sufficient." + // + // For IEEE double precision floating-point numbers converted into + // normalized diyfp's w = f * 2^e, with q = 64, + // + // e >= -1022 (min IEEE exponent) + // -52 (p - 1) + // -52 (p - 1, possibly normalize denormal IEEE numbers) + // -11 (normalize the diyfp) + // = -1137 + // + // and + // + // e <= +1023 (max IEEE exponent) + // -52 (p - 1) + // -11 (normalize the diyfp) + // = 960 + // + // This binary exponent range [-1137,960] results in a decimal exponent + // range [-307,324]. One does not need to store a cached power for each + // k in this range. For each such k it suffices to find a cached power + // such that the exponent of the product lies in [alpha,gamma]. + // This implies that the difference of the decimal exponents of adjacent + // table entries must be less than or equal to + // + // floor( (gamma - alpha) * log_10(2) ) = 8. + // + // (A smaller distance gamma-alpha would require a larger table.) + + // NB: + // Actually this function returns c, such that -60 <= e_c + e + 64 <= -34. + + constexpr int kCachedPowersSize = 79; + constexpr int kCachedPowersMinDecExp = -300; + constexpr int kCachedPowersDecStep = 8; + + static constexpr cached_power kCachedPowers[] = { - // make sure iterator fits the current value - if (this != pos.m_object) - { - JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); - } + { 0xAB70FE17C79AC6CA, -1060, -300 }, + { 0xFF77B1FCBEBCDC4F, -1034, -292 }, + { 0xBE5691EF416BD60C, -1007, -284 }, + { 0x8DD01FAD907FFC3C, -980, -276 }, + { 0xD3515C2831559A83, -954, -268 }, + { 0x9D71AC8FADA6C9B5, -927, -260 }, + { 0xEA9C227723EE8BCB, -901, -252 }, + { 0xAECC49914078536D, -874, -244 }, + { 0x823C12795DB6CE57, -847, -236 }, + { 0xC21094364DFB5637, -821, -228 }, + { 0x9096EA6F3848984F, -794, -220 }, + { 0xD77485CB25823AC7, -768, -212 }, + { 0xA086CFCD97BF97F4, -741, -204 }, + { 0xEF340A98172AACE5, -715, -196 }, + { 0xB23867FB2A35B28E, -688, -188 }, + { 0x84C8D4DFD2C63F3B, -661, -180 }, + { 0xC5DD44271AD3CDBA, -635, -172 }, + { 0x936B9FCEBB25C996, -608, -164 }, + { 0xDBAC6C247D62A584, -582, -156 }, + { 0xA3AB66580D5FDAF6, -555, -148 }, + { 0xF3E2F893DEC3F126, -529, -140 }, + { 0xB5B5ADA8AAFF80B8, -502, -132 }, + { 0x87625F056C7C4A8B, -475, -124 }, + { 0xC9BCFF6034C13053, -449, -116 }, + { 0x964E858C91BA2655, -422, -108 }, + { 0xDFF9772470297EBD, -396, -100 }, + { 0xA6DFBD9FB8E5B88F, -369, -92 }, + { 0xF8A95FCF88747D94, -343, -84 }, + { 0xB94470938FA89BCF, -316, -76 }, + { 0x8A08F0F8BF0F156B, -289, -68 }, + { 0xCDB02555653131B6, -263, -60 }, + { 0x993FE2C6D07B7FAC, -236, -52 }, + { 0xE45C10C42A2B3B06, -210, -44 }, + { 0xAA242499697392D3, -183, -36 }, + { 0xFD87B5F28300CA0E, -157, -28 }, + { 0xBCE5086492111AEB, -130, -20 }, + { 0x8CBCCC096F5088CC, -103, -12 }, + { 0xD1B71758E219652C, -77, -4 }, + { 0x9C40000000000000, -50, 4 }, + { 0xE8D4A51000000000, -24, 12 }, + { 0xAD78EBC5AC620000, 3, 20 }, + { 0x813F3978F8940984, 30, 28 }, + { 0xC097CE7BC90715B3, 56, 36 }, + { 0x8F7E32CE7BEA5C70, 83, 44 }, + { 0xD5D238A4ABE98068, 109, 52 }, + { 0x9F4F2726179A2245, 136, 60 }, + { 0xED63A231D4C4FB27, 162, 68 }, + { 0xB0DE65388CC8ADA8, 189, 76 }, + { 0x83C7088E1AAB65DB, 216, 84 }, + { 0xC45D1DF942711D9A, 242, 92 }, + { 0x924D692CA61BE758, 269, 100 }, + { 0xDA01EE641A708DEA, 295, 108 }, + { 0xA26DA3999AEF774A, 322, 116 }, + { 0xF209787BB47D6B85, 348, 124 }, + { 0xB454E4A179DD1877, 375, 132 }, + { 0x865B86925B9BC5C2, 402, 140 }, + { 0xC83553C5C8965D3D, 428, 148 }, + { 0x952AB45CFA97A0B3, 455, 156 }, + { 0xDE469FBD99A05FE3, 481, 164 }, + { 0xA59BC234DB398C25, 508, 172 }, + { 0xF6C69A72A3989F5C, 534, 180 }, + { 0xB7DCBF5354E9BECE, 561, 188 }, + { 0x88FCF317F22241E2, 588, 196 }, + { 0xCC20CE9BD35C78A5, 614, 204 }, + { 0x98165AF37B2153DF, 641, 212 }, + { 0xE2A0B5DC971F303A, 667, 220 }, + { 0xA8D9D1535CE3B396, 694, 228 }, + { 0xFB9B7CD9A4A7443C, 720, 236 }, + { 0xBB764C4CA7A44410, 747, 244 }, + { 0x8BAB8EEFB6409C1A, 774, 252 }, + { 0xD01FEF10A657842C, 800, 260 }, + { 0x9B10A4E5E9913129, 827, 268 }, + { 0xE7109BFBA19C0C9D, 853, 276 }, + { 0xAC2820D9623BF429, 880, 284 }, + { 0x80444B5E7AA7CF85, 907, 292 }, + { 0xBF21E44003ACDD2D, 933, 300 }, + { 0x8E679C2F5E44FF8F, 960, 308 }, + { 0xD433179D9C8CB841, 986, 316 }, + { 0x9E19DB92B4E31BA9, 1013, 324 }, + }; - IteratorType result = end(); + // This computation gives exactly the same results for k as + // k = ceil((kAlpha - e - 1) * 0.30102999566398114) + // for |e| <= 1500, but doesn't require floating-point operations. + // NB: log_10(2) ~= 78913 / 2^18 + assert(e >= -1500); + assert(e <= 1500); + const int f = kAlpha - e - 1; + const int k = (f * 78913) / (1 << 18) + (f > 0); + + const int index = (-kCachedPowersMinDecExp + k + (kCachedPowersDecStep - 1)) / kCachedPowersDecStep; + assert(index >= 0); + assert(index < kCachedPowersSize); + static_cast(kCachedPowersSize); // Fix warning. + + const cached_power cached = kCachedPowers[index]; + assert(kAlpha <= cached.e + e + 64); + assert(kGamma >= cached.e + e + 64); + + return cached; +} - switch (m_type) - { - case value_t::boolean: - case value_t::number_float: - case value_t::number_integer: - case value_t::number_unsigned: - case value_t::string: - { - if (not pos.m_it.primitive_iterator.is_begin()) - { - JSON_THROW(invalid_iterator::create(205, "iterator out of range")); - } - - if (is_string()) - { - AllocatorType alloc; - alloc.destroy(m_value.string); - alloc.deallocate(m_value.string, 1); - m_value.string = nullptr; - } - - m_type = value_t::null; - assert_invariant(); - break; - } - - case value_t::object: - { - result.m_it.object_iterator = m_value.object->erase(pos.m_it.object_iterator); - break; - } +/*! +For n != 0, returns k, such that pow10 := 10^(k-1) <= n < 10^k. +For n == 0, returns 1 and sets pow10 := 1. +*/ +inline int find_largest_pow10(const uint32_t n, uint32_t& pow10) +{ + // LCOV_EXCL_START + if (n >= 1000000000) + { + pow10 = 1000000000; + return 10; + } + // LCOV_EXCL_STOP + else if (n >= 100000000) + { + pow10 = 100000000; + return 9; + } + else if (n >= 10000000) + { + pow10 = 10000000; + return 8; + } + else if (n >= 1000000) + { + pow10 = 1000000; + return 7; + } + else if (n >= 100000) + { + pow10 = 100000; + return 6; + } + else if (n >= 10000) + { + pow10 = 10000; + return 5; + } + else if (n >= 1000) + { + pow10 = 1000; + return 4; + } + else if (n >= 100) + { + pow10 = 100; + return 3; + } + else if (n >= 10) + { + pow10 = 10; + return 2; + } + else + { + pow10 = 1; + return 1; + } +} - case value_t::array: - { - result.m_it.array_iterator = m_value.array->erase(pos.m_it.array_iterator); - break; - } +inline void grisu2_round(char* buf, int len, uint64_t dist, uint64_t delta, + uint64_t rest, uint64_t ten_k) +{ + assert(len >= 1); + assert(dist <= delta); + assert(rest <= delta); + assert(ten_k > 0); + + // <--------------------------- delta ----> + // <---- dist ---------> + // --------------[------------------+-------------------]-------------- + // M- w M+ + // + // ten_k + // <------> + // <---- rest ----> + // --------------[------------------+----+--------------]-------------- + // w V + // = buf * 10^k + // + // ten_k represents a unit-in-the-last-place in the decimal representation + // stored in buf. + // Decrement buf by ten_k while this takes buf closer to w. + + // The tests are written in this order to avoid overflow in unsigned + // integer arithmetic. + + while (rest < dist + and delta - rest >= ten_k + and (rest + ten_k < dist or dist - rest > rest + ten_k - dist)) + { + assert(buf[len - 1] != '0'); + buf[len - 1]--; + rest += ten_k; + } +} - default: - { - JSON_THROW(type_error::create(307, "cannot use erase() with " + type_name())); - } +/*! +Generates V = buffer * 10^decimal_exponent, such that M- <= V <= M+. +M- and M+ must be normalized and share the same exponent -60 <= e <= -32. +*/ +inline void grisu2_digit_gen(char* buffer, int& length, int& decimal_exponent, + diyfp M_minus, diyfp w, diyfp M_plus) +{ + static_assert(kAlpha >= -60, "internal error"); + static_assert(kGamma <= -32, "internal error"); + + // Generates the digits (and the exponent) of a decimal floating-point + // number V = buffer * 10^decimal_exponent in the range [M-, M+]. The diyfp's + // w, M- and M+ share the same exponent e, which satisfies alpha <= e <= gamma. + // + // <--------------------------- delta ----> + // <---- dist ---------> + // --------------[------------------+-------------------]-------------- + // M- w M+ + // + // Grisu2 generates the digits of M+ from left to right and stops as soon as + // V is in [M-,M+]. + + assert(M_plus.e >= kAlpha); + assert(M_plus.e <= kGamma); + + uint64_t delta = diyfp::sub(M_plus, M_minus).f; // (significand of (M+ - M-), implicit exponent is e) + uint64_t dist = diyfp::sub(M_plus, w ).f; // (significand of (M+ - w ), implicit exponent is e) + + // Split M+ = f * 2^e into two parts p1 and p2 (note: e < 0): + // + // M+ = f * 2^e + // = ((f div 2^-e) * 2^-e + (f mod 2^-e)) * 2^e + // = ((p1 ) * 2^-e + (p2 )) * 2^e + // = p1 + p2 * 2^e + + const diyfp one(uint64_t{1} << -M_plus.e, M_plus.e); + + uint32_t p1 = static_cast(M_plus.f >> -one.e); // p1 = f div 2^-e (Since -e >= 32, p1 fits into a 32-bit int.) + uint64_t p2 = M_plus.f & (one.f - 1); // p2 = f mod 2^-e + + // 1) + // + // Generate the digits of the integral part p1 = d[n-1]...d[1]d[0] + + assert(p1 > 0); + + uint32_t pow10; + const int k = find_largest_pow10(p1, pow10); + + // 10^(k-1) <= p1 < 10^k, pow10 = 10^(k-1) + // + // p1 = (p1 div 10^(k-1)) * 10^(k-1) + (p1 mod 10^(k-1)) + // = (d[k-1] ) * 10^(k-1) + (p1 mod 10^(k-1)) + // + // M+ = p1 + p2 * 2^e + // = d[k-1] * 10^(k-1) + (p1 mod 10^(k-1)) + p2 * 2^e + // = d[k-1] * 10^(k-1) + ((p1 mod 10^(k-1)) * 2^-e + p2) * 2^e + // = d[k-1] * 10^(k-1) + ( rest) * 2^e + // + // Now generate the digits d[n] of p1 from left to right (n = k-1,...,0) + // + // p1 = d[k-1]...d[n] * 10^n + d[n-1]...d[0] + // + // but stop as soon as + // + // rest * 2^e = (d[n-1]...d[0] * 2^-e + p2) * 2^e <= delta * 2^e + + int n = k; + while (n > 0) + { + // Invariants: + // M+ = buffer * 10^n + (p1 + p2 * 2^e) (buffer = 0 for n = k) + // pow10 = 10^(n-1) <= p1 < 10^n + // + const uint32_t d = p1 / pow10; // d = p1 div 10^(n-1) + const uint32_t r = p1 % pow10; // r = p1 mod 10^(n-1) + // + // M+ = buffer * 10^n + (d * 10^(n-1) + r) + p2 * 2^e + // = (buffer * 10 + d) * 10^(n-1) + (r + p2 * 2^e) + // + assert(d <= 9); + buffer[length++] = static_cast('0' + d); // buffer := buffer * 10 + d + // + // M+ = buffer * 10^(n-1) + (r + p2 * 2^e) + // + p1 = r; + n--; + // + // M+ = buffer * 10^n + (p1 + p2 * 2^e) + // pow10 = 10^n + // + + // Now check if enough digits have been generated. + // Compute + // + // p1 + p2 * 2^e = (p1 * 2^-e + p2) * 2^e = rest * 2^e + // + // Note: + // Since rest and delta share the same exponent e, it suffices to + // compare the significands. + const uint64_t rest = (uint64_t{p1} << -one.e) + p2; + if (rest <= delta) + { + // V = buffer * 10^n, with M- <= V <= M+. + + decimal_exponent += n; + + // We may now just stop. But instead look if the buffer could be + // decremented to bring V closer to w. + // + // pow10 = 10^n is now 1 ulp in the decimal representation V. + // The rounding procedure works with diyfp's with an implicit + // exponent of e. + // + // 10^n = (10^n * 2^-e) * 2^e = ulp * 2^e + // + const uint64_t ten_n = uint64_t{pow10} << -one.e; + grisu2_round(buffer, length, dist, delta, rest, ten_n); + + return; } - return result; + pow10 /= 10; + // + // pow10 = 10^(n-1) <= p1 < 10^n + // Invariants restored. } - /*! - @brief remove elements given an iterator range - - Removes the element specified by the range `[first; last)`. The iterator - @a first does not need to be dereferenceable if `first == last`: erasing - an empty range is a no-op. + // 2) + // + // The digits of the integral part have been generated: + // + // M+ = d[k-1]...d[1]d[0] + p2 * 2^e + // = buffer + p2 * 2^e + // + // Now generate the digits of the fractional part p2 * 2^e. + // + // Note: + // No decimal point is generated: the exponent is adjusted instead. + // + // p2 actually represents the fraction + // + // p2 * 2^e + // = p2 / 2^-e + // = d[-1] / 10^1 + d[-2] / 10^2 + ... + // + // Now generate the digits d[-m] of p1 from left to right (m = 1,2,...) + // + // p2 * 2^e = d[-1]d[-2]...d[-m] * 10^-m + // + 10^-m * (d[-m-1] / 10^1 + d[-m-2] / 10^2 + ...) + // + // using + // + // 10^m * p2 = ((10^m * p2) div 2^-e) * 2^-e + ((10^m * p2) mod 2^-e) + // = ( d) * 2^-e + ( r) + // + // or + // 10^m * p2 * 2^e = d + r * 2^e + // + // i.e. + // + // M+ = buffer + p2 * 2^e + // = buffer + 10^-m * (d + r * 2^e) + // = (buffer * 10^m + d) * 10^-m + 10^-m * r * 2^e + // + // and stop as soon as 10^-m * r * 2^e <= delta * 2^e + + assert(p2 > delta); + + int m = 0; + for (;;) + { + // Invariant: + // M+ = buffer * 10^-m + 10^-m * (d[-m-1] / 10 + d[-m-2] / 10^2 + ...) * 2^e + // = buffer * 10^-m + 10^-m * (p2 ) * 2^e + // = buffer * 10^-m + 10^-m * (1/10 * (10 * p2) ) * 2^e + // = buffer * 10^-m + 10^-m * (1/10 * ((10*p2 div 2^-e) * 2^-e + (10*p2 mod 2^-e)) * 2^e + // + assert(p2 <= UINT64_MAX / 10); + p2 *= 10; + const uint64_t d = p2 >> -one.e; // d = (10 * p2) div 2^-e + const uint64_t r = p2 & (one.f - 1); // r = (10 * p2) mod 2^-e + // + // M+ = buffer * 10^-m + 10^-m * (1/10 * (d * 2^-e + r) * 2^e + // = buffer * 10^-m + 10^-m * (1/10 * (d + r * 2^e)) + // = (buffer * 10 + d) * 10^(-m-1) + 10^(-m-1) * r * 2^e + // + assert(d <= 9); + buffer[length++] = static_cast('0' + d); // buffer := buffer * 10 + d + // + // M+ = buffer * 10^(-m-1) + 10^(-m-1) * r * 2^e + // + p2 = r; + m++; + // + // M+ = buffer * 10^-m + 10^-m * p2 * 2^e + // Invariant restored. + + // Check if enough digits have been generated. + // + // 10^-m * p2 * 2^e <= delta * 2^e + // p2 * 2^e <= 10^m * delta * 2^e + // p2 <= 10^m * delta + delta *= 10; + dist *= 10; + if (p2 <= delta) + { + break; + } + } - If called on a primitive type other than `null`, the resulting JSON value - will be `null`. + // V = buffer * 10^-m, with M- <= V <= M+. + + decimal_exponent -= m; + + // 1 ulp in the decimal representation is now 10^-m. + // Since delta and dist are now scaled by 10^m, we need to do the + // same with ulp in order to keep the units in sync. + // + // 10^m * 10^-m = 1 = 2^-e * 2^e = ten_m * 2^e + // + const uint64_t ten_m = one.f; + grisu2_round(buffer, length, dist, delta, p2, ten_m); + + // By construction this algorithm generates the shortest possible decimal + // number (Loitsch, Theorem 6.2) which rounds back to w. + // For an input number of precision p, at least + // + // N = 1 + ceil(p * log_10(2)) + // + // decimal digits are sufficient to identify all binary floating-point + // numbers (Matula, "In-and-Out conversions"). + // This implies that the algorithm does not produce more than N decimal + // digits. + // + // N = 17 for p = 53 (IEEE double precision) + // N = 9 for p = 24 (IEEE single precision) +} - @param[in] first iterator to the beginning of the range to remove - @param[in] last iterator past the end of the range to remove - @return Iterator following the last removed element. If the iterator @a - second refers to the last element, the `end()` iterator is returned. +/*! +v = buf * 10^decimal_exponent +len is the length of the buffer (number of decimal digits) +The buffer must be large enough, i.e. >= max_digits10. +*/ +inline void grisu2(char* buf, int& len, int& decimal_exponent, + diyfp m_minus, diyfp v, diyfp m_plus) +{ + assert(m_plus.e == m_minus.e); + assert(m_plus.e == v.e); + + // --------(-----------------------+-----------------------)-------- (A) + // m- v m+ + // + // --------------------(-----------+-----------------------)-------- (B) + // m- v m+ + // + // First scale v (and m- and m+) such that the exponent is in the range + // [alpha, gamma]. + + const cached_power cached = get_cached_power_for_binary_exponent(m_plus.e); + + const diyfp c_minus_k(cached.f, cached.e); // = c ~= 10^-k + + // The exponent of the products is = v.e + c_minus_k.e + q and is in the range [alpha,gamma] + const diyfp w = diyfp::mul(v, c_minus_k); + const diyfp w_minus = diyfp::mul(m_minus, c_minus_k); + const diyfp w_plus = diyfp::mul(m_plus, c_minus_k); + + // ----(---+---)---------------(---+---)---------------(---+---)---- + // w- w w+ + // = c*m- = c*v = c*m+ + // + // diyfp::mul rounds its result and c_minus_k is approximated too. w, w- and + // w+ are now off by a small amount. + // In fact: + // + // w - v * 10^k < 1 ulp + // + // To account for this inaccuracy, add resp. subtract 1 ulp. + // + // --------+---[---------------(---+---)---------------]---+-------- + // w- M- w M+ w+ + // + // Now any number in [M-, M+] (bounds included) will round to w when input, + // regardless of how the input rounding algorithm breaks ties. + // + // And digit_gen generates the shortest possible such number in [M-, M+]. + // Note that this does not mean that Grisu2 always generates the shortest + // possible number in the interval (m-, m+). + const diyfp M_minus(w_minus.f + 1, w_minus.e); + const diyfp M_plus (w_plus.f - 1, w_plus.e ); + + decimal_exponent = -cached.k; // = -(-k) = k + + grisu2_digit_gen(buf, len, decimal_exponent, M_minus, w, M_plus); +} - @tparam IteratorType an @ref iterator or @ref const_iterator +/*! +v = buf * 10^decimal_exponent +len is the length of the buffer (number of decimal digits) +The buffer must be large enough, i.e. >= max_digits10. +*/ +template +void grisu2(char* buf, int& len, int& decimal_exponent, FloatType value) +{ + static_assert(diyfp::kPrecision >= std::numeric_limits::digits + 3, + "internal error: not enough precision"); + + assert(std::isfinite(value)); + assert(value > 0); + + // If the neighbors (and boundaries) of 'value' are always computed for double-precision + // numbers, all float's can be recovered using strtod (and strtof). However, the resulting + // decimal representations are not exactly "short". + // + // The documentation for 'std::to_chars' (http://en.cppreference.com/w/cpp/utility/to_chars) + // says "value is converted to a string as if by std::sprintf in the default ("C") locale" + // and since sprintf promotes float's to double's, I think this is exactly what 'std::to_chars' + // does. + // On the other hand, the documentation for 'std::to_chars' requires that "parsing the + // representation using the corresponding std::from_chars function recovers value exactly". That + // indicates that single precision floating-point numbers should be recovered using + // 'std::strtof'. + // + // NB: If the neighbors are computed for single-precision numbers, there is a single float + // (7.0385307e-26f) which can't be recovered using strtod. The resulting double precision + // value is off by 1 ulp. +#if 0 + const boundaries w = compute_boundaries(static_cast(value)); +#else + const boundaries w = compute_boundaries(value); +#endif - @post Invalidates iterators and references at or after the point of the - erase, including the `end()` iterator. + grisu2(buf, len, decimal_exponent, w.minus, w.w, w.plus); +} - @throw type_error.307 if called on a `null` value; example: `"cannot use - erase() with null"` - @throw invalid_iterator.203 if called on iterators which does not belong - to the current JSON value; example: `"iterators do not fit current value"` - @throw invalid_iterator.204 if called on a primitive type with invalid - iterators (i.e., if `first != begin()` and `last != end()`); example: - `"iterators out of range"` +/*! +@brief appends a decimal representation of e to buf +@return a pointer to the element following the exponent. +@pre -1000 < e < 1000 +*/ +inline char* append_exponent(char* buf, int e) +{ + assert(e > -1000); + assert(e < 1000); - @complexity The complexity depends on the type: - - objects: `log(size()) + std::distance(first, last)` - - arrays: linear in the distance between @a first and @a last, plus linear - in the distance between @a last and end of the container - - strings: linear in the length of the string - - other types: constant + if (e < 0) + { + e = -e; + *buf++ = '-'; + } + else + { + *buf++ = '+'; + } - @liveexample{The example shows the result of `erase()` for different JSON - types.,erase__IteratorType_IteratorType} + uint32_t k = static_cast(e); + if (k < 10) + { + // Always print at least two digits in the exponent. + // This is for compatibility with printf("%g"). + *buf++ = '0'; + *buf++ = static_cast('0' + k); + } + else if (k < 100) + { + *buf++ = static_cast('0' + k / 10); + k %= 10; + *buf++ = static_cast('0' + k); + } + else + { + *buf++ = static_cast('0' + k / 100); + k %= 100; + *buf++ = static_cast('0' + k / 10); + k %= 10; + *buf++ = static_cast('0' + k); + } - @sa @ref erase(IteratorType) -- removes the element at a given position - @sa @ref erase(const typename object_t::key_type&) -- removes the element - from an object at the given key - @sa @ref erase(const size_type) -- removes the element from an array at - the given index + return buf; +} - @since version 1.0.0 - */ - template::value or - std::is_same::value, int>::type - = 0> - IteratorType erase(IteratorType first, IteratorType last) - { - // make sure iterator fits the current value - if (this != first.m_object or this != last.m_object) - { - JSON_THROW(invalid_iterator::create(203, "iterators do not fit current value")); - } +/*! +@brief prettify v = buf * 10^decimal_exponent - IteratorType result = end(); +If v is in the range [10^min_exp, 10^max_exp) it will be printed in fixed-point +notation. Otherwise it will be printed in exponential notation. - switch (m_type) - { - case value_t::boolean: - case value_t::number_float: - case value_t::number_integer: - case value_t::number_unsigned: - case value_t::string: - { - if (not first.m_it.primitive_iterator.is_begin() or not last.m_it.primitive_iterator.is_end()) - { - JSON_THROW(invalid_iterator::create(204, "iterators out of range")); - } +@pre min_exp < 0 +@pre max_exp > 0 +*/ +inline char* format_buffer(char* buf, int len, int decimal_exponent, + int min_exp, int max_exp) +{ + assert(min_exp < 0); + assert(max_exp > 0); - if (is_string()) - { - AllocatorType alloc; - alloc.destroy(m_value.string); - alloc.deallocate(m_value.string, 1); - m_value.string = nullptr; - } + const int k = len; + const int n = len + decimal_exponent; - m_type = value_t::null; - assert_invariant(); - break; - } + // v = buf * 10^(n-k) + // k is the length of the buffer (number of decimal digits) + // n is the position of the decimal point relative to the start of the buffer. - case value_t::object: - { - result.m_it.object_iterator = m_value.object->erase(first.m_it.object_iterator, - last.m_it.object_iterator); - break; - } + if (k <= n and n <= max_exp) + { + // digits[000] + // len <= max_exp + 2 + + std::memset(buf + k, '0', static_cast(n - k)); + // Make it look like a floating-point number (#362, #378) + buf[n + 0] = '.'; + buf[n + 1] = '0'; + return buf + (n + 2); + } - case value_t::array: - { - result.m_it.array_iterator = m_value.array->erase(first.m_it.array_iterator, - last.m_it.array_iterator); - break; - } + if (0 < n and n <= max_exp) + { + // dig.its + // len <= max_digits10 + 1 - default: - { - JSON_THROW(type_error::create(307, "cannot use erase() with " + type_name())); - } - } + assert(k > n); - return result; + std::memmove(buf + (n + 1), buf + n, static_cast(k - n)); + buf[n] = '.'; + return buf + (k + 1); } - /*! - @brief remove element from a JSON object given a key + if (min_exp < n and n <= 0) + { + // 0.[000]digits + // len <= 2 + (-min_exp - 1) + max_digits10 + + std::memmove(buf + (2 + -n), buf, static_cast(k)); + buf[0] = '0'; + buf[1] = '.'; + std::memset(buf + 2, '0', static_cast(-n)); + return buf + (2 + (-n) + k); + } - Removes elements from a JSON object with the key value @a key. + if (k == 1) + { + // dE+123 + // len <= 1 + 5 - @param[in] key value of the elements to remove + buf += 1; + } + else + { + // d.igitsE+123 + // len <= max_digits10 + 1 + 5 - @return Number of elements removed. If @a ObjectType is the default - `std::map` type, the return value will always be `0` (@a key was not - found) or `1` (@a key was found). + std::memmove(buf + 2, buf + 1, static_cast(k - 1)); + buf[1] = '.'; + buf += 1 + k; + } - @post References and iterators to the erased elements are invalidated. - Other references and iterators are not affected. + *buf++ = 'e'; + return append_exponent(buf, n - 1); +} - @throw type_error.307 when called on a type other than JSON object; - example: `"cannot use erase() with null"` +} // namespace dtoa_impl - @complexity `log(size()) + count(key)` +/*! +@brief generates a decimal representation of the floating-point number value in [first, last). - @liveexample{The example shows the effect of `erase()`.,erase__key_type} +The format of the resulting decimal representation is similar to printf's %g +format. Returns an iterator pointing past-the-end of the decimal representation. - @sa @ref erase(IteratorType) -- removes the element at a given position - @sa @ref erase(IteratorType, IteratorType) -- removes the elements in - the given range - @sa @ref erase(const size_type) -- removes the element from an array at - the given index +@note The input number must be finite, i.e. NaN's and Inf's are not supported. +@note The buffer must be large enough. +@note The result is NOT null-terminated. +*/ +template +char* to_chars(char* first, char* last, FloatType value) +{ + static_cast(last); // maybe unused - fix warning + assert(std::isfinite(value)); - @since version 1.0.0 - */ - size_type erase(const typename object_t::key_type& key) + // Use signbit(value) instead of (value < 0) since signbit works for -0. + if (std::signbit(value)) { - // this erase only works for objects - if (is_object()) - { - return m_value.object->erase(key); - } + value = -value; + *first++ = '-'; + } - JSON_THROW(type_error::create(307, "cannot use erase() with " + type_name())); + if (value == 0) // +-0 + { + *first++ = '0'; + // Make it look like a floating-point number (#362, #378) + *first++ = '.'; + *first++ = '0'; + return first; } - /*! - @brief remove element from a JSON array given an index + assert(last - first >= std::numeric_limits::max_digits10); - Removes element from a JSON array at the index @a idx. + // Compute v = buffer * 10^decimal_exponent. + // The decimal digits are stored in the buffer, which needs to be interpreted + // as an unsigned decimal integer. + // len is the length of the buffer, i.e. the number of decimal digits. + int len = 0; + int decimal_exponent = 0; + dtoa_impl::grisu2(first, len, decimal_exponent, value); - @param[in] idx index of the element to remove + assert(len <= std::numeric_limits::max_digits10); - @throw type_error.307 when called on a type other than JSON object; - example: `"cannot use erase() with null"` - @throw out_of_range.401 when `idx >= size()`; example: `"array index 17 - is out of range"` + // Format the buffer like printf("%.*g", prec, value) + constexpr int kMinExp = -4; + // Use digits10 here to increase compatibility with version 2. + constexpr int kMaxExp = std::numeric_limits::digits10; - @complexity Linear in distance between @a idx and the end of the container. + assert(last - first >= kMaxExp + 2); + assert(last - first >= 2 + (-kMinExp - 1) + std::numeric_limits::max_digits10); + assert(last - first >= std::numeric_limits::max_digits10 + 6); - @liveexample{The example shows the effect of `erase()`.,erase__size_type} + return dtoa_impl::format_buffer(first, len, decimal_exponent, kMinExp, kMaxExp); +} - @sa @ref erase(IteratorType) -- removes the element at a given position - @sa @ref erase(IteratorType, IteratorType) -- removes the elements in - the given range - @sa @ref erase(const typename object_t::key_type&) -- removes the element - from an object at the given key +} // namespace detail +} // namespace nlohmann - @since version 1.0.0 - */ - void erase(const size_type idx) - { - // this erase only works for arrays - if (is_array()) - { - if (idx >= size()) - { - JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range")); - } +// #include - m_value.array->erase(m_value.array->begin() + static_cast(idx)); - } - else - { - JSON_THROW(type_error::create(307, "cannot use erase() with " + type_name())); - } - } +// #include - /// @} +// #include +// #include - //////////// - // lookup // - //////////// - /// @name lookup - /// @{ - - /*! - @brief find an element in a JSON object +namespace nlohmann +{ +namespace detail +{ +/////////////////// +// serialization // +/////////////////// - Finds an element in a JSON object with key equivalent to @a key. If the - element is not found or the JSON value is not an object, end() is - returned. +template +class serializer +{ + using string_t = typename BasicJsonType::string_t; + using number_float_t = typename BasicJsonType::number_float_t; + using number_integer_t = typename BasicJsonType::number_integer_t; + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + static constexpr uint8_t UTF8_ACCEPT = 0; + static constexpr uint8_t UTF8_REJECT = 1; - @note This method always returns @ref end() when executed on a JSON type - that is not an object. + public: + /*! + @param[in] s output stream to serialize to + @param[in] ichar indentation character to use + */ + serializer(output_adapter_t s, const char ichar) + : o(std::move(s)), loc(std::localeconv()), + thousands_sep(loc->thousands_sep == nullptr ? '\0' : * (loc->thousands_sep)), + decimal_point(loc->decimal_point == nullptr ? '\0' : * (loc->decimal_point)), + indent_char(ichar), indent_string(512, indent_char) + {} - @param[in] key key value of the element to search for + // delete because of pointer members + serializer(const serializer&) = delete; + serializer& operator=(const serializer&) = delete; - @return Iterator to an element with key equivalent to @a key. If no such - element is found or the JSON value is not an object, past-the-end (see - @ref end()) iterator is returned. + /*! + @brief internal implementation of the serialization function - @complexity Logarithmic in the size of the JSON object. + This function is called by the public member function dump and organizes + the serialization internally. The indentation level is propagated as + additional parameter. In case of arrays and objects, the function is + called recursively. - @liveexample{The example shows how `find()` is used.,find__key_type} + - strings and object keys are escaped using `escape_string()` + - integer numbers are converted implicitly via `operator<<` + - floating-point numbers are converted to a string using `"%g"` format - @since version 1.0.0 + @param[in] val value to serialize + @param[in] pretty_print whether the output shall be pretty-printed + @param[in] indent_step the indent level + @param[in] current_indent the current indent level (only used internally) */ - iterator find(typename object_t::key_type key) + void dump(const BasicJsonType& val, const bool pretty_print, + const bool ensure_ascii, + const unsigned int indent_step, + const unsigned int current_indent = 0) { - auto result = end(); - - if (is_object()) + switch (val.m_type) { - result.m_it.object_iterator = m_value.object->find(key); - } + case value_t::object: + { + if (val.m_value.object->empty()) + { + o->write_characters("{}", 2); + return; + } - return result; - } + if (pretty_print) + { + o->write_characters("{\n", 2); - /*! - @brief find an element in a JSON object - @copydoc find(typename object_t::key_type) - */ - const_iterator find(typename object_t::key_type key) const - { - auto result = cend(); + // variable to hold indentation for recursive calls + const auto new_indent = current_indent + indent_step; + if (JSON_UNLIKELY(indent_string.size() < new_indent)) + { + indent_string.resize(indent_string.size() * 2, ' '); + } - if (is_object()) - { - result.m_it.object_iterator = m_value.object->find(key); - } + // first n-1 elements + auto i = val.m_value.object->cbegin(); + for (std::size_t cnt = 0; cnt < val.m_value.object->size() - 1; ++cnt, ++i) + { + o->write_characters(indent_string.c_str(), new_indent); + o->write_character('\"'); + dump_escaped(i->first, ensure_ascii); + o->write_characters("\": ", 3); + dump(i->second, true, ensure_ascii, indent_step, new_indent); + o->write_characters(",\n", 2); + } - return result; - } + // last element + assert(i != val.m_value.object->cend()); + assert(std::next(i) == val.m_value.object->cend()); + o->write_characters(indent_string.c_str(), new_indent); + o->write_character('\"'); + dump_escaped(i->first, ensure_ascii); + o->write_characters("\": ", 3); + dump(i->second, true, ensure_ascii, indent_step, new_indent); - /*! - @brief returns the number of occurrences of a key in a JSON object + o->write_character('\n'); + o->write_characters(indent_string.c_str(), current_indent); + o->write_character('}'); + } + else + { + o->write_character('{'); - Returns the number of elements with key @a key. If ObjectType is the - default `std::map` type, the return value will always be `0` (@a key was - not found) or `1` (@a key was found). + // first n-1 elements + auto i = val.m_value.object->cbegin(); + for (std::size_t cnt = 0; cnt < val.m_value.object->size() - 1; ++cnt, ++i) + { + o->write_character('\"'); + dump_escaped(i->first, ensure_ascii); + o->write_characters("\":", 2); + dump(i->second, false, ensure_ascii, indent_step, current_indent); + o->write_character(','); + } - @note This method always returns `0` when executed on a JSON type that is - not an object. + // last element + assert(i != val.m_value.object->cend()); + assert(std::next(i) == val.m_value.object->cend()); + o->write_character('\"'); + dump_escaped(i->first, ensure_ascii); + o->write_characters("\":", 2); + dump(i->second, false, ensure_ascii, indent_step, current_indent); - @param[in] key key value of the element to count + o->write_character('}'); + } - @return Number of elements with key @a key. If the JSON value is not an - object, the return value will be `0`. + return; + } - @complexity Logarithmic in the size of the JSON object. + case value_t::array: + { + if (val.m_value.array->empty()) + { + o->write_characters("[]", 2); + return; + } - @liveexample{The example shows how `count()` is used.,count} + if (pretty_print) + { + o->write_characters("[\n", 2); - @since version 1.0.0 - */ - size_type count(typename object_t::key_type key) const - { - // return 0 for all nonobject types - return is_object() ? m_value.object->count(key) : 0; - } + // variable to hold indentation for recursive calls + const auto new_indent = current_indent + indent_step; + if (JSON_UNLIKELY(indent_string.size() < new_indent)) + { + indent_string.resize(indent_string.size() * 2, ' '); + } - /// @} + // first n-1 elements + for (auto i = val.m_value.array->cbegin(); + i != val.m_value.array->cend() - 1; ++i) + { + o->write_characters(indent_string.c_str(), new_indent); + dump(*i, true, ensure_ascii, indent_step, new_indent); + o->write_characters(",\n", 2); + } + // last element + assert(not val.m_value.array->empty()); + o->write_characters(indent_string.c_str(), new_indent); + dump(val.m_value.array->back(), true, ensure_ascii, indent_step, new_indent); - /////////////// - // iterators // - /////////////// + o->write_character('\n'); + o->write_characters(indent_string.c_str(), current_indent); + o->write_character(']'); + } + else + { + o->write_character('['); - /// @name iterators - /// @{ + // first n-1 elements + for (auto i = val.m_value.array->cbegin(); + i != val.m_value.array->cend() - 1; ++i) + { + dump(*i, false, ensure_ascii, indent_step, current_indent); + o->write_character(','); + } - /*! - @brief returns an iterator to the first element + // last element + assert(not val.m_value.array->empty()); + dump(val.m_value.array->back(), false, ensure_ascii, indent_step, current_indent); - Returns an iterator to the first element. + o->write_character(']'); + } - @image html range-begin-end.svg "Illustration from cppreference.com" + return; + } - @return iterator to the first element + case value_t::string: + { + o->write_character('\"'); + dump_escaped(*val.m_value.string, ensure_ascii); + o->write_character('\"'); + return; + } - @complexity Constant. + case value_t::boolean: + { + if (val.m_value.boolean) + { + o->write_characters("true", 4); + } + else + { + o->write_characters("false", 5); + } + return; + } - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. + case value_t::number_integer: + { + dump_integer(val.m_value.number_integer); + return; + } - @liveexample{The following code shows an example for `begin()`.,begin} + case value_t::number_unsigned: + { + dump_integer(val.m_value.number_unsigned); + return; + } - @sa @ref cbegin() -- returns a const iterator to the beginning - @sa @ref end() -- returns an iterator to the end - @sa @ref cend() -- returns a const iterator to the end + case value_t::number_float: + { + dump_float(val.m_value.number_float); + return; + } - @since version 1.0.0 - */ - iterator begin() noexcept - { - iterator result(this); - result.set_begin(); - return result; - } + case value_t::discarded: + { + o->write_characters("", 11); + return; + } - /*! - @copydoc basic_json::cbegin() - */ - const_iterator begin() const noexcept - { - return cbegin(); + case value_t::null: + { + o->write_characters("null", 4); + return; + } + } } + private: /*! - @brief returns a const iterator to the first element - - Returns a const iterator to the first element. + @brief dump escaped string - @image html range-begin-end.svg "Illustration from cppreference.com" + Escape a string by replacing certain special characters by a sequence of an + escape character (backslash) and another character and other control + characters by a sequence of "\u" followed by a four-digit hex + representation. The escaped string is written to output stream @a o. - @return const iterator to the first element + @param[in] s the string to escape + @param[in] ensure_ascii whether to escape non-ASCII characters with + \uXXXX sequences - @complexity Constant. + @complexity Linear in the length of string @a s. + */ + void dump_escaped(const string_t& s, const bool ensure_ascii) + { + uint32_t codepoint; + uint8_t state = UTF8_ACCEPT; + std::size_t bytes = 0; // number of bytes written to string_buffer - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - Has the semantics of `const_cast(*this).begin()`. + for (std::size_t i = 0; i < s.size(); ++i) + { + const auto byte = static_cast(s[i]); - @liveexample{The following code shows an example for `cbegin()`.,cbegin} + switch (decode(state, codepoint, byte)) + { + case UTF8_ACCEPT: // decode found a new code point + { + switch (codepoint) + { + case 0x08: // backspace + { + string_buffer[bytes++] = '\\'; + string_buffer[bytes++] = 'b'; + break; + } - @sa @ref begin() -- returns an iterator to the beginning - @sa @ref end() -- returns an iterator to the end - @sa @ref cend() -- returns a const iterator to the end + case 0x09: // horizontal tab + { + string_buffer[bytes++] = '\\'; + string_buffer[bytes++] = 't'; + break; + } - @since version 1.0.0 - */ - const_iterator cbegin() const noexcept - { - const_iterator result(this); - result.set_begin(); - return result; - } + case 0x0A: // newline + { + string_buffer[bytes++] = '\\'; + string_buffer[bytes++] = 'n'; + break; + } - /*! - @brief returns an iterator to one past the last element + case 0x0C: // formfeed + { + string_buffer[bytes++] = '\\'; + string_buffer[bytes++] = 'f'; + break; + } - Returns an iterator to one past the last element. + case 0x0D: // carriage return + { + string_buffer[bytes++] = '\\'; + string_buffer[bytes++] = 'r'; + break; + } - @image html range-begin-end.svg "Illustration from cppreference.com" + case 0x22: // quotation mark + { + string_buffer[bytes++] = '\\'; + string_buffer[bytes++] = '\"'; + break; + } - @return iterator one past the last element + case 0x5C: // reverse solidus + { + string_buffer[bytes++] = '\\'; + string_buffer[bytes++] = '\\'; + break; + } - @complexity Constant. + default: + { + // escape control characters (0x00..0x1F) or, if + // ensure_ascii parameter is used, non-ASCII characters + if ((codepoint <= 0x1F) or (ensure_ascii and (codepoint >= 0x7F))) + { + if (codepoint <= 0xFFFF) + { + std::snprintf(string_buffer.data() + bytes, 7, "\\u%04x", + static_cast(codepoint)); + bytes += 6; + } + else + { + std::snprintf(string_buffer.data() + bytes, 13, "\\u%04x\\u%04x", + static_cast(0xD7C0 + (codepoint >> 10)), + static_cast(0xDC00 + (codepoint & 0x3FF))); + bytes += 12; + } + } + else + { + // copy byte to buffer (all previous bytes + // been copied have in default case above) + string_buffer[bytes++] = s[i]; + } + break; + } + } - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. + // write buffer and reset index; there must be 13 bytes + // left, as this is the maximal number of bytes to be + // written ("\uxxxx\uxxxx\0") for one code point + if (string_buffer.size() - bytes < 13) + { + o->write_characters(string_buffer.data(), bytes); + bytes = 0; + } + break; + } - @liveexample{The following code shows an example for `end()`.,end} + case UTF8_REJECT: // decode found invalid UTF-8 byte + { + std::stringstream ss; + ss << std::setw(2) << std::uppercase << std::setfill('0') << std::hex << static_cast(byte); + JSON_THROW(type_error::create(316, "invalid UTF-8 byte at index " + std::to_string(i) + ": 0x" + ss.str())); + } - @sa @ref cend() -- returns a const iterator to the end - @sa @ref begin() -- returns an iterator to the beginning - @sa @ref cbegin() -- returns a const iterator to the beginning + default: // decode found yet incomplete multi-byte code point + { + if (not ensure_ascii) + { + // code point will not be escaped - copy byte to buffer + string_buffer[bytes++] = s[i]; + } + break; + } + } + } - @since version 1.0.0 - */ - iterator end() noexcept - { - iterator result(this); - result.set_end(); - return result; + if (JSON_LIKELY(state == UTF8_ACCEPT)) + { + // write buffer + if (bytes > 0) + { + o->write_characters(string_buffer.data(), bytes); + } + } + else + { + // we finish reading, but do not accept: string was incomplete + std::stringstream ss; + ss << std::setw(2) << std::uppercase << std::setfill('0') << std::hex << static_cast(static_cast(s.back())); + JSON_THROW(type_error::create(316, "incomplete UTF-8 string; last byte: 0x" + ss.str())); + } } /*! - @copydoc basic_json::cend() + @brief dump an integer + + Dump a given integer to output stream @a o. Works internally with + @a number_buffer. + + @param[in] x integer number (signed or unsigned) to dump + @tparam NumberType either @a number_integer_t or @a number_unsigned_t */ - const_iterator end() const noexcept + template::value or + std::is_same::value, + int> = 0> + void dump_integer(NumberType x) { - return cend(); - } - - /*! - @brief returns a const iterator to one past the last element + // special case for "0" + if (x == 0) + { + o->write_character('0'); + return; + } - Returns a const iterator to one past the last element. + const bool is_negative = (x <= 0) and (x != 0); // see issue #755 + std::size_t i = 0; - @image html range-begin-end.svg "Illustration from cppreference.com" + while (x != 0) + { + // spare 1 byte for '\0' + assert(i < number_buffer.size() - 1); - @return const iterator one past the last element + const auto digit = std::labs(static_cast(x % 10)); + number_buffer[i++] = static_cast('0' + digit); + x /= 10; + } - @complexity Constant. + if (is_negative) + { + // make sure there is capacity for the '-' + assert(i < number_buffer.size() - 2); + number_buffer[i++] = '-'; + } - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - Has the semantics of `const_cast(*this).end()`. + std::reverse(number_buffer.begin(), number_buffer.begin() + i); + o->write_characters(number_buffer.data(), i); + } - @liveexample{The following code shows an example for `cend()`.,cend} + /*! + @brief dump a floating-point number - @sa @ref end() -- returns an iterator to the end - @sa @ref begin() -- returns an iterator to the beginning - @sa @ref cbegin() -- returns a const iterator to the beginning + Dump a given floating-point number to output stream @a o. Works internally + with @a number_buffer. - @since version 1.0.0 + @param[in] x floating-point number to dump */ - const_iterator cend() const noexcept + void dump_float(number_float_t x) { - const_iterator result(this); - result.set_end(); - return result; + // NaN / inf + if (not std::isfinite(x)) + { + o->write_characters("null", 4); + return; + } + + // If number_float_t is an IEEE-754 single or double precision number, + // use the Grisu2 algorithm to produce short numbers which are + // guaranteed to round-trip, using strtof and strtod, resp. + // + // NB: The test below works if == . + static constexpr bool is_ieee_single_or_double + = (std::numeric_limits::is_iec559 and std::numeric_limits::digits == 24 and std::numeric_limits::max_exponent == 128) or + (std::numeric_limits::is_iec559 and std::numeric_limits::digits == 53 and std::numeric_limits::max_exponent == 1024); + + dump_float(x, std::integral_constant()); } - /*! - @brief returns an iterator to the reverse-beginning + void dump_float(number_float_t x, std::true_type /*is_ieee_single_or_double*/) + { + char* begin = number_buffer.data(); + char* end = ::nlohmann::detail::to_chars(begin, begin + number_buffer.size(), x); - Returns an iterator to the reverse-beginning; that is, the last element. + o->write_characters(begin, static_cast(end - begin)); + } - @image html range-rbegin-rend.svg "Illustration from cppreference.com" + void dump_float(number_float_t x, std::false_type /*is_ieee_single_or_double*/) + { + // get number of digits for a float -> text -> float round-trip + static constexpr auto d = std::numeric_limits::max_digits10; - @complexity Constant. + // the actual conversion + std::ptrdiff_t len = snprintf(number_buffer.data(), number_buffer.size(), "%.*g", d, x); - @requirement This function helps `basic_json` satisfying the - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) - requirements: - - The complexity is constant. - - Has the semantics of `reverse_iterator(end())`. + // negative value indicates an error + assert(len > 0); + // check if buffer was large enough + assert(static_cast(len) < number_buffer.size()); - @liveexample{The following code shows an example for `rbegin()`.,rbegin} + // erase thousands separator + if (thousands_sep != '\0') + { + const auto end = std::remove(number_buffer.begin(), + number_buffer.begin() + len, thousands_sep); + std::fill(end, number_buffer.end(), '\0'); + assert((end - number_buffer.begin()) <= len); + len = (end - number_buffer.begin()); + } - @sa @ref crbegin() -- returns a const reverse iterator to the beginning - @sa @ref rend() -- returns a reverse iterator to the end - @sa @ref crend() -- returns a const reverse iterator to the end + // convert decimal point to '.' + if (decimal_point != '\0' and decimal_point != '.') + { + const auto dec_pos = std::find(number_buffer.begin(), number_buffer.end(), decimal_point); + if (dec_pos != number_buffer.end()) + { + *dec_pos = '.'; + } + } - @since version 1.0.0 - */ - reverse_iterator rbegin() noexcept - { - return reverse_iterator(end()); + o->write_characters(number_buffer.data(), static_cast(len)); + + // determine if need to append ".0" + const bool value_is_int_like = + std::none_of(number_buffer.begin(), number_buffer.begin() + len + 1, + [](char c) + { + return (c == '.' or c == 'e'); + }); + + if (value_is_int_like) + { + o->write_characters(".0", 2); + } } /*! - @copydoc basic_json::crbegin() + @brief check whether a string is UTF-8 encoded + + The function checks each byte of a string whether it is UTF-8 encoded. The + result of the check is stored in the @a state parameter. The function must + be called initially with state 0 (accept). State 1 means the string must + be rejected, because the current byte is not allowed. If the string is + completely processed, but the state is non-zero, the string ended + prematurely; that is, the last byte indicated more bytes should have + followed. + + @param[in,out] state the state of the decoding + @param[in,out] codep codepoint (valid only if resulting state is UTF8_ACCEPT) + @param[in] byte next byte to decode + @return new state + + @note The function has been edited: a std::array is used. + + @copyright Copyright (c) 2008-2009 Bjoern Hoehrmann + @sa http://bjoern.hoehrmann.de/utf-8/decoder/dfa/ */ - const_reverse_iterator rbegin() const noexcept + static uint8_t decode(uint8_t& state, uint32_t& codep, const uint8_t byte) noexcept { - return crbegin(); + static const std::array utf8d = + { + { + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 00..1F + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 20..3F + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 40..5F + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 60..7F + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, // 80..9F + 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, // A0..BF + 8, 8, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, // C0..DF + 0xA, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x4, 0x3, 0x3, // E0..EF + 0xB, 0x6, 0x6, 0x6, 0x5, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, // F0..FF + 0x0, 0x1, 0x2, 0x3, 0x5, 0x8, 0x7, 0x1, 0x1, 0x1, 0x4, 0x6, 0x1, 0x1, 0x1, 0x1, // s0..s0 + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, // s1..s2 + 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, // s3..s4 + 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, // s5..s6 + 1, 3, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 // s7..s8 + } + }; + + const uint8_t type = utf8d[byte]; + + codep = (state != UTF8_ACCEPT) + ? (byte & 0x3fu) | (codep << 6) + : static_cast(0xff >> type) & (byte); + + state = utf8d[256u + state * 16u + type]; + return state; } - /*! - @brief returns an iterator to the reverse-end + private: + /// the output of the serializer + output_adapter_t o = nullptr; + + /// a (hopefully) large enough character buffer + std::array number_buffer{{}}; + + /// the locale + const std::lconv* loc = nullptr; + /// the locale's thousand separator character + const char thousands_sep = '\0'; + /// the locale's decimal point character + const char decimal_point = '\0'; + + /// string buffer + std::array string_buffer{{}}; + + /// the indentation character + const char indent_char; + /// the indentation string + string_t indent_string; +}; +} +} - Returns an iterator to the reverse-end; that is, one before the first - element. +// #include - @image html range-rbegin-rend.svg "Illustration from cppreference.com" - @complexity Constant. +#include +#include - @requirement This function helps `basic_json` satisfying the - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) - requirements: - - The complexity is constant. - - Has the semantics of `reverse_iterator(begin())`. +namespace nlohmann +{ +namespace detail +{ +template +class json_ref +{ + public: + using value_type = BasicJsonType; - @liveexample{The following code shows an example for `rend()`.,rend} + json_ref(value_type&& value) + : owned_value(std::move(value)), value_ref(&owned_value), is_rvalue(true) + {} - @sa @ref crend() -- returns a const reverse iterator to the end - @sa @ref rbegin() -- returns a reverse iterator to the beginning - @sa @ref crbegin() -- returns a const reverse iterator to the beginning + json_ref(const value_type& value) + : value_ref(const_cast(&value)), is_rvalue(false) + {} - @since version 1.0.0 - */ - reverse_iterator rend() noexcept + json_ref(std::initializer_list init) + : owned_value(init), value_ref(&owned_value), is_rvalue(true) + {} + + template + json_ref(Args&& ... args) + : owned_value(std::forward(args)...), value_ref(&owned_value), is_rvalue(true) + {} + + // class should be movable only + json_ref(json_ref&&) = default; + json_ref(const json_ref&) = delete; + json_ref& operator=(const json_ref&) = delete; + + value_type moved_or_copied() const { - return reverse_iterator(begin()); + if (is_rvalue) + { + return std::move(*value_ref); + } + return *value_ref; } - /*! - @copydoc basic_json::crend() - */ - const_reverse_iterator rend() const noexcept + value_type const& operator*() const { - return crend(); + return *static_cast(value_ref); } - /*! - @brief returns a const reverse iterator to the last element + value_type const* operator->() const + { + return static_cast(value_ref); + } - Returns a const iterator to the reverse-beginning; that is, the last - element. + private: + mutable value_type owned_value = nullptr; + value_type* value_ref = nullptr; + const bool is_rvalue; +}; +} +} - @image html range-rbegin-rend.svg "Illustration from cppreference.com" +// #include - @complexity Constant. - @requirement This function helps `basic_json` satisfying the - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) - requirements: - - The complexity is constant. - - Has the semantics of `const_cast(*this).rbegin()`. +#include // assert +#include // accumulate +#include // string +#include // vector - @liveexample{The following code shows an example for `crbegin()`.,crbegin} +// #include - @sa @ref rbegin() -- returns a reverse iterator to the beginning - @sa @ref rend() -- returns a reverse iterator to the end - @sa @ref crend() -- returns a const reverse iterator to the end +// #include - @since version 1.0.0 - */ - const_reverse_iterator crbegin() const noexcept - { - return const_reverse_iterator(cend()); - } +// #include + + +namespace nlohmann +{ +template +class json_pointer +{ + // allow basic_json to access private members + NLOHMANN_BASIC_JSON_TPL_DECLARATION + friend class basic_json; + public: /*! - @brief returns a const reverse iterator to one before the first + @brief create JSON pointer - Returns a const reverse iterator to the reverse-end; that is, one before - the first element. + Create a JSON pointer according to the syntax described in + [Section 3 of RFC6901](https://tools.ietf.org/html/rfc6901#section-3). - @image html range-rbegin-rend.svg "Illustration from cppreference.com" + @param[in] s string representing the JSON pointer; if omitted, the empty + string is assumed which references the whole JSON value - @complexity Constant. + @throw parse_error.107 if the given JSON pointer @a s is nonempty and does + not begin with a slash (`/`); see example below - @requirement This function helps `basic_json` satisfying the - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) - requirements: - - The complexity is constant. - - Has the semantics of `const_cast(*this).rend()`. + @throw parse_error.108 if a tilde (`~`) in the given JSON pointer @a s is + not followed by `0` (representing `~`) or `1` (representing `/`); see + example below - @liveexample{The following code shows an example for `crend()`.,crend} + @liveexample{The example shows the construction several valid JSON pointers + as well as the exceptional behavior.,json_pointer} - @sa @ref rend() -- returns a reverse iterator to the end - @sa @ref rbegin() -- returns a reverse iterator to the beginning - @sa @ref crbegin() -- returns a const reverse iterator to the beginning + @since version 2.0.0 + */ + explicit json_pointer(const std::string& s = "") + : reference_tokens(split(s)) + {} - @since version 1.0.0 + /*! + @brief return a string representation of the JSON pointer + + @invariant For each JSON pointer `ptr`, it holds: + @code {.cpp} + ptr == json_pointer(ptr.to_string()); + @endcode + + @return a string representation of the JSON pointer + + @liveexample{The example shows the result of `to_string`., + json_pointer__to_string} + + @since version 2.0.0 */ - const_reverse_iterator crend() const noexcept + std::string to_string() const noexcept { - return const_reverse_iterator(cbegin()); + return std::accumulate(reference_tokens.begin(), reference_tokens.end(), + std::string{}, + [](const std::string & a, const std::string & b) + { + return a + "/" + escape(b); + }); } - private: - // forward declaration - template class iteration_proxy; + /// @copydoc to_string() + operator std::string() const + { + return to_string(); + } - public: /*! - @brief wrapper to access iterator member functions in range-based for - - This function allows to access @ref iterator::key() and @ref - iterator::value() during range-based for loops. In these loops, a - reference to the JSON values is returned, so there is no access to the - underlying iterator. + @param[in] s reference token to be converted into an array index - @liveexample{The following code shows how the wrapper is used,iterator_wrapper} + @return integer representation of @a s - @note The name of this function is not yet final and may change in the - future. + @throw out_of_range.404 if string @a s could not be converted to an integer */ - static iteration_proxy iterator_wrapper(reference cont) + static int array_index(const std::string& s) { - return iteration_proxy(cont); + std::size_t processed_chars = 0; + const int res = std::stoi(s, &processed_chars); + + // check if the string was completely read + if (JSON_UNLIKELY(processed_chars != s.size())) + { + JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + s + "'")); + } + + return res; } + private: /*! - @copydoc iterator_wrapper(reference) + @brief remove and return last reference pointer + @throw out_of_range.405 if JSON pointer has no parent */ - static iteration_proxy iterator_wrapper(const_reference cont) + std::string pop_back() { - return iteration_proxy(cont); - } + if (JSON_UNLIKELY(is_root())) + { + JSON_THROW(detail::out_of_range::create(405, "JSON pointer has no parent")); + } - /// @} + auto last = reference_tokens.back(); + reference_tokens.pop_back(); + return last; + } + /// return whether pointer points to the root document + bool is_root() const + { + return reference_tokens.empty(); + } - ////////////// - // capacity // - ////////////// + json_pointer top() const + { + if (JSON_UNLIKELY(is_root())) + { + JSON_THROW(detail::out_of_range::create(405, "JSON pointer has no parent")); + } - /// @name capacity - /// @{ + json_pointer result = *this; + result.reference_tokens = {reference_tokens[0]}; + return result; + } /*! - @brief checks whether the container is empty + @brief create and return a reference to the pointed to value - Checks if a JSON value has no elements. + @complexity Linear in the number of reference tokens. - @return The return value depends on the different types and is - defined as follows: - Value type | return value - ----------- | ------------- - null | `true` - boolean | `false` - string | `false` - number | `false` - object | result of function `object_t::empty()` - array | result of function `array_t::empty()` - - @note This function does not return whether a string stored as JSON value - is empty - it returns whether the JSON container itself is empty which is - false in the case of a string. - - @complexity Constant, as long as @ref array_t and @ref object_t satisfy - the Container concept; that is, their `empty()` functions have constant - complexity. - - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - Has the semantics of `begin() == end()`. - - @liveexample{The following code uses `empty()` to check if a JSON - object contains any elements.,empty} - - @sa @ref size() -- returns the number of elements - - @since version 1.0.0 + @throw parse_error.109 if array index is not a number + @throw type_error.313 if value cannot be unflattened */ - bool empty() const noexcept + BasicJsonType& get_and_create(BasicJsonType& j) const { - switch (m_type) + using size_type = typename BasicJsonType::size_type; + auto result = &j; + + // in case no reference tokens exist, return a reference to the JSON value + // j which will be overwritten by a primitive value + for (const auto& reference_token : reference_tokens) { - case value_t::null: + switch (result->m_type) { - // null values are empty - return true; - } + case detail::value_t::null: + { + if (reference_token == "0") + { + // start a new array if reference token is 0 + result = &result->operator[](0); + } + else + { + // start a new object otherwise + result = &result->operator[](reference_token); + } + break; + } - case value_t::array: - { - // delegate call to array_t::empty() - return m_value.array->empty(); - } + case detail::value_t::object: + { + // create an entry in the object + result = &result->operator[](reference_token); + break; + } - case value_t::object: - { - // delegate call to object_t::empty() - return m_value.object->empty(); - } + case detail::value_t::array: + { + // create an entry in the array + JSON_TRY + { + result = &result->operator[](static_cast(array_index(reference_token))); + } + JSON_CATCH(std::invalid_argument&) + { + JSON_THROW(detail::parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); + } + break; + } - default: - { - // all other types are nonempty - return false; + /* + The following code is only reached if there exists a reference + token _and_ the current value is primitive. In this case, we have + an error situation, because primitive values may only occur as + single value; that is, with an empty list of reference tokens. + */ + default: + JSON_THROW(detail::type_error::create(313, "invalid value to unflatten")); } } + + return *result; } /*! - @brief returns the number of elements - - Returns the number of elements in a JSON value. - - @return The return value depends on the different types and is - defined as follows: - Value type | return value - ----------- | ------------- - null | `0` - boolean | `1` - string | `1` - number | `1` - object | result of function object_t::size() - array | result of function array_t::size() - - @note This function does not return the length of a string stored as JSON - value - it returns the number of elements in the JSON value which is 1 in - the case of a string. + @brief return a reference to the pointed to value - @complexity Constant, as long as @ref array_t and @ref object_t satisfy - the Container concept; that is, their size() functions have constant - complexity. + @note This version does not throw if a value is not present, but tries to + create nested values instead. For instance, calling this function + with pointer `"/this/that"` on a null value is equivalent to calling + `operator[]("this").operator[]("that")` on that value, effectively + changing the null value to an object. - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - Has the semantics of `std::distance(begin(), end())`. + @param[in] ptr a JSON value - @liveexample{The following code calls `size()` on the different value - types.,size} + @return reference to the JSON value pointed to by the JSON pointer - @sa @ref empty() -- checks whether the container is empty - @sa @ref max_size() -- returns the maximal number of elements + @complexity Linear in the length of the JSON pointer. - @since version 1.0.0 + @throw parse_error.106 if an array index begins with '0' + @throw parse_error.109 if an array index was not a number + @throw out_of_range.404 if the JSON pointer can not be resolved */ - size_type size() const noexcept + BasicJsonType& get_unchecked(BasicJsonType* ptr) const { - switch (m_type) + using size_type = typename BasicJsonType::size_type; + for (const auto& reference_token : reference_tokens) { - case value_t::null: + // convert null values to arrays or objects before continuing + if (ptr->m_type == detail::value_t::null) { - // null values are empty - return 0; - } + // check if reference token is a number + const bool nums = + std::all_of(reference_token.begin(), reference_token.end(), + [](const char x) + { + return (x >= '0' and x <= '9'); + }); - case value_t::array: - { - // delegate call to array_t::size() - return m_value.array->size(); + // change value to array for numbers or "-" or to object otherwise + *ptr = (nums or reference_token == "-") + ? detail::value_t::array + : detail::value_t::object; } - case value_t::object: + switch (ptr->m_type) { - // delegate call to object_t::size() - return m_value.object->size(); - } + case detail::value_t::object: + { + // use unchecked object access + ptr = &ptr->operator[](reference_token); + break; + } - default: - { - // all other types have size 1 - return 1; + case detail::value_t::array: + { + // error condition (cf. RFC 6901, Sect. 4) + if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0')) + { + JSON_THROW(detail::parse_error::create(106, 0, + "array index '" + reference_token + + "' must not begin with '0'")); + } + + if (reference_token == "-") + { + // explicitly treat "-" as index beyond the end + ptr = &ptr->operator[](ptr->m_value.array->size()); + } + else + { + // convert array index to number; unchecked access + JSON_TRY + { + ptr = &ptr->operator[]( + static_cast(array_index(reference_token))); + } + JSON_CATCH(std::invalid_argument&) + { + JSON_THROW(detail::parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); + } + } + break; + } + + default: + JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); } } + + return *ptr; } /*! - @brief returns the maximum possible number of elements - - Returns the maximum number of elements a JSON value is able to hold due to - system or library implementation limitations, i.e. `std::distance(begin(), - end())` for the JSON value. - - @return The return value depends on the different types and is - defined as follows: - Value type | return value - ----------- | ------------- - null | `0` (same as `size()`) - boolean | `1` (same as `size()`) - string | `1` (same as `size()`) - number | `1` (same as `size()`) - object | result of function `object_t::max_size()` - array | result of function `array_t::max_size()` - - @complexity Constant, as long as @ref array_t and @ref object_t satisfy - the Container concept; that is, their `max_size()` functions have constant - complexity. - - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - Has the semantics of returning `b.size()` where `b` is the largest - possible JSON value. - - @liveexample{The following code calls `max_size()` on the different value - types. Note the output is implementation specific.,max_size} - - @sa @ref size() -- returns the number of elements - - @since version 1.0.0 + @throw parse_error.106 if an array index begins with '0' + @throw parse_error.109 if an array index was not a number + @throw out_of_range.402 if the array index '-' is used + @throw out_of_range.404 if the JSON pointer can not be resolved */ - size_type max_size() const noexcept + BasicJsonType& get_checked(BasicJsonType* ptr) const { - switch (m_type) + using size_type = typename BasicJsonType::size_type; + for (const auto& reference_token : reference_tokens) { - case value_t::array: + switch (ptr->m_type) { - // delegate call to array_t::max_size() - return m_value.array->max_size(); - } - - case value_t::object: - { - // delegate call to object_t::max_size() - return m_value.object->max_size(); - } + case detail::value_t::object: + { + // note: at performs range check + ptr = &ptr->at(reference_token); + break; + } - default: - { - // all other types have max_size() == size() - return size(); - } - } - } + case detail::value_t::array: + { + if (JSON_UNLIKELY(reference_token == "-")) + { + // "-" always fails the range check + JSON_THROW(detail::out_of_range::create(402, + "array index '-' (" + std::to_string(ptr->m_value.array->size()) + + ") is out of range")); + } - /// @} + // error condition (cf. RFC 6901, Sect. 4) + if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0')) + { + JSON_THROW(detail::parse_error::create(106, 0, + "array index '" + reference_token + + "' must not begin with '0'")); + } + // note: at performs range check + JSON_TRY + { + ptr = &ptr->at(static_cast(array_index(reference_token))); + } + JSON_CATCH(std::invalid_argument&) + { + JSON_THROW(detail::parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); + } + break; + } - /////////////// - // modifiers // - /////////////// + default: + JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); + } + } - /// @name modifiers - /// @{ + return *ptr; + } /*! - @brief clears the contents - - Clears the content of a JSON value and resets it to the default value as - if @ref basic_json(value_t) would have been called: - - Value type | initial value - ----------- | ------------- - null | `null` - boolean | `false` - string | `""` - number | `0` - object | `{}` - array | `[]` + @brief return a const reference to the pointed to value - @complexity Linear in the size of the JSON value. + @param[in] ptr a JSON value - @liveexample{The example below shows the effect of `clear()` to different - JSON types.,clear} + @return const reference to the JSON value pointed to by the JSON + pointer - @since version 1.0.0 + @throw parse_error.106 if an array index begins with '0' + @throw parse_error.109 if an array index was not a number + @throw out_of_range.402 if the array index '-' is used + @throw out_of_range.404 if the JSON pointer can not be resolved */ - void clear() noexcept + const BasicJsonType& get_unchecked(const BasicJsonType* ptr) const { - switch (m_type) + using size_type = typename BasicJsonType::size_type; + for (const auto& reference_token : reference_tokens) { - case value_t::number_integer: + switch (ptr->m_type) { - m_value.number_integer = 0; - break; - } + case detail::value_t::object: + { + // use unchecked object access + ptr = &ptr->operator[](reference_token); + break; + } - case value_t::number_unsigned: - { - m_value.number_unsigned = 0; - break; - } + case detail::value_t::array: + { + if (JSON_UNLIKELY(reference_token == "-")) + { + // "-" cannot be used for const access + JSON_THROW(detail::out_of_range::create(402, + "array index '-' (" + std::to_string(ptr->m_value.array->size()) + + ") is out of range")); + } - case value_t::number_float: - { - m_value.number_float = 0.0; - break; - } + // error condition (cf. RFC 6901, Sect. 4) + if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0')) + { + JSON_THROW(detail::parse_error::create(106, 0, + "array index '" + reference_token + + "' must not begin with '0'")); + } - case value_t::boolean: - { - m_value.boolean = false; - break; - } + // use unchecked array access + JSON_TRY + { + ptr = &ptr->operator[]( + static_cast(array_index(reference_token))); + } + JSON_CATCH(std::invalid_argument&) + { + JSON_THROW(detail::parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); + } + break; + } - case value_t::string: - { - m_value.string->clear(); - break; + default: + JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); } + } - case value_t::array: - { - m_value.array->clear(); - break; - } + return *ptr; + } - case value_t::object: + /*! + @throw parse_error.106 if an array index begins with '0' + @throw parse_error.109 if an array index was not a number + @throw out_of_range.402 if the array index '-' is used + @throw out_of_range.404 if the JSON pointer can not be resolved + */ + const BasicJsonType& get_checked(const BasicJsonType* ptr) const + { + using size_type = typename BasicJsonType::size_type; + for (const auto& reference_token : reference_tokens) + { + switch (ptr->m_type) { - m_value.object->clear(); - break; - } + case detail::value_t::object: + { + // note: at performs range check + ptr = &ptr->at(reference_token); + break; + } - default: - { - break; - } - } - } + case detail::value_t::array: + { + if (JSON_UNLIKELY(reference_token == "-")) + { + // "-" always fails the range check + JSON_THROW(detail::out_of_range::create(402, + "array index '-' (" + std::to_string(ptr->m_value.array->size()) + + ") is out of range")); + } - /*! - @brief add an object to an array + // error condition (cf. RFC 6901, Sect. 4) + if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0')) + { + JSON_THROW(detail::parse_error::create(106, 0, + "array index '" + reference_token + + "' must not begin with '0'")); + } - Appends the given element @a val to the end of the JSON value. If the - function is called on a JSON null value, an empty array is created before - appending @a val. + // note: at performs range check + JSON_TRY + { + ptr = &ptr->at(static_cast(array_index(reference_token))); + } + JSON_CATCH(std::invalid_argument&) + { + JSON_THROW(detail::parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); + } + break; + } - @param[in] val the value to add to the JSON array + default: + JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); + } + } - @throw type_error.308 when called on a type other than JSON array or - null; example: `"cannot use push_back() with number"` + return *ptr; + } - @complexity Amortized constant. + /*! + @brief split the string input to reference tokens - @liveexample{The example shows how `push_back()` and `+=` can be used to - add elements to a JSON array. Note how the `null` value was silently - converted to a JSON array.,push_back} + @note This function is only called by the json_pointer constructor. + All exceptions below are documented there. - @since version 1.0.0 + @throw parse_error.107 if the pointer is not empty or begins with '/' + @throw parse_error.108 if character '~' is not followed by '0' or '1' */ - void push_back(basic_json&& val) + static std::vector split(const std::string& reference_string) { - // push_back only works for null objects or arrays - if (not(is_null() or is_array())) + std::vector result; + + // special case: empty reference string -> no reference tokens + if (reference_string.empty()) { - JSON_THROW(type_error::create(308, "cannot use push_back() with " + type_name())); + return result; } - // transform null object into an array - if (is_null()) + // check if nonempty reference string begins with slash + if (JSON_UNLIKELY(reference_string[0] != '/')) { - m_type = value_t::array; - m_value = value_t::array; - assert_invariant(); + JSON_THROW(detail::parse_error::create(107, 1, + "JSON pointer must be empty or begin with '/' - was: '" + + reference_string + "'")); } - // add element to array (move semantics) - m_value.array->push_back(std::move(val)); - // invalidate object - val.m_type = value_t::null; + // extract the reference tokens: + // - slash: position of the last read slash (or end of string) + // - start: position after the previous slash + for ( + // search for the first slash after the first character + std::size_t slash = reference_string.find_first_of('/', 1), + // set the beginning of the first reference token + start = 1; + // we can stop if start == string::npos+1 = 0 + start != 0; + // set the beginning of the next reference token + // (will eventually be 0 if slash == std::string::npos) + start = slash + 1, + // find next slash + slash = reference_string.find_first_of('/', start)) + { + // use the text between the beginning of the reference token + // (start) and the last slash (slash). + auto reference_token = reference_string.substr(start, slash - start); + + // check reference tokens are properly escaped + for (std::size_t pos = reference_token.find_first_of('~'); + pos != std::string::npos; + pos = reference_token.find_first_of('~', pos + 1)) + { + assert(reference_token[pos] == '~'); + + // ~ must be followed by 0 or 1 + if (JSON_UNLIKELY(pos == reference_token.size() - 1 or + (reference_token[pos + 1] != '0' and + reference_token[pos + 1] != '1'))) + { + JSON_THROW(detail::parse_error::create(108, 0, "escape character '~' must be followed with '0' or '1'")); + } + } + + // finally, store the reference token + unescape(reference_token); + result.push_back(reference_token); + } + + return result; } /*! - @brief add an object to an array - @copydoc push_back(basic_json&&) + @brief replace all occurrences of a substring by another string + + @param[in,out] s the string to manipulate; changed so that all + occurrences of @a f are replaced with @a t + @param[in] f the substring to replace with @a t + @param[in] t the string to replace @a f + + @pre The search string @a f must not be empty. **This precondition is + enforced with an assertion.** + + @since version 2.0.0 */ - reference operator+=(basic_json&& val) + static void replace_substring(std::string& s, const std::string& f, + const std::string& t) { - push_back(std::move(val)); - return *this; + assert(not f.empty()); + for (auto pos = s.find(f); // find first occurrence of f + pos != std::string::npos; // make sure f was found + s.replace(pos, f.size(), t), // replace with t, and + pos = s.find(f, pos + t.size())) // find next occurrence of f + {} } - /*! - @brief add an object to an array - @copydoc push_back(basic_json&&) - */ - void push_back(const basic_json& val) + /// escape "~"" to "~0" and "/" to "~1" + static std::string escape(std::string s) { - // push_back only works for null objects or arrays - if (not(is_null() or is_array())) - { - JSON_THROW(type_error::create(308, "cannot use push_back() with " + type_name())); - } - - // transform null object into an array - if (is_null()) - { - m_type = value_t::array; - m_value = value_t::array; - assert_invariant(); - } - - // add element to array - m_value.array->push_back(val); + replace_substring(s, "~", "~0"); + replace_substring(s, "/", "~1"); + return s; } - /*! - @brief add an object to an array - @copydoc push_back(basic_json&&) - */ - reference operator+=(const basic_json& val) + /// unescape "~1" to tilde and "~0" to slash (order is important!) + static void unescape(std::string& s) { - push_back(val); - return *this; + replace_substring(s, "~1", "/"); + replace_substring(s, "~0", "~"); } /*! - @brief add an object to an object + @param[in] reference_string the reference string to the current value + @param[in] value the value to consider + @param[in,out] result the result object to insert values to - Inserts the given element @a val to the JSON object. If the function is - called on a JSON null value, an empty object is created before inserting - @a val. + @note Empty objects or arrays are flattened to `null`. + */ + static void flatten(const std::string& reference_string, + const BasicJsonType& value, + BasicJsonType& result) + { + switch (value.m_type) + { + case detail::value_t::array: + { + if (value.m_value.array->empty()) + { + // flatten empty array as null + result[reference_string] = nullptr; + } + else + { + // iterate array and use index as reference string + for (std::size_t i = 0; i < value.m_value.array->size(); ++i) + { + flatten(reference_string + "/" + std::to_string(i), + value.m_value.array->operator[](i), result); + } + } + break; + } - @param[in] val the value to add to the JSON object + case detail::value_t::object: + { + if (value.m_value.object->empty()) + { + // flatten empty object as null + result[reference_string] = nullptr; + } + else + { + // iterate object and use keys as reference string + for (const auto& element : *value.m_value.object) + { + flatten(reference_string + "/" + escape(element.first), element.second, result); + } + } + break; + } - @throw type_error.308 when called on a type other than JSON object or - null; example: `"cannot use push_back() with number"` + default: + { + // add primitive value with its reference string + result[reference_string] = value; + break; + } + } + } - @complexity Logarithmic in the size of the container, O(log(`size()`)). + /*! + @param[in] value flattened JSON - @liveexample{The example shows how `push_back()` and `+=` can be used to - add elements to a JSON object. Note how the `null` value was silently - converted to a JSON object.,push_back__object_t__value} + @return unflattened JSON - @since version 1.0.0 + @throw parse_error.109 if array index is not a number + @throw type_error.314 if value is not an object + @throw type_error.315 if object values are not primitive + @throw type_error.313 if value cannot be unflattened */ - void push_back(const typename object_t::value_type& val) + static BasicJsonType + unflatten(const BasicJsonType& value) { - // push_back only works for null objects or objects - if (not(is_null() or is_object())) + if (JSON_UNLIKELY(not value.is_object())) { - JSON_THROW(type_error::create(308, "cannot use push_back() with " + type_name())); + JSON_THROW(detail::type_error::create(314, "only objects can be unflattened")); } - // transform null object into an object - if (is_null()) + BasicJsonType result; + + // iterate the JSON object values + for (const auto& element : *value.m_value.object) { - m_type = value_t::object; - m_value = value_t::object; - assert_invariant(); + if (JSON_UNLIKELY(not element.second.is_primitive())) + { + JSON_THROW(detail::type_error::create(315, "values in object must be primitive")); + } + + // assign value to reference pointed to by JSON pointer; Note that if + // the JSON pointer is "" (i.e., points to the whole value), function + // get_and_create returns a reference to result itself. An assignment + // will then create a primitive value. + json_pointer(element.first).get_and_create(result) = element.second; } - // add element to array - m_value.object->insert(val); + return result; } - /*! - @brief add an object to an object - @copydoc push_back(const typename object_t::value_type&) - */ - reference operator+=(const typename object_t::value_type& val) + friend bool operator==(json_pointer const& lhs, + json_pointer const& rhs) noexcept { - push_back(val); - return *this; + return (lhs.reference_tokens == rhs.reference_tokens); } - /*! - @brief add an object to an object + friend bool operator!=(json_pointer const& lhs, + json_pointer const& rhs) noexcept + { + return not (lhs == rhs); + } - This function allows to use `push_back` with an initializer list. In case + /// the reference tokens + std::vector reference_tokens; +}; +} - 1. the current value is an object, - 2. the initializer list @a init contains only two elements, and - 3. the first element of @a init is a string, +// #include - @a init is converted into an object element and added using - @ref push_back(const typename object_t::value_type&). Otherwise, @a init - is converted to a JSON value and added using @ref push_back(basic_json&&). - @param[in] init an initializer list +#include - @complexity Linear in the size of the initializer list @a init. +// #include - @note This function is required to resolve an ambiguous overload error, - because pairs like `{"key", "value"}` can be both interpreted as - `object_t::value_type` or `std::initializer_list`, see - https://github.com/nlohmann/json/issues/235 for more information. +// #include - @liveexample{The example shows how initializer lists are treated as - objects when possible.,push_back__initializer_list} + +namespace nlohmann +{ +template +struct adl_serializer +{ + /*! + @brief convert a JSON value to any value type + + This function is usually called by the `get()` function of the + @ref basic_json class (either explicit or via conversion operators). + + @param[in] j JSON value to read from + @param[in,out] val value to write to */ - void push_back(std::initializer_list init) + template + static void from_json(BasicJsonType&& j, ValueType& val) noexcept( + noexcept(::nlohmann::from_json(std::forward(j), val))) { - if (is_object() and init.size() == 2 and init.begin()->is_string()) - { - const string_t key = *init.begin(); - push_back(typename object_t::value_type(key, *(init.begin() + 1))); - } - else - { - push_back(basic_json(init)); - } + ::nlohmann::from_json(std::forward(j), val); } /*! - @brief add an object to an object - @copydoc push_back(std::initializer_list) + @brief convert any value type to a JSON value + + This function is usually called by the constructors of the @ref basic_json + class. + + @param[in,out] j JSON value to write to + @param[in] val value to read from */ - reference operator+=(std::initializer_list init) + template + static void to_json(BasicJsonType& j, ValueType&& val) noexcept( + noexcept(::nlohmann::to_json(j, std::forward(val)))) { - push_back(init); - return *this; + ::nlohmann::to_json(j, std::forward(val)); } +}; +} - /*! - @brief add an object to an array - Creates a JSON value from the passed parameters @a args to the end of the - JSON value. If the function is called on a JSON null value, an empty array - is created before appending the value created from @a args. +/*! +@brief namespace for Niels Lohmann +@see https://github.com/nlohmann +@since version 1.0.0 +*/ +namespace nlohmann +{ - @param[in] args arguments to forward to a constructor of @ref basic_json - @tparam Args compatible types to create a @ref basic_json object +/*! +@brief a class to store JSON values - @throw type_error.311 when called on a type other than JSON array or - null; example: `"cannot use emplace_back() with number"` +@tparam ObjectType type for JSON objects (`std::map` by default; will be used +in @ref object_t) +@tparam ArrayType type for JSON arrays (`std::vector` by default; will be used +in @ref array_t) +@tparam StringType type for JSON strings and object keys (`std::string` by +default; will be used in @ref string_t) +@tparam BooleanType type for JSON booleans (`bool` by default; will be used +in @ref boolean_t) +@tparam NumberIntegerType type for JSON integer numbers (`int64_t` by +default; will be used in @ref number_integer_t) +@tparam NumberUnsignedType type for JSON unsigned integer numbers (@c +`uint64_t` by default; will be used in @ref number_unsigned_t) +@tparam NumberFloatType type for JSON floating-point numbers (`double` by +default; will be used in @ref number_float_t) +@tparam AllocatorType type of the allocator to use (`std::allocator` by +default) +@tparam JSONSerializer the serializer to resolve internal calls to `to_json()` +and `from_json()` (@ref adl_serializer by default) - @complexity Amortized constant. +@requirement The class satisfies the following concept requirements: +- Basic + - [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible): + JSON values can be default constructed. The result will be a JSON null + value. + - [MoveConstructible](http://en.cppreference.com/w/cpp/concept/MoveConstructible): + A JSON value can be constructed from an rvalue argument. + - [CopyConstructible](http://en.cppreference.com/w/cpp/concept/CopyConstructible): + A JSON value can be copy-constructed from an lvalue expression. + - [MoveAssignable](http://en.cppreference.com/w/cpp/concept/MoveAssignable): + A JSON value van be assigned from an rvalue argument. + - [CopyAssignable](http://en.cppreference.com/w/cpp/concept/CopyAssignable): + A JSON value can be copy-assigned from an lvalue expression. + - [Destructible](http://en.cppreference.com/w/cpp/concept/Destructible): + JSON values can be destructed. +- Layout + - [StandardLayoutType](http://en.cppreference.com/w/cpp/concept/StandardLayoutType): + JSON values have + [standard layout](http://en.cppreference.com/w/cpp/language/data_members#Standard_layout): + All non-static data members are private and standard layout types, the + class has no virtual functions or (virtual) base classes. +- Library-wide + - [EqualityComparable](http://en.cppreference.com/w/cpp/concept/EqualityComparable): + JSON values can be compared with `==`, see @ref + operator==(const_reference,const_reference). + - [LessThanComparable](http://en.cppreference.com/w/cpp/concept/LessThanComparable): + JSON values can be compared with `<`, see @ref + operator<(const_reference,const_reference). + - [Swappable](http://en.cppreference.com/w/cpp/concept/Swappable): + Any JSON lvalue or rvalue of can be swapped with any lvalue or rvalue of + other compatible types, using unqualified function call @ref swap(). + - [NullablePointer](http://en.cppreference.com/w/cpp/concept/NullablePointer): + JSON values can be compared against `std::nullptr_t` objects which are used + to model the `null` value. +- Container + - [Container](http://en.cppreference.com/w/cpp/concept/Container): + JSON values can be used like STL containers and provide iterator access. + - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer); + JSON values can be used like STL containers and provide reverse iterator + access. - @liveexample{The example shows how `push_back()` can be used to add - elements to a JSON array. Note how the `null` value was silently converted - to a JSON array.,emplace_back} +@invariant The member variables @a m_value and @a m_type have the following +relationship: +- If `m_type == value_t::object`, then `m_value.object != nullptr`. +- If `m_type == value_t::array`, then `m_value.array != nullptr`. +- If `m_type == value_t::string`, then `m_value.string != nullptr`. +The invariants are checked by member function assert_invariant(). - @since version 2.0.8 - */ - template - void emplace_back(Args&& ... args) - { - // emplace_back only works for null objects or arrays - if (not(is_null() or is_array())) - { - JSON_THROW(type_error::create(311, "cannot use emplace_back() with " + type_name())); - } +@internal +@note ObjectType trick from http://stackoverflow.com/a/9860911 +@endinternal - // transform null object into an array - if (is_null()) - { - m_type = value_t::array; - m_value = value_t::array; - assert_invariant(); - } +@see [RFC 7159: The JavaScript Object Notation (JSON) Data Interchange +Format](http://rfc7159.net/rfc7159) - // add element to array (perfect forwarding) - m_value.array->emplace_back(std::forward(args)...); - } +@since version 1.0.0 - /*! - @brief add an object to an object if key does not exist +@nosubgrouping +*/ +NLOHMANN_BASIC_JSON_TPL_DECLARATION +class basic_json +{ + private: + template friend struct detail::external_constructor; + friend ::nlohmann::json_pointer; + friend ::nlohmann::detail::parser; + friend ::nlohmann::detail::serializer; + template + friend class ::nlohmann::detail::iter_impl; + template + friend class ::nlohmann::detail::binary_writer; + template + friend class ::nlohmann::detail::binary_reader; - Inserts a new element into a JSON object constructed in-place with the - given @a args if there is no element with the key in the container. If the - function is called on a JSON null value, an empty object is created before - appending the value created from @a args. + /// workaround type for MSVC + using basic_json_t = NLOHMANN_BASIC_JSON_TPL; - @param[in] args arguments to forward to a constructor of @ref basic_json - @tparam Args compatible types to create a @ref basic_json object + // convenience aliases for types residing in namespace detail; + using lexer = ::nlohmann::detail::lexer; + using parser = ::nlohmann::detail::parser; - @return a pair consisting of an iterator to the inserted element, or the - already-existing element if no insertion happened, and a bool - denoting whether the insertion took place. + using primitive_iterator_t = ::nlohmann::detail::primitive_iterator_t; + template + using internal_iterator = ::nlohmann::detail::internal_iterator; + template + using iter_impl = ::nlohmann::detail::iter_impl; + template + using iteration_proxy = ::nlohmann::detail::iteration_proxy; + template using json_reverse_iterator = ::nlohmann::detail::json_reverse_iterator; - @throw type_error.311 when called on a type other than JSON object or - null; example: `"cannot use emplace() with number"` + template + using output_adapter_t = ::nlohmann::detail::output_adapter_t; - @complexity Logarithmic in the size of the container, O(log(`size()`)). + using binary_reader = ::nlohmann::detail::binary_reader; + template using binary_writer = ::nlohmann::detail::binary_writer; - @liveexample{The example shows how `emplace()` can be used to add elements - to a JSON object. Note how the `null` value was silently converted to a - JSON object. Further note how no value is added if there was already one - value stored with the same key.,emplace} + using serializer = ::nlohmann::detail::serializer; - @since version 2.0.8 - */ - template - std::pair emplace(Args&& ... args) - { - // emplace only works for null objects or arrays - if (not(is_null() or is_object())) - { - JSON_THROW(type_error::create(311, "cannot use emplace() with " + type_name())); - } + public: + using value_t = detail::value_t; + /// @copydoc nlohmann::json_pointer + using json_pointer = ::nlohmann::json_pointer; + template + using json_serializer = JSONSerializer; + /// helper type for initializer lists of basic_json values + using initializer_list_t = std::initializer_list>; - // transform null object into an object - if (is_null()) - { - m_type = value_t::object; - m_value = value_t::object; - assert_invariant(); - } + //////////////// + // exceptions // + //////////////// - // add element to array (perfect forwarding) - auto res = m_value.object->emplace(std::forward(args)...); - // create result iterator and set iterator to the result of emplace - auto it = begin(); - it.m_it.object_iterator = res.first; + /// @name exceptions + /// Classes to implement user-defined exceptions. + /// @{ - // return pair of iterator and boolean - return {it, res.second}; - } + /// @copydoc detail::exception + using exception = detail::exception; + /// @copydoc detail::parse_error + using parse_error = detail::parse_error; + /// @copydoc detail::invalid_iterator + using invalid_iterator = detail::invalid_iterator; + /// @copydoc detail::type_error + using type_error = detail::type_error; + /// @copydoc detail::out_of_range + using out_of_range = detail::out_of_range; + /// @copydoc detail::other_error + using other_error = detail::other_error; - /*! - @brief inserts element + /// @} - Inserts element @a val before iterator @a pos. - @param[in] pos iterator before which the content will be inserted; may be - the end() iterator - @param[in] val element to insert - @return iterator pointing to the inserted @a val. + ///////////////////// + // container types // + ///////////////////// - @throw type_error.309 if called on JSON values other than arrays; - example: `"cannot use insert() with string"` - @throw invalid_iterator.202 if @a pos is not an iterator of *this; - example: `"iterator does not fit current value"` + /// @name container types + /// The canonic container types to use @ref basic_json like any other STL + /// container. + /// @{ - @complexity Constant plus linear in the distance between @a pos and end of - the container. + /// the type of elements in a basic_json container + using value_type = basic_json; - @liveexample{The example shows how `insert()` is used.,insert} + /// the type of an element reference + using reference = value_type&; + /// the type of an element const reference + using const_reference = const value_type&; - @since version 1.0.0 - */ - iterator insert(const_iterator pos, const basic_json& val) - { - // insert only works for arrays - if (is_array()) - { - // check if iterator pos fits to this JSON value - if (pos.m_object != this) - { - JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); - } + /// a type to represent differences between iterators + using difference_type = std::ptrdiff_t; + /// a type to represent container sizes + using size_type = std::size_t; - // insert to array and return iterator - iterator result(this); - result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, val); - return result; - } + /// the allocator type + using allocator_type = AllocatorType; - JSON_THROW(type_error::create(309, "cannot use insert() with " + type_name())); - } + /// the type of an element pointer + using pointer = typename std::allocator_traits::pointer; + /// the type of an element const pointer + using const_pointer = typename std::allocator_traits::const_pointer; - /*! - @brief inserts element - @copydoc insert(const_iterator, const basic_json&) + /// an iterator for a basic_json container + using iterator = iter_impl; + /// a const iterator for a basic_json container + using const_iterator = iter_impl; + /// a reverse iterator for a basic_json container + using reverse_iterator = json_reverse_iterator; + /// a const reverse iterator for a basic_json container + using const_reverse_iterator = json_reverse_iterator; + + /// @} + + + /*! + @brief returns the allocator associated with the container */ - iterator insert(const_iterator pos, basic_json&& val) + static allocator_type get_allocator() { - return insert(pos, val); + return allocator_type(); } /*! - @brief inserts elements + @brief returns version information on the library - Inserts @a cnt copies of @a val before iterator @a pos. + This function returns a JSON object with information about the library, + including the version number and information on the platform and compiler. - @param[in] pos iterator before which the content will be inserted; may be - the end() iterator - @param[in] cnt number of copies of @a val to insert - @param[in] val element to insert - @return iterator pointing to the first element inserted, or @a pos if - `cnt==0` + @return JSON object holding version information + key | description + ----------- | --------------- + `compiler` | Information on the used compiler. It is an object with the following keys: `c++` (the used C++ standard), `family` (the compiler family; possible values are `clang`, `icc`, `gcc`, `ilecpp`, `msvc`, `pgcpp`, `sunpro`, and `unknown`), and `version` (the compiler version). + `copyright` | The copyright line for the library as string. + `name` | The name of the library as string. + `platform` | The used platform as string. Possible values are `win32`, `linux`, `apple`, `unix`, and `unknown`. + `url` | The URL of the project as string. + `version` | The version of the library. It is an object with the following keys: `major`, `minor`, and `patch` as defined by [Semantic Versioning](http://semver.org), and `string` (the version string). - @throw type_error.309 if called on JSON values other than arrays; example: - `"cannot use insert() with string"` - @throw invalid_iterator.202 if @a pos is not an iterator of *this; - example: `"iterator does not fit current value"` + @liveexample{The following code shows an example output of the `meta()` + function.,meta} - @complexity Linear in @a cnt plus linear in the distance between @a pos - and end of the container. + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. - @liveexample{The example shows how `insert()` is used.,insert__count} + @complexity Constant. - @since version 1.0.0 + @since 2.1.0 */ - iterator insert(const_iterator pos, size_type cnt, const basic_json& val) + static basic_json meta() { - // insert only works for arrays - if (is_array()) - { - // check if iterator pos fits to this JSON value - if (pos.m_object != this) - { - JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); - } + basic_json result; - // insert to array and return iterator - iterator result(this); - result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, cnt, val); - return result; - } + result["copyright"] = "(C) 2013-2017 Niels Lohmann"; + result["name"] = "JSON for Modern C++"; + result["url"] = "https://github.com/nlohmann/json"; + result["version"]["string"] = + std::to_string(NLOHMANN_JSON_VERSION_MAJOR) + "." + + std::to_string(NLOHMANN_JSON_VERSION_MINOR) + "." + + std::to_string(NLOHMANN_JSON_VERSION_PATCH); + result["version"]["major"] = NLOHMANN_JSON_VERSION_MAJOR; + result["version"]["minor"] = NLOHMANN_JSON_VERSION_MINOR; + result["version"]["patch"] = NLOHMANN_JSON_VERSION_PATCH; + +#ifdef _WIN32 + result["platform"] = "win32"; +#elif defined __linux__ + result["platform"] = "linux"; +#elif defined __APPLE__ + result["platform"] = "apple"; +#elif defined __unix__ + result["platform"] = "unix"; +#else + result["platform"] = "unknown"; +#endif + +#if defined(__ICC) || defined(__INTEL_COMPILER) + result["compiler"] = {{"family", "icc"}, {"version", __INTEL_COMPILER}}; +#elif defined(__clang__) + result["compiler"] = {{"family", "clang"}, {"version", __clang_version__}}; +#elif defined(__GNUC__) || defined(__GNUG__) + result["compiler"] = {{"family", "gcc"}, {"version", std::to_string(__GNUC__) + "." + std::to_string(__GNUC_MINOR__) + "." + std::to_string(__GNUC_PATCHLEVEL__)}}; +#elif defined(__HP_cc) || defined(__HP_aCC) + result["compiler"] = "hp" +#elif defined(__IBMCPP__) + result["compiler"] = {{"family", "ilecpp"}, {"version", __IBMCPP__}}; +#elif defined(_MSC_VER) + result["compiler"] = {{"family", "msvc"}, {"version", _MSC_VER}}; +#elif defined(__PGI) + result["compiler"] = {{"family", "pgcpp"}, {"version", __PGI}}; +#elif defined(__SUNPRO_CC) + result["compiler"] = {{"family", "sunpro"}, {"version", __SUNPRO_CC}}; +#else + result["compiler"] = {{"family", "unknown"}, {"version", "unknown"}}; +#endif - JSON_THROW(type_error::create(309, "cannot use insert() with " + type_name())); +#ifdef __cplusplus + result["compiler"]["c++"] = std::to_string(__cplusplus); +#else + result["compiler"]["c++"] = "unknown"; +#endif + return result; } - /*! - @brief inserts elements - Inserts elements from range `[first, last)` before iterator @a pos. + /////////////////////////// + // JSON value data types // + /////////////////////////// - @param[in] pos iterator before which the content will be inserted; may be - the end() iterator - @param[in] first begin of the range of elements to insert - @param[in] last end of the range of elements to insert + /// @name JSON value data types + /// The data types to store a JSON value. These types are derived from + /// the template arguments passed to class @ref basic_json. + /// @{ - @throw type_error.309 if called on JSON values other than arrays; example: - `"cannot use insert() with string"` - @throw invalid_iterator.202 if @a pos is not an iterator of *this; - example: `"iterator does not fit current value"` - @throw invalid_iterator.210 if @a first and @a last do not belong to the - same JSON value; example: `"iterators do not fit"` - @throw invalid_iterator.211 if @a first or @a last are iterators into - container for which insert is called; example: `"passed iterators may not - belong to container"` +#if defined(JSON_HAS_CPP_14) + // Use transparent comparator if possible, combined with perfect forwarding + // on find() and count() calls prevents unnecessary string construction. + using object_comparator_t = std::less<>; +#else + using object_comparator_t = std::less; +#endif - @return iterator pointing to the first element inserted, or @a pos if - `first==last` + /*! + @brief a type for an object - @complexity Linear in `std::distance(first, last)` plus linear in the - distance between @a pos and end of the container. + [RFC 7159](http://rfc7159.net/rfc7159) describes JSON objects as follows: + > An object is an unordered collection of zero or more name/value pairs, + > where a name is a string and a value is a string, number, boolean, null, + > object, or array. - @liveexample{The example shows how `insert()` is used.,insert__range} + To store objects in C++, a type is defined by the template parameters + described below. - @since version 1.0.0 - */ - iterator insert(const_iterator pos, const_iterator first, const_iterator last) - { - // insert only works for arrays - if (not is_array()) - { - JSON_THROW(type_error::create(309, "cannot use insert() with " + type_name())); - } + @tparam ObjectType the container to store objects (e.g., `std::map` or + `std::unordered_map`) + @tparam StringType the type of the keys or names (e.g., `std::string`). + The comparison function `std::less` is used to order elements + inside the container. + @tparam AllocatorType the allocator to use for objects (e.g., + `std::allocator`) - // check if iterator pos fits to this JSON value - if (pos.m_object != this) - { - JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); - } + #### Default type - // check if range iterators belong to the same JSON object - if (first.m_object != last.m_object) - { - JSON_THROW(invalid_iterator::create(210, "iterators do not fit")); - } + With the default values for @a ObjectType (`std::map`), @a StringType + (`std::string`), and @a AllocatorType (`std::allocator`), the default + value for @a object_t is: - if (first.m_object == this or last.m_object == this) - { - JSON_THROW(invalid_iterator::create(211, "passed iterators may not belong to container")); - } + @code {.cpp} + std::map< + std::string, // key_type + basic_json, // value_type + std::less, // key_compare + std::allocator> // allocator_type + > + @endcode - // insert to array and return iterator - iterator result(this); - result.m_it.array_iterator = m_value.array->insert( - pos.m_it.array_iterator, - first.m_it.array_iterator, - last.m_it.array_iterator); - return result; - } + #### Behavior - /*! - @brief inserts elements + The choice of @a object_t influences the behavior of the JSON class. With + the default type, objects have the following behavior: - Inserts elements from initializer list @a ilist before iterator @a pos. + - When all names are unique, objects will be interoperable in the sense + that all software implementations receiving that object will agree on + the name-value mappings. + - When the names within an object are not unique, it is unspecified which + one of the values for a given key will be chosen. For instance, + `{"key": 2, "key": 1}` could be equal to either `{"key": 1}` or + `{"key": 2}`. + - Internally, name/value pairs are stored in lexicographical order of the + names. Objects will also be serialized (see @ref dump) in this order. + For instance, `{"b": 1, "a": 2}` and `{"a": 2, "b": 1}` will be stored + and serialized as `{"a": 2, "b": 1}`. + - When comparing objects, the order of the name/value pairs is irrelevant. + This makes objects interoperable in the sense that they will not be + affected by these differences. For instance, `{"b": 1, "a": 2}` and + `{"a": 2, "b": 1}` will be treated as equal. - @param[in] pos iterator before which the content will be inserted; may be - the end() iterator - @param[in] ilist initializer list to insert the values from + #### Limits - @throw type_error.309 if called on JSON values other than arrays; example: - `"cannot use insert() with string"` - @throw invalid_iterator.202 if @a pos is not an iterator of *this; - example: `"iterator does not fit current value"` + [RFC 7159](http://rfc7159.net/rfc7159) specifies: + > An implementation may set limits on the maximum depth of nesting. - @return iterator pointing to the first element inserted, or @a pos if - `ilist` is empty + In this class, the object's limit of nesting is not explicitly constrained. + However, a maximum depth of nesting may be introduced by the compiler or + runtime environment. A theoretical limit can be queried by calling the + @ref max_size function of a JSON object. - @complexity Linear in `ilist.size()` plus linear in the distance between - @a pos and end of the container. + #### Storage - @liveexample{The example shows how `insert()` is used.,insert__ilist} + Objects are stored as pointers in a @ref basic_json type. That is, for any + access to object values, a pointer of type `object_t*` must be + dereferenced. - @since version 1.0.0 - */ - iterator insert(const_iterator pos, std::initializer_list ilist) - { - // insert only works for arrays - if (not is_array()) - { - JSON_THROW(type_error::create(309, "cannot use insert() with " + type_name())); - } + @sa @ref array_t -- type for an array value - // check if iterator pos fits to this JSON value - if (pos.m_object != this) - { - JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); - } + @since version 1.0.0 - // insert to array and return iterator - iterator result(this); - result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, ilist); - return result; - } + @note The order name/value pairs are added to the object is *not* + preserved by the library. Therefore, iterating an object may return + name/value pairs in a different order than they were originally stored. In + fact, keys will be traversed in alphabetical order as `std::map` with + `std::less` is used by default. Please note this behavior conforms to [RFC + 7159](http://rfc7159.net/rfc7159), because any order implements the + specified "unordered" nature of JSON objects. + */ + using object_t = ObjectType>>; /*! - @brief inserts elements - - Inserts elements from range `[first, last)`. - - @param[in] first begin of the range of elements to insert - @param[in] last end of the range of elements to insert + @brief a type for an array - @throw type_error.309 if called on JSON values other than objects; example: - `"cannot use insert() with string"` - @throw invalid_iterator.202 if iterator @a first or @a last does does not - point to an object; example: `"iterators first and last must point to - objects"` - @throw invalid_iterator.210 if @a first and @a last do not belong to the - same JSON value; example: `"iterators do not fit"` + [RFC 7159](http://rfc7159.net/rfc7159) describes JSON arrays as follows: + > An array is an ordered sequence of zero or more values. - @complexity Logarithmic: `O(N*log(size() + N))`, where `N` is the number - of elements to insert. + To store objects in C++, a type is defined by the template parameters + explained below. - @liveexample{The example shows how `insert()` is used.,insert__range_object} + @tparam ArrayType container type to store arrays (e.g., `std::vector` or + `std::list`) + @tparam AllocatorType allocator to use for arrays (e.g., `std::allocator`) - @since version 3.0.0 - */ - void insert(const_iterator first, const_iterator last) - { - // insert only works for objects - if (not is_object()) - { - JSON_THROW(type_error::create(309, "cannot use insert() with " + type_name())); - } + #### Default type - // check if range iterators belong to the same JSON object - if (first.m_object != last.m_object) - { - JSON_THROW(invalid_iterator::create(210, "iterators do not fit")); - } + With the default values for @a ArrayType (`std::vector`) and @a + AllocatorType (`std::allocator`), the default value for @a array_t is: - // passed iterators must belong to objects - if (not first.m_object->is_object() or not first.m_object->is_object()) - { - JSON_THROW(invalid_iterator::create(202, "iterators first and last must point to objects")); - } + @code {.cpp} + std::vector< + basic_json, // value_type + std::allocator // allocator_type + > + @endcode - m_value.object->insert(first.m_it.object_iterator, last.m_it.object_iterator); - } + #### Limits - /*! - @brief exchanges the values + [RFC 7159](http://rfc7159.net/rfc7159) specifies: + > An implementation may set limits on the maximum depth of nesting. - Exchanges the contents of the JSON value with those of @a other. Does not - invoke any move, copy, or swap operations on individual elements. All - iterators and references remain valid. The past-the-end iterator is - invalidated. + In this class, the array's limit of nesting is not explicitly constrained. + However, a maximum depth of nesting may be introduced by the compiler or + runtime environment. A theoretical limit can be queried by calling the + @ref max_size function of a JSON array. - @param[in,out] other JSON value to exchange the contents with + #### Storage - @complexity Constant. + Arrays are stored as pointers in a @ref basic_json type. That is, for any + access to array values, a pointer of type `array_t*` must be dereferenced. - @liveexample{The example below shows how JSON values can be swapped with - `swap()`.,swap__reference} + @sa @ref object_t -- type for an object value @since version 1.0.0 */ - void swap(reference other) noexcept ( - std::is_nothrow_move_constructible::value and - std::is_nothrow_move_assignable::value and - std::is_nothrow_move_constructible::value and - std::is_nothrow_move_assignable::value - ) - { - std::swap(m_type, other.m_type); - std::swap(m_value, other.m_value); - assert_invariant(); - } + using array_t = ArrayType>; /*! - @brief exchanges the values + @brief a type for a string - Exchanges the contents of a JSON array with those of @a other. Does not - invoke any move, copy, or swap operations on individual elements. All - iterators and references remain valid. The past-the-end iterator is - invalidated. + [RFC 7159](http://rfc7159.net/rfc7159) describes JSON strings as follows: + > A string is a sequence of zero or more Unicode characters. - @param[in,out] other array to exchange the contents with + To store objects in C++, a type is defined by the template parameter + described below. Unicode values are split by the JSON class into + byte-sized characters during deserialization. - @throw type_error.310 when JSON value is not an array; example: `"cannot - use swap() with string"` + @tparam StringType the container to store strings (e.g., `std::string`). + Note this container is used for keys/names in objects, see @ref object_t. - @complexity Constant. + #### Default type - @liveexample{The example below shows how arrays can be swapped with - `swap()`.,swap__array_t} + With the default values for @a StringType (`std::string`), the default + value for @a string_t is: - @since version 1.0.0 - */ - void swap(array_t& other) - { - // swap only works for arrays - if (is_array()) - { - std::swap(*(m_value.array), other); - } - else - { - JSON_THROW(type_error::create(310, "cannot use swap() with " + type_name())); - } - } + @code {.cpp} + std::string + @endcode - /*! - @brief exchanges the values + #### Encoding - Exchanges the contents of a JSON object with those of @a other. Does not - invoke any move, copy, or swap operations on individual elements. All - iterators and references remain valid. The past-the-end iterator is - invalidated. + Strings are stored in UTF-8 encoding. Therefore, functions like + `std::string::size()` or `std::string::length()` return the number of + bytes in the string rather than the number of characters or glyphs. - @param[in,out] other object to exchange the contents with + #### String comparison - @throw type_error.310 when JSON value is not an object; example: - `"cannot use swap() with string"` + [RFC 7159](http://rfc7159.net/rfc7159) states: + > Software implementations are typically required to test names of object + > members for equality. Implementations that transform the textual + > representation into sequences of Unicode code units and then perform the + > comparison numerically, code unit by code unit, are interoperable in the + > sense that implementations will agree in all cases on equality or + > inequality of two strings. For example, implementations that compare + > strings with escaped characters unconverted may incorrectly find that + > `"a\\b"` and `"a\u005Cb"` are not equal. - @complexity Constant. + This implementation is interoperable as it does compare strings code unit + by code unit. - @liveexample{The example below shows how objects can be swapped with - `swap()`.,swap__object_t} + #### Storage + + String values are stored as pointers in a @ref basic_json type. That is, + for any access to string values, a pointer of type `string_t*` must be + dereferenced. @since version 1.0.0 */ - void swap(object_t& other) - { - // swap only works for objects - if (is_object()) - { - std::swap(*(m_value.object), other); - } - else - { - JSON_THROW(type_error::create(310, "cannot use swap() with " + type_name())); - } - } + using string_t = StringType; /*! - @brief exchanges the values + @brief a type for a boolean - Exchanges the contents of a JSON string with those of @a other. Does not - invoke any move, copy, or swap operations on individual elements. All - iterators and references remain valid. The past-the-end iterator is - invalidated. + [RFC 7159](http://rfc7159.net/rfc7159) implicitly describes a boolean as a + type which differentiates the two literals `true` and `false`. - @param[in,out] other string to exchange the contents with + To store objects in C++, a type is defined by the template parameter @a + BooleanType which chooses the type to use. - @throw type_error.310 when JSON value is not a string; example: `"cannot - use swap() with boolean"` + #### Default type - @complexity Constant. + With the default values for @a BooleanType (`bool`), the default value for + @a boolean_t is: - @liveexample{The example below shows how strings can be swapped with - `swap()`.,swap__string_t} + @code {.cpp} + bool + @endcode + + #### Storage + + Boolean values are stored directly inside a @ref basic_json type. @since version 1.0.0 */ - void swap(string_t& other) - { - // swap only works for strings - if (is_string()) - { - std::swap(*(m_value.string), other); - } - else - { - JSON_THROW(type_error::create(310, "cannot use swap() with " + type_name())); - } - } + using boolean_t = BooleanType; - /// @} + /*! + @brief a type for a number (integer) - public: - ////////////////////////////////////////// - // lexicographical comparison operators // - ////////////////////////////////////////// + [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows: + > The representation of numbers is similar to that used in most + > programming languages. A number is represented in base 10 using decimal + > digits. It contains an integer component that may be prefixed with an + > optional minus sign, which may be followed by a fraction part and/or an + > exponent part. Leading zeros are not allowed. (...) Numeric values that + > cannot be represented in the grammar below (such as Infinity and NaN) + > are not permitted. - /// @name lexicographical comparison operators - /// @{ + This description includes both integer and floating-point numbers. + However, C++ allows more precise storage if it is known whether the number + is a signed integer, an unsigned integer or a floating-point number. + Therefore, three different types, @ref number_integer_t, @ref + number_unsigned_t and @ref number_float_t are used. - /*! - @brief comparison: equal + To store integer numbers in C++, a type is defined by the template + parameter @a NumberIntegerType which chooses the type to use. - Compares two JSON values for equality according to the following rules: - - Two JSON values are equal if (1) they are from the same type and (2) - their stored values are the same according to their respective - `operator==`. - - Integer and floating-point numbers are automatically converted before - comparison. Floating-point numbers are compared indirectly: two - floating-point numbers `f1` and `f2` are considered equal if neither - `f1 > f2` nor `f2 > f1` holds. Note than two NaN values are always - treated as unequal. - - Two JSON null values are equal. + #### Default type - @note NaN values never compare equal to themselves or to other NaN values. + With the default values for @a NumberIntegerType (`int64_t`), the default + value for @a number_integer_t is: - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether the values @a lhs and @a rhs are equal + @code {.cpp} + int64_t + @endcode - @complexity Linear. + #### Default behavior - @liveexample{The example demonstrates comparing several JSON - types.,operator__equal} + - The restrictions about leading zeros is not enforced in C++. Instead, + leading zeros in integer literals lead to an interpretation as octal + number. Internally, the value will be stored as decimal number. For + instance, the C++ integer literal `010` will be serialized to `8`. + During deserialization, leading zeros yield an error. + - Not-a-number (NaN) values will be serialized to `null`. - @since version 1.0.0 - */ - friend bool operator==(const_reference lhs, const_reference rhs) noexcept - { - const auto lhs_type = lhs.type(); - const auto rhs_type = rhs.type(); - - if (lhs_type == rhs_type) - { - switch (lhs_type) - { - case value_t::array: - { - return (*lhs.m_value.array) == *rhs.m_value.array; - } - case value_t::object: - { - return (*lhs.m_value.object) == *rhs.m_value.object; - } - case value_t::null: - { - return true; - } - case value_t::string: - { - return (*lhs.m_value.string) == *rhs.m_value.string; - } - case value_t::boolean: - { - return lhs.m_value.boolean == rhs.m_value.boolean; - } - case value_t::number_integer: - { - return lhs.m_value.number_integer == rhs.m_value.number_integer; - } - case value_t::number_unsigned: - { - return lhs.m_value.number_unsigned == rhs.m_value.number_unsigned; - } - case value_t::number_float: - { - return lhs.m_value.number_float == rhs.m_value.number_float; - } - default: - { - return false; - } - } - } - else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float) - { - return static_cast(lhs.m_value.number_integer) == rhs.m_value.number_float; - } - else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer) - { - return lhs.m_value.number_float == static_cast(rhs.m_value.number_integer); - } - else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_float) - { - return static_cast(lhs.m_value.number_unsigned) == rhs.m_value.number_float; - } - else if (lhs_type == value_t::number_float and rhs_type == value_t::number_unsigned) - { - return lhs.m_value.number_float == static_cast(rhs.m_value.number_unsigned); - } - else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_integer) - { - return static_cast(lhs.m_value.number_unsigned) == rhs.m_value.number_integer; - } - else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_unsigned) - { - return lhs.m_value.number_integer == static_cast(rhs.m_value.number_unsigned); - } + #### Limits - return false; - } + [RFC 7159](http://rfc7159.net/rfc7159) specifies: + > An implementation may set limits on the range and precision of numbers. - /*! - @brief comparison: equal - @copydoc operator==(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator==(const_reference lhs, const ScalarType rhs) noexcept - { - return (lhs == basic_json(rhs)); - } + When the default type is used, the maximal integer number that can be + stored is `9223372036854775807` (INT64_MAX) and the minimal integer number + that can be stored is `-9223372036854775808` (INT64_MIN). Integer numbers + that are out of range will yield over/underflow when used in a + constructor. During deserialization, too large or small integer numbers + will be automatically be stored as @ref number_unsigned_t or @ref + number_float_t. - /*! - @brief comparison: equal - @copydoc operator==(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator==(const ScalarType lhs, const_reference rhs) noexcept - { - return (basic_json(lhs) == rhs); - } + [RFC 7159](http://rfc7159.net/rfc7159) further states: + > Note that when such software is used, numbers that are integers and are + > in the range \f$[-2^{53}+1, 2^{53}-1]\f$ are interoperable in the sense + > that implementations will agree exactly on their numeric values. - /*! - @brief comparison: not equal + As this range is a subrange of the exactly supported range [INT64_MIN, + INT64_MAX], this class's integer type is interoperable. - Compares two JSON values for inequality by calculating `not (lhs == rhs)`. + #### Storage - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether the values @a lhs and @a rhs are not equal + Integer number values are stored directly inside a @ref basic_json type. - @complexity Linear. + @sa @ref number_float_t -- type for number values (floating-point) - @liveexample{The example demonstrates comparing several JSON - types.,operator__notequal} + @sa @ref number_unsigned_t -- type for number values (unsigned integer) @since version 1.0.0 */ - friend bool operator!=(const_reference lhs, const_reference rhs) noexcept - { - return not (lhs == rhs); - } + using number_integer_t = NumberIntegerType; /*! - @brief comparison: not equal - @copydoc operator!=(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator!=(const_reference lhs, const ScalarType rhs) noexcept - { - return (lhs != basic_json(rhs)); - } + @brief a type for a number (unsigned) - /*! - @brief comparison: not equal - @copydoc operator!=(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator!=(const ScalarType lhs, const_reference rhs) noexcept - { - return (basic_json(lhs) != rhs); - } + [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows: + > The representation of numbers is similar to that used in most + > programming languages. A number is represented in base 10 using decimal + > digits. It contains an integer component that may be prefixed with an + > optional minus sign, which may be followed by a fraction part and/or an + > exponent part. Leading zeros are not allowed. (...) Numeric values that + > cannot be represented in the grammar below (such as Infinity and NaN) + > are not permitted. - /*! - @brief comparison: less than + This description includes both integer and floating-point numbers. + However, C++ allows more precise storage if it is known whether the number + is a signed integer, an unsigned integer or a floating-point number. + Therefore, three different types, @ref number_integer_t, @ref + number_unsigned_t and @ref number_float_t are used. - Compares whether one JSON value @a lhs is less than another JSON value @a - rhs according to the following rules: - - If @a lhs and @a rhs have the same type, the values are compared using - the default `<` operator. - - Integer and floating-point numbers are automatically converted before - comparison - - In case @a lhs and @a rhs have different types, the values are ignored - and the order of the types is considered, see - @ref operator<(const value_t, const value_t). + To store unsigned integer numbers in C++, a type is defined by the + template parameter @a NumberUnsignedType which chooses the type to use. - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether @a lhs is less than @a rhs + #### Default type - @complexity Linear. + With the default values for @a NumberUnsignedType (`uint64_t`), the + default value for @a number_unsigned_t is: - @liveexample{The example demonstrates comparing several JSON - types.,operator__less} + @code {.cpp} + uint64_t + @endcode - @since version 1.0.0 - */ - friend bool operator<(const_reference lhs, const_reference rhs) noexcept - { - const auto lhs_type = lhs.type(); - const auto rhs_type = rhs.type(); + #### Default behavior - if (lhs_type == rhs_type) - { - switch (lhs_type) - { - case value_t::array: - { - return (*lhs.m_value.array) < (*rhs.m_value.array); - } - case value_t::object: - { - return (*lhs.m_value.object) < *rhs.m_value.object; - } - case value_t::null: - { - return false; - } - case value_t::string: - { - return (*lhs.m_value.string) < *rhs.m_value.string; - } - case value_t::boolean: - { - return lhs.m_value.boolean < rhs.m_value.boolean; - } - case value_t::number_integer: - { - return lhs.m_value.number_integer < rhs.m_value.number_integer; - } - case value_t::number_unsigned: - { - return lhs.m_value.number_unsigned < rhs.m_value.number_unsigned; - } - case value_t::number_float: - { - return lhs.m_value.number_float < rhs.m_value.number_float; - } - default: - { - return false; - } - } - } - else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float) - { - return static_cast(lhs.m_value.number_integer) < rhs.m_value.number_float; - } - else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer) - { - return lhs.m_value.number_float < static_cast(rhs.m_value.number_integer); - } - else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_float) - { - return static_cast(lhs.m_value.number_unsigned) < rhs.m_value.number_float; - } - else if (lhs_type == value_t::number_float and rhs_type == value_t::number_unsigned) - { - return lhs.m_value.number_float < static_cast(rhs.m_value.number_unsigned); - } - else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_unsigned) - { - return lhs.m_value.number_integer < static_cast(rhs.m_value.number_unsigned); - } - else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_integer) - { - return static_cast(lhs.m_value.number_unsigned) < rhs.m_value.number_integer; - } + - The restrictions about leading zeros is not enforced in C++. Instead, + leading zeros in integer literals lead to an interpretation as octal + number. Internally, the value will be stored as decimal number. For + instance, the C++ integer literal `010` will be serialized to `8`. + During deserialization, leading zeros yield an error. + - Not-a-number (NaN) values will be serialized to `null`. - // We only reach this line if we cannot compare values. In that case, - // we compare types. Note we have to call the operator explicitly, - // because MSVC has problems otherwise. - return operator<(lhs_type, rhs_type); - } + #### Limits - /*! - @brief comparison: less than - @copydoc operator<(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator<(const_reference lhs, const ScalarType rhs) noexcept - { - return (lhs < basic_json(rhs)); - } - - /*! - @brief comparison: less than - @copydoc operator<(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator<(const ScalarType lhs, const_reference rhs) noexcept - { - return (basic_json(lhs) < rhs); - } + [RFC 7159](http://rfc7159.net/rfc7159) specifies: + > An implementation may set limits on the range and precision of numbers. - /*! - @brief comparison: less than or equal + When the default type is used, the maximal integer number that can be + stored is `18446744073709551615` (UINT64_MAX) and the minimal integer + number that can be stored is `0`. Integer numbers that are out of range + will yield over/underflow when used in a constructor. During + deserialization, too large or small integer numbers will be automatically + be stored as @ref number_integer_t or @ref number_float_t. - Compares whether one JSON value @a lhs is less than or equal to another - JSON value by calculating `not (rhs < lhs)`. + [RFC 7159](http://rfc7159.net/rfc7159) further states: + > Note that when such software is used, numbers that are integers and are + > in the range \f$[-2^{53}+1, 2^{53}-1]\f$ are interoperable in the sense + > that implementations will agree exactly on their numeric values. - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether @a lhs is less than or equal to @a rhs + As this range is a subrange (when considered in conjunction with the + number_integer_t type) of the exactly supported range [0, UINT64_MAX], + this class's integer type is interoperable. - @complexity Linear. + #### Storage - @liveexample{The example demonstrates comparing several JSON - types.,operator__greater} + Integer number values are stored directly inside a @ref basic_json type. - @since version 1.0.0 - */ - friend bool operator<=(const_reference lhs, const_reference rhs) noexcept - { - return not (rhs < lhs); - } + @sa @ref number_float_t -- type for number values (floating-point) + @sa @ref number_integer_t -- type for number values (integer) - /*! - @brief comparison: less than or equal - @copydoc operator<=(const_reference, const_reference) + @since version 2.0.0 */ - template::value, int>::type = 0> - friend bool operator<=(const_reference lhs, const ScalarType rhs) noexcept - { - return (lhs <= basic_json(rhs)); - } + using number_unsigned_t = NumberUnsignedType; /*! - @brief comparison: less than or equal - @copydoc operator<=(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator<=(const ScalarType lhs, const_reference rhs) noexcept - { - return (basic_json(lhs) <= rhs); - } + @brief a type for a number (floating-point) - /*! - @brief comparison: greater than + [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows: + > The representation of numbers is similar to that used in most + > programming languages. A number is represented in base 10 using decimal + > digits. It contains an integer component that may be prefixed with an + > optional minus sign, which may be followed by a fraction part and/or an + > exponent part. Leading zeros are not allowed. (...) Numeric values that + > cannot be represented in the grammar below (such as Infinity and NaN) + > are not permitted. - Compares whether one JSON value @a lhs is greater than another - JSON value by calculating `not (lhs <= rhs)`. + This description includes both integer and floating-point numbers. + However, C++ allows more precise storage if it is known whether the number + is a signed integer, an unsigned integer or a floating-point number. + Therefore, three different types, @ref number_integer_t, @ref + number_unsigned_t and @ref number_float_t are used. - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether @a lhs is greater than to @a rhs + To store floating-point numbers in C++, a type is defined by the template + parameter @a NumberFloatType which chooses the type to use. - @complexity Linear. + #### Default type - @liveexample{The example demonstrates comparing several JSON - types.,operator__lessequal} + With the default values for @a NumberFloatType (`double`), the default + value for @a number_float_t is: - @since version 1.0.0 - */ - friend bool operator>(const_reference lhs, const_reference rhs) noexcept - { - return not (lhs <= rhs); - } + @code {.cpp} + double + @endcode - /*! - @brief comparison: greater than - @copydoc operator>(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator>(const_reference lhs, const ScalarType rhs) noexcept - { - return (lhs > basic_json(rhs)); - } + #### Default behavior - /*! - @brief comparison: greater than - @copydoc operator>(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator>(const ScalarType lhs, const_reference rhs) noexcept - { - return (basic_json(lhs) > rhs); - } + - The restrictions about leading zeros is not enforced in C++. Instead, + leading zeros in floating-point literals will be ignored. Internally, + the value will be stored as decimal number. For instance, the C++ + floating-point literal `01.2` will be serialized to `1.2`. During + deserialization, leading zeros yield an error. + - Not-a-number (NaN) values will be serialized to `null`. - /*! - @brief comparison: greater than or equal + #### Limits - Compares whether one JSON value @a lhs is greater than or equal to another - JSON value by calculating `not (lhs < rhs)`. + [RFC 7159](http://rfc7159.net/rfc7159) states: + > This specification allows implementations to set limits on the range and + > precision of numbers accepted. Since software that implements IEEE + > 754-2008 binary64 (double precision) numbers is generally available and + > widely used, good interoperability can be achieved by implementations + > that expect no more precision or range than these provide, in the sense + > that implementations will approximate JSON numbers within the expected + > precision. - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether @a lhs is greater than or equal to @a rhs + This implementation does exactly follow this approach, as it uses double + precision floating-point numbers. Note values smaller than + `-1.79769313486232e+308` and values greater than `1.79769313486232e+308` + will be stored as NaN internally and be serialized to `null`. - @complexity Linear. + #### Storage - @liveexample{The example demonstrates comparing several JSON - types.,operator__greaterequal} + Floating-point number values are stored directly inside a @ref basic_json + type. - @since version 1.0.0 - */ - friend bool operator>=(const_reference lhs, const_reference rhs) noexcept - { - return not (lhs < rhs); - } + @sa @ref number_integer_t -- type for number values (integer) - /*! - @brief comparison: greater than or equal - @copydoc operator>=(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator>=(const_reference lhs, const ScalarType rhs) noexcept - { - return (lhs >= basic_json(rhs)); - } + @sa @ref number_unsigned_t -- type for number values (unsigned integer) - /*! - @brief comparison: greater than or equal - @copydoc operator>=(const_reference, const_reference) + @since version 1.0.0 */ - template::value, int>::type = 0> - friend bool operator>=(const ScalarType lhs, const_reference rhs) noexcept - { - return (basic_json(lhs) >= rhs); - } + using number_float_t = NumberFloatType; /// @} private: - ///////////////////// - // output adapters // - ///////////////////// - /// abstract output adapter interface - template - class output_adapter + /// helper for exception-safe object creation + template + static T* create(Args&& ... args) { - public: - virtual void write_character(CharType c) = 0; - virtual void write_characters(const CharType* s, size_t length) = 0; - virtual ~output_adapter() {} - - static std::shared_ptr> create(std::vector& vec) - { - return std::shared_ptr(new output_vector_adapter(vec)); - } - - static std::shared_ptr> create(std::ostream& s) - { - return std::shared_ptr(new output_stream_adapter(s)); - } + AllocatorType alloc; + using AllocatorTraits = std::allocator_traits>; - static std::shared_ptr> create(std::string& s) + auto deleter = [&](T * object) { - return std::shared_ptr(new output_string_adapter(s)); - } - }; + AllocatorTraits::deallocate(alloc, object, 1); + }; + std::unique_ptr object(AllocatorTraits::allocate(alloc, 1), deleter); + AllocatorTraits::construct(alloc, object.get(), std::forward(args)...); + assert(object != nullptr); + return object.release(); + } - /// a type to simplify interfaces - template - using output_adapter_t = std::shared_ptr>; + //////////////////////// + // JSON value storage // + //////////////////////// - /// output adapter for byte vectors - template - class output_vector_adapter : public output_adapter - { - public: - output_vector_adapter(std::vector& vec) - : v(vec) - {} + /*! + @brief a JSON value - void write_character(CharType c) override - { - v.push_back(c); - } + The actual storage for a JSON value of the @ref basic_json class. This + union combines the different storage types for the JSON value types + defined in @ref value_t. - void write_characters(const CharType* s, size_t length) override - { - std::copy(s, s + length, std::back_inserter(v)); - } + JSON type | value_t type | used type + --------- | --------------- | ------------------------ + object | object | pointer to @ref object_t + array | array | pointer to @ref array_t + string | string | pointer to @ref string_t + boolean | boolean | @ref boolean_t + number | number_integer | @ref number_integer_t + number | number_unsigned | @ref number_unsigned_t + number | number_float | @ref number_float_t + null | null | *no value is stored* - private: - std::vector& v; - }; + @note Variable-length types (objects, arrays, and strings) are stored as + pointers. The size of the union should not exceed 64 bits if the default + value types are used. - /// putput adatpter for output streams - template - class output_stream_adapter : public output_adapter + @since version 1.0.0 + */ + union json_value { - public: - output_stream_adapter(std::basic_ostream& s) - : stream(s) - {} - - void write_character(CharType c) override - { - stream.put(c); - } - - void write_characters(const CharType* s, size_t length) override - { - stream.write(s, static_cast(length)); - } - - private: - std::basic_ostream& stream; - }; - - /// output adapter for basic_string - template - class output_string_adapter : public output_adapter - { - public: - output_string_adapter(std::string& s) - : str(s) - {} - - void write_character(CharType c) override - { - str.push_back(c); - } - - void write_characters(const CharType* s, size_t length) override - { - str.append(s, length); - } - - private: - std::basic_string& str; - }; - - - /////////////////// - // serialization // - /////////////////// - - /// @name serialization - /// @{ - - private: - /*! - @brief wrapper around the serialization functions - */ - class serializer - { - public: - /*! - @param[in] s output stream to serialize to - @param[in] ichar indentation character to use - */ - serializer(output_adapter_t s, const char ichar) - : o(s), loc(std::localeconv()), - thousands_sep(!loc->thousands_sep ? '\0' : loc->thousands_sep[0]), - decimal_point(!loc->decimal_point ? '\0' : loc->decimal_point[0]), - indent_char(ichar), indent_string(512, indent_char) - {} - - // delete because of pointer members - serializer(const serializer&) = delete; - serializer& operator=(const serializer&) = delete; - - /*! - @brief internal implementation of the serialization function - - This function is called by the public member function dump and - organizes the serialization internally. The indentation level is - propagated as additional parameter. In case of arrays and objects, the - function is called recursively. - - - strings and object keys are escaped using `escape_string()` - - integer numbers are converted implicitly via `operator<<` - - floating-point numbers are converted to a string using `"%g"` format + /// object (stored with pointer to save storage) + object_t* object; + /// array (stored with pointer to save storage) + array_t* array; + /// string (stored with pointer to save storage) + string_t* string; + /// boolean + boolean_t boolean; + /// number (integer) + number_integer_t number_integer; + /// number (unsigned integer) + number_unsigned_t number_unsigned; + /// number (floating-point) + number_float_t number_float; - @param[in] val value to serialize - @param[in] pretty_print whether the output shall be pretty-printed - @param[in] indent_step the indent level - @param[in] current_indent the current indent level (only used internally) - */ - void dump(const basic_json& val, - const bool pretty_print, - const unsigned int indent_step, - const unsigned int current_indent = 0) + /// default constructor (for null values) + json_value() = default; + /// constructor for booleans + json_value(boolean_t v) noexcept : boolean(v) {} + /// constructor for numbers (integer) + json_value(number_integer_t v) noexcept : number_integer(v) {} + /// constructor for numbers (unsigned) + json_value(number_unsigned_t v) noexcept : number_unsigned(v) {} + /// constructor for numbers (floating-point) + json_value(number_float_t v) noexcept : number_float(v) {} + /// constructor for empty values of a given type + json_value(value_t t) { - switch (val.m_type) + switch (t) { case value_t::object: { - if (val.m_value.object->empty()) - { - o->write_characters("{}", 2); - return; - } - - if (pretty_print) - { - o->write_characters("{\n", 2); - - // variable to hold indentation for recursive calls - const auto new_indent = current_indent + indent_step; - if (indent_string.size() < new_indent) - { - indent_string.resize(new_indent, ' '); - } - - // first n-1 elements - auto i = val.m_value.object->cbegin(); - for (size_t cnt = 0; cnt < val.m_value.object->size() - 1; ++cnt, ++i) - { - o->write_characters(indent_string.c_str(), new_indent); - o->write_character('\"'); - dump_escaped(i->first); - o->write_characters("\": ", 3); - dump(i->second, true, indent_step, new_indent); - o->write_characters(",\n", 2); - } - - // last element - assert(i != val.m_value.object->cend()); - o->write_characters(indent_string.c_str(), new_indent); - o->write_character('\"'); - dump_escaped(i->first); - o->write_characters("\": ", 3); - dump(i->second, true, indent_step, new_indent); - - o->write_character('\n'); - o->write_characters(indent_string.c_str(), current_indent); - o->write_character('}'); - } - else - { - o->write_character('{'); - - // first n-1 elements - auto i = val.m_value.object->cbegin(); - for (size_t cnt = 0; cnt < val.m_value.object->size() - 1; ++cnt, ++i) - { - o->write_character('\"'); - dump_escaped(i->first); - o->write_characters("\":", 2); - dump(i->second, false, indent_step, current_indent); - o->write_character(','); - } - - // last element - assert(i != val.m_value.object->cend()); - o->write_character('\"'); - dump_escaped(i->first); - o->write_characters("\":", 2); - dump(i->second, false, indent_step, current_indent); - - o->write_character('}'); - } - - return; + object = create(); + break; } case value_t::array: { - if (val.m_value.array->empty()) - { - o->write_characters("[]", 2); - return; - } - - if (pretty_print) - { - o->write_characters("[\n", 2); - - // variable to hold indentation for recursive calls - const auto new_indent = current_indent + indent_step; - if (indent_string.size() < new_indent) - { - indent_string.resize(new_indent, ' '); - } - - // first n-1 elements - for (auto i = val.m_value.array->cbegin(); i != val.m_value.array->cend() - 1; ++i) - { - o->write_characters(indent_string.c_str(), new_indent); - dump(*i, true, indent_step, new_indent); - o->write_characters(",\n", 2); - } - - // last element - assert(not val.m_value.array->empty()); - o->write_characters(indent_string.c_str(), new_indent); - dump(val.m_value.array->back(), true, indent_step, new_indent); - - o->write_character('\n'); - o->write_characters(indent_string.c_str(), current_indent); - o->write_character(']'); - } - else - { - o->write_character('['); - - // first n-1 elements - for (auto i = val.m_value.array->cbegin(); i != val.m_value.array->cend() - 1; ++i) - { - dump(*i, false, indent_step, current_indent); - o->write_character(','); - } - - // last element - assert(not val.m_value.array->empty()); - dump(val.m_value.array->back(), false, indent_step, current_indent); - - o->write_character(']'); - } - - return; + array = create(); + break; } case value_t::string: { - o->write_character('\"'); - dump_escaped(*val.m_value.string); - o->write_character('\"'); - return; + string = create(""); + break; } case value_t::boolean: { - if (val.m_value.boolean) - { - o->write_characters("true", 4); - } - else - { - o->write_characters("false", 5); - } - return; + boolean = boolean_t(false); + break; } case value_t::number_integer: { - dump_integer(val.m_value.number_integer); - return; + number_integer = number_integer_t(0); + break; } case value_t::number_unsigned: { - dump_integer(val.m_value.number_unsigned); - return; + number_unsigned = number_unsigned_t(0); + break; } case value_t::number_float: { - dump_float(val.m_value.number_float); - return; + number_float = number_float_t(0.0); + break; } - case value_t::discarded: + case value_t::null: { - o->write_characters("", 11); - return; + object = nullptr; // silence warning, see #821 + break; } - case value_t::null: + default: { - o->write_characters("null", 4); - return; + object = nullptr; // silence warning, see #821 + if (JSON_UNLIKELY(t == value_t::null)) + { + JSON_THROW(other_error::create(500, "961c151d2e87f2686a955a9be24d316f1362bf21 3.1.1")); // LCOV_EXCL_LINE + } + break; } } } - private: - /*! - @brief calculates the extra space to escape a JSON string - - @param[in] s the string to escape - @return the number of characters required to escape string @a s - - @complexity Linear in the length of string @a s. - */ - static std::size_t extra_space(const string_t& s) noexcept + /// constructor for strings + json_value(const string_t& value) { - return std::accumulate(s.begin(), s.end(), size_t{}, - [](size_t res, typename string_t::value_type c) - { - switch (c) - { - case '"': - case '\\': - case '\b': - case '\f': - case '\n': - case '\r': - case '\t': - { - // from c (1 byte) to \x (2 bytes) - return res + 1; - } + string = create(value); + } - case 0x00: - case 0x01: - case 0x02: - case 0x03: - case 0x04: - case 0x05: - case 0x06: - case 0x07: - case 0x0b: - case 0x0e: - case 0x0f: - case 0x10: - case 0x11: - case 0x12: - case 0x13: - case 0x14: - case 0x15: - case 0x16: - case 0x17: - case 0x18: - case 0x19: - case 0x1a: - case 0x1b: - case 0x1c: - case 0x1d: - case 0x1e: - case 0x1f: - { - // from c (1 byte) to \uxxxx (6 bytes) - return res + 5; - } + /// constructor for rvalue strings + json_value(string_t&& value) + { + string = create(std::move(value)); + } - default: - { - return res; - } - } - }); + /// constructor for objects + json_value(const object_t& value) + { + object = create(value); } - /*! - @brief dump escaped string + /// constructor for rvalue objects + json_value(object_t&& value) + { + object = create(std::move(value)); + } - Escape a string by replacing certain special characters by a sequence - of an escape character (backslash) and another character and other - control characters by a sequence of "\u" followed by a four-digit hex - representation. The escaped string is written to output stream @a o. + /// constructor for arrays + json_value(const array_t& value) + { + array = create(value); + } - @param[in] s the string to escape + /// constructor for rvalue arrays + json_value(array_t&& value) + { + array = create(std::move(value)); + } - @complexity Linear in the length of string @a s. - */ - void dump_escaped(const string_t& s) const + void destroy(value_t t) noexcept { - const auto space = extra_space(s); - if (space == 0) + switch (t) { - o->write_characters(s.c_str(), s.size()); - return; - } + case value_t::object: + { + AllocatorType alloc; + std::allocator_traits::destroy(alloc, object); + std::allocator_traits::deallocate(alloc, object, 1); + break; + } - // create a result string of necessary size - string_t result(s.size() + space, '\\'); - std::size_t pos = 0; + case value_t::array: + { + AllocatorType alloc; + std::allocator_traits::destroy(alloc, array); + std::allocator_traits::deallocate(alloc, array, 1); + break; + } - for (const auto& c : s) - { - switch (c) + case value_t::string: { - // quotation mark (0x22) - case '"': - { - result[pos + 1] = '"'; - pos += 2; - break; - } + AllocatorType alloc; + std::allocator_traits::destroy(alloc, string); + std::allocator_traits::deallocate(alloc, string, 1); + break; + } - // reverse solidus (0x5c) - case '\\': - { - // nothing to change - pos += 2; - break; - } + default: + { + break; + } + } + } + }; - // backspace (0x08) - case '\b': - { - result[pos + 1] = 'b'; - pos += 2; - break; - } + /*! + @brief checks the class invariants - // formfeed (0x0c) - case '\f': - { - result[pos + 1] = 'f'; - pos += 2; - break; - } + This function asserts the class invariants. It needs to be called at the + end of every constructor to make sure that created objects respect the + invariant. Furthermore, it has to be called each time the type of a JSON + value is changed, because the invariant expresses a relationship between + @a m_type and @a m_value. + */ + void assert_invariant() const noexcept + { + assert(m_type != value_t::object or m_value.object != nullptr); + assert(m_type != value_t::array or m_value.array != nullptr); + assert(m_type != value_t::string or m_value.string != nullptr); + } - // newline (0x0a) - case '\n': - { - result[pos + 1] = 'n'; - pos += 2; - break; - } + public: + ////////////////////////// + // JSON parser callback // + ////////////////////////// - // carriage return (0x0d) - case '\r': - { - result[pos + 1] = 'r'; - pos += 2; - break; - } + /*! + @brief parser event types - // horizontal tab (0x09) - case '\t': - { - result[pos + 1] = 't'; - pos += 2; - break; - } + The parser callback distinguishes the following events: + - `object_start`: the parser read `{` and started to process a JSON object + - `key`: the parser read a key of a value in an object + - `object_end`: the parser read `}` and finished processing a JSON object + - `array_start`: the parser read `[` and started to process a JSON array + - `array_end`: the parser read `]` and finished processing a JSON array + - `value`: the parser finished reading a JSON value - case 0x00: - case 0x01: - case 0x02: - case 0x03: - case 0x04: - case 0x05: - case 0x06: - case 0x07: - case 0x0b: - case 0x0e: - case 0x0f: - case 0x10: - case 0x11: - case 0x12: - case 0x13: - case 0x14: - case 0x15: - case 0x16: - case 0x17: - case 0x18: - case 0x19: - case 0x1a: - case 0x1b: - case 0x1c: - case 0x1d: - case 0x1e: - case 0x1f: - { - // convert a number 0..15 to its hex representation - // (0..f) - static const char hexify[16] = - { - '0', '1', '2', '3', '4', '5', '6', '7', - '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' - }; - - // print character c as \uxxxx - for (const char m : - { 'u', '0', '0', hexify[c >> 4], hexify[c & 0x0f] - }) - { - result[++pos] = m; - } + @image html callback_events.png "Example when certain parse events are triggered" - ++pos; - break; - } - - default: - { - // all other characters are added as-is - result[pos++] = c; - break; - } - } - } - - assert(pos == s.size() + space); - o->write_characters(result.c_str(), result.size()); - } + @sa @ref parser_callback_t for more information and examples + */ + using parse_event_t = typename parser::parse_event_t; - /*! - @brief dump an integer + /*! + @brief per-element parser callback type - Dump a given integer to output stream @a o. Works internally with - @a number_buffer. + With a parser callback function, the result of parsing a JSON text can be + influenced. When passed to @ref parse, it is called on certain events + (passed as @ref parse_event_t via parameter @a event) with a set recursion + depth @a depth and context JSON value @a parsed. The return value of the + callback function is a boolean indicating whether the element that emitted + the callback shall be kept or not. - @param[in] x integer number (signed or unsigned) to dump - @tparam NumberType either @a number_integer_t or @a number_unsigned_t - */ - template::value or - std::is_same::value, int> = 0> - void dump_integer(NumberType x) - { - // special case for "0" - if (x == 0) - { - o->write_character('0'); - return; - } + We distinguish six scenarios (determined by the event type) in which the + callback function can be called. The following table describes the values + of the parameters @a depth, @a event, and @a parsed. - const bool is_negative = x < 0; - size_t i = 0; + parameter @a event | description | parameter @a depth | parameter @a parsed + ------------------ | ----------- | ------------------ | ------------------- + parse_event_t::object_start | the parser read `{` and started to process a JSON object | depth of the parent of the JSON object | a JSON value with type discarded + parse_event_t::key | the parser read a key of a value in an object | depth of the currently parsed JSON object | a JSON string containing the key + parse_event_t::object_end | the parser read `}` and finished processing a JSON object | depth of the parent of the JSON object | the parsed JSON object + parse_event_t::array_start | the parser read `[` and started to process a JSON array | depth of the parent of the JSON array | a JSON value with type discarded + parse_event_t::array_end | the parser read `]` and finished processing a JSON array | depth of the parent of the JSON array | the parsed JSON array + parse_event_t::value | the parser finished reading a JSON value | depth of the value | the parsed JSON value - // spare 1 byte for '\0' - while (x != 0 and i < number_buffer.size() - 1) - { - const auto digit = std::labs(static_cast(x % 10)); - number_buffer[i++] = static_cast('0' + digit); - x /= 10; - } + @image html callback_events.png "Example when certain parse events are triggered" - // make sure the number has been processed completely - assert(x == 0); + Discarding a value (i.e., returning `false`) has different effects + depending on the context in which function was called: - if (is_negative) - { - // make sure there is capacity for the '-' - assert(i < number_buffer.size() - 2); - number_buffer[i++] = '-'; - } + - Discarded values in structured types are skipped. That is, the parser + will behave as if the discarded value was never read. + - In case a value outside a structured type is skipped, it is replaced + with `null`. This case happens if the top-level element is skipped. - std::reverse(number_buffer.begin(), number_buffer.begin() + i); - o->write_characters(number_buffer.data(), i); - } + @param[in] depth the depth of the recursion during parsing - /*! - @brief dump a floating-point number + @param[in] event an event of type parse_event_t indicating the context in + the callback function has been called - Dump a given floating-point number to output stream @a o. Works - internally with @a number_buffer. + @param[in,out] parsed the current intermediate parse result; note that + writing to this value has no effect for parse_event_t::key events - @param[in] x floating-point number to dump - */ - void dump_float(number_float_t x) - { - // NaN / inf - if (not std::isfinite(x) or std::isnan(x)) - { - o->write_characters("null", 4); - return; - } + @return Whether the JSON value which called the function during parsing + should be kept (`true`) or not (`false`). In the latter case, it is either + skipped completely or replaced by an empty discarded object. - // special case for 0.0 and -0.0 - if (x == 0) - { - if (std::signbit(x)) - { - o->write_characters("-0.0", 4); - } - else - { - o->write_characters("0.0", 3); - } - return; - } + @sa @ref parse for examples - // get number of digits for a text -> float -> text round-trip - static constexpr auto d = std::numeric_limits::digits10; + @since version 1.0.0 + */ + using parser_callback_t = typename parser::parser_callback_t; - // the actual conversion - std::ptrdiff_t len = snprintf(number_buffer.data(), number_buffer.size(), - "%.*g", d, x); - // negative value indicates an error - assert(len > 0); - // check if buffer was large enough - assert(static_cast(len) < number_buffer.size()); + ////////////////// + // constructors // + ////////////////// - // erase thousands separator - if (thousands_sep != '\0') - { - const auto end = std::remove(number_buffer.begin(), - number_buffer.begin() + len, - thousands_sep); - std::fill(end, number_buffer.end(), '\0'); - assert((end - number_buffer.begin()) <= len); - len = (end - number_buffer.begin()); - } + /// @name constructors and destructors + /// Constructors of class @ref basic_json, copy/move constructor, copy + /// assignment, static functions creating objects, and the destructor. + /// @{ - // convert decimal point to '.' - if (decimal_point != '\0' and decimal_point != '.') - { - for (auto& c : number_buffer) - { - if (c == decimal_point) - { - c = '.'; - break; - } - } - } + /*! + @brief create an empty value with a given type - o->write_characters(number_buffer.data(), static_cast(len)); + Create an empty JSON value with a given type. The value will be default + initialized with an empty value which depends on the type: - // determine if need to append ".0" - const bool value_is_int_like = std::none_of(number_buffer.begin(), - number_buffer.begin() + len + 1, - [](char c) - { - return c == '.' or c == 'e'; - }); + Value type | initial value + ----------- | ------------- + null | `null` + boolean | `false` + string | `""` + number | `0` + object | `{}` + array | `[]` - if (value_is_int_like) - { - o->write_characters(".0", 2); - } - } + @param[in] v the type of the value to create - private: - /// the output of the serializer - output_adapter_t o = nullptr; + @complexity Constant. - /// a (hopefully) large enough character buffer - std::array number_buffer{{}}; + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. - /// the locale - const std::lconv* loc = nullptr; - /// the locale's thousand separator character - const char thousands_sep = '\0'; - /// the locale's decimal point character - const char decimal_point = '\0'; + @liveexample{The following code shows the constructor for different @ref + value_t values,basic_json__value_t} - /// the indentation character - const char indent_char; + @sa @ref clear() -- restores the postcondition of this constructor - /// the indentation string - string_t indent_string; - }; + @since version 1.0.0 + */ + basic_json(const value_t v) + : m_type(v), m_value(v) + { + assert_invariant(); + } - public: /*! - @brief serialize to stream - - Serialize the given JSON value @a j to the output stream @a o. The JSON - value will be serialized using the @ref dump member function. - - - The indentation of the output can be controlled with the member variable - `width` of the output stream @a o. For instance, using the manipulator - `std::setw(4)` on @a o sets the indentation level to `4` and the - serialization result is the same as calling `dump(4)`. - - - The indentation characrer can be controlled with the member variable - `fill` of the output stream @a o. For instance, the manipulator - `std::setfill('\\t')` sets indentation to use a tab character rather than - the default space character. + @brief create a null object - @param[in,out] o stream to serialize to - @param[in] j JSON value to serialize + Create a `null` JSON value. It either takes a null pointer as parameter + (explicitly creating `null`) or no parameter (implicitly creating `null`). + The passed null pointer itself is not read -- it is only used to choose + the right constructor. - @return the stream @a o + @complexity Constant. - @complexity Linear. + @exceptionsafety No-throw guarantee: this constructor never throws + exceptions. - @liveexample{The example below shows the serialization with different - parameters to `width` to adjust the indentation level.,operator_serialize} + @liveexample{The following code shows the constructor with and without a + null pointer parameter.,basic_json__nullptr_t} - @since version 1.0.0; indentaction character added in version 3.0.0 + @since version 1.0.0 */ - friend std::ostream& operator<<(std::ostream& o, const basic_json& j) + basic_json(std::nullptr_t = nullptr) noexcept + : basic_json(value_t::null) { - // read width member and use it as indentation parameter if nonzero - const bool pretty_print = (o.width() > 0); - const auto indentation = (pretty_print ? o.width() : 0); - - // reset width to 0 for subsequent calls to this stream - o.width(0); - - // do the actual serialization - serializer s(output_adapter::create(o), o.fill()); - s.dump(j, pretty_print, static_cast(indentation)); - return o; + assert_invariant(); } /*! - @brief serialize to stream - @deprecated This stream operator is deprecated and will be removed in a - future version of the library. Please use - @ref std::ostream& operator<<(std::ostream&, const basic_json&) - instead; that is, replace calls like `j >> o;` with `o << j;`. - */ - JSON_DEPRECATED - friend std::ostream& operator>>(const basic_json& j, std::ostream& o) - { - return o << j; - } - - /// @} - - - ///////////////////// - // deserialization // - ///////////////////// - - /// @name deserialization - /// @{ + @brief create a JSON value - /*! - @brief deserialize from an array + This is a "catch all" constructor for all compatible JSON types; that is, + types for which a `to_json()` method exists. The constructor forwards the + parameter @a val to that method (to `json_serializer::to_json` method + with `U = uncvref_t`, to be exact). - This function reads from an array of 1-byte values. + Template type @a CompatibleType includes, but is not limited to, the + following types: + - **arrays**: @ref array_t and all kinds of compatible containers such as + `std::vector`, `std::deque`, `std::list`, `std::forward_list`, + `std::array`, `std::valarray`, `std::set`, `std::unordered_set`, + `std::multiset`, and `std::unordered_multiset` with a `value_type` from + which a @ref basic_json value can be constructed. + - **objects**: @ref object_t and all kinds of compatible associative + containers such as `std::map`, `std::unordered_map`, `std::multimap`, + and `std::unordered_multimap` with a `key_type` compatible to + @ref string_t and a `value_type` from which a @ref basic_json value can + be constructed. + - **strings**: @ref string_t, string literals, and all compatible string + containers can be used. + - **numbers**: @ref number_integer_t, @ref number_unsigned_t, + @ref number_float_t, and all convertible number types such as `int`, + `size_t`, `int64_t`, `float` or `double` can be used. + - **boolean**: @ref boolean_t / `bool` can be used. - @pre Each element of the container has a size of 1 byte. Violating this - precondition yields undefined behavior. **This precondition is enforced - with a static assertion.** + See the examples below. - @param[in] array array to read from - @param[in] cb a parser callback function of type @ref parser_callback_t - which is used to control the deserialization by filtering unwanted values - (optional) + @tparam CompatibleType a type such that: + - @a CompatibleType is not derived from `std::istream`, + - @a CompatibleType is not @ref basic_json (to avoid hijacking copy/move + constructors), + - @a CompatibleType is not a @ref basic_json nested type (e.g., + @ref json_pointer, @ref iterator, etc ...) + - @ref @ref json_serializer has a + `to_json(basic_json_t&, CompatibleType&&)` method - @return result of the deserialization + @tparam U = `uncvref_t` - @throw parse_error.101 if a parse error occurs; example: `""unexpected end - of input; expected string literal""` - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails + @param[in] val the value to be forwarded to the respective constructor - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. The complexity can be higher if the parser callback function - @a cb has a super-linear complexity. + @complexity Usually linear in the size of the passed @a val, also + depending on the implementation of the called `to_json()` + method. - @note A UTF-8 byte order mark is silently ignored. + @exceptionsafety Depends on the called constructor. For types directly + supported by the library (i.e., all types for which no `to_json()` function + was provided), strong guarantee holds: if an exception is thrown, there are + no changes to any JSON value. - @liveexample{The example below demonstrates the `parse()` function reading - from an array.,parse__array__parser_callback_t} + @liveexample{The following code shows the constructor with several + compatible types.,basic_json__CompatibleType} - @since version 2.0.3 + @since version 2.1.0 */ - template - static basic_json parse(T (&array)[N], - const parser_callback_t cb = nullptr) - { - // delegate the call to the iterator-range parse overload - return parse(std::begin(array), std::end(array), cb); - } - - template - static bool accept(T (&array)[N]) + template , + detail::enable_if_t< + detail::is_compatible_type::value, int> = 0> + basic_json(CompatibleType && val) noexcept(noexcept( + JSONSerializer::to_json(std::declval(), + std::forward(val)))) { - // delegate the call to the iterator-range accept overload - return accept(std::begin(array), std::end(array)); + JSONSerializer::to_json(*this, std::forward(val)); + assert_invariant(); } /*! - @brief deserialize from string literal - - @tparam CharT character/literal type with size of 1 byte - @param[in] s string literal to read a serialized JSON value from - @param[in] cb a parser callback function of type @ref parser_callback_t - which is used to control the deserialization by filtering unwanted values - (optional) + @brief create a container (array or object) from an initializer list - @return result of the deserialization + Creates a JSON value of type array or object from the passed initializer + list @a init. In case @a type_deduction is `true` (default), the type of + the JSON value to be created is deducted from the initializer list @a init + according to the following rules: - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails + 1. If the list is empty, an empty JSON object value `{}` is created. + 2. If the list consists of pairs whose first element is a string, a JSON + object value is created where the first elements of the pairs are + treated as keys and the second elements are as values. + 3. In all other cases, an array is created. - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. The complexity can be higher if the parser callback function - @a cb has a super-linear complexity. + The rules aim to create the best fit between a C++ initializer list and + JSON values. The rationale is as follows: - @note A UTF-8 byte order mark is silently ignored. - @note String containers like `std::string` or @ref string_t can be parsed - with @ref parse(const ContiguousContainer&, const parser_callback_t) - - @liveexample{The example below demonstrates the `parse()` function with - and without callback function.,parse__string__parser_callback_t} + 1. The empty initializer list is written as `{}` which is exactly an empty + JSON object. + 2. C++ has no way of describing mapped types other than to list a list of + pairs. As JSON requires that keys must be of type string, rule 2 is the + weakest constraint one can pose on initializer lists to interpret them + as an object. + 3. In all other cases, the initializer list could not be interpreted as + JSON object type, so interpreting it as JSON array type is safe. - @sa @ref parse(std::istream&, const parser_callback_t) for a version that - reads from an input stream + With the rules described above, the following JSON values cannot be + expressed by an initializer list: - @since version 1.0.0 (originally for @ref string_t) - */ - template::value and - std::is_integral::type>::value and - sizeof(typename std::remove_pointer::type) == 1, int>::type = 0> - static basic_json parse(const CharT s, - const parser_callback_t cb = nullptr) - { - return parser(input_adapter::create(s), cb).parse(true); - } + - the empty array (`[]`): use @ref array(initializer_list_t) + with an empty initializer list in this case + - arrays whose elements satisfy rule 2: use @ref + array(initializer_list_t) with the same initializer list + in this case - template::value and - std::is_integral::type>::value and - sizeof(typename std::remove_pointer::type) == 1, int>::type = 0> - static bool accept(const CharT s) - { - return parser(input_adapter::create(s)).accept(true); - } + @note When used without parentheses around an empty initializer list, @ref + basic_json() is called instead of this function, yielding the JSON null + value. - /*! - @brief deserialize from stream + @param[in] init initializer list with JSON values - @param[in,out] i stream to read a serialized JSON value from - @param[in] cb a parser callback function of type @ref parser_callback_t - which is used to control the deserialization by filtering unwanted values - (optional) + @param[in] type_deduction internal parameter; when set to `true`, the type + of the JSON value is deducted from the initializer list @a init; when set + to `false`, the type provided via @a manual_type is forced. This mode is + used by the functions @ref array(initializer_list_t) and + @ref object(initializer_list_t). - @return result of the deserialization + @param[in] manual_type internal parameter; when @a type_deduction is set + to `false`, the created JSON value will use the provided type (only @ref + value_t::array and @ref value_t::object are valid); when @a type_deduction + is set to `true`, this parameter has no effect - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails - @throw parse_error.111 if input stream is in a bad state + @throw type_error.301 if @a type_deduction is `false`, @a manual_type is + `value_t::object`, but @a init contains an element which is not a pair + whose first element is a string. In this case, the constructor could not + create an object. If @a type_deduction would have be `true`, an array + would have been created. See @ref object(initializer_list_t) + for an example. - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. The complexity can be higher if the parser callback function - @a cb has a super-linear complexity. + @complexity Linear in the size of the initializer list @a init. - @note A UTF-8 byte order mark is silently ignored. + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. - @liveexample{The example below demonstrates the `parse()` function with - and without callback function.,parse__istream__parser_callback_t} + @liveexample{The example below shows how JSON values are created from + initializer lists.,basic_json__list_init_t} - @sa @ref parse(const CharT, const parser_callback_t) for a version - that reads from a string + @sa @ref array(initializer_list_t) -- create a JSON array + value from an initializer list + @sa @ref object(initializer_list_t) -- create a JSON object + value from an initializer list @since version 1.0.0 */ - static basic_json parse(std::istream& i, - const parser_callback_t cb = nullptr) + basic_json(initializer_list_t init, + bool type_deduction = true, + value_t manual_type = value_t::array) { - return parser(input_adapter::create(i), cb).parse(true); - } + // check if each element is an array with two elements whose first + // element is a string + bool is_an_object = std::all_of(init.begin(), init.end(), + [](const detail::json_ref& element_ref) + { + return (element_ref->is_array() and element_ref->size() == 2 and (*element_ref)[0].is_string()); + }); - static bool accept(std::istream& i) - { - return parser(input_adapter::create(i)).accept(true); - } + // adjust type if type deduction is not wanted + if (not type_deduction) + { + // if array is wanted, do not create an object though possible + if (manual_type == value_t::array) + { + is_an_object = false; + } - /*! - @copydoc parse(std::istream&, const parser_callback_t) - */ - static basic_json parse(std::istream&& i, - const parser_callback_t cb = nullptr) - { - return parser(input_adapter::create(i), cb).parse(true); - } + // if object is wanted but impossible, throw an exception + if (JSON_UNLIKELY(manual_type == value_t::object and not is_an_object)) + { + JSON_THROW(type_error::create(301, "cannot create object from initializer list")); + } + } - static bool accept(std::istream&& i) - { - return parser(input_adapter::create(i)).accept(true); + if (is_an_object) + { + // the initializer list is a list of pairs -> create object + m_type = value_t::object; + m_value = value_t::object; + + std::for_each(init.begin(), init.end(), [this](const detail::json_ref& element_ref) + { + auto element = element_ref.moved_or_copied(); + m_value.object->emplace( + std::move(*((*element.m_value.array)[0].m_value.string)), + std::move((*element.m_value.array)[1])); + }); + } + else + { + // the initializer list describes an array -> create array + m_type = value_t::array; + m_value.array = create(init.begin(), init.end()); + } + + assert_invariant(); } /*! - @brief deserialize from an iterator range with contiguous storage - - This function reads from an iterator range of a container with contiguous - storage of 1-byte values. Compatible container types include - `std::vector`, `std::string`, `std::array`, `std::valarray`, and - `std::initializer_list`. Furthermore, C-style arrays can be used with - `std::begin()`/`std::end()`. User-defined containers can be used as long - as they implement random-access iterators and a contiguous storage. + @brief explicitly create an array from an initializer list - @pre The iterator range is contiguous. Violating this precondition yields - undefined behavior. **This precondition is enforced with an assertion.** - @pre Each element in the range has a size of 1 byte. Violating this - precondition yields undefined behavior. **This precondition is enforced - with a static assertion.** + Creates a JSON array value from a given initializer list. That is, given a + list of values `a, b, c`, creates the JSON value `[a, b, c]`. If the + initializer list is empty, the empty array `[]` is created. - @warning There is no way to enforce all preconditions at compile-time. If - the function is called with noncompliant iterators and with - assertions switched off, the behavior is undefined and will most - likely yield segmentation violation. + @note This function is only needed to express two edge cases that cannot + be realized with the initializer list constructor (@ref + basic_json(initializer_list_t, bool, value_t)). These cases + are: + 1. creating an array whose elements are all pairs whose first element is a + string -- in this case, the initializer list constructor would create an + object, taking the first elements as keys + 2. creating an empty array -- passing the empty initializer list to the + initializer list constructor yields an empty object - @tparam IteratorType iterator of container with contiguous storage - @param[in] first begin of the range to parse (included) - @param[in] last end of the range to parse (excluded) - @param[in] cb a parser callback function of type @ref parser_callback_t - which is used to control the deserialization by filtering unwanted values + @param[in] init initializer list with JSON values to create an array from (optional) - @return result of the deserialization + @return JSON array value - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails + @complexity Linear in the size of @a init. - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. The complexity can be higher if the parser callback function - @a cb has a super-linear complexity. + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. - @note A UTF-8 byte order mark is silently ignored. + @liveexample{The following code shows an example for the `array` + function.,array} - @liveexample{The example below demonstrates the `parse()` function reading - from an iterator range.,parse__iteratortype__parser_callback_t} + @sa @ref basic_json(initializer_list_t, bool, value_t) -- + create a JSON value from an initializer list + @sa @ref object(initializer_list_t) -- create a JSON object + value from an initializer list - @since version 2.0.3 + @since version 1.0.0 */ - template::iterator_category>::value, int>::type = 0> - static basic_json parse(IteratorType first, IteratorType last, - const parser_callback_t cb = nullptr) - { - return parser(input_adapter::create(first, last), cb).parse(true); - } - - template::iterator_category>::value, int>::type = 0> - static bool accept(IteratorType first, IteratorType last) + static basic_json array(initializer_list_t init = {}) { - return parser(input_adapter::create(first, last)).accept(true); + return basic_json(init, false, value_t::array); } /*! - @brief deserialize from a container with contiguous storage - - This function reads from a container with contiguous storage of 1-byte - values. Compatible container types include `std::vector`, `std::string`, - `std::array`, and `std::initializer_list`. User-defined containers can be - used as long as they implement random-access iterators and a contiguous - storage. - - @pre The container storage is contiguous. Violating this precondition - yields undefined behavior. **This precondition is enforced with an - assertion.** - @pre Each element of the container has a size of 1 byte. Violating this - precondition yields undefined behavior. **This precondition is enforced - with a static assertion.** + @brief explicitly create an object from an initializer list - @warning There is no way to enforce all preconditions at compile-time. If - the function is called with a noncompliant container and with - assertions switched off, the behavior is undefined and will most - likely yield segmentation violation. + Creates a JSON object value from a given initializer list. The initializer + lists elements must be pairs, and their first elements must be strings. If + the initializer list is empty, the empty object `{}` is created. - @tparam ContiguousContainer container type with contiguous storage - @param[in] c container to read from - @param[in] cb a parser callback function of type @ref parser_callback_t - which is used to control the deserialization by filtering unwanted values - (optional) + @note This function is only added for symmetry reasons. In contrast to the + related function @ref array(initializer_list_t), there are + no cases which can only be expressed by this function. That is, any + initializer list @a init can also be passed to the initializer list + constructor @ref basic_json(initializer_list_t, bool, value_t). - @return result of the deserialization + @param[in] init initializer list to create an object from (optional) - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails + @return JSON object value - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. The complexity can be higher if the parser callback function - @a cb has a super-linear complexity. + @throw type_error.301 if @a init is not a list of pairs whose first + elements are strings. In this case, no object can be created. When such a + value is passed to @ref basic_json(initializer_list_t, bool, value_t), + an array would have been created from the passed initializer list @a init. + See example below. - @note A UTF-8 byte order mark is silently ignored. + @complexity Linear in the size of @a init. - @liveexample{The example below demonstrates the `parse()` function reading - from a contiguous container.,parse__contiguouscontainer__parser_callback_t} + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. - @since version 2.0.3 - */ - template::value and - std::is_base_of< - std::random_access_iterator_tag, - typename std::iterator_traits()))>::iterator_category>::value - , int>::type = 0> - static basic_json parse(const ContiguousContainer& c, - const parser_callback_t cb = nullptr) - { - // delegate the call to the iterator-range parse overload - return parse(std::begin(c), std::end(c), cb); - } + @liveexample{The following code shows an example for the `object` + function.,object} - template::value and - std::is_base_of< - std::random_access_iterator_tag, - typename std::iterator_traits()))>::iterator_category>::value - , int>::type = 0> - static bool accept(const ContiguousContainer& c) - { - // delegate the call to the iterator-range accept overload - return accept(std::begin(c), std::end(c)); - } + @sa @ref basic_json(initializer_list_t, bool, value_t) -- + create a JSON value from an initializer list + @sa @ref array(initializer_list_t) -- create a JSON array + value from an initializer list - /*! - @brief deserialize from stream - @deprecated This stream operator is deprecated and will be removed in a - future version of the library. Please use - @ref std::istream& operator>>(std::istream&, basic_json&) - instead; that is, replace calls like `j << i;` with `i >> j;`. + @since version 1.0.0 */ - JSON_DEPRECATED - friend std::istream& operator<<(basic_json& j, std::istream& i) + static basic_json object(initializer_list_t init = {}) { - j = parser(input_adapter::create(i)).parse(false); - return i; + return basic_json(init, false, value_t::object); } /*! - @brief deserialize from stream + @brief construct an array with count copies of given value - Deserializes an input stream to a JSON value. + Constructs a JSON array value by creating @a cnt copies of a passed value. + In case @a cnt is `0`, an empty array is created. - @param[in,out] i input stream to read a serialized JSON value from - @param[in,out] j JSON value to write the deserialized input to + @param[in] cnt the number of JSON copies of @a val to create + @param[in] val the JSON value to copy - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails - @throw parse_error.111 if input stream is in a bad state + @post `std::distance(begin(),end()) == cnt` holds. - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. + @complexity Linear in @a cnt. - @note A UTF-8 byte order mark is silently ignored. + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. - @liveexample{The example below shows how a JSON value is constructed by - reading a serialization from a stream.,operator_deserialize} - - @sa parse(std::istream&, const parser_callback_t) for a variant with a - parser callback function to filter values while parsing + @liveexample{The following code shows examples for the @ref + basic_json(size_type\, const basic_json&) + constructor.,basic_json__size_type_basic_json} @since version 1.0.0 */ - friend std::istream& operator>>(std::istream& i, basic_json& j) + basic_json(size_type cnt, const basic_json& val) + : m_type(value_t::array) { - j = parser(input_adapter::create(i)).parse(false); - return i; + m_value.array = create(cnt, val); + assert_invariant(); } - /// @} - - /////////////////////////// - // convenience functions // - /////////////////////////// - /*! - @brief return the type as string - - Returns the type name as string to be used in error messages - usually to - indicate that a function was called on a wrong JSON type. - - @return basically a string representation of a the @a m_type member + @brief construct a JSON container given an iterator range - @complexity Constant. + Constructs the JSON value with the contents of the range `[first, last)`. + The semantics depends on the different types a JSON value can have: + - In case of a null type, invalid_iterator.206 is thrown. + - In case of other primitive types (number, boolean, or string), @a first + must be `begin()` and @a last must be `end()`. In this case, the value is + copied. Otherwise, invalid_iterator.204 is thrown. + - In case of structured types (array, object), the constructor behaves as + similar versions for `std::vector` or `std::map`; that is, a JSON array + or object is constructed from the values in the range. - @liveexample{The following code exemplifies `type_name()` for all JSON - types.,type_name} + @tparam InputIT an input iterator type (@ref iterator or @ref + const_iterator) - @since version 1.0.0, public since 2.1.0 - */ - std::string type_name() const - { - { - switch (m_type) - { - case value_t::null: - return "null"; - case value_t::object: - return "object"; - case value_t::array: - return "array"; - case value_t::string: - return "string"; - case value_t::boolean: - return "boolean"; - case value_t::discarded: - return "discarded"; - default: - return "number"; - } - } - } + @param[in] first begin of the range to copy from (included) + @param[in] last end of the range to copy from (excluded) + @pre Iterators @a first and @a last must be initialized. **This + precondition is enforced with an assertion (see warning).** If + assertions are switched off, a violation of this precondition yields + undefined behavior. - private: - ////////////////////// - // member variables // - ////////////////////// + @pre Range `[first, last)` is valid. Usually, this precondition cannot be + checked efficiently. Only certain edge cases are detected; see the + description of the exceptions below. A violation of this precondition + yields undefined behavior. - /// the type of the current element - value_t m_type = value_t::null; + @warning A precondition is enforced with a runtime assertion that will + result in calling `std::abort` if this precondition is not met. + Assertions can be disabled by defining `NDEBUG` at compile time. + See http://en.cppreference.com/w/cpp/error/assert for more + information. - /// the value of the current element - json_value m_value = {}; + @throw invalid_iterator.201 if iterators @a first and @a last are not + compatible (i.e., do not belong to the same JSON value). In this case, + the range `[first, last)` is undefined. + @throw invalid_iterator.204 if iterators @a first and @a last belong to a + primitive type (number, boolean, or string), but @a first does not point + to the first element any more. In this case, the range `[first, last)` is + undefined. See example code below. + @throw invalid_iterator.206 if iterators @a first and @a last belong to a + null value. In this case, the range `[first, last)` is undefined. + @complexity Linear in distance between @a first and @a last. - private: - /////////////// - // iterators // - /////////////// + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. - /*! - @brief an iterator for primitive JSON types + @liveexample{The example below shows several ways to create JSON values by + specifying a subrange with iterators.,basic_json__InputIt_InputIt} - This class models an iterator for primitive JSON types (boolean, number, - string). It's only purpose is to allow the iterator/const_iterator classes - to "iterate" over primitive values. Internally, the iterator is modeled by - a `difference_type` variable. Value begin_value (`0`) models the begin, - end_value (`1`) models past the end. + @since version 1.0.0 */ - class primitive_iterator_t + template::value or + std::is_same::value, int>::type = 0> + basic_json(InputIT first, InputIT last) { - public: + assert(first.m_object != nullptr); + assert(last.m_object != nullptr); - difference_type get_value() const noexcept - { - return m_it; - } - /// set iterator to a defined beginning - void set_begin() noexcept + // make sure iterator fits the current value + if (JSON_UNLIKELY(first.m_object != last.m_object)) { - m_it = begin_value; + JSON_THROW(invalid_iterator::create(201, "iterators are not compatible")); } - /// set iterator to a defined past the end - void set_end() noexcept - { - m_it = end_value; - } + // copy type from first iterator + m_type = first.m_object->m_type; - /// return whether the iterator can be dereferenced - constexpr bool is_begin() const noexcept + // check if iterator range is complete for primitive values + switch (m_type) { - return (m_it == begin_value); - } + case value_t::boolean: + case value_t::number_float: + case value_t::number_integer: + case value_t::number_unsigned: + case value_t::string: + { + if (JSON_UNLIKELY(not first.m_it.primitive_iterator.is_begin() + or not last.m_it.primitive_iterator.is_end())) + { + JSON_THROW(invalid_iterator::create(204, "iterators out of range")); + } + break; + } - /// return whether the iterator is at end - constexpr bool is_end() const noexcept - { - return (m_it == end_value); + default: + break; } - friend constexpr bool operator==(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept + switch (m_type) { - return lhs.m_it == rhs.m_it; - } + case value_t::number_integer: + { + m_value.number_integer = first.m_object->m_value.number_integer; + break; + } - friend constexpr bool operator!=(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return !(lhs == rhs); - } + case value_t::number_unsigned: + { + m_value.number_unsigned = first.m_object->m_value.number_unsigned; + break; + } - friend constexpr bool operator<(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it < rhs.m_it; - } + case value_t::number_float: + { + m_value.number_float = first.m_object->m_value.number_float; + break; + } - friend constexpr bool operator<=(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it <= rhs.m_it; - } + case value_t::boolean: + { + m_value.boolean = first.m_object->m_value.boolean; + break; + } - friend constexpr bool operator>(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it > rhs.m_it; - } + case value_t::string: + { + m_value = *first.m_object->m_value.string; + break; + } - friend constexpr bool operator>=(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it >= rhs.m_it; - } + case value_t::object: + { + m_value.object = create(first.m_it.object_iterator, + last.m_it.object_iterator); + break; + } - primitive_iterator_t operator+(difference_type i) - { - auto result = *this; - result += i; - return result; - } + case value_t::array: + { + m_value.array = create(first.m_it.array_iterator, + last.m_it.array_iterator); + break; + } - friend constexpr difference_type operator-(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it - rhs.m_it; + default: + JSON_THROW(invalid_iterator::create(206, "cannot construct with iterators from " + + std::string(first.m_object->type_name()))); } - friend std::ostream& operator<<(std::ostream& os, primitive_iterator_t it) - { - return os << it.m_it; - } + assert_invariant(); + } - primitive_iterator_t& operator++() - { - ++m_it; - return *this; - } - primitive_iterator_t operator++(int) - { - auto result = *this; - m_it++; - return result; - } + /////////////////////////////////////// + // other constructors and destructor // + /////////////////////////////////////// - primitive_iterator_t& operator--() - { - --m_it; - return *this; - } + /// @private + basic_json(const detail::json_ref& ref) + : basic_json(ref.moved_or_copied()) + {} - primitive_iterator_t operator--(int) - { - auto result = *this; - m_it--; - return result; - } + /*! + @brief copy constructor - primitive_iterator_t& operator+=(difference_type n) - { - m_it += n; - return *this; - } + Creates a copy of a given JSON value. - primitive_iterator_t& operator-=(difference_type n) - { - m_it -= n; - return *this; - } + @param[in] other the JSON value to copy - private: - static constexpr difference_type begin_value = 0; - static constexpr difference_type end_value = begin_value + 1; + @post `*this == other` - /// iterator as signed integer type - difference_type m_it = std::numeric_limits::denorm_min(); - }; + @complexity Linear in the size of @a other. - /*! - @brief an iterator value + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. - @note This structure could easily be a union, but MSVC currently does not - allow unions members with complex constructors, see - https://github.com/nlohmann/json/pull/105. - */ - struct internal_iterator - { - /// iterator for JSON objects - typename object_t::iterator object_iterator; - /// iterator for JSON arrays - typename array_t::iterator array_iterator; - /// generic iterator for all other types - primitive_iterator_t primitive_iterator; + @requirement This function helps `basic_json` satisfying the + [Container](http://en.cppreference.com/w/cpp/concept/Container) + requirements: + - The complexity is linear. + - As postcondition, it holds: `other == basic_json(other)`. - /// create an uninitialized internal_iterator - internal_iterator() noexcept - : object_iterator(), array_iterator(), primitive_iterator() - {} - }; + @liveexample{The following code shows an example for the copy + constructor.,basic_json__basic_json} - /// proxy class for the iterator_wrapper functions - template - class iteration_proxy + @since version 1.0.0 + */ + basic_json(const basic_json& other) + : m_type(other.m_type) { - private: - /// helper class for iteration - class iteration_proxy_internal + // check of passed value is valid + other.assert_invariant(); + + switch (m_type) { - private: - /// the iterator - IteratorType anchor; - /// an index for arrays (used to create key names) - size_t array_index = 0; + case value_t::object: + { + m_value = *other.m_value.object; + break; + } - public: - explicit iteration_proxy_internal(IteratorType it) noexcept - : anchor(it) - {} + case value_t::array: + { + m_value = *other.m_value.array; + break; + } - /// dereference operator (needed for range-based for) - iteration_proxy_internal& operator*() + case value_t::string: { - return *this; + m_value = *other.m_value.string; + break; } - /// increment operator (needed for range-based for) - iteration_proxy_internal& operator++() + case value_t::boolean: { - ++anchor; - ++array_index; + m_value = other.m_value.boolean; + break; + } - return *this; + case value_t::number_integer: + { + m_value = other.m_value.number_integer; + break; } - /// inequality operator (needed for range-based for) - bool operator!= (const iteration_proxy_internal& o) const + case value_t::number_unsigned: { - return anchor != o.anchor; + m_value = other.m_value.number_unsigned; + break; } - /// return key of the iterator - typename basic_json::string_t key() const + case value_t::number_float: { - assert(anchor.m_object != nullptr); + m_value = other.m_value.number_float; + break; + } - switch (anchor.m_object->type()) - { - // use integer array index as key - case value_t::array: - { - return std::to_string(array_index); - } - - // use key from the object - case value_t::object: - { - return anchor.key(); - } - - // use an empty key for all primitive types - default: - { - return ""; - } - } - } + default: + break; + } - /// return value of the iterator - typename IteratorType::reference value() const - { - return anchor.value(); - } - }; + assert_invariant(); + } - /// the container to iterate - typename IteratorType::reference container; + /*! + @brief move constructor - public: - /// construct iteration proxy from a container - explicit iteration_proxy(typename IteratorType::reference cont) - : container(cont) - {} + Move constructor. Constructs a JSON value with the contents of the given + value @a other using move semantics. It "steals" the resources from @a + other and leaves it as JSON null value. - /// return iterator begin (needed for range-based for) - iteration_proxy_internal begin() noexcept - { - return iteration_proxy_internal(container.begin()); - } + @param[in,out] other value to move to this object - /// return iterator end (needed for range-based for) - iteration_proxy_internal end() noexcept - { - return iteration_proxy_internal(container.end()); - } - }; + @post `*this` has the same value as @a other before the call. + @post @a other is a JSON null value. - public: - /*! - @brief a template for a random access iterator for the @ref basic_json class + @complexity Constant. - This class implements a both iterators (iterator and const_iterator) for the - @ref basic_json class. + @exceptionsafety No-throw guarantee: this constructor never throws + exceptions. - @note An iterator is called *initialized* when a pointer to a JSON value - has been set (e.g., by a constructor or a copy assignment). If the - iterator is default-constructed, it is *uninitialized* and most - methods are undefined. **The library uses assertions to detect calls - on uninitialized iterators.** + @requirement This function helps `basic_json` satisfying the + [MoveConstructible](http://en.cppreference.com/w/cpp/concept/MoveConstructible) + requirements. - @requirement The class satisfies the following concept requirements: - - [RandomAccessIterator](http://en.cppreference.com/w/cpp/concept/RandomAccessIterator): - The iterator that can be moved to point (forward and backward) to any - element in constant time. + @liveexample{The code below shows the move constructor explicitly called + via std::move.,basic_json__moveconstructor} - @since version 1.0.0, simplified in version 2.0.9 + @since version 1.0.0 */ - template - class iter_impl : public std::iterator + basic_json(basic_json&& other) noexcept + : m_type(std::move(other.m_type)), + m_value(std::move(other.m_value)) { - /// allow basic_json to access private members - friend class basic_json; - - // make sure U is basic_json or const basic_json - static_assert(std::is_same::value - or std::is_same::value, - "iter_impl only accepts (const) basic_json"); - - public: - /// the type of the values when the iterator is dereferenced - using value_type = typename basic_json::value_type; - /// a type to represent differences between iterators - using difference_type = typename basic_json::difference_type; - /// defines a pointer to the type iterated over (value_type) - using pointer = typename std::conditional::value, - typename basic_json::const_pointer, - typename basic_json::pointer>::type; - /// defines a reference to the type iterated over (value_type) - using reference = typename std::conditional::value, - typename basic_json::const_reference, - typename basic_json::reference>::type; - /// the category of the iterator - using iterator_category = std::bidirectional_iterator_tag; - - /// default constructor - iter_impl() = default; - - /*! - @brief constructor for a given JSON instance - @param[in] object pointer to a JSON object for this iterator - @pre object != nullptr - @post The iterator is initialized; i.e. `m_object != nullptr`. - */ - explicit iter_impl(pointer object) noexcept - : m_object(object) - { - assert(m_object != nullptr); - - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - m_it.object_iterator = typename object_t::iterator(); - break; - } - - case basic_json::value_t::array: - { - m_it.array_iterator = typename array_t::iterator(); - break; - } + // check that passed value is valid + other.assert_invariant(); - default: - { - m_it.primitive_iterator = primitive_iterator_t(); - break; - } - } - } + // invalidate payload + other.m_type = value_t::null; + other.m_value = {}; - /*! - @note The conventional copy constructor and copy assignment are - implicitly defined. - Combined with the following converting constructor and assigment, - they support: copy from iterator to iterator, - copy from const iterator to const iterator, - and conversion from iterator to const iterator. - However conversion from const iterator to iterator is not defined. - */ + assert_invariant(); + } - /*! - @brief converting constructor - @param[in] other non-const iterator to copy from - @note It is not checked whether @a other is initialized. - */ - iter_impl(const iter_impl& other) noexcept - : m_object(other.m_object), m_it(other.m_it) - {} + /*! + @brief copy assignment - /*! - @brief converting assignment - @param[in,out] other non-const iterator to copy from - @return const/non-const iterator - @note It is not checked whether @a other is initialized. - */ - iter_impl& operator=(const iter_impl& other) noexcept - { - m_object = other.m_object; - m_it = other.m_it; - return *this; - } + Copy assignment operator. Copies a JSON value via the "copy and swap" + strategy: It is expressed in terms of the copy constructor, destructor, + and the `swap()` member function. - private: - /*! - @brief set the iterator to the first value - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - void set_begin() noexcept - { - assert(m_object != nullptr); + @param[in] other value to copy from - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - m_it.object_iterator = m_object->m_value.object->begin(); - break; - } + @complexity Linear. - case basic_json::value_t::array: - { - m_it.array_iterator = m_object->m_value.array->begin(); - break; - } + @requirement This function helps `basic_json` satisfying the + [Container](http://en.cppreference.com/w/cpp/concept/Container) + requirements: + - The complexity is linear. - case basic_json::value_t::null: - { - // set to end so begin()==end() is true: null is empty - m_it.primitive_iterator.set_end(); - break; - } + @liveexample{The code below shows and example for the copy assignment. It + creates a copy of value `a` which is then swapped with `b`. Finally\, the + copy of `a` (which is the null value after the swap) is + destroyed.,basic_json__copyassignment} - default: - { - m_it.primitive_iterator.set_begin(); - break; - } - } - } + @since version 1.0.0 + */ + reference& operator=(basic_json other) noexcept ( + std::is_nothrow_move_constructible::value and + std::is_nothrow_move_assignable::value and + std::is_nothrow_move_constructible::value and + std::is_nothrow_move_assignable::value + ) + { + // check that passed value is valid + other.assert_invariant(); - /*! - @brief set the iterator past the last value - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - void set_end() noexcept - { - assert(m_object != nullptr); + using std::swap; + swap(m_type, other.m_type); + swap(m_value, other.m_value); - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - m_it.object_iterator = m_object->m_value.object->end(); - break; - } + assert_invariant(); + return *this; + } - case basic_json::value_t::array: - { - m_it.array_iterator = m_object->m_value.array->end(); - break; - } + /*! + @brief destructor - default: - { - m_it.primitive_iterator.set_end(); - break; - } - } - } + Destroys the JSON value and frees all allocated memory. - public: - /*! - @brief return a reference to the value pointed to by the iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - reference operator*() const - { - assert(m_object != nullptr); + @complexity Linear. - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - assert(m_it.object_iterator != m_object->m_value.object->end()); - return m_it.object_iterator->second; - } + @requirement This function helps `basic_json` satisfying the + [Container](http://en.cppreference.com/w/cpp/concept/Container) + requirements: + - The complexity is linear. + - All stored elements are destroyed and all memory is freed. - case basic_json::value_t::array: - { - assert(m_it.array_iterator != m_object->m_value.array->end()); - return *m_it.array_iterator; - } + @since version 1.0.0 + */ + ~basic_json() noexcept + { + assert_invariant(); + m_value.destroy(m_type); + } - case basic_json::value_t::null: - { - JSON_THROW(invalid_iterator::create(214, "cannot get value")); - } + /// @} - default: - { - if (m_it.primitive_iterator.is_begin()) - { - return *m_object; - } + public: + /////////////////////// + // object inspection // + /////////////////////// - JSON_THROW(invalid_iterator::create(214, "cannot get value")); - } - } - } + /// @name object inspection + /// Functions to inspect the type of a JSON value. + /// @{ - /*! - @brief dereference the iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - pointer operator->() const - { - assert(m_object != nullptr); + /*! + @brief serialization - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - assert(m_it.object_iterator != m_object->m_value.object->end()); - return &(m_it.object_iterator->second); - } + Serialization function for JSON values. The function tries to mimic + Python's `json.dumps()` function, and currently supports its @a indent + and @a ensure_ascii parameters. - case basic_json::value_t::array: - { - assert(m_it.array_iterator != m_object->m_value.array->end()); - return &*m_it.array_iterator; - } + @param[in] indent If indent is nonnegative, then array elements and object + members will be pretty-printed with that indent level. An indent level of + `0` will only insert newlines. `-1` (the default) selects the most compact + representation. + @param[in] indent_char The character to use for indentation if @a indent is + greater than `0`. The default is ` ` (space). + @param[in] ensure_ascii If @a ensure_ascii is true, all non-ASCII characters + in the output are escaped with `\uXXXX` sequences, and the result consists + of ASCII characters only. - default: - { - if (m_it.primitive_iterator.is_begin()) - { - return m_object; - } + @return string containing the serialization of the JSON value - JSON_THROW(invalid_iterator::create(214, "cannot get value")); - } - } - } + @throw type_error.316 if a string stored inside the JSON value is not + UTF-8 encoded - /*! - @brief post-increment (it++) - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl operator++(int) - { - auto result = *this; - ++(*this); - return result; - } + @complexity Linear. - /*! - @brief pre-increment (++it) - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl& operator++() - { - assert(m_object != nullptr); + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes in the JSON value. - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - std::advance(m_it.object_iterator, 1); - break; - } + @liveexample{The following example shows the effect of different @a indent\, + @a indent_char\, and @a ensure_ascii parameters to the result of the + serialization.,dump} - case basic_json::value_t::array: - { - std::advance(m_it.array_iterator, 1); - break; - } + @see https://docs.python.org/2/library/json.html#json.dump - default: - { - ++m_it.primitive_iterator; - break; - } - } + @since version 1.0.0; indentation character @a indent_char, option + @a ensure_ascii and exceptions added in version 3.0.0 + */ + string_t dump(const int indent = -1, const char indent_char = ' ', + const bool ensure_ascii = false) const + { + string_t result; + serializer s(detail::output_adapter(result), indent_char); - return *this; + if (indent >= 0) + { + s.dump(*this, true, ensure_ascii, static_cast(indent)); } - - /*! - @brief post-decrement (it--) - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl operator--(int) + else { - auto result = *this; - --(*this); - return result; + s.dump(*this, false, ensure_ascii, 0); } - /*! - @brief pre-decrement (--it) - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl& operator--() - { - assert(m_object != nullptr); + return result; + } - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - std::advance(m_it.object_iterator, -1); - break; - } + /*! + @brief return the type of the JSON value (explicit) - case basic_json::value_t::array: - { - std::advance(m_it.array_iterator, -1); - break; - } + Return the type of the JSON value as a value from the @ref value_t + enumeration. - default: - { - --m_it.primitive_iterator; - break; - } - } + @return the type of the JSON value + Value type | return value + ------------------------- | ------------------------- + null | value_t::null + boolean | value_t::boolean + string | value_t::string + number (integer) | value_t::number_integer + number (unsigned integer) | value_t::number_unsigned + number (floating-point) | value_t::number_float + object | value_t::object + array | value_t::array + discarded | value_t::discarded - return *this; - } + @complexity Constant. - /*! - @brief comparison: equal - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator==(const iter_impl& other) const - { - // if objects are not the same, the comparison is undefined - if (m_object != other.m_object) - { - JSON_THROW(invalid_iterator::create(212, "cannot compare iterators of different containers")); - } + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - assert(m_object != nullptr); + @liveexample{The following code exemplifies `type()` for all JSON + types.,type} - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - return (m_it.object_iterator == other.m_it.object_iterator); - } + @sa @ref operator value_t() -- return the type of the JSON value (implicit) + @sa @ref type_name() -- return the type as string - case basic_json::value_t::array: - { - return (m_it.array_iterator == other.m_it.array_iterator); - } + @since version 1.0.0 + */ + constexpr value_t type() const noexcept + { + return m_type; + } - default: - { - return (m_it.primitive_iterator == other.m_it.primitive_iterator); - } - } - } + /*! + @brief return whether type is primitive - /*! - @brief comparison: not equal - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator!=(const iter_impl& other) const - { - return not operator==(other); - } + This function returns true if and only if the JSON type is primitive + (string, number, boolean, or null). - /*! - @brief comparison: smaller - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator<(const iter_impl& other) const - { - // if objects are not the same, the comparison is undefined - if (m_object != other.m_object) - { - JSON_THROW(invalid_iterator::create(212, "cannot compare iterators of different containers")); - } + @return `true` if type is primitive (string, number, boolean, or null), + `false` otherwise. - assert(m_object != nullptr); + @complexity Constant. - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - JSON_THROW(invalid_iterator::create(213, "cannot compare order of object iterators")); - } + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - case basic_json::value_t::array: - { - return (m_it.array_iterator < other.m_it.array_iterator); - } + @liveexample{The following code exemplifies `is_primitive()` for all JSON + types.,is_primitive} - default: - { - return (m_it.primitive_iterator < other.m_it.primitive_iterator); - } - } - } + @sa @ref is_structured() -- returns whether JSON value is structured + @sa @ref is_null() -- returns whether JSON value is `null` + @sa @ref is_string() -- returns whether JSON value is a string + @sa @ref is_boolean() -- returns whether JSON value is a boolean + @sa @ref is_number() -- returns whether JSON value is a number - /*! - @brief comparison: less than or equal - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator<=(const iter_impl& other) const - { - return not other.operator < (*this); - } + @since version 1.0.0 + */ + constexpr bool is_primitive() const noexcept + { + return is_null() or is_string() or is_boolean() or is_number(); + } - /*! - @brief comparison: greater than - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator>(const iter_impl& other) const - { - return not operator<=(other); - } + /*! + @brief return whether type is structured - /*! - @brief comparison: greater than or equal - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator>=(const iter_impl& other) const - { - return not operator<(other); - } + This function returns true if and only if the JSON type is structured + (array or object). - /*! - @brief add to iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl& operator+=(difference_type i) - { - assert(m_object != nullptr); + @return `true` if type is structured (array or object), `false` otherwise. - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - JSON_THROW(invalid_iterator::create(209, "cannot use offsets with object iterators")); - } + @complexity Constant. - case basic_json::value_t::array: - { - std::advance(m_it.array_iterator, i); - break; - } + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - default: - { - m_it.primitive_iterator += i; - break; - } - } + @liveexample{The following code exemplifies `is_structured()` for all JSON + types.,is_structured} - return *this; - } + @sa @ref is_primitive() -- returns whether value is primitive + @sa @ref is_array() -- returns whether value is an array + @sa @ref is_object() -- returns whether value is an object - /*! - @brief subtract from iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl& operator-=(difference_type i) - { - return operator+=(-i); - } + @since version 1.0.0 + */ + constexpr bool is_structured() const noexcept + { + return is_array() or is_object(); + } - /*! - @brief add to iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl operator+(difference_type i) const - { - auto result = *this; - result += i; - return result; - } + /*! + @brief return whether value is null - /*! - @brief addition of distance and iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - friend iter_impl operator+(difference_type i, const iter_impl& it) - { - auto result = it; - result += i; - return result; - } + This function returns true if and only if the JSON value is null. - /*! - @brief subtract from iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl operator-(difference_type i) const - { - auto result = *this; - result -= i; - return result; - } + @return `true` if type is null, `false` otherwise. - /*! - @brief return difference - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - difference_type operator-(const iter_impl& other) const - { - assert(m_object != nullptr); + @complexity Constant. - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - JSON_THROW(invalid_iterator::create(209, "cannot use offsets with object iterators")); - } + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - case basic_json::value_t::array: - { - return m_it.array_iterator - other.m_it.array_iterator; - } + @liveexample{The following code exemplifies `is_null()` for all JSON + types.,is_null} - default: - { - return m_it.primitive_iterator - other.m_it.primitive_iterator; - } - } - } + @since version 1.0.0 + */ + constexpr bool is_null() const noexcept + { + return (m_type == value_t::null); + } - /*! - @brief access to successor - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - reference operator[](difference_type n) const - { - assert(m_object != nullptr); + /*! + @brief return whether value is a boolean - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - JSON_THROW(invalid_iterator::create(208, "cannot use operator[] for object iterators")); - } + This function returns true if and only if the JSON value is a boolean. - case basic_json::value_t::array: - { - return *std::next(m_it.array_iterator, n); - } + @return `true` if type is boolean, `false` otherwise. - case basic_json::value_t::null: - { - JSON_THROW(invalid_iterator::create(214, "cannot get value")); - } + @complexity Constant. - default: - { - if (m_it.primitive_iterator.get_value() == -n) - { - return *m_object; - } + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - JSON_THROW(invalid_iterator::create(214, "cannot get value")); - } - } - } + @liveexample{The following code exemplifies `is_boolean()` for all JSON + types.,is_boolean} - /*! - @brief return the key of an object iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - typename object_t::key_type key() const - { - assert(m_object != nullptr); + @since version 1.0.0 + */ + constexpr bool is_boolean() const noexcept + { + return (m_type == value_t::boolean); + } - if (m_object->is_object()) - { - return m_it.object_iterator->first; - } + /*! + @brief return whether value is a number - JSON_THROW(invalid_iterator::create(207, "cannot use key() for non-object iterators")); - } + This function returns true if and only if the JSON value is a number. This + includes both integer (signed and unsigned) and floating-point values. - /*! - @brief return the value of an iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - reference value() const - { - return operator*(); - } + @return `true` if type is number (regardless whether integer, unsigned + integer or floating-type), `false` otherwise. - private: - /// associated JSON instance - pointer m_object = nullptr; - /// the actual iterator of the associated instance - struct internal_iterator m_it = internal_iterator(); - }; + @complexity Constant. - /*! - @brief a template for a reverse iterator class + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - @tparam Base the base iterator type to reverse. Valid types are @ref - iterator (to create @ref reverse_iterator) and @ref const_iterator (to - create @ref const_reverse_iterator). + @liveexample{The following code exemplifies `is_number()` for all JSON + types.,is_number} - @requirement The class satisfies the following concept requirements: - - [RandomAccessIterator](http://en.cppreference.com/w/cpp/concept/RandomAccessIterator): - The iterator that can be moved to point (forward and backward) to any - element in constant time. - - [OutputIterator](http://en.cppreference.com/w/cpp/concept/OutputIterator): - It is possible to write to the pointed-to element (only if @a Base is - @ref iterator). + @sa @ref is_number_integer() -- check if value is an integer or unsigned + integer number + @sa @ref is_number_unsigned() -- check if value is an unsigned integer + number + @sa @ref is_number_float() -- check if value is a floating-point number @since version 1.0.0 */ - template - class json_reverse_iterator : public std::reverse_iterator + constexpr bool is_number() const noexcept { - public: - /// shortcut to the reverse iterator adaptor - using base_iterator = std::reverse_iterator; - /// the reference type for the pointed-to element - using reference = typename Base::reference; - - /// create reverse iterator from iterator - json_reverse_iterator(const typename base_iterator::iterator_type& it) noexcept - : base_iterator(it) - {} + return is_number_integer() or is_number_float(); + } - /// create reverse iterator from base class - json_reverse_iterator(const base_iterator& it) noexcept - : base_iterator(it) - {} + /*! + @brief return whether value is an integer number - /// post-increment (it++) - json_reverse_iterator operator++(int) - { - return static_cast(base_iterator::operator++(1)); - } + This function returns true if and only if the JSON value is a signed or + unsigned integer number. This excludes floating-point values. - /// pre-increment (++it) - json_reverse_iterator& operator++() - { - return static_cast(base_iterator::operator++()); - } + @return `true` if type is an integer or unsigned integer number, `false` + otherwise. - /// post-decrement (it--) - json_reverse_iterator operator--(int) - { - return static_cast(base_iterator::operator--(1)); - } + @complexity Constant. - /// pre-decrement (--it) - json_reverse_iterator& operator--() - { - return static_cast(base_iterator::operator--()); - } + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - /// add to iterator - json_reverse_iterator& operator+=(difference_type i) - { - return static_cast(base_iterator::operator+=(i)); - } + @liveexample{The following code exemplifies `is_number_integer()` for all + JSON types.,is_number_integer} - /// add to iterator - json_reverse_iterator operator+(difference_type i) const - { - return static_cast(base_iterator::operator+(i)); - } + @sa @ref is_number() -- check if value is a number + @sa @ref is_number_unsigned() -- check if value is an unsigned integer + number + @sa @ref is_number_float() -- check if value is a floating-point number - /// subtract from iterator - json_reverse_iterator operator-(difference_type i) const - { - return static_cast(base_iterator::operator-(i)); - } + @since version 1.0.0 + */ + constexpr bool is_number_integer() const noexcept + { + return (m_type == value_t::number_integer or m_type == value_t::number_unsigned); + } - /// return difference - difference_type operator-(const json_reverse_iterator& other) const - { - return base_iterator(*this) - base_iterator(other); - } + /*! + @brief return whether value is an unsigned integer number - /// access to successor - reference operator[](difference_type n) const - { - return *(this->operator+(n)); - } + This function returns true if and only if the JSON value is an unsigned + integer number. This excludes floating-point and signed integer values. - /// return the key of an object iterator - typename object_t::key_type key() const - { - auto it = --this->base(); - return it.key(); - } + @return `true` if type is an unsigned integer number, `false` otherwise. - /// return the value of an iterator - reference value() const - { - auto it = --this->base(); - return it.operator * (); - } - }; + @complexity Constant. + + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. + @liveexample{The following code exemplifies `is_number_unsigned()` for all + JSON types.,is_number_unsigned} - private: - //////////////////// - // input adapters // - //////////////////// + @sa @ref is_number() -- check if value is a number + @sa @ref is_number_integer() -- check if value is an integer or unsigned + integer number + @sa @ref is_number_float() -- check if value is a floating-point number - /// abstract input adapter interface - class input_adapter + @since version 2.0.0 + */ + constexpr bool is_number_unsigned() const noexcept { - public: - virtual int get_character() = 0; - virtual std::string read(size_t offset, size_t length) = 0; - virtual ~input_adapter() {} + return (m_type == value_t::number_unsigned); + } - // native support + /*! + @brief return whether value is a floating-point number - /// input adapter for input stream - static std::shared_ptr create(std::istream& i) - { - return std::shared_ptr(new cached_input_stream_adapter<16384>(i)); - } + This function returns true if and only if the JSON value is a + floating-point number. This excludes signed and unsigned integer values. - /// input adapter for input stream - static std::shared_ptr create(std::istream&& i) - { - return std::shared_ptr(new cached_input_stream_adapter<16384>(i)); - } + @return `true` if type is a floating-point number, `false` otherwise. - /// input adapter for buffer - static std::shared_ptr create(const char* b, size_t l) - { - return std::shared_ptr(new input_buffer_adapter(b, l)); - } + @complexity Constant. - // derived support + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - /// input adapter for string literal - template::value and - std::is_integral::type>::value and - sizeof(typename std::remove_pointer::type) == 1, int>::type = 0> - static std::shared_ptr create(CharT b) - { - return create(reinterpret_cast(b), - std::strlen(reinterpret_cast(b))); - } + @liveexample{The following code exemplifies `is_number_float()` for all + JSON types.,is_number_float} - /// input adapter for iterator range with contiguous storage - template::iterator_category, std::random_access_iterator_tag>::value - , int>::type - = 0> - static std::shared_ptr create(IteratorType first, IteratorType last) - { - // assertion to check that the iterator range is indeed contiguous, - // see http://stackoverflow.com/a/35008842/266378 for more discussion - assert(std::accumulate(first, last, std::pair(true, 0), - [&first](std::pair res, decltype(*first) val) - { - res.first &= (val == *(std::next(std::addressof(*first), res.second++))); - return res; - }).first); + @sa @ref is_number() -- check if value is number + @sa @ref is_number_integer() -- check if value is an integer number + @sa @ref is_number_unsigned() -- check if value is an unsigned integer + number - // assertion to check that each element is 1 byte long - static_assert(sizeof(typename std::iterator_traits::value_type) == 1, - "each element in the iterator range must have the size of 1 byte"); + @since version 1.0.0 + */ + constexpr bool is_number_float() const noexcept + { + return (m_type == value_t::number_float); + } - return create(reinterpret_cast(&(*first)), - static_cast(std::distance(first, last))); - } + /*! + @brief return whether value is an object - /// input adapter for array - template - static std::shared_ptr create(T (&array)[N]) - { - // delegate the call to the iterator-range overload - return create(std::begin(array), std::end(array)); - } + This function returns true if and only if the JSON value is an object. - /// input adapter for contiguous container - template::value and - std::is_base_of< - std::random_access_iterator_tag, - typename std::iterator_traits()))>::iterator_category>::value - , int>::type = 0> - static std::shared_ptr create(const ContiguousContainer& c) - { - // delegate the call to the iterator-range overload - return create(std::begin(c), std::end(c)); - } - }; + @return `true` if type is object, `false` otherwise. + + @complexity Constant. + + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - /// a type to simplify interfaces - using input_adapter_t = std::shared_ptr; + @liveexample{The following code exemplifies `is_object()` for all JSON + types.,is_object} - /// input adapter for cached stream input - template - class cached_input_stream_adapter : public input_adapter + @since version 1.0.0 + */ + constexpr bool is_object() const noexcept { - public: - cached_input_stream_adapter(std::istream& i) - : is(i), start_position(is.tellg()) - { - // immediately abort if stream is erroneous - if (JSON_UNLIKELY(i.fail())) - { - JSON_THROW(parse_error::create(111, 0, "bad input stream")); - } + return (m_type == value_t::object); + } - fill_buffer(); + /*! + @brief return whether value is an array - // skip byte order mark - if (fill_size >= 3 and buffer[0] == '\xEF' and buffer[1] == '\xBB' and buffer[2] == '\xBF') - { - buffer_pos += 3; - processed_chars += 3; - } - } + This function returns true if and only if the JSON value is an array. - ~cached_input_stream_adapter() override - { - // clear stream flags - is.clear(); - // We initially read a lot of characters into the buffer, and we - // may not have processed all of them. Therefore, we need to - // "rewind" the stream after the last processed char. - is.seekg(start_position); - is.ignore(static_cast(processed_chars)); - // clear stream flags - is.clear(); - } + @return `true` if type is array, `false` otherwise. - int get_character() override - { - // check if refilling is necessary and possible - if (buffer_pos == fill_size and not eof) - { - fill_buffer(); + @complexity Constant. - // check and remember that filling did not yield new input - if (fill_size == 0) - { - eof = true; - return std::char_traits::eof(); - } + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - // the buffer is ready - buffer_pos = 0; - } + @liveexample{The following code exemplifies `is_array()` for all JSON + types.,is_array} - ++processed_chars; - assert(buffer_pos < buffer.size()); - return buffer[buffer_pos++] & 0xFF; - } + @since version 1.0.0 + */ + constexpr bool is_array() const noexcept + { + return (m_type == value_t::array); + } - std::string read(size_t offset, size_t length) override - { - // create buffer - std::string result(length, '\0'); + /*! + @brief return whether value is a string - // save stream position - const auto current_pos = is.tellg(); - // save stream flags - const auto flags = is.rdstate(); + This function returns true if and only if the JSON value is a string. - // clear stream flags - is.clear(); - // set stream position - is.seekg(static_cast(offset)); - // read bytes - is.read(&result[0], static_cast(length)); + @return `true` if type is string, `false` otherwise. - // reset stream position - is.seekg(current_pos); - // reset stream flags - is.setstate(flags); + @complexity Constant. - return result; - } + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - private: - void fill_buffer() - { - // fill - is.read(buffer.data(), static_cast(buffer.size())); - // store number of bytes in the buffer - fill_size = static_cast(is.gcount()); - } + @liveexample{The following code exemplifies `is_string()` for all JSON + types.,is_string} + + @since version 1.0.0 + */ + constexpr bool is_string() const noexcept + { + return (m_type == value_t::string); + } + + /*! + @brief return whether value is discarded - /// the associated input stream - std::istream& is; + This function returns true if and only if the JSON value was discarded + during parsing with a callback function (see @ref parser_callback_t). - /// chars returned via get_character() - size_t processed_chars = 0; - /// chars processed in the current buffer - size_t buffer_pos = 0; + @note This function will always be `false` for JSON values after parsing. + That is, discarded values can only occur during parsing, but will be + removed when inside a structured value or replaced by null in other cases. - /// whether stream reached eof - bool eof = false; - /// how many chars have been copied to the buffer by last (re)fill - size_t fill_size = 0; + @return `true` if type is discarded, `false` otherwise. - /// position of the stream when we started - const std::streampos start_position; + @complexity Constant. - /// internal buffer - std::array buffer{{}}; - }; + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. + + @liveexample{The following code exemplifies `is_discarded()` for all JSON + types.,is_discarded} - /// input adapter for buffer input - class input_buffer_adapter : public input_adapter + @since version 1.0.0 + */ + constexpr bool is_discarded() const noexcept { - public: - input_buffer_adapter(const char* b, size_t l) - : input_adapter(), cursor(b), limit(b + l), start(b) - { - // skip byte order mark - if (l >= 3 and b[0] == '\xEF' and b[1] == '\xBB' and b[2] == '\xBF') - { - cursor += 3; - } - } + return (m_type == value_t::discarded); + } - // delete because of pointer members - input_buffer_adapter(const input_buffer_adapter&) = delete; - input_buffer_adapter& operator=(input_buffer_adapter&) = delete; + /*! + @brief return the type of the JSON value (implicit) - int get_character() noexcept override - { - if (JSON_LIKELY(cursor < limit)) - { - return *(cursor++) & 0xFF; - } - else - { - return std::char_traits::eof(); - } - } + Implicitly return the type of the JSON value as a value from the @ref + value_t enumeration. - std::string read(size_t offset, size_t length) override - { - // avoid reading too many characters - const size_t max_length = static_cast(limit - start); - return std::string(start + offset, (std::min)(length, max_length - offset)); - } + @return the type of the JSON value - private: - /// pointer to the current character - const char* cursor; - /// pointer past the last character - const char* limit; - /// pointer to the first character - const char* start; - }; + @complexity Constant. - ////////////////////////////////////////// - // binary serialization/deserialization // - ////////////////////////////////////////// + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - /// @name binary serialization/deserialization support - /// @{ + @liveexample{The following code exemplifies the @ref value_t operator for + all JSON types.,operator__value_t} - private: - /*! - @brief deserialization of CBOR and MessagePack values + @sa @ref type() -- return the type of the JSON value (explicit) + @sa @ref type_name() -- return the type as string + + @since version 1.0.0 */ - class binary_reader + constexpr operator value_t() const noexcept { - public: - /*! - @brief create a binary reader - - @param[in] adapter input adapter to read from - */ - explicit binary_reader(input_adapter_t adapter) - : ia(adapter), is_little_endian(little_endianess()) - { - assert(ia); - } - - /*! - @brief create a JSON value from CBOR input + return m_type; + } - @param[in] get_char whether a new character should be retrieved from - the input (true, default) or whether the last - read character should be considered instead + /// @} - @return JSON value created from CBOR input + private: + ////////////////// + // value access // + ////////////////// - @throw parse_error.110 if input ended unexpectedly - @throw parse_error.112 if unsupported byte was read - */ - basic_json parse_cbor(const bool get_char = true) + /// get a boolean (explicit) + boolean_t get_impl(boolean_t* /*unused*/) const + { + if (JSON_LIKELY(is_boolean())) { - switch (get_char ? get() : current) - { - // EOF - case std::char_traits::eof(): - { - JSON_THROW(parse_error::create(110, chars_read, "unexpected end of input")); - } + return m_value.boolean; + } - // Integer 0x00..0x17 (0..23) - case 0x00: - case 0x01: - case 0x02: - case 0x03: - case 0x04: - case 0x05: - case 0x06: - case 0x07: - case 0x08: - case 0x09: - case 0x0a: - case 0x0b: - case 0x0c: - case 0x0d: - case 0x0e: - case 0x0f: - case 0x10: - case 0x11: - case 0x12: - case 0x13: - case 0x14: - case 0x15: - case 0x16: - case 0x17: - { - return static_cast(current); - } + JSON_THROW(type_error::create(302, "type must be boolean, but is " + std::string(type_name()))); + } - case 0x18: // Unsigned integer (one-byte uint8_t follows) - { - return get_number(); - } + /// get a pointer to the value (object) + object_t* get_impl_ptr(object_t* /*unused*/) noexcept + { + return is_object() ? m_value.object : nullptr; + } - case 0x19: // Unsigned integer (two-byte uint16_t follows) - { - return get_number(); - } + /// get a pointer to the value (object) + constexpr const object_t* get_impl_ptr(const object_t* /*unused*/) const noexcept + { + return is_object() ? m_value.object : nullptr; + } - case 0x1a: // Unsigned integer (four-byte uint32_t follows) - { - return get_number(); - } + /// get a pointer to the value (array) + array_t* get_impl_ptr(array_t* /*unused*/) noexcept + { + return is_array() ? m_value.array : nullptr; + } - case 0x1b: // Unsigned integer (eight-byte uint64_t follows) - { - return get_number(); - } + /// get a pointer to the value (array) + constexpr const array_t* get_impl_ptr(const array_t* /*unused*/) const noexcept + { + return is_array() ? m_value.array : nullptr; + } - // Negative integer -1-0x00..-1-0x17 (-1..-24) - case 0x20: - case 0x21: - case 0x22: - case 0x23: - case 0x24: - case 0x25: - case 0x26: - case 0x27: - case 0x28: - case 0x29: - case 0x2a: - case 0x2b: - case 0x2c: - case 0x2d: - case 0x2e: - case 0x2f: - case 0x30: - case 0x31: - case 0x32: - case 0x33: - case 0x34: - case 0x35: - case 0x36: - case 0x37: - { - return static_cast(0x20 - 1 - current); - } + /// get a pointer to the value (string) + string_t* get_impl_ptr(string_t* /*unused*/) noexcept + { + return is_string() ? m_value.string : nullptr; + } - case 0x38: // Negative integer (one-byte uint8_t follows) - { - // must be uint8_t ! - return static_cast(-1) - get_number(); - } + /// get a pointer to the value (string) + constexpr const string_t* get_impl_ptr(const string_t* /*unused*/) const noexcept + { + return is_string() ? m_value.string : nullptr; + } - case 0x39: // Negative integer -1-n (two-byte uint16_t follows) - { - return static_cast(-1) - get_number(); - } + /// get a pointer to the value (boolean) + boolean_t* get_impl_ptr(boolean_t* /*unused*/) noexcept + { + return is_boolean() ? &m_value.boolean : nullptr; + } - case 0x3a: // Negative integer -1-n (four-byte uint32_t follows) - { - return static_cast(-1) - get_number(); - } + /// get a pointer to the value (boolean) + constexpr const boolean_t* get_impl_ptr(const boolean_t* /*unused*/) const noexcept + { + return is_boolean() ? &m_value.boolean : nullptr; + } - case 0x3b: // Negative integer -1-n (eight-byte uint64_t follows) - { - return static_cast(-1) - static_cast(get_number()); - } + /// get a pointer to the value (integer number) + number_integer_t* get_impl_ptr(number_integer_t* /*unused*/) noexcept + { + return is_number_integer() ? &m_value.number_integer : nullptr; + } - // UTF-8 string (0x00..0x17 bytes follow) - case 0x60: - case 0x61: - case 0x62: - case 0x63: - case 0x64: - case 0x65: - case 0x66: - case 0x67: - case 0x68: - case 0x69: - case 0x6a: - case 0x6b: - case 0x6c: - case 0x6d: - case 0x6e: - case 0x6f: - case 0x70: - case 0x71: - case 0x72: - case 0x73: - case 0x74: - case 0x75: - case 0x76: - case 0x77: - case 0x78: // UTF-8 string (one-byte uint8_t for n follows) - case 0x79: // UTF-8 string (two-byte uint16_t for n follow) - case 0x7a: // UTF-8 string (four-byte uint32_t for n follow) - case 0x7b: // UTF-8 string (eight-byte uint64_t for n follow) - case 0x7f: // UTF-8 string (indefinite length) - { - return get_cbor_string(); - } - - // array (0x00..0x17 data items follow) - case 0x80: - case 0x81: - case 0x82: - case 0x83: - case 0x84: - case 0x85: - case 0x86: - case 0x87: - case 0x88: - case 0x89: - case 0x8a: - case 0x8b: - case 0x8c: - case 0x8d: - case 0x8e: - case 0x8f: - case 0x90: - case 0x91: - case 0x92: - case 0x93: - case 0x94: - case 0x95: - case 0x96: - case 0x97: - { - basic_json result = value_t::array; - const auto len = static_cast(current & 0x1f); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_cbor()); - } - return result; - } - - case 0x98: // array (one-byte uint8_t for n follows) - { - basic_json result = value_t::array; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_cbor()); - } - return result; - } + /// get a pointer to the value (integer number) + constexpr const number_integer_t* get_impl_ptr(const number_integer_t* /*unused*/) const noexcept + { + return is_number_integer() ? &m_value.number_integer : nullptr; + } - case 0x99: // array (two-byte uint16_t for n follow) - { - basic_json result = value_t::array; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_cbor()); - } - return result; - } + /// get a pointer to the value (unsigned number) + number_unsigned_t* get_impl_ptr(number_unsigned_t* /*unused*/) noexcept + { + return is_number_unsigned() ? &m_value.number_unsigned : nullptr; + } - case 0x9a: // array (four-byte uint32_t for n follow) - { - basic_json result = value_t::array; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_cbor()); - } - return result; - } + /// get a pointer to the value (unsigned number) + constexpr const number_unsigned_t* get_impl_ptr(const number_unsigned_t* /*unused*/) const noexcept + { + return is_number_unsigned() ? &m_value.number_unsigned : nullptr; + } - case 0x9b: // array (eight-byte uint64_t for n follow) - { - basic_json result = value_t::array; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_cbor()); - } - return result; - } + /// get a pointer to the value (floating-point number) + number_float_t* get_impl_ptr(number_float_t* /*unused*/) noexcept + { + return is_number_float() ? &m_value.number_float : nullptr; + } - case 0x9f: // array (indefinite length) - { - basic_json result = value_t::array; - while (get() != 0xff) - { - result.push_back(parse_cbor(false)); - } - return result; - } - - // map (0x00..0x17 pairs of data items follow) - case 0xa0: - case 0xa1: - case 0xa2: - case 0xa3: - case 0xa4: - case 0xa5: - case 0xa6: - case 0xa7: - case 0xa8: - case 0xa9: - case 0xaa: - case 0xab: - case 0xac: - case 0xad: - case 0xae: - case 0xaf: - case 0xb0: - case 0xb1: - case 0xb2: - case 0xb3: - case 0xb4: - case 0xb5: - case 0xb6: - case 0xb7: - { - basic_json result = value_t::object; - const auto len = static_cast(current & 0x1f); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_cbor_string(); - result[key] = parse_cbor(); - } - return result; - } + /// get a pointer to the value (floating-point number) + constexpr const number_float_t* get_impl_ptr(const number_float_t* /*unused*/) const noexcept + { + return is_number_float() ? &m_value.number_float : nullptr; + } - case 0xb8: // map (one-byte uint8_t for n follows) - { - basic_json result = value_t::object; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_cbor_string(); - result[key] = parse_cbor(); - } - return result; - } + /*! + @brief helper function to implement get_ref() - case 0xb9: // map (two-byte uint16_t for n follow) - { - basic_json result = value_t::object; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_cbor_string(); - result[key] = parse_cbor(); - } - return result; - } + This function helps to implement get_ref() without code duplication for + const and non-const overloads - case 0xba: // map (four-byte uint32_t for n follow) - { - basic_json result = value_t::object; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_cbor_string(); - result[key] = parse_cbor(); - } - return result; - } + @tparam ThisType will be deduced as `basic_json` or `const basic_json` - case 0xbb: // map (eight-byte uint64_t for n follow) - { - basic_json result = value_t::object; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_cbor_string(); - result[key] = parse_cbor(); - } - return result; - } + @throw type_error.303 if ReferenceType does not match underlying value + type of the current JSON + */ + template + static ReferenceType get_ref_impl(ThisType& obj) + { + // delegate the call to get_ptr<>() + auto ptr = obj.template get_ptr::type>(); - case 0xbf: // map (indefinite length) - { - basic_json result = value_t::object; - while (get() != 0xff) - { - auto key = get_cbor_string(); - result[key] = parse_cbor(); - } - return result; - } + if (JSON_LIKELY(ptr != nullptr)) + { + return *ptr; + } - case 0xf4: // false - { - return false; - } + JSON_THROW(type_error::create(303, "incompatible ReferenceType for get_ref, actual type is " + std::string(obj.type_name()))); + } - case 0xf5: // true - { - return true; - } + public: + /// @name value access + /// Direct access to the stored value of a JSON value. + /// @{ - case 0xf6: // null - { - return value_t::null; - } + /*! + @brief get special-case overload - case 0xf9: // Half-Precision Float (two-byte IEEE 754) - { - const int byte1 = get(); - check_eof(); - const int byte2 = get(); - check_eof(); + This overloads avoids a lot of template boilerplate, it can be seen as the + identity method - // code from RFC 7049, Appendix D, Figure 3: - // As half-precision floating-point numbers were only added - // to IEEE 754 in 2008, today's programming platforms often - // still only have limited support for them. It is very - // easy to include at least decoding support for them even - // without such support. An example of a small decoder for - // half-precision floating-point numbers in the C language - // is shown in Fig. 3. - const int half = (byte1 << 8) + byte2; - const int exp = (half >> 10) & 0x1f; - const int mant = half & 0x3ff; - double val; - if (exp == 0) - { - val = std::ldexp(mant, -24); - } - else if (exp != 31) - { - val = std::ldexp(mant + 1024, exp - 25); - } - else - { - val = mant == 0 - ? std::numeric_limits::infinity() - : std::numeric_limits::quiet_NaN(); - } - return (half & 0x8000) != 0 ? -val : val; - } + @tparam BasicJsonType == @ref basic_json - case 0xfa: // Single-Precision Float (four-byte IEEE 754) - { - return get_number(); - } + @return a copy of *this - case 0xfb: // Double-Precision Float (eight-byte IEEE 754) - { - return get_number(); - } + @complexity Constant. - default: // anything else (0xFF is handled inside the other types) - { - std::stringstream ss; - ss << std::setw(2) << std::setfill('0') << std::hex << current; - JSON_THROW(parse_error::create(112, chars_read, "error reading CBOR; last byte: 0x" + ss.str())); - } - } - } + @since version 2.1.0 + */ + template::type, basic_json_t>::value, + int> = 0> + basic_json get() const + { + return *this; + } - /*! - @brief create a JSON value from MessagePack input + /*! + @brief get a value (explicit) - @return JSON value created from MessagePack input + Explicit type conversion between the JSON value and a compatible value + which is [CopyConstructible](http://en.cppreference.com/w/cpp/concept/CopyConstructible) + and [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible). + The value is converted by calling the @ref json_serializer + `from_json()` method. - @throw parse_error.110 if input ended unexpectedly - @throw parse_error.112 if unsupported byte was read - */ - basic_json parse_msgpack() - { - switch (get()) - { - // EOF - case std::char_traits::eof(): - { - JSON_THROW(parse_error::create(110, chars_read, "unexpected end of input")); - } + The function is equivalent to executing + @code {.cpp} + ValueType ret; + JSONSerializer::from_json(*this, ret); + return ret; + @endcode - // positive fixint - case 0x00: - case 0x01: - case 0x02: - case 0x03: - case 0x04: - case 0x05: - case 0x06: - case 0x07: - case 0x08: - case 0x09: - case 0x0a: - case 0x0b: - case 0x0c: - case 0x0d: - case 0x0e: - case 0x0f: - case 0x10: - case 0x11: - case 0x12: - case 0x13: - case 0x14: - case 0x15: - case 0x16: - case 0x17: - case 0x18: - case 0x19: - case 0x1a: - case 0x1b: - case 0x1c: - case 0x1d: - case 0x1e: - case 0x1f: - case 0x20: - case 0x21: - case 0x22: - case 0x23: - case 0x24: - case 0x25: - case 0x26: - case 0x27: - case 0x28: - case 0x29: - case 0x2a: - case 0x2b: - case 0x2c: - case 0x2d: - case 0x2e: - case 0x2f: - case 0x30: - case 0x31: - case 0x32: - case 0x33: - case 0x34: - case 0x35: - case 0x36: - case 0x37: - case 0x38: - case 0x39: - case 0x3a: - case 0x3b: - case 0x3c: - case 0x3d: - case 0x3e: - case 0x3f: - case 0x40: - case 0x41: - case 0x42: - case 0x43: - case 0x44: - case 0x45: - case 0x46: - case 0x47: - case 0x48: - case 0x49: - case 0x4a: - case 0x4b: - case 0x4c: - case 0x4d: - case 0x4e: - case 0x4f: - case 0x50: - case 0x51: - case 0x52: - case 0x53: - case 0x54: - case 0x55: - case 0x56: - case 0x57: - case 0x58: - case 0x59: - case 0x5a: - case 0x5b: - case 0x5c: - case 0x5d: - case 0x5e: - case 0x5f: - case 0x60: - case 0x61: - case 0x62: - case 0x63: - case 0x64: - case 0x65: - case 0x66: - case 0x67: - case 0x68: - case 0x69: - case 0x6a: - case 0x6b: - case 0x6c: - case 0x6d: - case 0x6e: - case 0x6f: - case 0x70: - case 0x71: - case 0x72: - case 0x73: - case 0x74: - case 0x75: - case 0x76: - case 0x77: - case 0x78: - case 0x79: - case 0x7a: - case 0x7b: - case 0x7c: - case 0x7d: - case 0x7e: - case 0x7f: - { - return static_cast(current); - } - - // fixmap - case 0x80: - case 0x81: - case 0x82: - case 0x83: - case 0x84: - case 0x85: - case 0x86: - case 0x87: - case 0x88: - case 0x89: - case 0x8a: - case 0x8b: - case 0x8c: - case 0x8d: - case 0x8e: - case 0x8f: - { - basic_json result = value_t::object; - const auto len = static_cast(current & 0x0f); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_msgpack_string(); - result[key] = parse_msgpack(); - } - return result; - } - - // fixarray - case 0x90: - case 0x91: - case 0x92: - case 0x93: - case 0x94: - case 0x95: - case 0x96: - case 0x97: - case 0x98: - case 0x99: - case 0x9a: - case 0x9b: - case 0x9c: - case 0x9d: - case 0x9e: - case 0x9f: - { - basic_json result = value_t::array; - const auto len = static_cast(current & 0x0f); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_msgpack()); - } - return result; - } - - // fixstr - case 0xa0: - case 0xa1: - case 0xa2: - case 0xa3: - case 0xa4: - case 0xa5: - case 0xa6: - case 0xa7: - case 0xa8: - case 0xa9: - case 0xaa: - case 0xab: - case 0xac: - case 0xad: - case 0xae: - case 0xaf: - case 0xb0: - case 0xb1: - case 0xb2: - case 0xb3: - case 0xb4: - case 0xb5: - case 0xb6: - case 0xb7: - case 0xb8: - case 0xb9: - case 0xba: - case 0xbb: - case 0xbc: - case 0xbd: - case 0xbe: - case 0xbf: - { - return get_msgpack_string(); - } - - case 0xc0: // nil - { - return value_t::null; - } - - case 0xc2: // false - { - return false; - } + This overloads is chosen if: + - @a ValueType is not @ref basic_json, + - @ref json_serializer has a `from_json()` method of the form + `void from_json(const basic_json&, ValueType&)`, and + - @ref json_serializer does not have a `from_json()` method of + the form `ValueType from_json(const basic_json&)` - case 0xc3: // true - { - return true; - } - - case 0xca: // float 32 - { - return get_number(); - } + @tparam ValueTypeCV the provided value type + @tparam ValueType the returned value type - case 0xcb: // float 64 - { - return get_number(); - } + @return copy of the JSON value, converted to @a ValueType - case 0xcc: // uint 8 - { - return get_number(); - } + @throw what @ref json_serializer `from_json()` method throws - case 0xcd: // uint 16 - { - return get_number(); - } + @liveexample{The example below shows several conversions from JSON values + to other types. There a few things to note: (1) Floating-point numbers can + be converted to integers\, (2) A JSON array can be converted to a standard + `std::vector`\, (3) A JSON object can be converted to C++ + associative containers such as `std::unordered_map`.,get__ValueType_const} - case 0xce: // uint 32 - { - return get_number(); - } + @since version 2.1.0 + */ + template, + detail::enable_if_t < + not std::is_same::value and + detail::has_from_json::value and + not detail::has_non_default_from_json::value, + int> = 0> + ValueType get() const noexcept(noexcept( + JSONSerializer::from_json(std::declval(), std::declval()))) + { + // we cannot static_assert on ValueTypeCV being non-const, because + // there is support for get(), which is why we + // still need the uncvref + static_assert(not std::is_reference::value, + "get() cannot be used with reference types, you might want to use get_ref()"); + static_assert(std::is_default_constructible::value, + "types must be DefaultConstructible when used with get()"); - case 0xcf: // uint 64 - { - return get_number(); - } + ValueType ret; + JSONSerializer::from_json(*this, ret); + return ret; + } - case 0xd0: // int 8 - { - return get_number(); - } + /*! + @brief get a value (explicit); special case - case 0xd1: // int 16 - { - return get_number(); - } + Explicit type conversion between the JSON value and a compatible value + which is **not** [CopyConstructible](http://en.cppreference.com/w/cpp/concept/CopyConstructible) + and **not** [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible). + The value is converted by calling the @ref json_serializer + `from_json()` method. - case 0xd2: // int 32 - { - return get_number(); - } + The function is equivalent to executing + @code {.cpp} + return JSONSerializer::from_json(*this); + @endcode - case 0xd3: // int 64 - { - return get_number(); - } + This overloads is chosen if: + - @a ValueType is not @ref basic_json and + - @ref json_serializer has a `from_json()` method of the form + `ValueType from_json(const basic_json&)` - case 0xd9: // str 8 - case 0xda: // str 16 - case 0xdb: // str 32 - { - return get_msgpack_string(); - } + @note If @ref json_serializer has both overloads of + `from_json()`, this one is chosen. - case 0xdc: // array 16 - { - basic_json result = value_t::array; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_msgpack()); - } - return result; - } + @tparam ValueTypeCV the provided value type + @tparam ValueType the returned value type - case 0xdd: // array 32 - { - basic_json result = value_t::array; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_msgpack()); - } - return result; - } + @return copy of the JSON value, converted to @a ValueType - case 0xde: // map 16 - { - basic_json result = value_t::object; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_msgpack_string(); - result[key] = parse_msgpack(); - } - return result; - } + @throw what @ref json_serializer `from_json()` method throws - case 0xdf: // map 32 - { - basic_json result = value_t::object; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_msgpack_string(); - result[key] = parse_msgpack(); - } - return result; - } - - // positive fixint - case 0xe0: - case 0xe1: - case 0xe2: - case 0xe3: - case 0xe4: - case 0xe5: - case 0xe6: - case 0xe7: - case 0xe8: - case 0xe9: - case 0xea: - case 0xeb: - case 0xec: - case 0xed: - case 0xee: - case 0xef: - case 0xf0: - case 0xf1: - case 0xf2: - case 0xf3: - case 0xf4: - case 0xf5: - case 0xf6: - case 0xf7: - case 0xf8: - case 0xf9: - case 0xfa: - case 0xfb: - case 0xfc: - case 0xfd: - case 0xfe: - case 0xff: - { - return static_cast(current); - } - - default: // anything else - { - std::stringstream ss; - ss << std::setw(2) << std::setfill('0') << std::hex << current; - JSON_THROW(parse_error::create(112, chars_read, "error reading MessagePack; last byte: 0x" + ss.str())); - } - } - } + @since version 2.1.0 + */ + template, + detail::enable_if_t::value and + detail::has_non_default_from_json::value, + int> = 0> + ValueType get() const noexcept(noexcept( + JSONSerializer::from_json(std::declval()))) + { + static_assert(not std::is_reference::value, + "get() cannot be used with reference types, you might want to use get_ref()"); + return JSONSerializer::from_json(*this); + } - /*! - @brief determine system byte order + /*! + @brief get a pointer value (explicit) - @return true iff system's byte order is little endian + Explicit pointer access to the internally stored JSON value. No copies are + made. - @note from http://stackoverflow.com/a/1001328/266378 - */ - static bool little_endianess() noexcept - { - int num = 1; - return (*reinterpret_cast(&num) == 1); - } + @warning The pointer becomes invalid if the underlying JSON object + changes. - private: - /*! - @brief get next character from the input + @tparam PointerType pointer type; must be a pointer to @ref array_t, @ref + object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, + @ref number_unsigned_t, or @ref number_float_t. - This function provides the interface to the used input adapter. It does - not throw in case the input reached EOF, but returns - `std::char_traits::eof()` in that case. + @return pointer to the internally stored JSON value if the requested + pointer type @a PointerType fits to the JSON value; `nullptr` otherwise - @return character read from the input - */ - int get() - { - ++chars_read; - return (current = ia->get_character()); - } + @complexity Constant. - /* - @brief read a number from the input + @liveexample{The example below shows how pointers to internal values of a + JSON value can be requested. Note that no type conversions are made and a + `nullptr` is returned if the value and the requested pointer type does not + match.,get__PointerType} - @tparam T the type of the number + @sa @ref get_ptr() for explicit pointer-member access - @return number of type @a T + @since version 1.0.0 + */ + template::value, int>::type = 0> + PointerType get() noexcept + { + // delegate the call to get_ptr + return get_ptr(); + } - @note This function needs to respect the system's endianess, because - bytes in CBOR and MessagePack are stored in network order (big - endian) and therefore need reordering on little endian systems. + /*! + @brief get a pointer value (explicit) + @copydoc get() + */ + template::value, int>::type = 0> + constexpr const PointerType get() const noexcept + { + // delegate the call to get_ptr + return get_ptr(); + } - @throw parse_error.110 if input has less than `sizeof(T)` bytes - */ - template - T get_number() - { - // step 1: read input into array with system's byte order - std::array vec; - for (size_t i = 0; i < sizeof(T); ++i) - { - get(); - check_eof(); + /*! + @brief get a pointer value (implicit) - // reverse byte order prior to conversion if necessary - if (is_little_endian) - { - vec[sizeof(T) - i - 1] = static_cast(current); - } - else - { - vec[i] = static_cast(current); // LCOV_EXCL_LINE - } - } + Implicit pointer access to the internally stored JSON value. No copies are + made. - // step 2: convert array into number of type T and return - T result; - std::memcpy(&result, vec.data(), sizeof(T)); - return result; - } + @warning Writing data to the pointee of the result yields an undefined + state. - /*! - @brief create a string by reading characters from the input + @tparam PointerType pointer type; must be a pointer to @ref array_t, @ref + object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, + @ref number_unsigned_t, or @ref number_float_t. Enforced by a static + assertion. - @param[in] len number of bytes to read + @return pointer to the internally stored JSON value if the requested + pointer type @a PointerType fits to the JSON value; `nullptr` otherwise - @return string created by reading @a len bytes + @complexity Constant. - @throw parse_error.110 if input has less than @a len bytes - */ - std::string get_string(const size_t len) - { - std::string result; - for (size_t i = 0; i < len; ++i) - { - get(); - check_eof(); - result.append(1, static_cast(current)); - } - return result; - } + @liveexample{The example below shows how pointers to internal values of a + JSON value can be requested. Note that no type conversions are made and a + `nullptr` is returned if the value and the requested pointer type does not + match.,get_ptr} - /*! - @brief reads a CBOR string + @since version 1.0.0 + */ + template::value, int>::type = 0> + PointerType get_ptr() noexcept + { + // get the type of the PointerType (remove pointer and const) + using pointee_t = typename std::remove_const::type>::type>::type; + // make sure the type matches the allowed types + static_assert( + std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + , "incompatible pointer type"); - This function first reads starting bytes to determine the expected - string length and then copies this number of bytes into a string. - Additionally, CBOR's strings with indefinite lengths are supported. + // delegate the call to get_impl_ptr<>() + return get_impl_ptr(static_cast(nullptr)); + } - @return string + /*! + @brief get a pointer value (implicit) + @copydoc get_ptr() + */ + template::value and + std::is_const::type>::value, int>::type = 0> + constexpr const PointerType get_ptr() const noexcept + { + // get the type of the PointerType (remove pointer and const) + using pointee_t = typename std::remove_const::type>::type>::type; + // make sure the type matches the allowed types + static_assert( + std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + , "incompatible pointer type"); - @throw parse_error.110 if input ended - @throw parse_error.113 if an unexpexted byte is read - */ - std::string get_cbor_string() - { - check_eof(); + // delegate the call to get_impl_ptr<>() const + return get_impl_ptr(static_cast(nullptr)); + } - switch (current) - { - // UTF-8 string (0x00..0x17 bytes follow) - case 0x60: - case 0x61: - case 0x62: - case 0x63: - case 0x64: - case 0x65: - case 0x66: - case 0x67: - case 0x68: - case 0x69: - case 0x6a: - case 0x6b: - case 0x6c: - case 0x6d: - case 0x6e: - case 0x6f: - case 0x70: - case 0x71: - case 0x72: - case 0x73: - case 0x74: - case 0x75: - case 0x76: - case 0x77: - { - const auto len = static_cast(current & 0x1f); - return get_string(len); - } + /*! + @brief get a reference value (implicit) - case 0x78: // UTF-8 string (one-byte uint8_t for n follows) - { - const auto len = static_cast(get_number()); - return get_string(len); - } + Implicit reference access to the internally stored JSON value. No copies + are made. - case 0x79: // UTF-8 string (two-byte uint16_t for n follow) - { - const auto len = static_cast(get_number()); - return get_string(len); - } + @warning Writing data to the referee of the result yields an undefined + state. - case 0x7a: // UTF-8 string (four-byte uint32_t for n follow) - { - const auto len = static_cast(get_number()); - return get_string(len); - } + @tparam ReferenceType reference type; must be a reference to @ref array_t, + @ref object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, or + @ref number_float_t. Enforced by static assertion. - case 0x7b: // UTF-8 string (eight-byte uint64_t for n follow) - { - const auto len = static_cast(get_number()); - return get_string(len); - } + @return reference to the internally stored JSON value if the requested + reference type @a ReferenceType fits to the JSON value; throws + type_error.303 otherwise - case 0x7f: // UTF-8 string (indefinite length) - { - std::string result; - while (get() != 0xff) - { - check_eof(); - result.append(1, static_cast(current)); - } - return result; - } + @throw type_error.303 in case passed type @a ReferenceType is incompatible + with the stored JSON value; see example below - default: - { - std::stringstream ss; - ss << std::setw(2) << std::setfill('0') << std::hex << current; - JSON_THROW(parse_error::create(113, chars_read, "expected a CBOR string; last byte: 0x" + ss.str())); - } - } - } + @complexity Constant. - /*! - @brief reads a MessagePack string + @liveexample{The example shows several calls to `get_ref()`.,get_ref} - This function first reads starting bytes to determine the expected - string length and then copies this number of bytes into a string. + @since version 1.1.0 + */ + template::value, int>::type = 0> + ReferenceType get_ref() + { + // delegate call to get_ref_impl + return get_ref_impl(*this); + } - @return string + /*! + @brief get a reference value (implicit) + @copydoc get_ref() + */ + template::value and + std::is_const::type>::value, int>::type = 0> + ReferenceType get_ref() const + { + // delegate call to get_ref_impl + return get_ref_impl(*this); + } - @throw parse_error.110 if input ended - @throw parse_error.113 if an unexpexted byte is read - */ - std::string get_msgpack_string() - { - check_eof(); + /*! + @brief get a value (implicit) - switch (current) - { - // fixstr - case 0xa0: - case 0xa1: - case 0xa2: - case 0xa3: - case 0xa4: - case 0xa5: - case 0xa6: - case 0xa7: - case 0xa8: - case 0xa9: - case 0xaa: - case 0xab: - case 0xac: - case 0xad: - case 0xae: - case 0xaf: - case 0xb0: - case 0xb1: - case 0xb2: - case 0xb3: - case 0xb4: - case 0xb5: - case 0xb6: - case 0xb7: - case 0xb8: - case 0xb9: - case 0xba: - case 0xbb: - case 0xbc: - case 0xbd: - case 0xbe: - case 0xbf: - { - const auto len = static_cast(current & 0x1f); - return get_string(len); - } + Implicit type conversion between the JSON value and a compatible value. + The call is realized by calling @ref get() const. - case 0xd9: // str 8 - { - const auto len = static_cast(get_number()); - return get_string(len); - } + @tparam ValueType non-pointer type compatible to the JSON value, for + instance `int` for JSON integer numbers, `bool` for JSON booleans, or + `std::vector` types for JSON arrays. The character type of @ref string_t + as well as an initializer list of this type is excluded to avoid + ambiguities as these types implicitly convert to `std::string`. - case 0xda: // str 16 - { - const auto len = static_cast(get_number()); - return get_string(len); - } + @return copy of the JSON value, converted to type @a ValueType - case 0xdb: // str 32 - { - const auto len = static_cast(get_number()); - return get_string(len); - } + @throw type_error.302 in case passed type @a ValueType is incompatible + to the JSON value type (e.g., the JSON value is of type boolean, but a + string is requested); see example below - default: - { - std::stringstream ss; - ss << std::setw(2) << std::setfill('0') << std::hex << current; - JSON_THROW(parse_error::create(113, chars_read, "expected a MessagePack string; last byte: 0x" + ss.str())); - } - } - } + @complexity Linear in the size of the JSON value. - /*! - @brief check if input ended - @throw parse_error.110 if input ended - */ - void check_eof() const - { - if (JSON_UNLIKELY(current == std::char_traits::eof())) - { - JSON_THROW(parse_error::create(110, chars_read, "unexpected end of input")); - } - } + @liveexample{The example below shows several conversions from JSON values + to other types. There a few things to note: (1) Floating-point numbers can + be converted to integers\, (2) A JSON array can be converted to a standard + `std::vector`\, (3) A JSON object can be converted to C++ + associative containers such as `std::unordered_map`.,operator__ValueType} - private: - /// input adapter - input_adapter_t ia = nullptr; + @since version 1.0.0 + */ + template < typename ValueType, typename std::enable_if < + not std::is_pointer::value and + not std::is_same>::value and + not std::is_same::value +#ifndef _MSC_VER // fix for issue #167 operator<< ambiguity under VS2015 + and not std::is_same>::value +#endif +#if defined(JSON_HAS_CPP_17) + and not std::is_same::value +#endif + , int >::type = 0 > + operator ValueType() const + { + // delegate the call to get<>() const + return get(); + } - /// the current character - int current = std::char_traits::eof(); + /// @} - /// the number of characters read - size_t chars_read = 0; - /// whether we can assume little endianess - const bool is_little_endian = true; - }; + //////////////////// + // element access // + //////////////////// + + /// @name element access + /// Access to the JSON value. + /// @{ /*! - @brief serialization to CBOR and MessagePack values + @brief access specified array element with bounds checking + + Returns a reference to the element at specified location @a idx, with + bounds checking. + + @param[in] idx index of the element to access + + @return reference to the element at index @a idx + + @throw type_error.304 if the JSON value is not an array; in this case, + calling `at` with an index makes no sense. See example below. + @throw out_of_range.401 if the index @a idx is out of range of the array; + that is, `idx >= size()`. See example below. + + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes in the JSON value. + + @complexity Constant. + + @since version 1.0.0 + + @liveexample{The example below shows how array elements can be read and + written using `at()`. It also demonstrates the different exceptions that + can be thrown.,at__size_type} */ - class binary_writer + reference at(size_type idx) { - public: - /*! - @brief create a binary writer - - @param[in] adapter output adapter to write to - */ - explicit binary_writer(output_adapter_t adapter) - : is_little_endian(binary_reader::little_endianess()), oa(adapter) + // at only works for arrays + if (JSON_LIKELY(is_array())) { - assert(oa); + JSON_TRY + { + return m_value.array->at(idx); + } + JSON_CATCH (std::out_of_range&) + { + // create better exception explanation + JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range")); + } } - - /*! - @brief[in] j JSON value to serialize - */ - void write_cbor(const basic_json& j) + else { - switch (j.type()) - { - case value_t::null: - { - oa->write_character(0xf6); - break; - } + JSON_THROW(type_error::create(304, "cannot use at() with " + std::string(type_name()))); + } + } - case value_t::boolean: - { - oa->write_character(j.m_value.boolean ? 0xf5 : 0xf4); - break; - } + /*! + @brief access specified array element with bounds checking - case value_t::number_integer: - { - if (j.m_value.number_integer >= 0) - { - // CBOR does not differentiate between positive signed - // integers and unsigned integers. Therefore, we used the - // code from the value_t::number_unsigned case here. - if (j.m_value.number_integer <= 0x17) - { - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_integer <= (std::numeric_limits::max)()) - { - oa->write_character(0x18); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_integer <= (std::numeric_limits::max)()) - { - oa->write_character(0x19); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_integer <= (std::numeric_limits::max)()) - { - oa->write_character(0x1a); - write_number(static_cast(j.m_value.number_integer)); - } - else - { - oa->write_character(0x1b); - write_number(static_cast(j.m_value.number_integer)); - } - } - else - { - // The conversions below encode the sign in the first - // byte, and the value is converted to a positive number. - const auto positive_number = -1 - j.m_value.number_integer; - if (j.m_value.number_integer >= -24) - { - write_number(static_cast(0x20 + positive_number)); - } - else if (positive_number <= (std::numeric_limits::max)()) - { - oa->write_character(0x38); - write_number(static_cast(positive_number)); - } - else if (positive_number <= (std::numeric_limits::max)()) - { - oa->write_character(0x39); - write_number(static_cast(positive_number)); - } - else if (positive_number <= (std::numeric_limits::max)()) - { - oa->write_character(0x3a); - write_number(static_cast(positive_number)); - } - else - { - oa->write_character(0x3b); - write_number(static_cast(positive_number)); - } - } - break; - } + Returns a const reference to the element at specified location @a idx, + with bounds checking. - case value_t::number_unsigned: - { - if (j.m_value.number_unsigned <= 0x17) - { - write_number(static_cast(j.m_value.number_unsigned)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - oa->write_character(0x18); - write_number(static_cast(j.m_value.number_unsigned)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - oa->write_character(0x19); - write_number(static_cast(j.m_value.number_unsigned)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - oa->write_character(0x1a); - write_number(static_cast(j.m_value.number_unsigned)); - } - else - { - oa->write_character(0x1b); - write_number(static_cast(j.m_value.number_unsigned)); - } - break; - } + @param[in] idx index of the element to access - case value_t::number_float: - { - // Double-Precision Float - oa->write_character(0xfb); - write_number(j.m_value.number_float); - break; - } + @return const reference to the element at index @a idx - case value_t::string: - { - // step 1: write control byte and the string length - const auto N = j.m_value.string->size(); - if (N <= 0x17) - { - write_number(static_cast(0x60 + N)); - } - else if (N <= 0xff) - { - oa->write_character(0x78); - write_number(static_cast(N)); - } - else if (N <= 0xffff) - { - oa->write_character(0x79); - write_number(static_cast(N)); - } - else if (N <= 0xffffffff) - { - oa->write_character(0x7a); - write_number(static_cast(N)); - } - // LCOV_EXCL_START - else if (N <= 0xffffffffffffffff) - { - oa->write_character(0x7b); - write_number(static_cast(N)); - } - // LCOV_EXCL_STOP + @throw type_error.304 if the JSON value is not an array; in this case, + calling `at` with an index makes no sense. See example below. + @throw out_of_range.401 if the index @a idx is out of range of the array; + that is, `idx >= size()`. See example below. - // step 2: write the string - oa->write_characters(reinterpret_cast(j.m_value.string->c_str()), - j.m_value.string->size()); - break; - } + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes in the JSON value. - case value_t::array: - { - // step 1: write control byte and the array size - const auto N = j.m_value.array->size(); - if (N <= 0x17) - { - write_number(static_cast(0x80 + N)); - } - else if (N <= 0xff) - { - oa->write_character(0x98); - write_number(static_cast(N)); - } - else if (N <= 0xffff) - { - oa->write_character(0x99); - write_number(static_cast(N)); - } - else if (N <= 0xffffffff) - { - oa->write_character(0x9a); - write_number(static_cast(N)); - } - // LCOV_EXCL_START - else if (N <= 0xffffffffffffffff) - { - oa->write_character(0x9b); - write_number(static_cast(N)); - } - // LCOV_EXCL_STOP + @complexity Constant. - // step 2: write each element - for (const auto& el : *j.m_value.array) - { - write_cbor(el); - } - break; - } + @since version 1.0.0 - case value_t::object: - { - // step 1: write control byte and the object size - const auto N = j.m_value.object->size(); - if (N <= 0x17) - { - write_number(static_cast(0xa0 + N)); - } - else if (N <= 0xff) - { - oa->write_character(0xb8); - write_number(static_cast(N)); - } - else if (N <= 0xffff) - { - oa->write_character(0xb9); - write_number(static_cast(N)); - } - else if (N <= 0xffffffff) - { - oa->write_character(0xba); - write_number(static_cast(N)); - } - // LCOV_EXCL_START - else if (N <= 0xffffffffffffffff) - { - oa->write_character(0xbb); - write_number(static_cast(N)); - } - // LCOV_EXCL_STOP + @liveexample{The example below shows how array elements can be read using + `at()`. It also demonstrates the different exceptions that can be thrown., + at__size_type_const} + */ + const_reference at(size_type idx) const + { + // at only works for arrays + if (JSON_LIKELY(is_array())) + { + JSON_TRY + { + return m_value.array->at(idx); + } + JSON_CATCH (std::out_of_range&) + { + // create better exception explanation + JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range")); + } + } + else + { + JSON_THROW(type_error::create(304, "cannot use at() with " + std::string(type_name()))); + } + } - // step 2: write each element - for (const auto& el : *j.m_value.object) - { - write_cbor(el.first); - write_cbor(el.second); - } - break; - } + /*! + @brief access specified object element with bounds checking - default: - { - break; - } + Returns a reference to the element at with specified key @a key, with + bounds checking. + + @param[in] key key of the element to access + + @return reference to the element at key @a key + + @throw type_error.304 if the JSON value is not an object; in this case, + calling `at` with a key makes no sense. See example below. + @throw out_of_range.403 if the key @a key is is not stored in the object; + that is, `find(key) == end()`. See example below. + + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes in the JSON value. + + @complexity Logarithmic in the size of the container. + + @sa @ref operator[](const typename object_t::key_type&) for unchecked + access by reference + @sa @ref value() for access by value with a default value + + @since version 1.0.0 + + @liveexample{The example below shows how object elements can be read and + written using `at()`. It also demonstrates the different exceptions that + can be thrown.,at__object_t_key_type} + */ + reference at(const typename object_t::key_type& key) + { + // at only works for objects + if (JSON_LIKELY(is_object())) + { + JSON_TRY + { + return m_value.object->at(key); + } + JSON_CATCH (std::out_of_range&) + { + // create better exception explanation + JSON_THROW(out_of_range::create(403, "key '" + key + "' not found")); } } + else + { + JSON_THROW(type_error::create(304, "cannot use at() with " + std::string(type_name()))); + } + } + + /*! + @brief access specified object element with bounds checking + + Returns a const reference to the element at with specified key @a key, + with bounds checking. + + @param[in] key key of the element to access + + @return const reference to the element at key @a key + + @throw type_error.304 if the JSON value is not an object; in this case, + calling `at` with a key makes no sense. See example below. + @throw out_of_range.403 if the key @a key is is not stored in the object; + that is, `find(key) == end()`. See example below. + + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes in the JSON value. - /*! - @brief[in] j JSON value to serialize - */ - void write_msgpack(const basic_json& j) + @complexity Logarithmic in the size of the container. + + @sa @ref operator[](const typename object_t::key_type&) for unchecked + access by reference + @sa @ref value() for access by value with a default value + + @since version 1.0.0 + + @liveexample{The example below shows how object elements can be read using + `at()`. It also demonstrates the different exceptions that can be thrown., + at__object_t_key_type_const} + */ + const_reference at(const typename object_t::key_type& key) const + { + // at only works for objects + if (JSON_LIKELY(is_object())) { - switch (j.type()) + JSON_TRY { - case value_t::null: - { - // nil - oa->write_character(0xc0); - break; - } + return m_value.object->at(key); + } + JSON_CATCH (std::out_of_range&) + { + // create better exception explanation + JSON_THROW(out_of_range::create(403, "key '" + key + "' not found")); + } + } + else + { + JSON_THROW(type_error::create(304, "cannot use at() with " + std::string(type_name()))); + } + } - case value_t::boolean: - { - // true and false - oa->write_character(j.m_value.boolean ? 0xc3 : 0xc2); - break; - } + /*! + @brief access specified array element - case value_t::number_integer: - { - if (j.m_value.number_integer >= 0) - { - // MessagePack does not differentiate between positive - // signed integers and unsigned integers. Therefore, we - // used the code from the value_t::number_unsigned case - // here. - if (j.m_value.number_unsigned < 128) - { - // positive fixnum - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 8 - oa->write_character(0xcc); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 16 - oa->write_character(0xcd); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 32 - oa->write_character(0xce); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 64 - oa->write_character(0xcf); - write_number(static_cast(j.m_value.number_integer)); - } - } - else - { - if (j.m_value.number_integer >= -32) - { - // negative fixnum - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_integer >= (std::numeric_limits::min)() and j.m_value.number_integer <= (std::numeric_limits::max)()) - { - // int 8 - oa->write_character(0xd0); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_integer >= (std::numeric_limits::min)() and j.m_value.number_integer <= (std::numeric_limits::max)()) - { - // int 16 - oa->write_character(0xd1); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_integer >= (std::numeric_limits::min)() and j.m_value.number_integer <= (std::numeric_limits::max)()) - { - // int 32 - oa->write_character(0xd2); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_integer >= (std::numeric_limits::min)() and j.m_value.number_integer <= (std::numeric_limits::max)()) - { - // int 64 - oa->write_character(0xd3); - write_number(static_cast(j.m_value.number_integer)); - } - } - break; - } + Returns a reference to the element at specified location @a idx. - case value_t::number_unsigned: - { - if (j.m_value.number_unsigned < 128) - { - // positive fixnum - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 8 - oa->write_character(0xcc); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 16 - oa->write_character(0xcd); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 32 - oa->write_character(0xce); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 64 - oa->write_character(0xcf); - write_number(static_cast(j.m_value.number_integer)); - } - break; - } + @note If @a idx is beyond the range of the array (i.e., `idx >= size()`), + then the array is silently filled up with `null` values to make `idx` a + valid reference to the last stored element. - case value_t::number_float: - { - // float 64 - oa->write_character(0xcb); - write_number(j.m_value.number_float); - break; - } + @param[in] idx index of the element to access - case value_t::string: - { - // step 1: write control byte and the string length - const auto N = j.m_value.string->size(); - if (N <= 31) - { - // fixstr - write_number(static_cast(0xa0 | N)); - } - else if (N <= 255) - { - // str 8 - oa->write_character(0xd9); - write_number(static_cast(N)); - } - else if (N <= 65535) - { - // str 16 - oa->write_character(0xda); - write_number(static_cast(N)); - } - else if (N <= 4294967295) - { - // str 32 - oa->write_character(0xdb); - write_number(static_cast(N)); - } + @return reference to the element at index @a idx - // step 2: write the string - oa->write_characters(reinterpret_cast(j.m_value.string->c_str()), - j.m_value.string->size()); - break; - } + @throw type_error.305 if the JSON value is not an array or null; in that + cases, using the [] operator with an index makes no sense. - case value_t::array: - { - // step 1: write control byte and the array size - const auto N = j.m_value.array->size(); - if (N <= 15) - { - // fixarray - write_number(static_cast(0x90 | N)); - } - else if (N <= 0xffff) - { - // array 16 - oa->write_character(0xdc); - write_number(static_cast(N)); - } - else if (N <= 0xffffffff) - { - // array 32 - oa->write_character(0xdd); - write_number(static_cast(N)); - } + @complexity Constant if @a idx is in the range of the array. Otherwise + linear in `idx - size()`. - // step 2: write each element - for (const auto& el : *j.m_value.array) - { - write_msgpack(el); - } - break; - } + @liveexample{The example below shows how array elements can be read and + written using `[]` operator. Note the addition of `null` + values.,operatorarray__size_type} - case value_t::object: - { - // step 1: write control byte and the object size - const auto N = j.m_value.object->size(); - if (N <= 15) - { - // fixmap - write_number(static_cast(0x80 | (N & 0xf))); - } - else if (N <= 65535) - { - // map 16 - oa->write_character(0xde); - write_number(static_cast(N)); - } - else if (N <= 4294967295) - { - // map 32 - oa->write_character(0xdf); - write_number(static_cast(N)); - } + @since version 1.0.0 + */ + reference operator[](size_type idx) + { + // implicitly convert null value to an empty array + if (is_null()) + { + m_type = value_t::array; + m_value.array = create(); + assert_invariant(); + } + + // operator[] only works for arrays + if (JSON_LIKELY(is_array())) + { + // fill up array with null values if given idx is outside range + if (idx >= m_value.array->size()) + { + m_value.array->insert(m_value.array->end(), + idx - m_value.array->size() + 1, + basic_json()); + } + + return m_value.array->operator[](idx); + } + + JSON_THROW(type_error::create(305, "cannot use operator[] with " + std::string(type_name()))); + } + + /*! + @brief access specified array element + + Returns a const reference to the element at specified location @a idx. + + @param[in] idx index of the element to access + + @return const reference to the element at index @a idx + + @throw type_error.305 if the JSON value is not an array; in that case, + using the [] operator with an index makes no sense. + + @complexity Constant. + + @liveexample{The example below shows how array elements can be read using + the `[]` operator.,operatorarray__size_type_const} + + @since version 1.0.0 + */ + const_reference operator[](size_type idx) const + { + // const operator[] only works for arrays + if (JSON_LIKELY(is_array())) + { + return m_value.array->operator[](idx); + } + + JSON_THROW(type_error::create(305, "cannot use operator[] with " + std::string(type_name()))); + } + + /*! + @brief access specified object element + + Returns a reference to the element at with specified key @a key. + + @note If @a key is not found in the object, then it is silently added to + the object and filled with a `null` value to make `key` a valid reference. + In case the value was `null` before, it is converted to an object. + + @param[in] key key of the element to access + + @return reference to the element at key @a key + + @throw type_error.305 if the JSON value is not an object or null; in that + cases, using the [] operator with a key makes no sense. + + @complexity Logarithmic in the size of the container. + + @liveexample{The example below shows how object elements can be read and + written using the `[]` operator.,operatorarray__key_type} + + @sa @ref at(const typename object_t::key_type&) for access by reference + with range checking + @sa @ref value() for access by value with a default value + + @since version 1.0.0 + */ + reference operator[](const typename object_t::key_type& key) + { + // implicitly convert null value to an empty object + if (is_null()) + { + m_type = value_t::object; + m_value.object = create(); + assert_invariant(); + } + + // operator[] only works for objects + if (JSON_LIKELY(is_object())) + { + return m_value.object->operator[](key); + } + + JSON_THROW(type_error::create(305, "cannot use operator[] with " + std::string(type_name()))); + } + + /*! + @brief read-only access specified object element + + Returns a const reference to the element at with specified key @a key. No + bounds checking is performed. + + @warning If the element with key @a key does not exist, the behavior is + undefined. + + @param[in] key key of the element to access + + @return const reference to the element at key @a key + + @pre The element with key @a key must exist. **This precondition is + enforced with an assertion.** + + @throw type_error.305 if the JSON value is not an object; in that case, + using the [] operator with a key makes no sense. + + @complexity Logarithmic in the size of the container. + + @liveexample{The example below shows how object elements can be read using + the `[]` operator.,operatorarray__key_type_const} + + @sa @ref at(const typename object_t::key_type&) for access by reference + with range checking + @sa @ref value() for access by value with a default value + + @since version 1.0.0 + */ + const_reference operator[](const typename object_t::key_type& key) const + { + // const operator[] only works for objects + if (JSON_LIKELY(is_object())) + { + assert(m_value.object->find(key) != m_value.object->end()); + return m_value.object->find(key)->second; + } + + JSON_THROW(type_error::create(305, "cannot use operator[] with " + std::string(type_name()))); + } + + /*! + @brief access specified object element + + Returns a reference to the element at with specified key @a key. + + @note If @a key is not found in the object, then it is silently added to + the object and filled with a `null` value to make `key` a valid reference. + In case the value was `null` before, it is converted to an object. + + @param[in] key key of the element to access + + @return reference to the element at key @a key + + @throw type_error.305 if the JSON value is not an object or null; in that + cases, using the [] operator with a key makes no sense. + + @complexity Logarithmic in the size of the container. + + @liveexample{The example below shows how object elements can be read and + written using the `[]` operator.,operatorarray__key_type} + + @sa @ref at(const typename object_t::key_type&) for access by reference + with range checking + @sa @ref value() for access by value with a default value + + @since version 1.1.0 + */ + template + reference operator[](T* key) + { + // implicitly convert null to object + if (is_null()) + { + m_type = value_t::object; + m_value = value_t::object; + assert_invariant(); + } + + // at only works for objects + if (JSON_LIKELY(is_object())) + { + return m_value.object->operator[](key); + } + + JSON_THROW(type_error::create(305, "cannot use operator[] with " + std::string(type_name()))); + } + + /*! + @brief read-only access specified object element + + Returns a const reference to the element at with specified key @a key. No + bounds checking is performed. + + @warning If the element with key @a key does not exist, the behavior is + undefined. + + @param[in] key key of the element to access + + @return const reference to the element at key @a key + + @pre The element with key @a key must exist. **This precondition is + enforced with an assertion.** + + @throw type_error.305 if the JSON value is not an object; in that case, + using the [] operator with a key makes no sense. + + @complexity Logarithmic in the size of the container. + + @liveexample{The example below shows how object elements can be read using + the `[]` operator.,operatorarray__key_type_const} + + @sa @ref at(const typename object_t::key_type&) for access by reference + with range checking + @sa @ref value() for access by value with a default value + + @since version 1.1.0 + */ + template + const_reference operator[](T* key) const + { + // at only works for objects + if (JSON_LIKELY(is_object())) + { + assert(m_value.object->find(key) != m_value.object->end()); + return m_value.object->find(key)->second; + } + + JSON_THROW(type_error::create(305, "cannot use operator[] with " + std::string(type_name()))); + } + + /*! + @brief access specified object element with default value + + Returns either a copy of an object's element at the specified key @a key + or a given default value if no element with key @a key exists. + + The function is basically equivalent to executing + @code {.cpp} + try { + return at(key); + } catch(out_of_range) { + return default_value; + } + @endcode + + @note Unlike @ref at(const typename object_t::key_type&), this function + does not throw if the given key @a key was not found. + + @note Unlike @ref operator[](const typename object_t::key_type& key), this + function does not implicitly add an element to the position defined by @a + key. This function is furthermore also applicable to const objects. + + @param[in] key key of the element to access + @param[in] default_value the value to return if @a key is not found + + @tparam ValueType type compatible to JSON values, for instance `int` for + JSON integer numbers, `bool` for JSON booleans, or `std::vector` types for + JSON arrays. Note the type of the expected value at @a key and the default + value @a default_value must be compatible. + + @return copy of the element at key @a key or @a default_value if @a key + is not found + + @throw type_error.306 if the JSON value is not an object; in that case, + using `value()` with a key makes no sense. + + @complexity Logarithmic in the size of the container. + + @liveexample{The example below shows how object elements can be queried + with a default value.,basic_json__value} + + @sa @ref at(const typename object_t::key_type&) for access by reference + with range checking + @sa @ref operator[](const typename object_t::key_type&) for unchecked + access by reference + + @since version 1.0.0 + */ + template::value, int>::type = 0> + ValueType value(const typename object_t::key_type& key, const ValueType& default_value) const + { + // at only works for objects + if (JSON_LIKELY(is_object())) + { + // if key is found, return value and given default value otherwise + const auto it = find(key); + if (it != end()) + { + return *it; + } + + return default_value; + } + + JSON_THROW(type_error::create(306, "cannot use value() with " + std::string(type_name()))); + } + + /*! + @brief overload for a default value of type const char* + @copydoc basic_json::value(const typename object_t::key_type&, ValueType) const + */ + string_t value(const typename object_t::key_type& key, const char* default_value) const + { + return value(key, string_t(default_value)); + } + + /*! + @brief access specified object element via JSON Pointer with default value + + Returns either a copy of an object's element at the specified key @a key + or a given default value if no element with key @a key exists. + + The function is basically equivalent to executing + @code {.cpp} + try { + return at(ptr); + } catch(out_of_range) { + return default_value; + } + @endcode + + @note Unlike @ref at(const json_pointer&), this function does not throw + if the given key @a key was not found. + + @param[in] ptr a JSON pointer to the element to access + @param[in] default_value the value to return if @a ptr found no value + + @tparam ValueType type compatible to JSON values, for instance `int` for + JSON integer numbers, `bool` for JSON booleans, or `std::vector` types for + JSON arrays. Note the type of the expected value at @a key and the default + value @a default_value must be compatible. + + @return copy of the element at key @a key or @a default_value if @a key + is not found + + @throw type_error.306 if the JSON value is not an objec; in that case, + using `value()` with a key makes no sense. + + @complexity Logarithmic in the size of the container. + + @liveexample{The example below shows how object elements can be queried + with a default value.,basic_json__value_ptr} + + @sa @ref operator[](const json_pointer&) for unchecked access by reference + + @since version 2.0.2 + */ + template::value, int>::type = 0> + ValueType value(const json_pointer& ptr, const ValueType& default_value) const + { + // at only works for objects + if (JSON_LIKELY(is_object())) + { + // if pointer resolves a value, return it or use default value + JSON_TRY + { + return ptr.get_checked(this); + } + JSON_CATCH (out_of_range&) + { + return default_value; + } + } + + JSON_THROW(type_error::create(306, "cannot use value() with " + std::string(type_name()))); + } + + /*! + @brief overload for a default value of type const char* + @copydoc basic_json::value(const json_pointer&, ValueType) const + */ + string_t value(const json_pointer& ptr, const char* default_value) const + { + return value(ptr, string_t(default_value)); + } + + /*! + @brief access the first element + + Returns a reference to the first element in the container. For a JSON + container `c`, the expression `c.front()` is equivalent to `*c.begin()`. + + @return In case of a structured type (array or object), a reference to the + first element is returned. In case of number, string, or boolean values, a + reference to the value is returned. + + @complexity Constant. + + @pre The JSON value must not be `null` (would throw `std::out_of_range`) + or an empty array or object (undefined behavior, **guarded by + assertions**). + @post The JSON value remains unchanged. + + @throw invalid_iterator.214 when called on `null` value + + @liveexample{The following code shows an example for `front()`.,front} + + @sa @ref back() -- access the last element + + @since version 1.0.0 + */ + reference front() + { + return *begin(); + } + + /*! + @copydoc basic_json::front() + */ + const_reference front() const + { + return *cbegin(); + } + + /*! + @brief access the last element + + Returns a reference to the last element in the container. For a JSON + container `c`, the expression `c.back()` is equivalent to + @code {.cpp} + auto tmp = c.end(); + --tmp; + return *tmp; + @endcode + + @return In case of a structured type (array or object), a reference to the + last element is returned. In case of number, string, or boolean values, a + reference to the value is returned. + + @complexity Constant. + + @pre The JSON value must not be `null` (would throw `std::out_of_range`) + or an empty array or object (undefined behavior, **guarded by + assertions**). + @post The JSON value remains unchanged. + + @throw invalid_iterator.214 when called on a `null` value. See example + below. + + @liveexample{The following code shows an example for `back()`.,back} + + @sa @ref front() -- access the first element + + @since version 1.0.0 + */ + reference back() + { + auto tmp = end(); + --tmp; + return *tmp; + } + + /*! + @copydoc basic_json::back() + */ + const_reference back() const + { + auto tmp = cend(); + --tmp; + return *tmp; + } + + /*! + @brief remove element given an iterator + + Removes the element specified by iterator @a pos. The iterator @a pos must + be valid and dereferenceable. Thus the `end()` iterator (which is valid, + but is not dereferenceable) cannot be used as a value for @a pos. + + If called on a primitive type other than `null`, the resulting JSON value + will be `null`. + + @param[in] pos iterator to the element to remove + @return Iterator following the last removed element. If the iterator @a + pos refers to the last element, the `end()` iterator is returned. + + @tparam IteratorType an @ref iterator or @ref const_iterator + + @post Invalidates iterators and references at or after the point of the + erase, including the `end()` iterator. + + @throw type_error.307 if called on a `null` value; example: `"cannot use + erase() with null"` + @throw invalid_iterator.202 if called on an iterator which does not belong + to the current JSON value; example: `"iterator does not fit current + value"` + @throw invalid_iterator.205 if called on a primitive type with invalid + iterator (i.e., any iterator which is not `begin()`); example: `"iterator + out of range"` + + @complexity The complexity depends on the type: + - objects: amortized constant + - arrays: linear in distance between @a pos and the end of the container + - strings: linear in the length of the string + - other types: constant + + @liveexample{The example shows the result of `erase()` for different JSON + types.,erase__IteratorType} + + @sa @ref erase(IteratorType, IteratorType) -- removes the elements in + the given range + @sa @ref erase(const typename object_t::key_type&) -- removes the element + from an object at the given key + @sa @ref erase(const size_type) -- removes the element from an array at + the given index + + @since version 1.0.0 + */ + template::value or + std::is_same::value, int>::type + = 0> + IteratorType erase(IteratorType pos) + { + // make sure iterator fits the current value + if (JSON_UNLIKELY(this != pos.m_object)) + { + JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); + } + + IteratorType result = end(); + + switch (m_type) + { + case value_t::boolean: + case value_t::number_float: + case value_t::number_integer: + case value_t::number_unsigned: + case value_t::string: + { + if (JSON_UNLIKELY(not pos.m_it.primitive_iterator.is_begin())) + { + JSON_THROW(invalid_iterator::create(205, "iterator out of range")); + } + + if (is_string()) + { + AllocatorType alloc; + std::allocator_traits::destroy(alloc, m_value.string); + std::allocator_traits::deallocate(alloc, m_value.string, 1); + m_value.string = nullptr; + } + + m_type = value_t::null; + assert_invariant(); + break; + } + + case value_t::object: + { + result.m_it.object_iterator = m_value.object->erase(pos.m_it.object_iterator); + break; + } + + case value_t::array: + { + result.m_it.array_iterator = m_value.array->erase(pos.m_it.array_iterator); + break; + } + + default: + JSON_THROW(type_error::create(307, "cannot use erase() with " + std::string(type_name()))); + } + + return result; + } + + /*! + @brief remove elements given an iterator range + + Removes the element specified by the range `[first; last)`. The iterator + @a first does not need to be dereferenceable if `first == last`: erasing + an empty range is a no-op. + + If called on a primitive type other than `null`, the resulting JSON value + will be `null`. + + @param[in] first iterator to the beginning of the range to remove + @param[in] last iterator past the end of the range to remove + @return Iterator following the last removed element. If the iterator @a + second refers to the last element, the `end()` iterator is returned. + + @tparam IteratorType an @ref iterator or @ref const_iterator + + @post Invalidates iterators and references at or after the point of the + erase, including the `end()` iterator. + + @throw type_error.307 if called on a `null` value; example: `"cannot use + erase() with null"` + @throw invalid_iterator.203 if called on iterators which does not belong + to the current JSON value; example: `"iterators do not fit current value"` + @throw invalid_iterator.204 if called on a primitive type with invalid + iterators (i.e., if `first != begin()` and `last != end()`); example: + `"iterators out of range"` + + @complexity The complexity depends on the type: + - objects: `log(size()) + std::distance(first, last)` + - arrays: linear in the distance between @a first and @a last, plus linear + in the distance between @a last and end of the container + - strings: linear in the length of the string + - other types: constant + + @liveexample{The example shows the result of `erase()` for different JSON + types.,erase__IteratorType_IteratorType} + + @sa @ref erase(IteratorType) -- removes the element at a given position + @sa @ref erase(const typename object_t::key_type&) -- removes the element + from an object at the given key + @sa @ref erase(const size_type) -- removes the element from an array at + the given index + + @since version 1.0.0 + */ + template::value or + std::is_same::value, int>::type + = 0> + IteratorType erase(IteratorType first, IteratorType last) + { + // make sure iterator fits the current value + if (JSON_UNLIKELY(this != first.m_object or this != last.m_object)) + { + JSON_THROW(invalid_iterator::create(203, "iterators do not fit current value")); + } + + IteratorType result = end(); + + switch (m_type) + { + case value_t::boolean: + case value_t::number_float: + case value_t::number_integer: + case value_t::number_unsigned: + case value_t::string: + { + if (JSON_LIKELY(not first.m_it.primitive_iterator.is_begin() + or not last.m_it.primitive_iterator.is_end())) + { + JSON_THROW(invalid_iterator::create(204, "iterators out of range")); + } + + if (is_string()) + { + AllocatorType alloc; + std::allocator_traits::destroy(alloc, m_value.string); + std::allocator_traits::deallocate(alloc, m_value.string, 1); + m_value.string = nullptr; + } + + m_type = value_t::null; + assert_invariant(); + break; + } + + case value_t::object: + { + result.m_it.object_iterator = m_value.object->erase(first.m_it.object_iterator, + last.m_it.object_iterator); + break; + } + + case value_t::array: + { + result.m_it.array_iterator = m_value.array->erase(first.m_it.array_iterator, + last.m_it.array_iterator); + break; + } + + default: + JSON_THROW(type_error::create(307, "cannot use erase() with " + std::string(type_name()))); + } + + return result; + } + + /*! + @brief remove element from a JSON object given a key + + Removes elements from a JSON object with the key value @a key. + + @param[in] key value of the elements to remove + + @return Number of elements removed. If @a ObjectType is the default + `std::map` type, the return value will always be `0` (@a key was not + found) or `1` (@a key was found). + + @post References and iterators to the erased elements are invalidated. + Other references and iterators are not affected. + + @throw type_error.307 when called on a type other than JSON object; + example: `"cannot use erase() with null"` + + @complexity `log(size()) + count(key)` + + @liveexample{The example shows the effect of `erase()`.,erase__key_type} + + @sa @ref erase(IteratorType) -- removes the element at a given position + @sa @ref erase(IteratorType, IteratorType) -- removes the elements in + the given range + @sa @ref erase(const size_type) -- removes the element from an array at + the given index + + @since version 1.0.0 + */ + size_type erase(const typename object_t::key_type& key) + { + // this erase only works for objects + if (JSON_LIKELY(is_object())) + { + return m_value.object->erase(key); + } + + JSON_THROW(type_error::create(307, "cannot use erase() with " + std::string(type_name()))); + } + + /*! + @brief remove element from a JSON array given an index + + Removes element from a JSON array at the index @a idx. + + @param[in] idx index of the element to remove + + @throw type_error.307 when called on a type other than JSON object; + example: `"cannot use erase() with null"` + @throw out_of_range.401 when `idx >= size()`; example: `"array index 17 + is out of range"` + + @complexity Linear in distance between @a idx and the end of the container. + + @liveexample{The example shows the effect of `erase()`.,erase__size_type} + + @sa @ref erase(IteratorType) -- removes the element at a given position + @sa @ref erase(IteratorType, IteratorType) -- removes the elements in + the given range + @sa @ref erase(const typename object_t::key_type&) -- removes the element + from an object at the given key + + @since version 1.0.0 + */ + void erase(const size_type idx) + { + // this erase only works for arrays + if (JSON_LIKELY(is_array())) + { + if (JSON_UNLIKELY(idx >= size())) + { + JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range")); + } + + m_value.array->erase(m_value.array->begin() + static_cast(idx)); + } + else + { + JSON_THROW(type_error::create(307, "cannot use erase() with " + std::string(type_name()))); + } + } + + /// @} + + + //////////// + // lookup // + //////////// + + /// @name lookup + /// @{ + + /*! + @brief find an element in a JSON object + + Finds an element in a JSON object with key equivalent to @a key. If the + element is not found or the JSON value is not an object, end() is + returned. + + @note This method always returns @ref end() when executed on a JSON type + that is not an object. + + @param[in] key key value of the element to search for. + + @return Iterator to an element with key equivalent to @a key. If no such + element is found or the JSON value is not an object, past-the-end (see + @ref end()) iterator is returned. + + @complexity Logarithmic in the size of the JSON object. + + @liveexample{The example shows how `find()` is used.,find__key_type} + + @since version 1.0.0 + */ + template + iterator find(KeyT&& key) + { + auto result = end(); + + if (is_object()) + { + result.m_it.object_iterator = m_value.object->find(std::forward(key)); + } + + return result; + } + + /*! + @brief find an element in a JSON object + @copydoc find(KeyT&&) + */ + template + const_iterator find(KeyT&& key) const + { + auto result = cend(); + + if (is_object()) + { + result.m_it.object_iterator = m_value.object->find(std::forward(key)); + } + + return result; + } + + /*! + @brief returns the number of occurrences of a key in a JSON object + + Returns the number of elements with key @a key. If ObjectType is the + default `std::map` type, the return value will always be `0` (@a key was + not found) or `1` (@a key was found). + + @note This method always returns `0` when executed on a JSON type that is + not an object. + + @param[in] key key value of the element to count + + @return Number of elements with key @a key. If the JSON value is not an + object, the return value will be `0`. + + @complexity Logarithmic in the size of the JSON object. + + @liveexample{The example shows how `count()` is used.,count} + + @since version 1.0.0 + */ + template + size_type count(KeyT&& key) const + { + // return 0 for all nonobject types + return is_object() ? m_value.object->count(std::forward(key)) : 0; + } + + /// @} + + + /////////////// + // iterators // + /////////////// + + /// @name iterators + /// @{ + + /*! + @brief returns an iterator to the first element + + Returns an iterator to the first element. + + @image html range-begin-end.svg "Illustration from cppreference.com" + + @return iterator to the first element + + @complexity Constant. + + @requirement This function helps `basic_json` satisfying the + [Container](http://en.cppreference.com/w/cpp/concept/Container) + requirements: + - The complexity is constant. + + @liveexample{The following code shows an example for `begin()`.,begin} + + @sa @ref cbegin() -- returns a const iterator to the beginning + @sa @ref end() -- returns an iterator to the end + @sa @ref cend() -- returns a const iterator to the end + + @since version 1.0.0 + */ + iterator begin() noexcept + { + iterator result(this); + result.set_begin(); + return result; + } + + /*! + @copydoc basic_json::cbegin() + */ + const_iterator begin() const noexcept + { + return cbegin(); + } + + /*! + @brief returns a const iterator to the first element + + Returns a const iterator to the first element. + + @image html range-begin-end.svg "Illustration from cppreference.com" + + @return const iterator to the first element + + @complexity Constant. + + @requirement This function helps `basic_json` satisfying the + [Container](http://en.cppreference.com/w/cpp/concept/Container) + requirements: + - The complexity is constant. + - Has the semantics of `const_cast(*this).begin()`. + + @liveexample{The following code shows an example for `cbegin()`.,cbegin} + + @sa @ref begin() -- returns an iterator to the beginning + @sa @ref end() -- returns an iterator to the end + @sa @ref cend() -- returns a const iterator to the end + + @since version 1.0.0 + */ + const_iterator cbegin() const noexcept + { + const_iterator result(this); + result.set_begin(); + return result; + } + + /*! + @brief returns an iterator to one past the last element + + Returns an iterator to one past the last element. + + @image html range-begin-end.svg "Illustration from cppreference.com" + + @return iterator one past the last element + + @complexity Constant. + + @requirement This function helps `basic_json` satisfying the + [Container](http://en.cppreference.com/w/cpp/concept/Container) + requirements: + - The complexity is constant. + + @liveexample{The following code shows an example for `end()`.,end} + + @sa @ref cend() -- returns a const iterator to the end + @sa @ref begin() -- returns an iterator to the beginning + @sa @ref cbegin() -- returns a const iterator to the beginning + + @since version 1.0.0 + */ + iterator end() noexcept + { + iterator result(this); + result.set_end(); + return result; + } + + /*! + @copydoc basic_json::cend() + */ + const_iterator end() const noexcept + { + return cend(); + } + + /*! + @brief returns a const iterator to one past the last element + + Returns a const iterator to one past the last element. + + @image html range-begin-end.svg "Illustration from cppreference.com" + + @return const iterator one past the last element + + @complexity Constant. + + @requirement This function helps `basic_json` satisfying the + [Container](http://en.cppreference.com/w/cpp/concept/Container) + requirements: + - The complexity is constant. + - Has the semantics of `const_cast(*this).end()`. + + @liveexample{The following code shows an example for `cend()`.,cend} + + @sa @ref end() -- returns an iterator to the end + @sa @ref begin() -- returns an iterator to the beginning + @sa @ref cbegin() -- returns a const iterator to the beginning + + @since version 1.0.0 + */ + const_iterator cend() const noexcept + { + const_iterator result(this); + result.set_end(); + return result; + } + + /*! + @brief returns an iterator to the reverse-beginning + + Returns an iterator to the reverse-beginning; that is, the last element. + + @image html range-rbegin-rend.svg "Illustration from cppreference.com" + + @complexity Constant. + + @requirement This function helps `basic_json` satisfying the + [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) + requirements: + - The complexity is constant. + - Has the semantics of `reverse_iterator(end())`. + + @liveexample{The following code shows an example for `rbegin()`.,rbegin} + + @sa @ref crbegin() -- returns a const reverse iterator to the beginning + @sa @ref rend() -- returns a reverse iterator to the end + @sa @ref crend() -- returns a const reverse iterator to the end + + @since version 1.0.0 + */ + reverse_iterator rbegin() noexcept + { + return reverse_iterator(end()); + } + + /*! + @copydoc basic_json::crbegin() + */ + const_reverse_iterator rbegin() const noexcept + { + return crbegin(); + } + + /*! + @brief returns an iterator to the reverse-end + + Returns an iterator to the reverse-end; that is, one before the first + element. + + @image html range-rbegin-rend.svg "Illustration from cppreference.com" + + @complexity Constant. + + @requirement This function helps `basic_json` satisfying the + [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) + requirements: + - The complexity is constant. + - Has the semantics of `reverse_iterator(begin())`. + + @liveexample{The following code shows an example for `rend()`.,rend} + + @sa @ref crend() -- returns a const reverse iterator to the end + @sa @ref rbegin() -- returns a reverse iterator to the beginning + @sa @ref crbegin() -- returns a const reverse iterator to the beginning + + @since version 1.0.0 + */ + reverse_iterator rend() noexcept + { + return reverse_iterator(begin()); + } + + /*! + @copydoc basic_json::crend() + */ + const_reverse_iterator rend() const noexcept + { + return crend(); + } + + /*! + @brief returns a const reverse iterator to the last element + + Returns a const iterator to the reverse-beginning; that is, the last + element. + + @image html range-rbegin-rend.svg "Illustration from cppreference.com" + + @complexity Constant. + + @requirement This function helps `basic_json` satisfying the + [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) + requirements: + - The complexity is constant. + - Has the semantics of `const_cast(*this).rbegin()`. + + @liveexample{The following code shows an example for `crbegin()`.,crbegin} + + @sa @ref rbegin() -- returns a reverse iterator to the beginning + @sa @ref rend() -- returns a reverse iterator to the end + @sa @ref crend() -- returns a const reverse iterator to the end + + @since version 1.0.0 + */ + const_reverse_iterator crbegin() const noexcept + { + return const_reverse_iterator(cend()); + } + + /*! + @brief returns a const reverse iterator to one before the first + + Returns a const reverse iterator to the reverse-end; that is, one before + the first element. + + @image html range-rbegin-rend.svg "Illustration from cppreference.com" + + @complexity Constant. + + @requirement This function helps `basic_json` satisfying the + [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) + requirements: + - The complexity is constant. + - Has the semantics of `const_cast(*this).rend()`. + + @liveexample{The following code shows an example for `crend()`.,crend} + + @sa @ref rend() -- returns a reverse iterator to the end + @sa @ref rbegin() -- returns a reverse iterator to the beginning + @sa @ref crbegin() -- returns a const reverse iterator to the beginning + + @since version 1.0.0 + */ + const_reverse_iterator crend() const noexcept + { + return const_reverse_iterator(cbegin()); + } + + public: + /*! + @brief wrapper to access iterator member functions in range-based for + + This function allows to access @ref iterator::key() and @ref + iterator::value() during range-based for loops. In these loops, a + reference to the JSON values is returned, so there is no access to the + underlying iterator. + + For loop without iterator_wrapper: + + @code{cpp} + for (auto it = j_object.begin(); it != j_object.end(); ++it) + { + std::cout << "key: " << it.key() << ", value:" << it.value() << '\n'; + } + @endcode + + Range-based for loop without iterator proxy: + + @code{cpp} + for (auto it : j_object) + { + // "it" is of type json::reference and has no key() member + std::cout << "value: " << it << '\n'; + } + @endcode + + Range-based for loop with iterator proxy: + + @code{cpp} + for (auto it : json::iterator_wrapper(j_object)) + { + std::cout << "key: " << it.key() << ", value:" << it.value() << '\n'; + } + @endcode + + @note When iterating over an array, `key()` will return the index of the + element as string (see example). + + @param[in] ref reference to a JSON value + @return iteration proxy object wrapping @a ref with an interface to use in + range-based for loops + + @liveexample{The following code shows how the wrapper is used,iterator_wrapper} + + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes in the JSON value. + + @complexity Constant. + + @note The name of this function is not yet final and may change in the + future. + + @deprecated This stream operator is deprecated and will be removed in + future 4.0.0 of the library. Please use @ref items() instead; + that is, replace `json::iterator_wrapper(j)` with `j.items()`. + */ + JSON_DEPRECATED + static iteration_proxy iterator_wrapper(reference ref) noexcept + { + return ref.items(); + } + + /*! + @copydoc iterator_wrapper(reference) + */ + JSON_DEPRECATED + static iteration_proxy iterator_wrapper(const_reference ref) noexcept + { + return ref.items(); + } + + /*! + @brief helper to access iterator member functions in range-based for + + This function allows to access @ref iterator::key() and @ref + iterator::value() during range-based for loops. In these loops, a + reference to the JSON values is returned, so there is no access to the + underlying iterator. + + For loop without `items()` function: + + @code{cpp} + for (auto it = j_object.begin(); it != j_object.end(); ++it) + { + std::cout << "key: " << it.key() << ", value:" << it.value() << '\n'; + } + @endcode + + Range-based for loop without `items()` function: + + @code{cpp} + for (auto it : j_object) + { + // "it" is of type json::reference and has no key() member + std::cout << "value: " << it << '\n'; + } + @endcode + + Range-based for loop with `items()` function: + + @code{cpp} + for (auto it : j_object.items()) + { + std::cout << "key: " << it.key() << ", value:" << it.value() << '\n'; + } + @endcode + + @note When iterating over an array, `key()` will return the index of the + element as string (see example). For primitive types (e.g., numbers), + `key()` returns an empty string. + + @return iteration proxy object wrapping @a ref with an interface to use in + range-based for loops + + @liveexample{The following code shows how the function is used.,items} + + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes in the JSON value. + + @complexity Constant. + + @since version 3.x.x. + */ + iteration_proxy items() noexcept + { + return iteration_proxy(*this); + } + + /*! + @copydoc items() + */ + iteration_proxy items() const noexcept + { + return iteration_proxy(*this); + } + + /// @} + + + ////////////// + // capacity // + ////////////// + + /// @name capacity + /// @{ + + /*! + @brief checks whether the container is empty. + + Checks if a JSON value has no elements (i.e. whether its @ref size is `0`). + + @return The return value depends on the different types and is + defined as follows: + Value type | return value + ----------- | ------------- + null | `true` + boolean | `false` + string | `false` + number | `false` + object | result of function `object_t::empty()` + array | result of function `array_t::empty()` + + @liveexample{The following code uses `empty()` to check if a JSON + object contains any elements.,empty} + + @complexity Constant, as long as @ref array_t and @ref object_t satisfy + the Container concept; that is, their `empty()` functions have constant + complexity. + + @iterators No changes. + + @exceptionsafety No-throw guarantee: this function never throws exceptions. + + @note This function does not return whether a string stored as JSON value + is empty - it returns whether the JSON container itself is empty which is + false in the case of a string. + + @requirement This function helps `basic_json` satisfying the + [Container](http://en.cppreference.com/w/cpp/concept/Container) + requirements: + - The complexity is constant. + - Has the semantics of `begin() == end()`. + + @sa @ref size() -- returns the number of elements + + @since version 1.0.0 + */ + bool empty() const noexcept + { + switch (m_type) + { + case value_t::null: + { + // null values are empty + return true; + } + + case value_t::array: + { + // delegate call to array_t::empty() + return m_value.array->empty(); + } + + case value_t::object: + { + // delegate call to object_t::empty() + return m_value.object->empty(); + } + + default: + { + // all other types are nonempty + return false; + } + } + } + + /*! + @brief returns the number of elements + + Returns the number of elements in a JSON value. + + @return The return value depends on the different types and is + defined as follows: + Value type | return value + ----------- | ------------- + null | `0` + boolean | `1` + string | `1` + number | `1` + object | result of function object_t::size() + array | result of function array_t::size() + + @liveexample{The following code calls `size()` on the different value + types.,size} + + @complexity Constant, as long as @ref array_t and @ref object_t satisfy + the Container concept; that is, their size() functions have constant + complexity. + + @iterators No changes. + + @exceptionsafety No-throw guarantee: this function never throws exceptions. + + @note This function does not return the length of a string stored as JSON + value - it returns the number of elements in the JSON value which is 1 in + the case of a string. + + @requirement This function helps `basic_json` satisfying the + [Container](http://en.cppreference.com/w/cpp/concept/Container) + requirements: + - The complexity is constant. + - Has the semantics of `std::distance(begin(), end())`. + + @sa @ref empty() -- checks whether the container is empty + @sa @ref max_size() -- returns the maximal number of elements + + @since version 1.0.0 + */ + size_type size() const noexcept + { + switch (m_type) + { + case value_t::null: + { + // null values are empty + return 0; + } + + case value_t::array: + { + // delegate call to array_t::size() + return m_value.array->size(); + } + + case value_t::object: + { + // delegate call to object_t::size() + return m_value.object->size(); + } + + default: + { + // all other types have size 1 + return 1; + } + } + } + + /*! + @brief returns the maximum possible number of elements + + Returns the maximum number of elements a JSON value is able to hold due to + system or library implementation limitations, i.e. `std::distance(begin(), + end())` for the JSON value. + + @return The return value depends on the different types and is + defined as follows: + Value type | return value + ----------- | ------------- + null | `0` (same as `size()`) + boolean | `1` (same as `size()`) + string | `1` (same as `size()`) + number | `1` (same as `size()`) + object | result of function `object_t::max_size()` + array | result of function `array_t::max_size()` + + @liveexample{The following code calls `max_size()` on the different value + types. Note the output is implementation specific.,max_size} + + @complexity Constant, as long as @ref array_t and @ref object_t satisfy + the Container concept; that is, their `max_size()` functions have constant + complexity. + + @iterators No changes. + + @exceptionsafety No-throw guarantee: this function never throws exceptions. + + @requirement This function helps `basic_json` satisfying the + [Container](http://en.cppreference.com/w/cpp/concept/Container) + requirements: + - The complexity is constant. + - Has the semantics of returning `b.size()` where `b` is the largest + possible JSON value. + + @sa @ref size() -- returns the number of elements + + @since version 1.0.0 + */ + size_type max_size() const noexcept + { + switch (m_type) + { + case value_t::array: + { + // delegate call to array_t::max_size() + return m_value.array->max_size(); + } + + case value_t::object: + { + // delegate call to object_t::max_size() + return m_value.object->max_size(); + } + + default: + { + // all other types have max_size() == size() + return size(); + } + } + } + + /// @} + + + /////////////// + // modifiers // + /////////////// + + /// @name modifiers + /// @{ + + /*! + @brief clears the contents + + Clears the content of a JSON value and resets it to the default value as + if @ref basic_json(value_t) would have been called with the current value + type from @ref type(): + + Value type | initial value + ----------- | ------------- + null | `null` + boolean | `false` + string | `""` + number | `0` + object | `{}` + array | `[]` + + @post Has the same effect as calling + @code {.cpp} + *this = basic_json(type()); + @endcode + + @liveexample{The example below shows the effect of `clear()` to different + JSON types.,clear} + + @complexity Linear in the size of the JSON value. + + @iterators All iterators, pointers and references related to this container + are invalidated. + + @exceptionsafety No-throw guarantee: this function never throws exceptions. + + @sa @ref basic_json(value_t) -- constructor that creates an object with the + same value than calling `clear()` + + @since version 1.0.0 + */ + void clear() noexcept + { + switch (m_type) + { + case value_t::number_integer: + { + m_value.number_integer = 0; + break; + } + + case value_t::number_unsigned: + { + m_value.number_unsigned = 0; + break; + } + + case value_t::number_float: + { + m_value.number_float = 0.0; + break; + } + + case value_t::boolean: + { + m_value.boolean = false; + break; + } + + case value_t::string: + { + m_value.string->clear(); + break; + } + + case value_t::array: + { + m_value.array->clear(); + break; + } + + case value_t::object: + { + m_value.object->clear(); + break; + } + + default: + break; + } + } + + /*! + @brief add an object to an array + + Appends the given element @a val to the end of the JSON value. If the + function is called on a JSON null value, an empty array is created before + appending @a val. + + @param[in] val the value to add to the JSON array + + @throw type_error.308 when called on a type other than JSON array or + null; example: `"cannot use push_back() with number"` + + @complexity Amortized constant. + + @liveexample{The example shows how `push_back()` and `+=` can be used to + add elements to a JSON array. Note how the `null` value was silently + converted to a JSON array.,push_back} + + @since version 1.0.0 + */ + void push_back(basic_json&& val) + { + // push_back only works for null objects or arrays + if (JSON_UNLIKELY(not(is_null() or is_array()))) + { + JSON_THROW(type_error::create(308, "cannot use push_back() with " + std::string(type_name()))); + } + + // transform null object into an array + if (is_null()) + { + m_type = value_t::array; + m_value = value_t::array; + assert_invariant(); + } + + // add element to array (move semantics) + m_value.array->push_back(std::move(val)); + // invalidate object + val.m_type = value_t::null; + } + + /*! + @brief add an object to an array + @copydoc push_back(basic_json&&) + */ + reference operator+=(basic_json&& val) + { + push_back(std::move(val)); + return *this; + } + + /*! + @brief add an object to an array + @copydoc push_back(basic_json&&) + */ + void push_back(const basic_json& val) + { + // push_back only works for null objects or arrays + if (JSON_UNLIKELY(not(is_null() or is_array()))) + { + JSON_THROW(type_error::create(308, "cannot use push_back() with " + std::string(type_name()))); + } + + // transform null object into an array + if (is_null()) + { + m_type = value_t::array; + m_value = value_t::array; + assert_invariant(); + } + + // add element to array + m_value.array->push_back(val); + } + + /*! + @brief add an object to an array + @copydoc push_back(basic_json&&) + */ + reference operator+=(const basic_json& val) + { + push_back(val); + return *this; + } + + /*! + @brief add an object to an object + + Inserts the given element @a val to the JSON object. If the function is + called on a JSON null value, an empty object is created before inserting + @a val. + + @param[in] val the value to add to the JSON object + + @throw type_error.308 when called on a type other than JSON object or + null; example: `"cannot use push_back() with number"` + + @complexity Logarithmic in the size of the container, O(log(`size()`)). + + @liveexample{The example shows how `push_back()` and `+=` can be used to + add elements to a JSON object. Note how the `null` value was silently + converted to a JSON object.,push_back__object_t__value} + + @since version 1.0.0 + */ + void push_back(const typename object_t::value_type& val) + { + // push_back only works for null objects or objects + if (JSON_UNLIKELY(not(is_null() or is_object()))) + { + JSON_THROW(type_error::create(308, "cannot use push_back() with " + std::string(type_name()))); + } + + // transform null object into an object + if (is_null()) + { + m_type = value_t::object; + m_value = value_t::object; + assert_invariant(); + } + + // add element to array + m_value.object->insert(val); + } + + /*! + @brief add an object to an object + @copydoc push_back(const typename object_t::value_type&) + */ + reference operator+=(const typename object_t::value_type& val) + { + push_back(val); + return *this; + } + + /*! + @brief add an object to an object + + This function allows to use `push_back` with an initializer list. In case + + 1. the current value is an object, + 2. the initializer list @a init contains only two elements, and + 3. the first element of @a init is a string, + + @a init is converted into an object element and added using + @ref push_back(const typename object_t::value_type&). Otherwise, @a init + is converted to a JSON value and added using @ref push_back(basic_json&&). + + @param[in] init an initializer list + + @complexity Linear in the size of the initializer list @a init. + + @note This function is required to resolve an ambiguous overload error, + because pairs like `{"key", "value"}` can be both interpreted as + `object_t::value_type` or `std::initializer_list`, see + https://github.com/nlohmann/json/issues/235 for more information. + + @liveexample{The example shows how initializer lists are treated as + objects when possible.,push_back__initializer_list} + */ + void push_back(initializer_list_t init) + { + if (is_object() and init.size() == 2 and (*init.begin())->is_string()) + { + basic_json&& key = init.begin()->moved_or_copied(); + push_back(typename object_t::value_type( + std::move(key.get_ref()), (init.begin() + 1)->moved_or_copied())); + } + else + { + push_back(basic_json(init)); + } + } + + /*! + @brief add an object to an object + @copydoc push_back(initializer_list_t) + */ + reference operator+=(initializer_list_t init) + { + push_back(init); + return *this; + } + + /*! + @brief add an object to an array + + Creates a JSON value from the passed parameters @a args to the end of the + JSON value. If the function is called on a JSON null value, an empty array + is created before appending the value created from @a args. + + @param[in] args arguments to forward to a constructor of @ref basic_json + @tparam Args compatible types to create a @ref basic_json object + + @throw type_error.311 when called on a type other than JSON array or + null; example: `"cannot use emplace_back() with number"` + + @complexity Amortized constant. + + @liveexample{The example shows how `push_back()` can be used to add + elements to a JSON array. Note how the `null` value was silently converted + to a JSON array.,emplace_back} + + @since version 2.0.8 + */ + template + void emplace_back(Args&& ... args) + { + // emplace_back only works for null objects or arrays + if (JSON_UNLIKELY(not(is_null() or is_array()))) + { + JSON_THROW(type_error::create(311, "cannot use emplace_back() with " + std::string(type_name()))); + } + + // transform null object into an array + if (is_null()) + { + m_type = value_t::array; + m_value = value_t::array; + assert_invariant(); + } + + // add element to array (perfect forwarding) + m_value.array->emplace_back(std::forward(args)...); + } + + /*! + @brief add an object to an object if key does not exist + + Inserts a new element into a JSON object constructed in-place with the + given @a args if there is no element with the key in the container. If the + function is called on a JSON null value, an empty object is created before + appending the value created from @a args. - // step 2: write each element - for (const auto& el : *j.m_value.object) - { - write_msgpack(el.first); - write_msgpack(el.second); - } - break; - } + @param[in] args arguments to forward to a constructor of @ref basic_json + @tparam Args compatible types to create a @ref basic_json object - default: - { - break; - } - } - } + @return a pair consisting of an iterator to the inserted element, or the + already-existing element if no insertion happened, and a bool + denoting whether the insertion took place. - private: - /* - @brief write a number to output input + @throw type_error.311 when called on a type other than JSON object or + null; example: `"cannot use emplace() with number"` + + @complexity Logarithmic in the size of the container, O(log(`size()`)). - @param[in] n number of type @a T - @tparam T the type of the number + @liveexample{The example shows how `emplace()` can be used to add elements + to a JSON object. Note how the `null` value was silently converted to a + JSON object. Further note how no value is added if there was already one + value stored with the same key.,emplace} - @note This function needs to respect the system's endianess, because - bytes in CBOR and MessagePack are stored in network order (big - endian) and therefore need reordering on little endian systems. - */ - template - void write_number(T n) + @since version 2.0.8 + */ + template + std::pair emplace(Args&& ... args) + { + // emplace only works for null objects or arrays + if (JSON_UNLIKELY(not(is_null() or is_object()))) { - // step 1: write number to array of length T - std::array vec; - std::memcpy(vec.data(), &n, sizeof(T)); + JSON_THROW(type_error::create(311, "cannot use emplace() with " + std::string(type_name()))); + } - // step 2: write array to output (with possible reordering) - for (size_t i = 0; i < sizeof(T); ++i) - { - // reverse byte order prior to conversion if necessary - if (is_little_endian) - { - oa->write_character(vec[sizeof(T) - i - 1]); - } - else - { - oa->write_character(vec[i]); // LCOV_EXCL_LINE - } - } + // transform null object into an object + if (is_null()) + { + m_type = value_t::object; + m_value = value_t::object; + assert_invariant(); } - private: - /// whether we can assume little endianess - const bool is_little_endian = true; + // add element to array (perfect forwarding) + auto res = m_value.object->emplace(std::forward(args)...); + // create result iterator and set iterator to the result of emplace + auto it = begin(); + it.m_it.object_iterator = res.first; - /// the output - output_adapter_t oa = nullptr; - }; + // return pair of iterator and boolean + return {it, res.second}; + } - public: /*! - @brief create a CBOR serialization of a given JSON value - - Serializes a given JSON value @a j to a byte vector using the CBOR (Concise - Binary Object Representation) serialization format. CBOR is a binary - serialization format which aims to be more compact than JSON itself, yet - more efficient to parse. + @brief inserts element - The library uses the following mapping from JSON values types to - CBOR types according to the CBOR specification (RFC 7049): + Inserts element @a val before iterator @a pos. - JSON value type | value/range | CBOR type | first byte - --------------- | ------------------------------------------ | ---------------------------------- | --------------- - null | `null` | Null | 0xf6 - boolean | `true` | True | 0xf5 - boolean | `false` | False | 0xf4 - number_integer | -9223372036854775808..-2147483649 | Negative integer (8 bytes follow) | 0x3b - number_integer | -2147483648..-32769 | Negative integer (4 bytes follow) | 0x3a - number_integer | -32768..-129 | Negative integer (2 bytes follow) | 0x39 - number_integer | -128..-25 | Negative integer (1 byte follow) | 0x38 - number_integer | -24..-1 | Negative integer | 0x20..0x37 - number_integer | 0..23 | Integer | 0x00..0x17 - number_integer | 24..255 | Unsigned integer (1 byte follow) | 0x18 - number_integer | 256..65535 | Unsigned integer (2 bytes follow) | 0x19 - number_integer | 65536..4294967295 | Unsigned integer (4 bytes follow) | 0x1a - number_integer | 4294967296..18446744073709551615 | Unsigned integer (8 bytes follow) | 0x1b - number_unsigned | 0..23 | Integer | 0x00..0x17 - number_unsigned | 24..255 | Unsigned integer (1 byte follow) | 0x18 - number_unsigned | 256..65535 | Unsigned integer (2 bytes follow) | 0x19 - number_unsigned | 65536..4294967295 | Unsigned integer (4 bytes follow) | 0x1a - number_unsigned | 4294967296..18446744073709551615 | Unsigned integer (8 bytes follow) | 0x1b - number_float | *any value* | Double-Precision Float | 0xfb - string | *length*: 0..23 | UTF-8 string | 0x60..0x77 - string | *length*: 23..255 | UTF-8 string (1 byte follow) | 0x78 - string | *length*: 256..65535 | UTF-8 string (2 bytes follow) | 0x79 - string | *length*: 65536..4294967295 | UTF-8 string (4 bytes follow) | 0x7a - string | *length*: 4294967296..18446744073709551615 | UTF-8 string (8 bytes follow) | 0x7b - array | *size*: 0..23 | array | 0x80..0x97 - array | *size*: 23..255 | array (1 byte follow) | 0x98 - array | *size*: 256..65535 | array (2 bytes follow) | 0x99 - array | *size*: 65536..4294967295 | array (4 bytes follow) | 0x9a - array | *size*: 4294967296..18446744073709551615 | array (8 bytes follow) | 0x9b - object | *size*: 0..23 | map | 0xa0..0xb7 - object | *size*: 23..255 | map (1 byte follow) | 0xb8 - object | *size*: 256..65535 | map (2 bytes follow) | 0xb9 - object | *size*: 65536..4294967295 | map (4 bytes follow) | 0xba - object | *size*: 4294967296..18446744073709551615 | map (8 bytes follow) | 0xbb + @param[in] pos iterator before which the content will be inserted; may be + the end() iterator + @param[in] val element to insert + @return iterator pointing to the inserted @a val. - @note The mapping is **complete** in the sense that any JSON value type - can be converted to a CBOR value. + @throw type_error.309 if called on JSON values other than arrays; + example: `"cannot use insert() with string"` + @throw invalid_iterator.202 if @a pos is not an iterator of *this; + example: `"iterator does not fit current value"` - @note The following CBOR types are not used in the conversion: - - byte strings (0x40..0x5f) - - UTF-8 strings terminated by "break" (0x7f) - - arrays terminated by "break" (0x9f) - - maps terminated by "break" (0xbf) - - date/time (0xc0..0xc1) - - bignum (0xc2..0xc3) - - decimal fraction (0xc4) - - bigfloat (0xc5) - - tagged items (0xc6..0xd4, 0xd8..0xdb) - - expected conversions (0xd5..0xd7) - - simple values (0xe0..0xf3, 0xf8) - - undefined (0xf7) - - half and single-precision floats (0xf9-0xfa) - - break (0xff) + @complexity Constant plus linear in the distance between @a pos and end of + the container. - @param[in] j JSON value to serialize - @return MessagePack serialization as byte vector + @liveexample{The example shows how `insert()` is used.,insert} - @complexity Linear in the size of the JSON value @a j. + @since version 1.0.0 + */ + iterator insert(const_iterator pos, const basic_json& val) + { + // insert only works for arrays + if (JSON_LIKELY(is_array())) + { + // check if iterator pos fits to this JSON value + if (JSON_UNLIKELY(pos.m_object != this)) + { + JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); + } - @liveexample{The example shows the serialization of a JSON value to a byte - vector in CBOR format.,to_cbor} + // insert to array and return iterator + iterator result(this); + result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, val); + return result; + } - @sa http://cbor.io - @sa @ref from_cbor(const std::vector&, const size_t) for the - analogous deserialization - @sa @ref to_msgpack(const basic_json& for the related MessagePack format + JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name()))); + } - @since version 2.0.9 + /*! + @brief inserts element + @copydoc insert(const_iterator, const basic_json&) */ - static std::vector to_cbor(const basic_json& j) + iterator insert(const_iterator pos, basic_json&& val) { - std::vector result; - binary_writer bw(output_adapter::create(result)); - bw.write_cbor(j); - return result; + return insert(pos, val); } /*! - @brief create a MessagePack serialization of a given JSON value - - Serializes a given JSON value @a j to a byte vector using the MessagePack - serialization format. MessagePack is a binary serialization format which - aims to be more compact than JSON itself, yet more efficient to parse. - - The library uses the following mapping from JSON values types to - MessagePack types according to the MessagePack specification: - - JSON value type | value/range | MessagePack type | first byte - --------------- | --------------------------------- | ---------------- | ---------- - null | `null` | nil | 0xc0 - boolean | `true` | true | 0xc3 - boolean | `false` | false | 0xc2 - number_integer | -9223372036854775808..-2147483649 | int64 | 0xd3 - number_integer | -2147483648..-32769 | int32 | 0xd2 - number_integer | -32768..-129 | int16 | 0xd1 - number_integer | -128..-33 | int8 | 0xd0 - number_integer | -32..-1 | negative fixint | 0xe0..0xff - number_integer | 0..127 | positive fixint | 0x00..0x7f - number_integer | 128..255 | uint 8 | 0xcc - number_integer | 256..65535 | uint 16 | 0xcd - number_integer | 65536..4294967295 | uint 32 | 0xce - number_integer | 4294967296..18446744073709551615 | uint 64 | 0xcf - number_unsigned | 0..127 | positive fixint | 0x00..0x7f - number_unsigned | 128..255 | uint 8 | 0xcc - number_unsigned | 256..65535 | uint 16 | 0xcd - number_unsigned | 65536..4294967295 | uint 32 | 0xce - number_unsigned | 4294967296..18446744073709551615 | uint 64 | 0xcf - number_float | *any value* | float 64 | 0xcb - string | *length*: 0..31 | fixstr | 0xa0..0xbf - string | *length*: 32..255 | str 8 | 0xd9 - string | *length*: 256..65535 | str 16 | 0xda - string | *length*: 65536..4294967295 | str 32 | 0xdb - array | *size*: 0..15 | fixarray | 0x90..0x9f - array | *size*: 16..65535 | array 16 | 0xdc - array | *size*: 65536..4294967295 | array 32 | 0xdd - object | *size*: 0..15 | fix map | 0x80..0x8f - object | *size*: 16..65535 | map 16 | 0xde - object | *size*: 65536..4294967295 | map 32 | 0xdf - - @note The mapping is **complete** in the sense that any JSON value type - can be converted to a MessagePack value. - - @note The following values can **not** be converted to a MessagePack value: - - strings with more than 4294967295 bytes - - arrays with more than 4294967295 elements - - objects with more than 4294967295 elements - - @note The following MessagePack types are not used in the conversion: - - bin 8 - bin 32 (0xc4..0xc6) - - ext 8 - ext 32 (0xc7..0xc9) - - float 32 (0xca) - - fixext 1 - fixext 16 (0xd4..0xd8) + @brief inserts elements - @note Any MessagePack output created @ref to_msgpack can be successfully - parsed by @ref from_msgpack. + Inserts @a cnt copies of @a val before iterator @a pos. - @param[in] j JSON value to serialize - @return MessagePack serialization as byte vector + @param[in] pos iterator before which the content will be inserted; may be + the end() iterator + @param[in] cnt number of copies of @a val to insert + @param[in] val element to insert + @return iterator pointing to the first element inserted, or @a pos if + `cnt==0` - @complexity Linear in the size of the JSON value @a j. + @throw type_error.309 if called on JSON values other than arrays; example: + `"cannot use insert() with string"` + @throw invalid_iterator.202 if @a pos is not an iterator of *this; + example: `"iterator does not fit current value"` - @liveexample{The example shows the serialization of a JSON value to a byte - vector in MessagePack format.,to_msgpack} + @complexity Linear in @a cnt plus linear in the distance between @a pos + and end of the container. - @sa http://msgpack.org - @sa @ref from_msgpack(const std::vector&, const size_t) for the - analogous deserialization - @sa @ref to_cbor(const basic_json& for the related CBOR format + @liveexample{The example shows how `insert()` is used.,insert__count} - @since version 2.0.9 + @since version 1.0.0 */ - static std::vector to_msgpack(const basic_json& j) + iterator insert(const_iterator pos, size_type cnt, const basic_json& val) { - std::vector result; - binary_writer bw(output_adapter::create(result)); - bw.write_msgpack(j); - return result; + // insert only works for arrays + if (JSON_LIKELY(is_array())) + { + // check if iterator pos fits to this JSON value + if (JSON_UNLIKELY(pos.m_object != this)) + { + JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); + } + + // insert to array and return iterator + iterator result(this); + result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, cnt, val); + return result; + } + + JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name()))); } /*! - @brief create a JSON value from a byte vector in CBOR format - - Deserializes a given byte vector @a v to a JSON value using the CBOR - (Concise Binary Object Representation) serialization format. + @brief inserts elements - The library maps CBOR types to JSON value types as follows: + Inserts elements from range `[first, last)` before iterator @a pos. - CBOR type | JSON value type | first byte - ---------------------- | --------------- | ---------- - Integer | number_unsigned | 0x00..0x17 - Unsigned integer | number_unsigned | 0x18 - Unsigned integer | number_unsigned | 0x19 - Unsigned integer | number_unsigned | 0x1a - Unsigned integer | number_unsigned | 0x1b - Negative integer | number_integer | 0x20..0x37 - Negative integer | number_integer | 0x38 - Negative integer | number_integer | 0x39 - Negative integer | number_integer | 0x3a - Negative integer | number_integer | 0x3b - Negative integer | number_integer | 0x40..0x57 - UTF-8 string | string | 0x60..0x77 - UTF-8 string | string | 0x78 - UTF-8 string | string | 0x79 - UTF-8 string | string | 0x7a - UTF-8 string | string | 0x7b - UTF-8 string | string | 0x7f - array | array | 0x80..0x97 - array | array | 0x98 - array | array | 0x99 - array | array | 0x9a - array | array | 0x9b - array | array | 0x9f - map | object | 0xa0..0xb7 - map | object | 0xb8 - map | object | 0xb9 - map | object | 0xba - map | object | 0xbb - map | object | 0xbf - False | `false` | 0xf4 - True | `true` | 0xf5 - Nill | `null` | 0xf6 - Half-Precision Float | number_float | 0xf9 - Single-Precision Float | number_float | 0xfa - Double-Precision Float | number_float | 0xfb + @param[in] pos iterator before which the content will be inserted; may be + the end() iterator + @param[in] first begin of the range of elements to insert + @param[in] last end of the range of elements to insert - @warning The mapping is **incomplete** in the sense that not all CBOR - types can be converted to a JSON value. The following CBOR types - are not supported and will yield parse errors (parse_error.112): - - byte strings (0x40..0x5f) - - date/time (0xc0..0xc1) - - bignum (0xc2..0xc3) - - decimal fraction (0xc4) - - bigfloat (0xc5) - - tagged items (0xc6..0xd4, 0xd8..0xdb) - - expected conversions (0xd5..0xd7) - - simple values (0xe0..0xf3, 0xf8) - - undefined (0xf7) + @throw type_error.309 if called on JSON values other than arrays; example: + `"cannot use insert() with string"` + @throw invalid_iterator.202 if @a pos is not an iterator of *this; + example: `"iterator does not fit current value"` + @throw invalid_iterator.210 if @a first and @a last do not belong to the + same JSON value; example: `"iterators do not fit"` + @throw invalid_iterator.211 if @a first or @a last are iterators into + container for which insert is called; example: `"passed iterators may not + belong to container"` - @warning CBOR allows map keys of any type, whereas JSON only allows - strings as keys in object values. Therefore, CBOR maps with keys - other than UTF-8 strings are rejected (parse_error.113). + @return iterator pointing to the first element inserted, or @a pos if + `first==last` - @note Any CBOR output created @ref to_cbor can be successfully parsed by - @ref from_cbor. + @complexity Linear in `std::distance(first, last)` plus linear in the + distance between @a pos and end of the container. - @param[in] v a byte vector in CBOR format - @param[in] start_index the index to start reading from @a v (0 by default) - @return deserialized JSON value + @liveexample{The example shows how `insert()` is used.,insert__range} - @throw parse_error.110 if the given vector ends prematurely - @throw parse_error.112 if unsupported features from CBOR were - used in the given vector @a v or if the input is not valid CBOR - @throw parse_error.113 if a string was expected as map key, but not found + @since version 1.0.0 + */ + iterator insert(const_iterator pos, const_iterator first, const_iterator last) + { + // insert only works for arrays + if (JSON_UNLIKELY(not is_array())) + { + JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name()))); + } - @complexity Linear in the size of the byte vector @a v. + // check if iterator pos fits to this JSON value + if (JSON_UNLIKELY(pos.m_object != this)) + { + JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); + } - @liveexample{The example shows the deserialization of a byte vector in CBOR - format to a JSON value.,from_cbor} + // check if range iterators belong to the same JSON object + if (JSON_UNLIKELY(first.m_object != last.m_object)) + { + JSON_THROW(invalid_iterator::create(210, "iterators do not fit")); + } - @sa http://cbor.io - @sa @ref to_cbor(const basic_json&) for the analogous serialization - @sa @ref from_msgpack(const std::vector&, const size_t) for the - related MessagePack format + if (JSON_UNLIKELY(first.m_object == this)) + { + JSON_THROW(invalid_iterator::create(211, "passed iterators may not belong to container")); + } - @since version 2.0.9, parameter @a start_index since 2.1.1 - */ - static basic_json from_cbor(const std::vector& v, - const size_t start_index = 0) - { - binary_reader br(input_adapter::create(v.begin() + static_cast(start_index), v.end())); - return br.parse_cbor(); + // insert to array and return iterator + iterator result(this); + result.m_it.array_iterator = m_value.array->insert( + pos.m_it.array_iterator, + first.m_it.array_iterator, + last.m_it.array_iterator); + return result; } - /*! - @brief create a JSON value from a byte vector in MessagePack format + @brief inserts elements - Deserializes a given byte vector @a v to a JSON value using the MessagePack - serialization format. + Inserts elements from initializer list @a ilist before iterator @a pos. - The library maps MessagePack types to JSON value types as follows: + @param[in] pos iterator before which the content will be inserted; may be + the end() iterator + @param[in] ilist initializer list to insert the values from - MessagePack type | JSON value type | first byte - ---------------- | --------------- | ---------- - positive fixint | number_unsigned | 0x00..0x7f - fixmap | object | 0x80..0x8f - fixarray | array | 0x90..0x9f - fixstr | string | 0xa0..0xbf - nil | `null` | 0xc0 - false | `false` | 0xc2 - true | `true` | 0xc3 - float 32 | number_float | 0xca - float 64 | number_float | 0xcb - uint 8 | number_unsigned | 0xcc - uint 16 | number_unsigned | 0xcd - uint 32 | number_unsigned | 0xce - uint 64 | number_unsigned | 0xcf - int 8 | number_integer | 0xd0 - int 16 | number_integer | 0xd1 - int 32 | number_integer | 0xd2 - int 64 | number_integer | 0xd3 - str 8 | string | 0xd9 - str 16 | string | 0xda - str 32 | string | 0xdb - array 16 | array | 0xdc - array 32 | array | 0xdd - map 16 | object | 0xde - map 32 | object | 0xdf - negative fixint | number_integer | 0xe0-0xff + @throw type_error.309 if called on JSON values other than arrays; example: + `"cannot use insert() with string"` + @throw invalid_iterator.202 if @a pos is not an iterator of *this; + example: `"iterator does not fit current value"` - @warning The mapping is **incomplete** in the sense that not all - MessagePack types can be converted to a JSON value. The following - MessagePack types are not supported and will yield parse errors: - - bin 8 - bin 32 (0xc4..0xc6) - - ext 8 - ext 32 (0xc7..0xc9) - - fixext 1 - fixext 16 (0xd4..0xd8) + @return iterator pointing to the first element inserted, or @a pos if + `ilist` is empty - @note Any MessagePack output created @ref to_msgpack can be successfully - parsed by @ref from_msgpack. + @complexity Linear in `ilist.size()` plus linear in the distance between + @a pos and end of the container. - @param[in] v a byte vector in MessagePack format - @param[in] start_index the index to start reading from @a v (0 by default) - @return deserialized JSON value + @liveexample{The example shows how `insert()` is used.,insert__ilist} - @throw parse_error.110 if the given vector ends prematurely - @throw parse_error.112 if unsupported features from MessagePack were - used in the given vector @a v or if the input is not valid MessagePack - @throw parse_error.113 if a string was expected as map key, but not found + @since version 1.0.0 + */ + iterator insert(const_iterator pos, initializer_list_t ilist) + { + // insert only works for arrays + if (JSON_UNLIKELY(not is_array())) + { + JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name()))); + } - @complexity Linear in the size of the byte vector @a v. + // check if iterator pos fits to this JSON value + if (JSON_UNLIKELY(pos.m_object != this)) + { + JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); + } - @liveexample{The example shows the deserialization of a byte vector in - MessagePack format to a JSON value.,from_msgpack} + // insert to array and return iterator + iterator result(this); + result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, ilist.begin(), ilist.end()); + return result; + } - @sa http://msgpack.org - @sa @ref to_msgpack(const basic_json&) for the analogous serialization - @sa @ref from_cbor(const std::vector&, const size_t) for the - related CBOR format + /*! + @brief inserts elements - @since version 2.0.9, parameter @a start_index since 2.1.1 - */ - static basic_json from_msgpack(const std::vector& v, - const size_t start_index = 0) - { - binary_reader br(input_adapter::create(v.begin() + static_cast(start_index), v.end())); - return br.parse_msgpack(); - } + Inserts elements from range `[first, last)`. - /// @} + @param[in] first begin of the range of elements to insert + @param[in] last end of the range of elements to insert - ////////////////////// - // lexer and parser // - ////////////////////// + @throw type_error.309 if called on JSON values other than objects; example: + `"cannot use insert() with string"` + @throw invalid_iterator.202 if iterator @a first or @a last does does not + point to an object; example: `"iterators first and last must point to + objects"` + @throw invalid_iterator.210 if @a first and @a last do not belong to the + same JSON value; example: `"iterators do not fit"` - private: - /*! - @brief lexical analysis + @complexity Logarithmic: `O(N*log(size() + N))`, where `N` is the number + of elements to insert. + + @liveexample{The example shows how `insert()` is used.,insert__range_object} - This class organizes the lexical analysis during JSON deserialization. + @since version 3.0.0 */ - class lexer + void insert(const_iterator first, const_iterator last) { - public: - /// token types for the parser - enum class token_type - { - uninitialized, ///< indicating the scanner is uninitialized - literal_true, ///< the `true` literal - literal_false, ///< the `false` literal - literal_null, ///< the `null` literal - value_string, ///< a string -- use get_string() for actual value - value_unsigned, ///< an unsigned integer -- use get_number_unsigned() for actual value - value_integer, ///< a signed integer -- use get_number_integer() for actual value - value_float, ///< an floating point number -- use get_number_float() for actual value - begin_array, ///< the character for array begin `[` - begin_object, ///< the character for object begin `{` - end_array, ///< the character for array end `]` - end_object, ///< the character for object end `}` - name_separator, ///< the name separator `:` - value_separator, ///< the value separator `,` - parse_error, ///< indicating a parse error - end_of_input, ///< indicating the end of the input buffer - literal_or_value ///< a literal or the begin of a value (only for diagnostics) - }; - - /// return name of values of type token_type (only used for errors) - static const char* token_type_name(const token_type t) noexcept + // insert only works for objects + if (JSON_UNLIKELY(not is_object())) { - switch (t) - { - case token_type::uninitialized: - return ""; - case token_type::literal_true: - return "true literal"; - case token_type::literal_false: - return "false literal"; - case token_type::literal_null: - return "null literal"; - case token_type::value_string: - return "string literal"; - case lexer::token_type::value_unsigned: - case lexer::token_type::value_integer: - case lexer::token_type::value_float: - return "number literal"; - case token_type::begin_array: - return "'['"; - case token_type::begin_object: - return "'{'"; - case token_type::end_array: - return "']'"; - case token_type::end_object: - return "'}'"; - case token_type::name_separator: - return "':'"; - case token_type::value_separator: - return "','"; - case token_type::parse_error: - return ""; - case token_type::end_of_input: - return "end of input"; - case token_type::literal_or_value: - return "'[', '{', or a literal"; - default: - { - // catch non-enum values - return "unknown token"; // LCOV_EXCL_LINE - } - } + JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name()))); } - explicit lexer(input_adapter_t adapter) - : ia(adapter), decimal_point_char(get_decimal_point()) - {} - - // delete because of pointer members - lexer(const lexer&) = delete; - lexer& operator=(lexer&) = delete; - - private: - ///////////////////// - // locales - ///////////////////// + // check if range iterators belong to the same JSON object + if (JSON_UNLIKELY(first.m_object != last.m_object)) + { + JSON_THROW(invalid_iterator::create(210, "iterators do not fit")); + } - /// return the locale-dependent decimal point - static char get_decimal_point() noexcept + // passed iterators must belong to objects + if (JSON_UNLIKELY(not first.m_object->is_object())) { - const auto loc = localeconv(); - assert(loc != nullptr); - return (loc->decimal_point == nullptr) ? '.' : loc->decimal_point[0]; + JSON_THROW(invalid_iterator::create(202, "iterators first and last must point to objects")); } - ///////////////////// - // scan functions - ///////////////////// + m_value.object->insert(first.m_it.object_iterator, last.m_it.object_iterator); + } - /*! - @brief get codepoint from 4 hex characters following `\u` + /*! + @brief updates a JSON object from another object, overwriting existing keys - @return codepoint or -1 in case of an error (e.g. EOF or non-hex - character) - */ - int get_codepoint() - { - // this function only makes sense after reading `\u` - assert(current == 'u'); - int codepoint = 0; + Inserts all values from JSON object @a j and overwrites existing keys. - // byte 1: \uXxxx - switch (get()) - { - case '0': - break; - case '1': - codepoint += 0x1000; - break; - case '2': - codepoint += 0x2000; - break; - case '3': - codepoint += 0x3000; - break; - case '4': - codepoint += 0x4000; - break; - case '5': - codepoint += 0x5000; - break; - case '6': - codepoint += 0x6000; - break; - case '7': - codepoint += 0x7000; - break; - case '8': - codepoint += 0x8000; - break; - case '9': - codepoint += 0x9000; - break; - case 'A': - case 'a': - codepoint += 0xa000; - break; - case 'B': - case 'b': - codepoint += 0xb000; - break; - case 'C': - case 'c': - codepoint += 0xc000; - break; - case 'D': - case 'd': - codepoint += 0xd000; - break; - case 'E': - case 'e': - codepoint += 0xe000; - break; - case 'F': - case 'f': - codepoint += 0xf000; - break; - default: - return -1; - } + @param[in] j JSON object to read values from - // byte 2: \uxXxx - switch (get()) - { - case '0': - break; - case '1': - codepoint += 0x0100; - break; - case '2': - codepoint += 0x0200; - break; - case '3': - codepoint += 0x0300; - break; - case '4': - codepoint += 0x0400; - break; - case '5': - codepoint += 0x0500; - break; - case '6': - codepoint += 0x0600; - break; - case '7': - codepoint += 0x0700; - break; - case '8': - codepoint += 0x0800; - break; - case '9': - codepoint += 0x0900; - break; - case 'A': - case 'a': - codepoint += 0x0a00; - break; - case 'B': - case 'b': - codepoint += 0x0b00; - break; - case 'C': - case 'c': - codepoint += 0x0c00; - break; - case 'D': - case 'd': - codepoint += 0x0d00; - break; - case 'E': - case 'e': - codepoint += 0x0e00; - break; - case 'F': - case 'f': - codepoint += 0x0f00; - break; - default: - return -1; - } + @throw type_error.312 if called on JSON values other than objects; example: + `"cannot use update() with string"` - // byte 3: \uxxXx - switch (get()) - { - case '0': - break; - case '1': - codepoint += 0x0010; - break; - case '2': - codepoint += 0x0020; - break; - case '3': - codepoint += 0x0030; - break; - case '4': - codepoint += 0x0040; - break; - case '5': - codepoint += 0x0050; - break; - case '6': - codepoint += 0x0060; - break; - case '7': - codepoint += 0x0070; - break; - case '8': - codepoint += 0x0080; - break; - case '9': - codepoint += 0x0090; - break; - case 'A': - case 'a': - codepoint += 0x00a0; - break; - case 'B': - case 'b': - codepoint += 0x00b0; - break; - case 'C': - case 'c': - codepoint += 0x00c0; - break; - case 'D': - case 'd': - codepoint += 0x00d0; - break; - case 'E': - case 'e': - codepoint += 0x00e0; - break; - case 'F': - case 'f': - codepoint += 0x00f0; - break; - default: - return -1; - } + @complexity O(N*log(size() + N)), where N is the number of elements to + insert. - // byte 4: \uxxxX - switch (get()) - { - case '0': - break; - case '1': - codepoint += 0x0001; - break; - case '2': - codepoint += 0x0002; - break; - case '3': - codepoint += 0x0003; - break; - case '4': - codepoint += 0x0004; - break; - case '5': - codepoint += 0x0005; - break; - case '6': - codepoint += 0x0006; - break; - case '7': - codepoint += 0x0007; - break; - case '8': - codepoint += 0x0008; - break; - case '9': - codepoint += 0x0009; - break; - case 'A': - case 'a': - codepoint += 0x000a; - break; - case 'B': - case 'b': - codepoint += 0x000b; - break; - case 'C': - case 'c': - codepoint += 0x000c; - break; - case 'D': - case 'd': - codepoint += 0x000d; - break; - case 'E': - case 'e': - codepoint += 0x000e; - break; - case 'F': - case 'f': - codepoint += 0x000f; - break; - default: - return -1; - } + @liveexample{The example shows how `update()` is used.,update} + + @sa https://docs.python.org/3.6/library/stdtypes.html#dict.update - return codepoint; + @since version 3.0.0 + */ + void update(const_reference j) + { + // implicitly convert null value to an empty object + if (is_null()) + { + m_type = value_t::object; + m_value.object = create(); + assert_invariant(); } - /*! - @brief scan a string literal + if (JSON_UNLIKELY(not is_object())) + { + JSON_THROW(type_error::create(312, "cannot use update() with " + std::string(type_name()))); + } + if (JSON_UNLIKELY(not j.is_object())) + { + JSON_THROW(type_error::create(312, "cannot use update() with " + std::string(j.type_name()))); + } - This function scans a string according to Sect. 7 of RFC 7159. While - scanning, bytes are escaped and copied into buffer yytext. Then the - function returns successfully, yytext is null-terminated and yylen - contains the number of bytes in the string. + for (auto it = j.cbegin(); it != j.cend(); ++it) + { + m_value.object->operator[](it.key()) = it.value(); + } + } - @return token_type::value_string if string could be successfully - scanned, token_type::parse_error otherwise + /*! + @brief updates a JSON object from another object, overwriting existing keys - @note In case of errors, variable error_message contains a textual - description. - */ - token_type scan_string() - { - // reset yytext (ignore opening quote) - reset(); + Inserts all values from from range `[first, last)` and overwrites existing + keys. - // we entered the function by reading an open quote - assert(current == '\"'); + @param[in] first begin of the range of elements to insert + @param[in] last end of the range of elements to insert - while (true) - { - // get next character - switch (get()) - { - // end of file while parsing string - case std::char_traits::eof(): - { - error_message = "invalid string: missing closing quote"; - return token_type::parse_error; - } + @throw type_error.312 if called on JSON values other than objects; example: + `"cannot use update() with string"` + @throw invalid_iterator.202 if iterator @a first or @a last does does not + point to an object; example: `"iterators first and last must point to + objects"` + @throw invalid_iterator.210 if @a first and @a last do not belong to the + same JSON value; example: `"iterators do not fit"` - // closing quote - case '\"': - { - // terminate yytext - add('\0'); - --yylen; - return token_type::value_string; - } + @complexity O(N*log(size() + N)), where N is the number of elements to + insert. - // escapes - case '\\': - { - switch (get()) - { - // quotation mark - case '\"': - add('\"'); - break; - // reverse solidus - case '\\': - add('\\'); - break; - // solidus - case '/': - add('/'); - break; - // backspace - case 'b': - add('\b'); - break; - // form feed - case 'f': - add('\f'); - break; - // line feed - case 'n': - add('\n'); - break; - // carriage return - case 'r': - add('\r'); - break; - // tab - case 't': - add('\t'); - break; - - // unicode escapes - case 'u': - { - int codepoint; - int codepoint1 = get_codepoint(); + @liveexample{The example shows how `update()` is used__range.,update} - if (JSON_UNLIKELY(codepoint1 == -1)) - { - error_message = "invalid string: '\\u' must be followed by 4 hex digits"; - return token_type::parse_error; - } + @sa https://docs.python.org/3.6/library/stdtypes.html#dict.update - // check if code point is a high surrogate - if (0xD800 <= codepoint1 and codepoint1 <= 0xDBFF) - { - // expect next \uxxxx entry - if (JSON_LIKELY(get() == '\\' and get() == 'u')) - { - const int codepoint2 = get_codepoint(); - - if (JSON_UNLIKELY(codepoint2 == -1)) - { - error_message = "invalid string: '\\u' must be followed by 4 hex digits"; - return token_type::parse_error; - } - - // check if codepoint2 is a low surrogate - if (JSON_LIKELY(0xDC00 <= codepoint2 and codepoint2 <= 0xDFFF)) - { - codepoint = - // high surrogate occupies the most significant 22 bits - (codepoint1 << 10) - // low surrogate occupies the least significant 15 bits - + codepoint2 - // there is still the 0xD800, 0xDC00 and 0x10000 noise - // in the result so we have to subtract with: - // (0xD800 << 10) + DC00 - 0x10000 = 0x35FDC00 - - 0x35FDC00; - } - else - { - error_message = "invalid string: surrogate U+DC00..U+DFFF must be followed by U+DC00..U+DFFF"; - return token_type::parse_error; - } - } - else - { - error_message = "invalid string: surrogate U+DC00..U+DFFF must be followed by U+DC00..U+DFFF"; - return token_type::parse_error; - } - } - else - { - if (JSON_UNLIKELY(0xDC00 <= codepoint1 and codepoint1 <= 0xDFFF)) - { - error_message = "invalid string: surrogate U+DC00..U+DFFF must follow U+D800..U+DBFF"; - return token_type::parse_error; - } + @since version 3.0.0 + */ + void update(const_iterator first, const_iterator last) + { + // implicitly convert null value to an empty object + if (is_null()) + { + m_type = value_t::object; + m_value.object = create(); + assert_invariant(); + } - // only work with first code point - codepoint = codepoint1; - } + if (JSON_UNLIKELY(not is_object())) + { + JSON_THROW(type_error::create(312, "cannot use update() with " + std::string(type_name()))); + } - // result of the above calculation yields a proper codepoint - assert(0x00 <= codepoint and codepoint <= 0x10FFFF); + // check if range iterators belong to the same JSON object + if (JSON_UNLIKELY(first.m_object != last.m_object)) + { + JSON_THROW(invalid_iterator::create(210, "iterators do not fit")); + } - // translate code point to bytes - if (codepoint < 0x80) - { - // 1-byte characters: 0xxxxxxx (ASCII) - add(codepoint); - } - else if (codepoint <= 0x7ff) - { - // 2-byte characters: 110xxxxx 10xxxxxx - add(0xC0 | (codepoint >> 6)); - add(0x80 | (codepoint & 0x3F)); - } - else if (codepoint <= 0xffff) - { - // 3-byte characters: 1110xxxx 10xxxxxx 10xxxxxx - add(0xE0 | (codepoint >> 12)); - add(0x80 | ((codepoint >> 6) & 0x3F)); - add(0x80 | (codepoint & 0x3F)); - } - else - { - // 4-byte characters: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx - add(0xF0 | (codepoint >> 18)); - add(0x80 | ((codepoint >> 12) & 0x3F)); - add(0x80 | ((codepoint >> 6) & 0x3F)); - add(0x80 | (codepoint & 0x3F)); - } + // passed iterators must belong to objects + if (JSON_UNLIKELY(not first.m_object->is_object() + or not first.m_object->is_object())) + { + JSON_THROW(invalid_iterator::create(202, "iterators first and last must point to objects")); + } - break; - } + for (auto it = first; it != last; ++it) + { + m_value.object->operator[](it.key()) = it.value(); + } + } - // other characters after escape - default: - error_message = "invalid string: forbidden character after backslash"; - return token_type::parse_error; - } + /*! + @brief exchanges the values - break; - } + Exchanges the contents of the JSON value with those of @a other. Does not + invoke any move, copy, or swap operations on individual elements. All + iterators and references remain valid. The past-the-end iterator is + invalidated. - // invalid control characters - case 0x00: - case 0x01: - case 0x02: - case 0x03: - case 0x04: - case 0x05: - case 0x06: - case 0x07: - case 0x08: - case 0x09: - case 0x0a: - case 0x0b: - case 0x0c: - case 0x0d: - case 0x0e: - case 0x0f: - case 0x10: - case 0x11: - case 0x12: - case 0x13: - case 0x14: - case 0x15: - case 0x16: - case 0x17: - case 0x18: - case 0x19: - case 0x1a: - case 0x1b: - case 0x1c: - case 0x1d: - case 0x1e: - case 0x1f: - { - error_message = "invalid string: control character must be escaped"; - return token_type::parse_error; - } + @param[in,out] other JSON value to exchange the contents with - // U+0020..U+007F (except U+0022 (quote) and U+005C (backspace)) - case 0x20: - case 0x21: - case 0x23: - case 0x24: - case 0x25: - case 0x26: - case 0x27: - case 0x28: - case 0x29: - case 0x2a: - case 0x2b: - case 0x2c: - case 0x2d: - case 0x2e: - case 0x2f: - case 0x30: - case 0x31: - case 0x32: - case 0x33: - case 0x34: - case 0x35: - case 0x36: - case 0x37: - case 0x38: - case 0x39: - case 0x3a: - case 0x3b: - case 0x3c: - case 0x3d: - case 0x3e: - case 0x3f: - case 0x40: - case 0x41: - case 0x42: - case 0x43: - case 0x44: - case 0x45: - case 0x46: - case 0x47: - case 0x48: - case 0x49: - case 0x4a: - case 0x4b: - case 0x4c: - case 0x4d: - case 0x4e: - case 0x4f: - case 0x50: - case 0x51: - case 0x52: - case 0x53: - case 0x54: - case 0x55: - case 0x56: - case 0x57: - case 0x58: - case 0x59: - case 0x5a: - case 0x5b: - case 0x5d: - case 0x5e: - case 0x5f: - case 0x60: - case 0x61: - case 0x62: - case 0x63: - case 0x64: - case 0x65: - case 0x66: - case 0x67: - case 0x68: - case 0x69: - case 0x6a: - case 0x6b: - case 0x6c: - case 0x6d: - case 0x6e: - case 0x6f: - case 0x70: - case 0x71: - case 0x72: - case 0x73: - case 0x74: - case 0x75: - case 0x76: - case 0x77: - case 0x78: - case 0x79: - case 0x7a: - case 0x7b: - case 0x7c: - case 0x7d: - case 0x7e: - case 0x7f: - { - add(current); - break; - } + @complexity Constant. - // U+0080..U+07FF: bytes C2..DF 80..BF - case 0xc2: - case 0xc3: - case 0xc4: - case 0xc5: - case 0xc6: - case 0xc7: - case 0xc8: - case 0xc9: - case 0xca: - case 0xcb: - case 0xcc: - case 0xcd: - case 0xce: - case 0xcf: - case 0xd0: - case 0xd1: - case 0xd2: - case 0xd3: - case 0xd4: - case 0xd5: - case 0xd6: - case 0xd7: - case 0xd8: - case 0xd9: - case 0xda: - case 0xdb: - case 0xdc: - case 0xdd: - case 0xde: - case 0xdf: - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - continue; - } + @liveexample{The example below shows how JSON values can be swapped with + `swap()`.,swap__reference} - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } + @since version 1.0.0 + */ + void swap(reference other) noexcept ( + std::is_nothrow_move_constructible::value and + std::is_nothrow_move_assignable::value and + std::is_nothrow_move_constructible::value and + std::is_nothrow_move_assignable::value + ) + { + std::swap(m_type, other.m_type); + std::swap(m_value, other.m_value); + assert_invariant(); + } - // U+0800..U+0FFF: bytes E0 A0..BF 80..BF - case 0xe0: - { - add(current); - get(); - if (JSON_LIKELY(0xa0 <= current and current <= 0xbf)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - continue; - } - } + /*! + @brief exchanges the values - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } + Exchanges the contents of a JSON array with those of @a other. Does not + invoke any move, copy, or swap operations on individual elements. All + iterators and references remain valid. The past-the-end iterator is + invalidated. - // U+1000..U+CFFF: bytes E1..EC 80..BF 80..BF - // U+E000..U+FFFF: bytes EE..EF 80..BF 80..BF - case 0xe1: - case 0xe2: - case 0xe3: - case 0xe4: - case 0xe5: - case 0xe6: - case 0xe7: - case 0xe8: - case 0xe9: - case 0xea: - case 0xeb: - case 0xec: - case 0xee: - case 0xef: - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - continue; - } - } + @param[in,out] other array to exchange the contents with - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } + @throw type_error.310 when JSON value is not an array; example: `"cannot + use swap() with string"` - // U+D000..U+D7FF: bytes ED 80..9F 80..BF - case 0xed: - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0x9f)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - continue; - } - } + @complexity Constant. - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } + @liveexample{The example below shows how arrays can be swapped with + `swap()`.,swap__array_t} - // U+10000..U+3FFFF F0 90..BF 80..BF 80..BF - case 0xf0: - { - add(current); - get(); - if (JSON_LIKELY(0x90 <= current and current <= 0xbf)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - continue; - } - } - } + @since version 1.0.0 + */ + void swap(array_t& other) + { + // swap only works for arrays + if (JSON_LIKELY(is_array())) + { + std::swap(*(m_value.array), other); + } + else + { + JSON_THROW(type_error::create(310, "cannot use swap() with " + std::string(type_name()))); + } + } - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } + /*! + @brief exchanges the values - // U+40000..U+FFFFF F1..F3 80..BF 80..BF 80..BF - case 0xf1: - case 0xf2: - case 0xf3: - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - continue; - } - } - } + Exchanges the contents of a JSON object with those of @a other. Does not + invoke any move, copy, or swap operations on individual elements. All + iterators and references remain valid. The past-the-end iterator is + invalidated. - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } + @param[in,out] other object to exchange the contents with - // U+100000..U+10FFFF F4 80..8F 80..BF 80..BF - case 0xf4: - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0x8f)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - continue; - } - } - } + @throw type_error.310 when JSON value is not an object; example: + `"cannot use swap() with string"` - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } + @complexity Constant. - // remaining bytes (80..C1 and F5..FF) are ill-formed - default: - { - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } - } - } - } + @liveexample{The example below shows how objects can be swapped with + `swap()`.,swap__object_t} - static void strtof(float& f, const char* str, char** endptr) noexcept + @since version 1.0.0 + */ + void swap(object_t& other) + { + // swap only works for objects + if (JSON_LIKELY(is_object())) { - f = std::strtof(str, endptr); + std::swap(*(m_value.object), other); } - - static void strtof(double& f, const char* str, char** endptr) noexcept + else { - f = std::strtod(str, endptr); + JSON_THROW(type_error::create(310, "cannot use swap() with " + std::string(type_name()))); } + } + + /*! + @brief exchanges the values + + Exchanges the contents of a JSON string with those of @a other. Does not + invoke any move, copy, or swap operations on individual elements. All + iterators and references remain valid. The past-the-end iterator is + invalidated. + + @param[in,out] other string to exchange the contents with + + @throw type_error.310 when JSON value is not a string; example: `"cannot + use swap() with boolean"` + + @complexity Constant. + + @liveexample{The example below shows how strings can be swapped with + `swap()`.,swap__string_t} - static void strtof(long double& f, const char* str, char** endptr) noexcept + @since version 1.0.0 + */ + void swap(string_t& other) + { + // swap only works for strings + if (JSON_LIKELY(is_string())) + { + std::swap(*(m_value.string), other); + } + else { - f = std::strtold(str, endptr); + JSON_THROW(type_error::create(310, "cannot use swap() with " + std::string(type_name()))); } + } - /*! - @brief scan a number literal - - This function scans a string according to Sect. 6 of RFC 7159. + /// @} - The function is realized with a deterministic finite state machine - derived from the grammar described in RFC 7159. Starting in state - "init", the input is read and used to determined the next state. Only - state "done" accepts the number. State "error" is a trap state to model - errors. In the table below, "anything" means any character but the ones - listed before. + public: + ////////////////////////////////////////// + // lexicographical comparison operators // + ////////////////////////////////////////// - state | 0 | 1-9 | e E | + | - | . | anything - ---------|----------|----------|----------|---------|---------|----------|----------- - init | zero | any1 | [error] | [error] | minus | [error] | [error] - minus | zero | any1 | [error] | [error] | [error] | [error] | [error] - zero | done | done | exponent | done | done | decimal1 | done - any1 | any1 | any1 | exponent | done | done | decimal1 | done - decimal1 | decimal2 | [error] | [error] | [error] | [error] | [error] | [error] - decimal2 | decimal2 | decimal2 | exponent | done | done | done | done - exponent | any2 | any2 | [error] | sign | sign | [error] | [error] - sign | any2 | any2 | [error] | [error] | [error] | [error] | [error] - any2 | any2 | any2 | done | done | done | done | done + /// @name lexicographical comparison operators + /// @{ - The state machine is realized with one label per state (prefixed with - "scan_number_") and `goto` statements between them. The state machine - contains cycles, but any cycle can be left when EOF is read. Therefore, - the function is guaranteed to terminate. + /*! + @brief comparison: equal - During scanning, the read bytes are stored in yytext. This string is - then converted to a signed integer, an unsigned integer, or a - floating-point number. + Compares two JSON values for equality according to the following rules: + - Two JSON values are equal if (1) they are from the same type and (2) + their stored values are the same according to their respective + `operator==`. + - Integer and floating-point numbers are automatically converted before + comparison. Note than two NaN values are always treated as unequal. + - Two JSON null values are equal. - @return token_type::value_unsigned, token_type::value_integer, or - token_type::value_float if number could be successfully scanned, - token_type::parse_error otherwise + @note Floating-point inside JSON values numbers are compared with + `json::number_float_t::operator==` which is `double::operator==` by + default. To compare floating-point while respecting an epsilon, an alternative + [comparison function](https://github.com/mariokonrad/marnav/blob/master/src/marnav/math/floatingpoint.hpp#L34-#L39) + could be used, for instance + @code {.cpp} + template::value, T>::type> + inline bool is_same(T a, T b, T epsilon = std::numeric_limits::epsilon()) noexcept + { + return std::abs(a - b) <= epsilon; + } + @endcode - @note The scanner is independent of the current locale. Internally, the - locale's decimal point is used instead of `.` to work with the - locale-dependent converters. - */ - token_type scan_number() - { - // reset yytext to store the number's bytes - reset(); + @note NaN values never compare equal to themselves or to other NaN values. - // the type of the parsed number; initially set to unsigned; will be - // changed if minus sign, decimal point or exponent is read - token_type number_type = token_type::value_unsigned; + @param[in] lhs first JSON value to consider + @param[in] rhs second JSON value to consider + @return whether the values @a lhs and @a rhs are equal - // state (init): we just found out we need to scan a number - switch (current) - { - case '-': - { - add(current); - goto scan_number_minus; - } + @exceptionsafety No-throw guarantee: this function never throws exceptions. - case '0': - { - add(current); - goto scan_number_zero; - } + @complexity Linear. - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_any1; - } + @liveexample{The example demonstrates comparing several JSON + types.,operator__equal} - default: - { - // all other characters are rejected outside scan_number() - assert(false); // LCOV_EXCL_LINE - } - } + @since version 1.0.0 + */ + friend bool operator==(const_reference lhs, const_reference rhs) noexcept + { + const auto lhs_type = lhs.type(); + const auto rhs_type = rhs.type(); -scan_number_minus: - // state: we just parsed a leading minus sign - number_type = token_type::value_integer; - switch (get()) + if (lhs_type == rhs_type) + { + switch (lhs_type) { - case '0': - { - add(current); - goto scan_number_zero; - } + case value_t::array: + return (*lhs.m_value.array == *rhs.m_value.array); + + case value_t::object: + return (*lhs.m_value.object == *rhs.m_value.object); + + case value_t::null: + return true; + + case value_t::string: + return (*lhs.m_value.string == *rhs.m_value.string); - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_any1; - } + case value_t::boolean: + return (lhs.m_value.boolean == rhs.m_value.boolean); - default: - { - error_message = "invalid number; expected digit after '-'"; - return token_type::parse_error; - } - } + case value_t::number_integer: + return (lhs.m_value.number_integer == rhs.m_value.number_integer); -scan_number_zero: - // state: we just parse a zero (maybe with a leading minus sign) - switch (get()) - { - case '.': - { - add(decimal_point_char); - goto scan_number_decimal1; - } + case value_t::number_unsigned: + return (lhs.m_value.number_unsigned == rhs.m_value.number_unsigned); - case 'e': - case 'E': - { - add(current); - goto scan_number_exponent; - } + case value_t::number_float: + return (lhs.m_value.number_float == rhs.m_value.number_float); default: - { - goto scan_number_done; - } + return false; } + } + else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float) + { + return (static_cast(lhs.m_value.number_integer) == rhs.m_value.number_float); + } + else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer) + { + return (lhs.m_value.number_float == static_cast(rhs.m_value.number_integer)); + } + else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_float) + { + return (static_cast(lhs.m_value.number_unsigned) == rhs.m_value.number_float); + } + else if (lhs_type == value_t::number_float and rhs_type == value_t::number_unsigned) + { + return (lhs.m_value.number_float == static_cast(rhs.m_value.number_unsigned)); + } + else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_integer) + { + return (static_cast(lhs.m_value.number_unsigned) == rhs.m_value.number_integer); + } + else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_unsigned) + { + return (lhs.m_value.number_integer == static_cast(rhs.m_value.number_unsigned)); + } -scan_number_any1: - // state: we just parsed a number 0-9 (maybe with a leading minus sign) - switch (get()) - { - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_any1; - } + return false; + } - case '.': - { - add(decimal_point_char); - goto scan_number_decimal1; - } + /*! + @brief comparison: equal + @copydoc operator==(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator==(const_reference lhs, const ScalarType rhs) noexcept + { + return (lhs == basic_json(rhs)); + } - case 'e': - case 'E': - { - add(current); - goto scan_number_exponent; - } + /*! + @brief comparison: equal + @copydoc operator==(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator==(const ScalarType lhs, const_reference rhs) noexcept + { + return (basic_json(lhs) == rhs); + } - default: - { - goto scan_number_done; - } - } + /*! + @brief comparison: not equal -scan_number_decimal1: - // state: we just parsed a decimal point - number_type = token_type::value_float; - switch (get()) - { - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_decimal2; - } + Compares two JSON values for inequality by calculating `not (lhs == rhs)`. - default: - { - error_message = "invalid number; expected digit after '.'"; - return token_type::parse_error; - } - } + @param[in] lhs first JSON value to consider + @param[in] rhs second JSON value to consider + @return whether the values @a lhs and @a rhs are not equal -scan_number_decimal2: - // we just parsed at least one number after a decimal point - switch (get()) - { - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_decimal2; - } + @complexity Linear. - case 'e': - case 'E': - { - add(current); - goto scan_number_exponent; - } + @exceptionsafety No-throw guarantee: this function never throws exceptions. - default: - { - goto scan_number_done; - } - } + @liveexample{The example demonstrates comparing several JSON + types.,operator__notequal} -scan_number_exponent: - // we just parsed an exponent - number_type = token_type::value_float; - switch (get()) - { - case '+': - case '-': - { - add(current); - goto scan_number_sign; - } + @since version 1.0.0 + */ + friend bool operator!=(const_reference lhs, const_reference rhs) noexcept + { + return not (lhs == rhs); + } - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_any2; - } + /*! + @brief comparison: not equal + @copydoc operator!=(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator!=(const_reference lhs, const ScalarType rhs) noexcept + { + return (lhs != basic_json(rhs)); + } - default: - { - error_message = "invalid number; expected '+', '-', or digit after exponent"; - return token_type::parse_error; - } - } + /*! + @brief comparison: not equal + @copydoc operator!=(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator!=(const ScalarType lhs, const_reference rhs) noexcept + { + return (basic_json(lhs) != rhs); + } -scan_number_sign: - // we just parsed an exponent sign - switch (get()) - { - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_any2; - } + /*! + @brief comparison: less than - default: - { - error_message = "invalid number; expected digit after exponent sign"; - return token_type::parse_error; - } - } + Compares whether one JSON value @a lhs is less than another JSON value @a + rhs according to the following rules: + - If @a lhs and @a rhs have the same type, the values are compared using + the default `<` operator. + - Integer and floating-point numbers are automatically converted before + comparison + - In case @a lhs and @a rhs have different types, the values are ignored + and the order of the types is considered, see + @ref operator<(const value_t, const value_t). -scan_number_any2: - // we just parsed a number after the exponent or exponent sign - switch (get()) - { - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_any2; - } + @param[in] lhs first JSON value to consider + @param[in] rhs second JSON value to consider + @return whether @a lhs is less than @a rhs - default: - { - goto scan_number_done; - } - } + @complexity Linear. -scan_number_done: - // unget the character after the number (we only read it to know - // that we are done scanning a number) - --chars_read; - next_unget = true; + @exceptionsafety No-throw guarantee: this function never throws exceptions. + + @liveexample{The example demonstrates comparing several JSON + types.,operator__less} - // terminate token - add('\0'); - --yylen; + @since version 1.0.0 + */ + friend bool operator<(const_reference lhs, const_reference rhs) noexcept + { + const auto lhs_type = lhs.type(); + const auto rhs_type = rhs.type(); - // try to parse integers first and fall back to floats - if (number_type == token_type::value_unsigned) + if (lhs_type == rhs_type) + { + switch (lhs_type) { - char* endptr = nullptr; - errno = 0; - const auto x = std::strtoull(yytext.data(), &endptr, 10); + case value_t::array: + return (*lhs.m_value.array) < (*rhs.m_value.array); - // we checked the number format before - assert(endptr == yytext.data() + yylen); + case value_t::object: + return *lhs.m_value.object < *rhs.m_value.object; - if (errno == 0) - { - value_unsigned = static_cast(x); - if (value_unsigned == x) - { - return token_type::value_unsigned; - } - } - } - else if (number_type == token_type::value_integer) - { - char* endptr = nullptr; - errno = 0; - const auto x = std::strtoll(yytext.data(), &endptr, 10); + case value_t::null: + return false; - // we checked the number format before - assert(endptr == yytext.data() + yylen); + case value_t::string: + return *lhs.m_value.string < *rhs.m_value.string; - if (errno == 0) - { - value_integer = static_cast(x); - if (value_integer == x) - { - return token_type::value_integer; - } - } - } + case value_t::boolean: + return lhs.m_value.boolean < rhs.m_value.boolean; - // this code is reached if we parse a floating-point number or if - // an integer conversion above failed - strtof(value_float, yytext.data(), nullptr); - return token_type::value_float; - } + case value_t::number_integer: + return lhs.m_value.number_integer < rhs.m_value.number_integer; - /*! - @param[in] literal_text the literal text to expect - @param[in] length the length of the passed literal text - @param[in] return_type the token type to return on success - */ - token_type scan_literal(const char* literal_text, const size_t length, - token_type return_type) - { - assert(current == literal_text[0]); - for (size_t i = 1; i < length; ++i) - { - if (JSON_UNLIKELY(get() != literal_text[i])) - { - error_message = "invalid literal"; - return token_type::parse_error; - } - } - return return_type; - } + case value_t::number_unsigned: + return lhs.m_value.number_unsigned < rhs.m_value.number_unsigned; - ///////////////////// - // input management - ///////////////////// + case value_t::number_float: + return lhs.m_value.number_float < rhs.m_value.number_float; - /// reset yytext - void reset() noexcept - { - yylen = 0; - start_pos = chars_read - 1; + default: + return false; + } } - - /// get a character from the input - int get() + else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float) { - ++chars_read; - return next_unget - ? (next_unget = false, current) - : (current = ia->get_character()); + return static_cast(lhs.m_value.number_integer) < rhs.m_value.number_float; } - - /// add a character to yytext - void add(int c) + else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer) { - // resize yytext if necessary; this condition is deemed unlikely, - // because we start with a 1024-byte buffer - if (JSON_UNLIKELY((yylen + 1 > yytext.capacity()))) - { - yytext.resize(2 * yytext.capacity(), '\0'); - } - assert(yylen < yytext.size()); - yytext[yylen++] = static_cast(c); + return lhs.m_value.number_float < static_cast(rhs.m_value.number_integer); } - - public: - ///////////////////// - // value getters - ///////////////////// - - /// return integer value - constexpr number_integer_t get_number_integer() const noexcept + else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_float) { - return value_integer; + return static_cast(lhs.m_value.number_unsigned) < rhs.m_value.number_float; } - - /// return unsigned integer value - constexpr number_unsigned_t get_number_unsigned() const noexcept + else if (lhs_type == value_t::number_float and rhs_type == value_t::number_unsigned) { - return value_unsigned; + return lhs.m_value.number_float < static_cast(rhs.m_value.number_unsigned); } - - /// return floating-point value - constexpr number_float_t get_number_float() const noexcept + else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_unsigned) { - return value_float; + return lhs.m_value.number_integer < static_cast(rhs.m_value.number_unsigned); } - - /// return string value - const std::string get_string() + else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_integer) { - // yytext cannot be returned as char*, because it may contain a - // null byte (parsed as "\u0000") - return std::string(yytext.data(), yylen); + return static_cast(lhs.m_value.number_unsigned) < rhs.m_value.number_integer; } - ///////////////////// - // diagnostics - ///////////////////// + // We only reach this line if we cannot compare values. In that case, + // we compare types. Note we have to call the operator explicitly, + // because MSVC has problems otherwise. + return operator<(lhs_type, rhs_type); + } - /// return position of last read token - constexpr size_t get_position() const noexcept - { - return chars_read; - } + /*! + @brief comparison: less than + @copydoc operator<(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator<(const_reference lhs, const ScalarType rhs) noexcept + { + return (lhs < basic_json(rhs)); + } - /// return the last read token (for errors only) - std::string get_token_string() const - { - // get the raw byte sequence of the last token - std::string s = ia->read(start_pos, chars_read - start_pos); + /*! + @brief comparison: less than + @copydoc operator<(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator<(const ScalarType lhs, const_reference rhs) noexcept + { + return (basic_json(lhs) < rhs); + } - // escape control characters - std::string result; - for (auto c : s) - { - if (c == '\0' or c == std::char_traits::eof()) - { - // ignore EOF - continue; - } - else if ('\x00' <= c and c <= '\x1f') - { - // escape control characters - std::stringstream ss; - ss << "(c) << ">"; - result += ss.str(); - } - else - { - // add character as is - result.append(1, c); - } - } + /*! + @brief comparison: less than or equal - return result; - } + Compares whether one JSON value @a lhs is less than or equal to another + JSON value by calculating `not (rhs < lhs)`. - /// return syntax error message - constexpr const char* get_error_message() const noexcept - { - return error_message; - } + @param[in] lhs first JSON value to consider + @param[in] rhs second JSON value to consider + @return whether @a lhs is less than or equal to @a rhs - ///////////////////// - // actual scanner - ///////////////////// + @complexity Linear. - token_type scan() - { - // read next character and ignore whitespace - do - { - get(); - } - while (current == ' ' or current == '\t' or current == '\n' or current == '\r'); - - switch (current) - { - // structural characters - case '[': - return token_type::begin_array; - case ']': - return token_type::end_array; - case '{': - return token_type::begin_object; - case '}': - return token_type::end_object; - case ':': - return token_type::name_separator; - case ',': - return token_type::value_separator; - - // literals - case 't': - return scan_literal("true", 4, token_type::literal_true); - case 'f': - return scan_literal("false", 5, token_type::literal_false); - case 'n': - return scan_literal("null", 4, token_type::literal_null); - - // string - case '\"': - return scan_string(); - - // number - case '-': - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - return scan_number(); - - // end of input (the null byte is needed when parsing from - // string literals) - case '\0': - case std::char_traits::eof(): - return token_type::end_of_input; + @exceptionsafety No-throw guarantee: this function never throws exceptions. - // error - default: - error_message = "invalid literal"; - return token_type::parse_error; - } - } + @liveexample{The example demonstrates comparing several JSON + types.,operator__greater} - private: - /// input adapter - input_adapter_t ia = nullptr; + @since version 1.0.0 + */ + friend bool operator<=(const_reference lhs, const_reference rhs) noexcept + { + return not (rhs < lhs); + } - /// the current character - int current = std::char_traits::eof(); + /*! + @brief comparison: less than or equal + @copydoc operator<=(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator<=(const_reference lhs, const ScalarType rhs) noexcept + { + return (lhs <= basic_json(rhs)); + } - /// whether get() should return the last character again - bool next_unget = false; + /*! + @brief comparison: less than or equal + @copydoc operator<=(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator<=(const ScalarType lhs, const_reference rhs) noexcept + { + return (basic_json(lhs) <= rhs); + } - /// the number of characters read - size_t chars_read = 0; - /// the start position of the current token - size_t start_pos = 0; + /*! + @brief comparison: greater than - /// buffer for variable-length tokens (numbers, strings) - std::vector yytext = std::vector(1024, '\0'); - /// current index in yytext - size_t yylen = 0; + Compares whether one JSON value @a lhs is greater than another + JSON value by calculating `not (lhs <= rhs)`. - /// a description of occurred lexer errors - const char* error_message = ""; + @param[in] lhs first JSON value to consider + @param[in] rhs second JSON value to consider + @return whether @a lhs is greater than to @a rhs - // number values - number_integer_t value_integer = 0; - number_unsigned_t value_unsigned = 0; - number_float_t value_float = 0; + @complexity Linear. - /// the decimal point - const char decimal_point_char = '.'; - }; + @exceptionsafety No-throw guarantee: this function never throws exceptions. - /*! - @brief syntax analysis + @liveexample{The example demonstrates comparing several JSON + types.,operator__lessequal} - This class implements a recursive decent parser. + @since version 1.0.0 */ - class parser + friend bool operator>(const_reference lhs, const_reference rhs) noexcept { - public: - /// a parser reading from an input adapter - explicit parser(input_adapter_t adapter, - const parser_callback_t cb = nullptr) - : callback(cb), m_lexer(adapter) - {} - - /*! - @brief public parser interface - - @param[in] strict whether to expect the last token to be EOF - @return parsed JSON value + return not (lhs <= rhs); + } - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails - */ - basic_json parse(const bool strict = true) - { - // read first token - get_token(); + /*! + @brief comparison: greater than + @copydoc operator>(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator>(const_reference lhs, const ScalarType rhs) noexcept + { + return (lhs > basic_json(rhs)); + } - basic_json result = parse_internal(true); - result.assert_invariant(); + /*! + @brief comparison: greater than + @copydoc operator>(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator>(const ScalarType lhs, const_reference rhs) noexcept + { + return (basic_json(lhs) > rhs); + } - if (strict) - { - get_token(); - expect(lexer::token_type::end_of_input); - } + /*! + @brief comparison: greater than or equal - // return parser result and replace it with null in case the - // top-level value was discarded by the callback function - return result.is_discarded() ? basic_json() : std::move(result); - } + Compares whether one JSON value @a lhs is greater than or equal to another + JSON value by calculating `not (lhs < rhs)`. - /*! - @brief public accept interface + @param[in] lhs first JSON value to consider + @param[in] rhs second JSON value to consider + @return whether @a lhs is greater than or equal to @a rhs - @param[in] strict whether to expect the last token to be EOF - @return whether the input is a proper JSON text - */ - bool accept(const bool strict = true) - { - // read first token - get_token(); + @complexity Linear. - if (not accept_internal()) - { - return false; - } + @exceptionsafety No-throw guarantee: this function never throws exceptions. - if (strict and get_token() != lexer::token_type::end_of_input) - { - return false; - } + @liveexample{The example demonstrates comparing several JSON + types.,operator__greaterequal} - return true; - } + @since version 1.0.0 + */ + friend bool operator>=(const_reference lhs, const_reference rhs) noexcept + { + return not (lhs < rhs); + } - private: - /*! - @brief the actual parser - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails - */ - basic_json parse_internal(bool keep) - { - auto result = basic_json(value_t::discarded); + /*! + @brief comparison: greater than or equal + @copydoc operator>=(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator>=(const_reference lhs, const ScalarType rhs) noexcept + { + return (lhs >= basic_json(rhs)); + } - switch (last_token) - { - case lexer::token_type::begin_object: - { - if (keep and (not callback - or ((keep = callback(depth++, parse_event_t::object_start, result)) != 0))) - { - // explicitly set result to object to cope with {} - result.m_type = value_t::object; - result.m_value = value_t::object; - } + /*! + @brief comparison: greater than or equal + @copydoc operator>=(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator>=(const ScalarType lhs, const_reference rhs) noexcept + { + return (basic_json(lhs) >= rhs); + } - // read next token - get_token(); + /// @} - // closing } -> we are done - if (last_token == lexer::token_type::end_object) - { - if (keep and callback and not callback(--depth, parse_event_t::object_end, result)) - { - result = basic_json(value_t::discarded); - } - return result; - } + /////////////////// + // serialization // + /////////////////// - // parse values - while (true) - { - // store key - expect(lexer::token_type::value_string); - const auto key = m_lexer.get_string(); + /// @name serialization + /// @{ - bool keep_tag = false; - if (keep) - { - if (callback) - { - basic_json k(key); - keep_tag = callback(depth, parse_event_t::key, k); - } - else - { - keep_tag = true; - } - } + /*! + @brief serialize to stream - // parse separator (:) - get_token(); - expect(lexer::token_type::name_separator); + Serialize the given JSON value @a j to the output stream @a o. The JSON + value will be serialized using the @ref dump member function. - // parse and add value - get_token(); - auto value = parse_internal(keep); - if (keep and keep_tag and not value.is_discarded()) - { - result[key] = std::move(value); - } + - The indentation of the output can be controlled with the member variable + `width` of the output stream @a o. For instance, using the manipulator + `std::setw(4)` on @a o sets the indentation level to `4` and the + serialization result is the same as calling `dump(4)`. - // comma -> next value - get_token(); - if (last_token == lexer::token_type::value_separator) - { - get_token(); - continue; - } + - The indentation character can be controlled with the member variable + `fill` of the output stream @a o. For instance, the manipulator + `std::setfill('\\t')` sets indentation to use a tab character rather than + the default space character. - // closing } - expect(lexer::token_type::end_object); - break; - } + @param[in,out] o stream to serialize to + @param[in] j JSON value to serialize - if (keep and callback and not callback(--depth, parse_event_t::object_end, result)) - { - result = basic_json(value_t::discarded); - } + @return the stream @a o - return result; - } + @throw type_error.316 if a string stored inside the JSON value is not + UTF-8 encoded - case lexer::token_type::begin_array: - { - if (keep and (not callback - or ((keep = callback(depth++, parse_event_t::array_start, result)) != 0))) - { - // explicitly set result to object to cope with [] - result.m_type = value_t::array; - result.m_value = value_t::array; - } + @complexity Linear. - // read next token - get_token(); + @liveexample{The example below shows the serialization with different + parameters to `width` to adjust the indentation level.,operator_serialize} - // closing ] -> we are done - if (last_token == lexer::token_type::end_array) - { - if (callback and not callback(--depth, parse_event_t::array_end, result)) - { - result = basic_json(value_t::discarded); - } - return result; - } + @since version 1.0.0; indentation character added in version 3.0.0 + */ + friend std::ostream& operator<<(std::ostream& o, const basic_json& j) + { + // read width member and use it as indentation parameter if nonzero + const bool pretty_print = (o.width() > 0); + const auto indentation = (pretty_print ? o.width() : 0); - // parse values - while (true) - { - // parse value - auto value = parse_internal(keep); - if (keep and not value.is_discarded()) - { - result.push_back(std::move(value)); - } + // reset width to 0 for subsequent calls to this stream + o.width(0); - // comma -> next value - get_token(); - if (last_token == lexer::token_type::value_separator) - { - get_token(); - continue; - } + // do the actual serialization + serializer s(detail::output_adapter(o), o.fill()); + s.dump(j, pretty_print, false, static_cast(indentation)); + return o; + } - // closing ] - expect(lexer::token_type::end_array); - break; - } + /*! + @brief serialize to stream + @deprecated This stream operator is deprecated and will be removed in + future 4.0.0 of the library. Please use + @ref operator<<(std::ostream&, const basic_json&) + instead; that is, replace calls like `j >> o;` with `o << j;`. + @since version 1.0.0; deprecated since version 3.0.0 + */ + JSON_DEPRECATED + friend std::ostream& operator>>(const basic_json& j, std::ostream& o) + { + return o << j; + } - if (keep and callback and not callback(--depth, parse_event_t::array_end, result)) - { - result = basic_json(value_t::discarded); - } + /// @} - return result; - } - case lexer::token_type::literal_null: - { - result.m_type = value_t::null; - break; - } + ///////////////////// + // deserialization // + ///////////////////// - case lexer::token_type::value_string: - { - result = basic_json(m_lexer.get_string()); - break; - } + /// @name deserialization + /// @{ - case lexer::token_type::literal_true: - { - result.m_type = value_t::boolean; - result.m_value = true; - break; - } + /*! + @brief deserialize from a compatible input + + This function reads from a compatible input. Examples are: + - an array of 1-byte values + - strings with character/literal type with size of 1 byte + - input streams + - container with contiguous storage of 1-byte values. Compatible container + types include `std::vector`, `std::string`, `std::array`, + `std::valarray`, and `std::initializer_list`. Furthermore, C-style + arrays can be used with `std::begin()`/`std::end()`. User-defined + containers can be used as long as they implement random-access iterators + and a contiguous storage. - case lexer::token_type::literal_false: - { - result.m_type = value_t::boolean; - result.m_value = false; - break; - } + @pre Each element of the container has a size of 1 byte. Violating this + precondition yields undefined behavior. **This precondition is enforced + with a static assertion.** - case lexer::token_type::value_unsigned: - { - result.m_type = value_t::number_unsigned; - result.m_value = m_lexer.get_number_unsigned(); - break; - } + @pre The container storage is contiguous. Violating this precondition + yields undefined behavior. **This precondition is enforced with an + assertion.** + @pre Each element of the container has a size of 1 byte. Violating this + precondition yields undefined behavior. **This precondition is enforced + with a static assertion.** - case lexer::token_type::value_integer: - { - result.m_type = value_t::number_integer; - result.m_value = m_lexer.get_number_integer(); - break; - } + @warning There is no way to enforce all preconditions at compile-time. If + the function is called with a noncompliant container and with + assertions switched off, the behavior is undefined and will most + likely yield segmentation violation. - case lexer::token_type::value_float: - { - result.m_type = value_t::number_float; - result.m_value = m_lexer.get_number_float(); + @param[in] i input to read from + @param[in] cb a parser callback function of type @ref parser_callback_t + which is used to control the deserialization by filtering unwanted values + (optional) - // throw in case of infinity or NAN - if (JSON_UNLIKELY(not std::isfinite(result.m_value.number_float))) - { - JSON_THROW(out_of_range::create(406, "number overflow parsing '" + m_lexer.get_token_string() + "'")); - } + @return result of the deserialization - break; - } + @throw parse_error.101 if a parse error occurs; example: `""unexpected end + of input; expected string literal""` + @throw parse_error.102 if to_unicode fails or surrogate error + @throw parse_error.103 if to_unicode fails - case lexer::token_type::parse_error: - { - // using "uninitialized" to avoid "expected" message - expect(lexer::token_type::uninitialized); - } + @complexity Linear in the length of the input. The parser is a predictive + LL(1) parser. The complexity can be higher if the parser callback function + @a cb has a super-linear complexity. - default: - { - // the last token was unexpected; we expected a value - expect(lexer::token_type::literal_or_value); - } - } + @note A UTF-8 byte order mark is silently ignored. - if (keep and callback and not callback(depth, parse_event_t::value, result)) - { - result = basic_json(value_t::discarded); - } - return result; - } + @liveexample{The example below demonstrates the `parse()` function reading + from an array.,parse__array__parser_callback_t} - /*! - @brief the acutal acceptor + @liveexample{The example below demonstrates the `parse()` function with + and without callback function.,parse__string__parser_callback_t} - @invariant 1. The last token is not yet processed. Therefore, the - caller of this function must make sure a token has - been read. - 2. When this function returns, the last token is processed. - That is, the last read character was already considered. + @liveexample{The example below demonstrates the `parse()` function with + and without callback function.,parse__istream__parser_callback_t} - This invariant makes sure that no token needs to be "unput". - */ - bool accept_internal() - { - switch (last_token) - { - case lexer::token_type::begin_object: - { - // read next token - get_token(); + @liveexample{The example below demonstrates the `parse()` function reading + from a contiguous container.,parse__contiguouscontainer__parser_callback_t} - // closing } -> we are done - if (last_token == lexer::token_type::end_object) - { - return true; - } + @since version 2.0.3 (contiguous containers) + */ + static basic_json parse(detail::input_adapter i, + const parser_callback_t cb = nullptr, + const bool allow_exceptions = true) + { + basic_json result; + parser(i, cb, allow_exceptions).parse(true, result); + return result; + } - // parse values - while (true) - { - // parse key - if (last_token != lexer::token_type::value_string) - { - return false; - } + /*! + @copydoc basic_json parse(detail::input_adapter, const parser_callback_t) + */ + static basic_json parse(detail::input_adapter& i, + const parser_callback_t cb = nullptr, + const bool allow_exceptions = true) + { + basic_json result; + parser(i, cb, allow_exceptions).parse(true, result); + return result; + } - // parse separator (:) - get_token(); - if (last_token != lexer::token_type::name_separator) - { - return false; - } + static bool accept(detail::input_adapter i) + { + return parser(i).accept(true); + } - // parse value - get_token(); - if (not accept_internal()) - { - return false; - } + static bool accept(detail::input_adapter& i) + { + return parser(i).accept(true); + } - // comma -> next value - get_token(); - if (last_token == lexer::token_type::value_separator) - { - get_token(); - continue; - } + /*! + @brief deserialize from an iterator range with contiguous storage - // closing } - if (last_token != lexer::token_type::end_object) - { - return false; - } + This function reads from an iterator range of a container with contiguous + storage of 1-byte values. Compatible container types include + `std::vector`, `std::string`, `std::array`, `std::valarray`, and + `std::initializer_list`. Furthermore, C-style arrays can be used with + `std::begin()`/`std::end()`. User-defined containers can be used as long + as they implement random-access iterators and a contiguous storage. - return true; - } - } + @pre The iterator range is contiguous. Violating this precondition yields + undefined behavior. **This precondition is enforced with an assertion.** + @pre Each element in the range has a size of 1 byte. Violating this + precondition yields undefined behavior. **This precondition is enforced + with a static assertion.** - case lexer::token_type::begin_array: - { - // read next token - get_token(); + @warning There is no way to enforce all preconditions at compile-time. If + the function is called with noncompliant iterators and with + assertions switched off, the behavior is undefined and will most + likely yield segmentation violation. - // closing ] -> we are done - if (last_token == lexer::token_type::end_array) - { - return true; - } + @tparam IteratorType iterator of container with contiguous storage + @param[in] first begin of the range to parse (included) + @param[in] last end of the range to parse (excluded) + @param[in] cb a parser callback function of type @ref parser_callback_t + which is used to control the deserialization by filtering unwanted values + (optional) + @param[in] allow_exceptions whether to throw exceptions in case of a + parse error (optional, true by default) - // parse values - while (true) - { - // parse value - if (not accept_internal()) - { - return false; - } + @return result of the deserialization - // comma -> next value - get_token(); - if (last_token == lexer::token_type::value_separator) - { - get_token(); - continue; - } + @throw parse_error.101 in case of an unexpected token + @throw parse_error.102 if to_unicode fails or surrogate error + @throw parse_error.103 if to_unicode fails - // closing ] - if (last_token != lexer::token_type::end_array) - { - return false; - } + @complexity Linear in the length of the input. The parser is a predictive + LL(1) parser. The complexity can be higher if the parser callback function + @a cb has a super-linear complexity. - return true; - } - } + @note A UTF-8 byte order mark is silently ignored. - case lexer::token_type::literal_false: - case lexer::token_type::literal_null: - case lexer::token_type::literal_true: - case lexer::token_type::value_float: - case lexer::token_type::value_integer: - case lexer::token_type::value_string: - case lexer::token_type::value_unsigned: - { - return true; - } + @liveexample{The example below demonstrates the `parse()` function reading + from an iterator range.,parse__iteratortype__parser_callback_t} - default: - { - // the last token was unexpected - return false; - } - } - } + @since version 2.0.3 + */ + template::iterator_category>::value, int>::type = 0> + static basic_json parse(IteratorType first, IteratorType last, + const parser_callback_t cb = nullptr, + const bool allow_exceptions = true) + { + basic_json result; + parser(detail::input_adapter(first, last), cb, allow_exceptions).parse(true, result); + return result; + } - /// get next token from lexer - typename lexer::token_type get_token() - { - return (last_token = m_lexer.scan()); - } + template::iterator_category>::value, int>::type = 0> + static bool accept(IteratorType first, IteratorType last) + { + return parser(detail::input_adapter(first, last)).accept(true); + } - /*! - @throw parse_error.101 if expected token did not occur - */ - void expect(typename lexer::token_type t) - { - if (JSON_UNLIKELY(t != last_token)) - { - errored = true; - expected = t; - throw_exception(); - } - } + /*! + @brief deserialize from stream + @deprecated This stream operator is deprecated and will be removed in + version 4.0.0 of the library. Please use + @ref operator>>(std::istream&, basic_json&) + instead; that is, replace calls like `j << i;` with `i >> j;`. + @since version 1.0.0; deprecated since version 3.0.0 + */ + JSON_DEPRECATED + friend std::istream& operator<<(basic_json& j, std::istream& i) + { + return operator>>(i, j); + } - [[noreturn]] void throw_exception() const - { - std::string error_msg = "syntax error - "; - if (last_token == lexer::token_type::parse_error) - { - error_msg += std::string(m_lexer.get_error_message()) + "; last read: '" + m_lexer.get_token_string() + "'"; - } - else - { - error_msg += "unexpected " + std::string(lexer::token_type_name(last_token)); - } + /*! + @brief deserialize from stream - if (expected != lexer::token_type::uninitialized) - { - error_msg += "; expected " + std::string(lexer::token_type_name(expected)); - } + Deserializes an input stream to a JSON value. - JSON_THROW(parse_error::create(101, m_lexer.get_position(), error_msg)); - } + @param[in,out] i input stream to read a serialized JSON value from + @param[in,out] j JSON value to write the deserialized input to - private: - /// current level of recursion - int depth = 0; - /// callback function - const parser_callback_t callback = nullptr; - /// the type of the last read token - typename lexer::token_type last_token = lexer::token_type::uninitialized; - /// the lexer - lexer m_lexer; - /// whether a syntax error occurred - bool errored = false; - /// possible reason for the syntax error - typename lexer::token_type expected = lexer::token_type::uninitialized; - }; + @throw parse_error.101 in case of an unexpected token + @throw parse_error.102 if to_unicode fails or surrogate error + @throw parse_error.103 if to_unicode fails - public: - /*! - @brief JSON Pointer + @complexity Linear in the length of the input. The parser is a predictive + LL(1) parser. + + @note A UTF-8 byte order mark is silently ignored. - A JSON pointer defines a string syntax for identifying a specific value - within a JSON document. It can be used with functions `at` and - `operator[]`. Furthermore, JSON pointers are the base for JSON patches. + @liveexample{The example below shows how a JSON value is constructed by + reading a serialization from a stream.,operator_deserialize} - @sa [RFC 6901](https://tools.ietf.org/html/rfc6901) + @sa parse(std::istream&, const parser_callback_t) for a variant with a + parser callback function to filter values while parsing - @since version 2.0.0 + @since version 1.0.0 */ - class json_pointer + friend std::istream& operator>>(std::istream& i, basic_json& j) { - /// allow basic_json to access private members - friend class basic_json; - - public: - /*! - @brief create JSON pointer - - Create a JSON pointer according to the syntax described in - [Section 3 of RFC6901](https://tools.ietf.org/html/rfc6901#section-3). + parser(detail::input_adapter(i)).parse(false, j); + return i; + } - @param[in] s string representing the JSON pointer; if omitted, the - empty string is assumed which references the whole JSON - value + /// @} - @throw parse_error.107 if the given JSON pointer @a s is nonempty and - does not begin with a slash (`/`); see example below + /////////////////////////// + // convenience functions // + /////////////////////////// - @throw parse_error.108 if a tilde (`~`) in the given JSON pointer @a s - is not followed by `0` (representing `~`) or `1` (representing `/`); - see example below + /*! + @brief return the type as string - @liveexample{The example shows the construction several valid JSON - pointers as well as the exceptional behavior.,json_pointer} + Returns the type name as string to be used in error messages - usually to + indicate that a function was called on a wrong JSON type. - @since version 2.0.0 - */ - explicit json_pointer(const std::string& s = "") - : reference_tokens(split(s)) - {} + @return a string representation of a the @a m_type member: + Value type | return value + ----------- | ------------- + null | `"null"` + boolean | `"boolean"` + string | `"string"` + number | `"number"` (for all number types) + object | `"object"` + array | `"array"` + discarded | `"discarded"` - /*! - @brief return a string representation of the JSON pointer + @exceptionsafety No-throw guarantee: this function never throws exceptions. - @invariant For each JSON pointer `ptr`, it holds: - @code {.cpp} - ptr == json_pointer(ptr.to_string()); - @endcode + @complexity Constant. - @return a string representation of the JSON pointer + @liveexample{The following code exemplifies `type_name()` for all JSON + types.,type_name} - @liveexample{The example shows the result of `to_string`., - json_pointer__to_string} + @sa @ref type() -- return the type of the JSON value + @sa @ref operator value_t() -- return the type of the JSON value (implicit) - @since version 2.0.0 - */ - std::string to_string() const noexcept + @since version 1.0.0, public since 2.1.0, `const char*` and `noexcept` + since 3.0.0 + */ + const char* type_name() const noexcept + { { - return std::accumulate(reference_tokens.begin(), - reference_tokens.end(), std::string{}, - [](const std::string & a, const std::string & b) + switch (m_type) { - return a + "/" + escape(b); - }); + case value_t::null: + return "null"; + case value_t::object: + return "object"; + case value_t::array: + return "array"; + case value_t::string: + return "string"; + case value_t::boolean: + return "boolean"; + case value_t::discarded: + return "discarded"; + default: + return "number"; + } } + } - /// @copydoc to_string() - operator std::string() const - { - return to_string(); - } - private: - /*! - @brief remove and return last reference pointer - @throw out_of_range.405 if JSON pointer has no parent - */ - std::string pop_back() - { - if (is_root()) - { - JSON_THROW(out_of_range::create(405, "JSON pointer has no parent")); - } + private: + ////////////////////// + // member variables // + ////////////////////// - auto last = reference_tokens.back(); - reference_tokens.pop_back(); - return last; - } + /// the type of the current element + value_t m_type = value_t::null; - /// return whether pointer points to the root document - bool is_root() const - { - return reference_tokens.empty(); - } + /// the value of the current element + json_value m_value = {}; - json_pointer top() const - { - if (is_root()) - { - JSON_THROW(out_of_range::create(405, "JSON pointer has no parent")); - } + ////////////////////////////////////////// + // binary serialization/deserialization // + ////////////////////////////////////////// - json_pointer result = *this; - result.reference_tokens = {reference_tokens[0]}; - return result; - } + /// @name binary serialization/deserialization support + /// @{ - /*! - @brief create and return a reference to the pointed to value + public: + /*! + @brief create a CBOR serialization of a given JSON value - @complexity Linear in the number of reference tokens. + Serializes a given JSON value @a j to a byte vector using the CBOR (Concise + Binary Object Representation) serialization format. CBOR is a binary + serialization format which aims to be more compact than JSON itself, yet + more efficient to parse. - @throw parse_error.109 if array index is not a number - @throw type_error.313 if value cannot be unflattened - */ - reference get_and_create(reference j) const - { - pointer result = &j; + The library uses the following mapping from JSON values types to + CBOR types according to the CBOR specification (RFC 7049): - // in case no reference tokens exist, return a reference to the - // JSON value j which will be overwritten by a primitive value - for (const auto& reference_token : reference_tokens) - { - switch (result->m_type) - { - case value_t::null: - { - if (reference_token == "0") - { - // start a new array if reference token is 0 - result = &result->operator[](0); - } - else - { - // start a new object otherwise - result = &result->operator[](reference_token); - } - break; - } + JSON value type | value/range | CBOR type | first byte + --------------- | ------------------------------------------ | ---------------------------------- | --------------- + null | `null` | Null | 0xF6 + boolean | `true` | True | 0xF5 + boolean | `false` | False | 0xF4 + number_integer | -9223372036854775808..-2147483649 | Negative integer (8 bytes follow) | 0x3B + number_integer | -2147483648..-32769 | Negative integer (4 bytes follow) | 0x3A + number_integer | -32768..-129 | Negative integer (2 bytes follow) | 0x39 + number_integer | -128..-25 | Negative integer (1 byte follow) | 0x38 + number_integer | -24..-1 | Negative integer | 0x20..0x37 + number_integer | 0..23 | Integer | 0x00..0x17 + number_integer | 24..255 | Unsigned integer (1 byte follow) | 0x18 + number_integer | 256..65535 | Unsigned integer (2 bytes follow) | 0x19 + number_integer | 65536..4294967295 | Unsigned integer (4 bytes follow) | 0x1A + number_integer | 4294967296..18446744073709551615 | Unsigned integer (8 bytes follow) | 0x1B + number_unsigned | 0..23 | Integer | 0x00..0x17 + number_unsigned | 24..255 | Unsigned integer (1 byte follow) | 0x18 + number_unsigned | 256..65535 | Unsigned integer (2 bytes follow) | 0x19 + number_unsigned | 65536..4294967295 | Unsigned integer (4 bytes follow) | 0x1A + number_unsigned | 4294967296..18446744073709551615 | Unsigned integer (8 bytes follow) | 0x1B + number_float | *any value* | Double-Precision Float | 0xFB + string | *length*: 0..23 | UTF-8 string | 0x60..0x77 + string | *length*: 23..255 | UTF-8 string (1 byte follow) | 0x78 + string | *length*: 256..65535 | UTF-8 string (2 bytes follow) | 0x79 + string | *length*: 65536..4294967295 | UTF-8 string (4 bytes follow) | 0x7A + string | *length*: 4294967296..18446744073709551615 | UTF-8 string (8 bytes follow) | 0x7B + array | *size*: 0..23 | array | 0x80..0x97 + array | *size*: 23..255 | array (1 byte follow) | 0x98 + array | *size*: 256..65535 | array (2 bytes follow) | 0x99 + array | *size*: 65536..4294967295 | array (4 bytes follow) | 0x9A + array | *size*: 4294967296..18446744073709551615 | array (8 bytes follow) | 0x9B + object | *size*: 0..23 | map | 0xA0..0xB7 + object | *size*: 23..255 | map (1 byte follow) | 0xB8 + object | *size*: 256..65535 | map (2 bytes follow) | 0xB9 + object | *size*: 65536..4294967295 | map (4 bytes follow) | 0xBA + object | *size*: 4294967296..18446744073709551615 | map (8 bytes follow) | 0xBB - case value_t::object: - { - // create an entry in the object - result = &result->operator[](reference_token); - break; - } + @note The mapping is **complete** in the sense that any JSON value type + can be converted to a CBOR value. - case value_t::array: - { - // create an entry in the array - JSON_TRY - { - result = &result->operator[](static_cast(std::stoi(reference_token))); - } - JSON_CATCH (std::invalid_argument&) - { - JSON_THROW(parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); - } - break; - } + @note If NaN or Infinity are stored inside a JSON number, they are + serialized properly. This behavior differs from the @ref dump() + function which serializes NaN or Infinity to `null`. - /* - The following code is only reached if there exists a - reference token _and_ the current value is primitive. In - this case, we have an error situation, because primitive - values may only occur as single value; that is, with an - empty list of reference tokens. - */ - default: - { - JSON_THROW(type_error::create(313, "invalid value to unflatten")); - } - } - } + @note The following CBOR types are not used in the conversion: + - byte strings (0x40..0x5F) + - UTF-8 strings terminated by "break" (0x7F) + - arrays terminated by "break" (0x9F) + - maps terminated by "break" (0xBF) + - date/time (0xC0..0xC1) + - bignum (0xC2..0xC3) + - decimal fraction (0xC4) + - bigfloat (0xC5) + - tagged items (0xC6..0xD4, 0xD8..0xDB) + - expected conversions (0xD5..0xD7) + - simple values (0xE0..0xF3, 0xF8) + - undefined (0xF7) + - half and single-precision floats (0xF9-0xFA) + - break (0xFF) - return *result; - } + @param[in] j JSON value to serialize + @return MessagePack serialization as byte vector - /*! - @brief return a reference to the pointed to value + @complexity Linear in the size of the JSON value @a j. - @note This version does not throw if a value is not present, but tries - to create nested values instead. For instance, calling this function - with pointer `"/this/that"` on a null value is equivalent to calling - `operator[]("this").operator[]("that")` on that value, effectively - changing the null value to an object. + @liveexample{The example shows the serialization of a JSON value to a byte + vector in CBOR format.,to_cbor} - @param[in] ptr a JSON value + @sa http://cbor.io + @sa @ref from_cbor(detail::input_adapter, const bool strict) for the + analogous deserialization + @sa @ref to_msgpack(const basic_json&) for the related MessagePack format + @sa @ref to_ubjson(const basic_json&, const bool, const bool) for the + related UBJSON format - @return reference to the JSON value pointed to by the JSON pointer + @since version 2.0.9 + */ + static std::vector to_cbor(const basic_json& j) + { + std::vector result; + to_cbor(j, result); + return result; + } - @complexity Linear in the length of the JSON pointer. + static void to_cbor(const basic_json& j, detail::output_adapter o) + { + binary_writer(o).write_cbor(j); + } - @throw parse_error.106 if an array index begins with '0' - @throw parse_error.109 if an array index was not a number - @throw out_of_range.404 if the JSON pointer can not be resolved - */ - reference get_unchecked(pointer ptr) const - { - for (const auto& reference_token : reference_tokens) - { - // convert null values to arrays or objects before continuing - if (ptr->m_type == value_t::null) - { - // check if reference token is a number - const bool nums = std::all_of(reference_token.begin(), - reference_token.end(), - [](const char x) - { - return (x >= '0' and x <= '9'); - }); + static void to_cbor(const basic_json& j, detail::output_adapter o) + { + binary_writer(o).write_cbor(j); + } - // change value to array for numbers or "-" or to object - // otherwise - if (nums or reference_token == "-") - { - *ptr = value_t::array; - } - else - { - *ptr = value_t::object; - } - } + /*! + @brief create a MessagePack serialization of a given JSON value - switch (ptr->m_type) - { - case value_t::object: - { - // use unchecked object access - ptr = &ptr->operator[](reference_token); - break; - } + Serializes a given JSON value @a j to a byte vector using the MessagePack + serialization format. MessagePack is a binary serialization format which + aims to be more compact than JSON itself, yet more efficient to parse. - case value_t::array: - { - // error condition (cf. RFC 6901, Sect. 4) - if (reference_token.size() > 1 and reference_token[0] == '0') - { - JSON_THROW(parse_error::create(106, 0, "array index '" + reference_token + "' must not begin with '0'")); - } + The library uses the following mapping from JSON values types to + MessagePack types according to the MessagePack specification: - if (reference_token == "-") - { - // explicitly treat "-" as index beyond the end - ptr = &ptr->operator[](ptr->m_value.array->size()); - } - else - { - // convert array index to number; unchecked access - JSON_TRY - { - ptr = &ptr->operator[](static_cast(std::stoi(reference_token))); - } - JSON_CATCH (std::invalid_argument&) - { - JSON_THROW(parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); - } - } - break; - } + JSON value type | value/range | MessagePack type | first byte + --------------- | --------------------------------- | ---------------- | ---------- + null | `null` | nil | 0xC0 + boolean | `true` | true | 0xC3 + boolean | `false` | false | 0xC2 + number_integer | -9223372036854775808..-2147483649 | int64 | 0xD3 + number_integer | -2147483648..-32769 | int32 | 0xD2 + number_integer | -32768..-129 | int16 | 0xD1 + number_integer | -128..-33 | int8 | 0xD0 + number_integer | -32..-1 | negative fixint | 0xE0..0xFF + number_integer | 0..127 | positive fixint | 0x00..0x7F + number_integer | 128..255 | uint 8 | 0xCC + number_integer | 256..65535 | uint 16 | 0xCD + number_integer | 65536..4294967295 | uint 32 | 0xCE + number_integer | 4294967296..18446744073709551615 | uint 64 | 0xCF + number_unsigned | 0..127 | positive fixint | 0x00..0x7F + number_unsigned | 128..255 | uint 8 | 0xCC + number_unsigned | 256..65535 | uint 16 | 0xCD + number_unsigned | 65536..4294967295 | uint 32 | 0xCE + number_unsigned | 4294967296..18446744073709551615 | uint 64 | 0xCF + number_float | *any value* | float 64 | 0xCB + string | *length*: 0..31 | fixstr | 0xA0..0xBF + string | *length*: 32..255 | str 8 | 0xD9 + string | *length*: 256..65535 | str 16 | 0xDA + string | *length*: 65536..4294967295 | str 32 | 0xDB + array | *size*: 0..15 | fixarray | 0x90..0x9F + array | *size*: 16..65535 | array 16 | 0xDC + array | *size*: 65536..4294967295 | array 32 | 0xDD + object | *size*: 0..15 | fix map | 0x80..0x8F + object | *size*: 16..65535 | map 16 | 0xDE + object | *size*: 65536..4294967295 | map 32 | 0xDF - default: - { - JSON_THROW(out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); - } - } - } + @note The mapping is **complete** in the sense that any JSON value type + can be converted to a MessagePack value. - return *ptr; - } + @note The following values can **not** be converted to a MessagePack value: + - strings with more than 4294967295 bytes + - arrays with more than 4294967295 elements + - objects with more than 4294967295 elements - /*! - @throw parse_error.106 if an array index begins with '0' - @throw parse_error.109 if an array index was not a number - @throw out_of_range.402 if the array index '-' is used - @throw out_of_range.404 if the JSON pointer can not be resolved - */ - reference get_checked(pointer ptr) const - { - for (const auto& reference_token : reference_tokens) - { - switch (ptr->m_type) - { - case value_t::object: - { - // note: at performs range check - ptr = &ptr->at(reference_token); - break; - } + @note The following MessagePack types are not used in the conversion: + - bin 8 - bin 32 (0xC4..0xC6) + - ext 8 - ext 32 (0xC7..0xC9) + - float 32 (0xCA) + - fixext 1 - fixext 16 (0xD4..0xD8) - case value_t::array: - { - if (reference_token == "-") - { - // "-" always fails the range check - JSON_THROW(out_of_range::create(402, "array index '-' (" + - std::to_string(ptr->m_value.array->size()) + - ") is out of range")); - } + @note Any MessagePack output created @ref to_msgpack can be successfully + parsed by @ref from_msgpack. - // error condition (cf. RFC 6901, Sect. 4) - if (reference_token.size() > 1 and reference_token[0] == '0') - { - JSON_THROW(parse_error::create(106, 0, "array index '" + reference_token + "' must not begin with '0'")); - } + @note If NaN or Infinity are stored inside a JSON number, they are + serialized properly. This behavior differs from the @ref dump() + function which serializes NaN or Infinity to `null`. - // note: at performs range check - JSON_TRY - { - ptr = &ptr->at(static_cast(std::stoi(reference_token))); - } - JSON_CATCH (std::invalid_argument&) - { - JSON_THROW(parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); - } - break; - } + @param[in] j JSON value to serialize + @return MessagePack serialization as byte vector - default: - { - JSON_THROW(out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); - } - } - } + @complexity Linear in the size of the JSON value @a j. - return *ptr; - } + @liveexample{The example shows the serialization of a JSON value to a byte + vector in MessagePack format.,to_msgpack} + + @sa http://msgpack.org + @sa @ref from_msgpack(const std::vector&, const size_t) for the + analogous deserialization + @sa @ref to_cbor(const basic_json& for the related CBOR format + @sa @ref to_ubjson(const basic_json&, const bool, const bool) for the + related UBJSON format + + @since version 2.0.9 + */ + static std::vector to_msgpack(const basic_json& j) + { + std::vector result; + to_msgpack(j, result); + return result; + } + + static void to_msgpack(const basic_json& j, detail::output_adapter o) + { + binary_writer(o).write_msgpack(j); + } + + static void to_msgpack(const basic_json& j, detail::output_adapter o) + { + binary_writer(o).write_msgpack(j); + } + + /*! + @brief create a UBJSON serialization of a given JSON value - /*! - @brief return a const reference to the pointed to value + Serializes a given JSON value @a j to a byte vector using the UBJSON + (Universal Binary JSON) serialization format. UBJSON aims to be more compact + than JSON itself, yet more efficient to parse. - @param[in] ptr a JSON value + The library uses the following mapping from JSON values types to + UBJSON types according to the UBJSON specification: + + JSON value type | value/range | UBJSON type | marker + --------------- | --------------------------------- | ----------- | ------ + null | `null` | null | `Z` + boolean | `true` | true | `T` + boolean | `false` | false | `F` + number_integer | -9223372036854775808..-2147483649 | int64 | `L` + number_integer | -2147483648..-32769 | int32 | `l` + number_integer | -32768..-129 | int16 | `I` + number_integer | -128..127 | int8 | `i` + number_integer | 128..255 | uint8 | `U` + number_integer | 256..32767 | int16 | `I` + number_integer | 32768..2147483647 | int32 | `l` + number_integer | 2147483648..9223372036854775807 | int64 | `L` + number_unsigned | 0..127 | int8 | `i` + number_unsigned | 128..255 | uint8 | `U` + number_unsigned | 256..32767 | int16 | `I` + number_unsigned | 32768..2147483647 | int32 | `l` + number_unsigned | 2147483648..9223372036854775807 | int64 | `L` + number_float | *any value* | float64 | `D` + string | *with shortest length indicator* | string | `S` + array | *see notes on optimized format* | array | `[` + object | *see notes on optimized format* | map | `{` - @return const reference to the JSON value pointed to by the JSON - pointer + @note The mapping is **complete** in the sense that any JSON value type + can be converted to a UBJSON value. - @throw parse_error.106 if an array index begins with '0' - @throw parse_error.109 if an array index was not a number - @throw out_of_range.402 if the array index '-' is used - @throw out_of_range.404 if the JSON pointer can not be resolved - */ - const_reference get_unchecked(const_pointer ptr) const - { - for (const auto& reference_token : reference_tokens) - { - switch (ptr->m_type) - { - case value_t::object: - { - // use unchecked object access - ptr = &ptr->operator[](reference_token); - break; - } + @note The following values can **not** be converted to a UBJSON value: + - strings with more than 9223372036854775807 bytes (theoretical) + - unsigned integer numbers above 9223372036854775807 - case value_t::array: - { - if (reference_token == "-") - { - // "-" cannot be used for const access - JSON_THROW(out_of_range::create(402, "array index '-' (" + - std::to_string(ptr->m_value.array->size()) + - ") is out of range")); - } + @note The following markers are not used in the conversion: + - `Z`: no-op values are not created. + - `C`: single-byte strings are serialized with `S` markers. - // error condition (cf. RFC 6901, Sect. 4) - if (reference_token.size() > 1 and reference_token[0] == '0') - { - JSON_THROW(parse_error::create(106, 0, "array index '" + reference_token + "' must not begin with '0'")); - } + @note Any UBJSON output created @ref to_ubjson can be successfully parsed + by @ref from_ubjson. - // use unchecked array access - JSON_TRY - { - ptr = &ptr->operator[](static_cast(std::stoi(reference_token))); - } - JSON_CATCH (std::invalid_argument&) - { - JSON_THROW(parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); - } - break; - } + @note If NaN or Infinity are stored inside a JSON number, they are + serialized properly. This behavior differs from the @ref dump() + function which serializes NaN or Infinity to `null`. - default: - { - JSON_THROW(out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); - } - } - } + @note The optimized formats for containers are supported: Parameter + @a use_size adds size information to the beginning of a container and + removes the closing marker. Parameter @a use_type further checks + whether all elements of a container have the same type and adds the + type marker to the beginning of the container. The @a use_type + parameter must only be used together with @a use_size = true. Note + that @a use_size = true alone may result in larger representations - + the benefit of this parameter is that the receiving side is + immediately informed on the number of elements of the container. - return *ptr; - } + @param[in] j JSON value to serialize + @param[in] use_size whether to add size annotations to container types + @param[in] use_type whether to add type annotations to container types + (must be combined with @a use_size = true) + @return UBJSON serialization as byte vector - /*! - @throw parse_error.106 if an array index begins with '0' - @throw parse_error.109 if an array index was not a number - @throw out_of_range.402 if the array index '-' is used - @throw out_of_range.404 if the JSON pointer can not be resolved - */ - const_reference get_checked(const_pointer ptr) const - { - for (const auto& reference_token : reference_tokens) - { - switch (ptr->m_type) - { - case value_t::object: - { - // note: at performs range check - ptr = &ptr->at(reference_token); - break; - } + @complexity Linear in the size of the JSON value @a j. - case value_t::array: - { - if (reference_token == "-") - { - // "-" always fails the range check - JSON_THROW(out_of_range::create(402, "array index '-' (" + - std::to_string(ptr->m_value.array->size()) + - ") is out of range")); - } + @liveexample{The example shows the serialization of a JSON value to a byte + vector in UBJSON format.,to_ubjson} - // error condition (cf. RFC 6901, Sect. 4) - if (reference_token.size() > 1 and reference_token[0] == '0') - { - JSON_THROW(parse_error::create(106, 0, "array index '" + reference_token + "' must not begin with '0'")); - } + @sa http://ubjson.org + @sa @ref from_ubjson(detail::input_adapter, const bool strict) for the + analogous deserialization + @sa @ref to_cbor(const basic_json& for the related CBOR format + @sa @ref to_msgpack(const basic_json&) for the related MessagePack format - // note: at performs range check - JSON_TRY - { - ptr = &ptr->at(static_cast(std::stoi(reference_token))); - } - JSON_CATCH (std::invalid_argument&) - { - JSON_THROW(parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); - } - break; - } + @since version 3.1.0 + */ + static std::vector to_ubjson(const basic_json& j, + const bool use_size = false, + const bool use_type = false) + { + std::vector result; + to_ubjson(j, result, use_size, use_type); + return result; + } - default: - { - JSON_THROW(out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); - } - } - } + static void to_ubjson(const basic_json& j, detail::output_adapter o, + const bool use_size = false, const bool use_type = false) + { + binary_writer(o).write_ubjson(j, use_size, use_type); + } - return *ptr; - } + static void to_ubjson(const basic_json& j, detail::output_adapter o, + const bool use_size = false, const bool use_type = false) + { + binary_writer(o).write_ubjson(j, use_size, use_type); + } - /*! - @brief split the string input to reference tokens + /*! + @brief create a JSON value from an input in CBOR format - @note This function is only called by the json_pointer constructor. - All exceptions below are documented there. + Deserializes a given input @a i to a JSON value using the CBOR (Concise + Binary Object Representation) serialization format. - @throw parse_error.107 if the pointer is not empty or begins with '/' - @throw parse_error.108 if character '~' is not followed by '0' or '1' - */ - static std::vector split(const std::string& reference_string) - { - std::vector result; + The library maps CBOR types to JSON value types as follows: - // special case: empty reference string -> no reference tokens - if (reference_string.empty()) - { - return result; - } + CBOR type | JSON value type | first byte + ---------------------- | --------------- | ---------- + Integer | number_unsigned | 0x00..0x17 + Unsigned integer | number_unsigned | 0x18 + Unsigned integer | number_unsigned | 0x19 + Unsigned integer | number_unsigned | 0x1A + Unsigned integer | number_unsigned | 0x1B + Negative integer | number_integer | 0x20..0x37 + Negative integer | number_integer | 0x38 + Negative integer | number_integer | 0x39 + Negative integer | number_integer | 0x3A + Negative integer | number_integer | 0x3B + Negative integer | number_integer | 0x40..0x57 + UTF-8 string | string | 0x60..0x77 + UTF-8 string | string | 0x78 + UTF-8 string | string | 0x79 + UTF-8 string | string | 0x7A + UTF-8 string | string | 0x7B + UTF-8 string | string | 0x7F + array | array | 0x80..0x97 + array | array | 0x98 + array | array | 0x99 + array | array | 0x9A + array | array | 0x9B + array | array | 0x9F + map | object | 0xA0..0xB7 + map | object | 0xB8 + map | object | 0xB9 + map | object | 0xBA + map | object | 0xBB + map | object | 0xBF + False | `false` | 0xF4 + True | `true` | 0xF5 + Nill | `null` | 0xF6 + Half-Precision Float | number_float | 0xF9 + Single-Precision Float | number_float | 0xFA + Double-Precision Float | number_float | 0xFB - // check if nonempty reference string begins with slash - if (reference_string[0] != '/') - { - JSON_THROW(parse_error::create(107, 1, "JSON pointer must be empty or begin with '/' - was: '" + reference_string + "'")); - } + @warning The mapping is **incomplete** in the sense that not all CBOR + types can be converted to a JSON value. The following CBOR types + are not supported and will yield parse errors (parse_error.112): + - byte strings (0x40..0x5F) + - date/time (0xC0..0xC1) + - bignum (0xC2..0xC3) + - decimal fraction (0xC4) + - bigfloat (0xC5) + - tagged items (0xC6..0xD4, 0xD8..0xDB) + - expected conversions (0xD5..0xD7) + - simple values (0xE0..0xF3, 0xF8) + - undefined (0xF7) - // extract the reference tokens: - // - slash: position of the last read slash (or end of string) - // - start: position after the previous slash - for ( - // search for the first slash after the first character - size_t slash = reference_string.find_first_of('/', 1), - // set the beginning of the first reference token - start = 1; - // we can stop if start == string::npos+1 = 0 - start != 0; - // set the beginning of the next reference token - // (will eventually be 0 if slash == std::string::npos) - start = slash + 1, - // find next slash - slash = reference_string.find_first_of('/', start)) - { - // use the text between the beginning of the reference token - // (start) and the last slash (slash). - auto reference_token = reference_string.substr(start, slash - start); + @warning CBOR allows map keys of any type, whereas JSON only allows + strings as keys in object values. Therefore, CBOR maps with keys + other than UTF-8 strings are rejected (parse_error.113). - // check reference tokens are properly escaped - for (size_t pos = reference_token.find_first_of('~'); - pos != std::string::npos; - pos = reference_token.find_first_of('~', pos + 1)) - { - assert(reference_token[pos] == '~'); + @note Any CBOR output created @ref to_cbor can be successfully parsed by + @ref from_cbor. - // ~ must be followed by 0 or 1 - if (pos == reference_token.size() - 1 or - (reference_token[pos + 1] != '0' and - reference_token[pos + 1] != '1')) - { - JSON_THROW(parse_error::create(108, 0, "escape character '~' must be followed with '0' or '1'")); - } - } + @param[in] i an input in CBOR format convertible to an input adapter + @param[in] strict whether to expect the input to be consumed until EOF + (true by default) + @return deserialized JSON value - // finally, store the reference token - unescape(reference_token); - result.push_back(reference_token); - } + @throw parse_error.110 if the given input ends prematurely or the end of + file was not reached when @a strict was set to true + @throw parse_error.112 if unsupported features from CBOR were + used in the given input @a v or if the input is not valid CBOR + @throw parse_error.113 if a string was expected as map key, but not found - return result; - } + @complexity Linear in the size of the input @a i. - /*! - @brief replace all occurrences of a substring by another string + @liveexample{The example shows the deserialization of a byte vector in CBOR + format to a JSON value.,from_cbor} - @param[in,out] s the string to manipulate; changed so that all - occurrences of @a f are replaced with @a t - @param[in] f the substring to replace with @a t - @param[in] t the string to replace @a f + @sa http://cbor.io + @sa @ref to_cbor(const basic_json&) for the analogous serialization + @sa @ref from_msgpack(detail::input_adapter, const bool) for the + related MessagePack format + @sa @ref from_ubjson(detail::input_adapter, const bool) for the related + UBJSON format - @pre The search string @a f must not be empty. **This precondition is - enforced with an assertion.** + @since version 2.0.9; parameter @a start_index since 2.1.1; changed to + consume input adapters, removed start_index parameter, and added + @a strict parameter since 3.0.0 + */ + static basic_json from_cbor(detail::input_adapter i, + const bool strict = true) + { + return binary_reader(i).parse_cbor(strict); + } - @since version 2.0.0 - */ - static void replace_substring(std::string& s, - const std::string& f, - const std::string& t) - { - assert(not f.empty()); + /*! + @copydoc from_cbor(detail::input_adapter, const bool) + */ + template::value, int> = 0> + static basic_json from_cbor(A1 && a1, A2 && a2, const bool strict = true) + { + return binary_reader(detail::input_adapter(std::forward(a1), std::forward(a2))).parse_cbor(strict); + } - for ( - size_t pos = s.find(f); // find first occurrence of f - pos != std::string::npos; // make sure f was found - s.replace(pos, f.size(), t), // replace with t - pos = s.find(f, pos + t.size()) // find next occurrence of f - ); - } + /*! + @brief create a JSON value from an input in MessagePack format - /// escape tilde and slash - static std::string escape(std::string s) - { - // escape "~"" to "~0" and "/" to "~1" - replace_substring(s, "~", "~0"); - replace_substring(s, "/", "~1"); - return s; - } + Deserializes a given input @a i to a JSON value using the MessagePack + serialization format. - /// unescape tilde and slash - static void unescape(std::string& s) - { - // first transform any occurrence of the sequence '~1' to '/' - replace_substring(s, "~1", "/"); - // then transform any occurrence of the sequence '~0' to '~' - replace_substring(s, "~0", "~"); - } + The library maps MessagePack types to JSON value types as follows: - /*! - @param[in] reference_string the reference string to the current value - @param[in] value the value to consider - @param[in,out] result the result object to insert values to + MessagePack type | JSON value type | first byte + ---------------- | --------------- | ---------- + positive fixint | number_unsigned | 0x00..0x7F + fixmap | object | 0x80..0x8F + fixarray | array | 0x90..0x9F + fixstr | string | 0xA0..0xBF + nil | `null` | 0xC0 + false | `false` | 0xC2 + true | `true` | 0xC3 + float 32 | number_float | 0xCA + float 64 | number_float | 0xCB + uint 8 | number_unsigned | 0xCC + uint 16 | number_unsigned | 0xCD + uint 32 | number_unsigned | 0xCE + uint 64 | number_unsigned | 0xCF + int 8 | number_integer | 0xD0 + int 16 | number_integer | 0xD1 + int 32 | number_integer | 0xD2 + int 64 | number_integer | 0xD3 + str 8 | string | 0xD9 + str 16 | string | 0xDA + str 32 | string | 0xDB + array 16 | array | 0xDC + array 32 | array | 0xDD + map 16 | object | 0xDE + map 32 | object | 0xDF + negative fixint | number_integer | 0xE0-0xFF - @note Empty objects or arrays are flattened to `null`. - */ - static void flatten(const std::string& reference_string, - const basic_json& value, - basic_json& result) - { - switch (value.m_type) - { - case value_t::array: - { - if (value.m_value.array->empty()) - { - // flatten empty array as null - result[reference_string] = nullptr; - } - else - { - // iterate array and use index as reference string - for (size_t i = 0; i < value.m_value.array->size(); ++i) - { - flatten(reference_string + "/" + std::to_string(i), - value.m_value.array->operator[](i), result); - } - } - break; - } + @warning The mapping is **incomplete** in the sense that not all + MessagePack types can be converted to a JSON value. The following + MessagePack types are not supported and will yield parse errors: + - bin 8 - bin 32 (0xC4..0xC6) + - ext 8 - ext 32 (0xC7..0xC9) + - fixext 1 - fixext 16 (0xD4..0xD8) - case value_t::object: - { - if (value.m_value.object->empty()) - { - // flatten empty object as null - result[reference_string] = nullptr; - } - else - { - // iterate object and use keys as reference string - for (const auto& element : *value.m_value.object) - { - flatten(reference_string + "/" + escape(element.first), - element.second, result); - } - } - break; - } + @note Any MessagePack output created @ref to_msgpack can be successfully + parsed by @ref from_msgpack. - default: - { - // add primitive value with its reference string - result[reference_string] = value; - break; - } - } - } + @param[in] i an input in MessagePack format convertible to an input + adapter + @param[in] strict whether to expect the input to be consumed until EOF + (true by default) - /*! - @param[in] value flattened JSON + @throw parse_error.110 if the given input ends prematurely or the end of + file was not reached when @a strict was set to true + @throw parse_error.112 if unsupported features from MessagePack were + used in the given input @a i or if the input is not valid MessagePack + @throw parse_error.113 if a string was expected as map key, but not found - @return unflattened JSON + @complexity Linear in the size of the input @a i. - @throw parse_error.109 if array index is not a number - @throw type_error.314 if value is not an object - @throw type_error.315 if object values are not primitive - @throw type_error.313 if value cannot be unflattened - */ - static basic_json unflatten(const basic_json& value) - { - if (not value.is_object()) - { - JSON_THROW(type_error::create(314, "only objects can be unflattened")); - } + @liveexample{The example shows the deserialization of a byte vector in + MessagePack format to a JSON value.,from_msgpack} - basic_json result; + @sa http://msgpack.org + @sa @ref to_msgpack(const basic_json&) for the analogous serialization + @sa @ref from_cbor(detail::input_adapter, const bool) for the related CBOR + format + @sa @ref from_ubjson(detail::input_adapter, const bool) for the related + UBJSON format + + @since version 2.0.9; parameter @a start_index since 2.1.1; changed to + consume input adapters, removed start_index parameter, and added + @a strict parameter since 3.0.0 + */ + static basic_json from_msgpack(detail::input_adapter i, + const bool strict = true) + { + return binary_reader(i).parse_msgpack(strict); + } - // iterate the JSON object values - for (const auto& element : *value.m_value.object) - { - if (not element.second.is_primitive()) - { - JSON_THROW(type_error::create(315, "values in object must be primitive")); - } + /*! + @copydoc from_msgpack(detail::input_adapter, const bool) + */ + template::value, int> = 0> + static basic_json from_msgpack(A1 && a1, A2 && a2, const bool strict = true) + { + return binary_reader(detail::input_adapter(std::forward(a1), std::forward(a2))).parse_msgpack(strict); + } - // assign value to reference pointed to by JSON pointer; Note - // that if the JSON pointer is "" (i.e., points to the whole - // value), function get_and_create returns a reference to - // result itself. An assignment will then create a primitive - // value. - json_pointer(element.first).get_and_create(result) = element.second; - } + /*! + @brief create a JSON value from an input in UBJSON format + + Deserializes a given input @a i to a JSON value using the UBJSON (Universal + Binary JSON) serialization format. + + The library maps UBJSON types to JSON value types as follows: + + UBJSON type | JSON value type | marker + ----------- | --------------------------------------- | ------ + no-op | *no value, next value is read* | `N` + null | `null` | `Z` + false | `false` | `F` + true | `true` | `T` + float32 | number_float | `d` + float64 | number_float | `D` + uint8 | number_unsigned | `U` + int8 | number_integer | `i` + int16 | number_integer | `I` + int32 | number_integer | `l` + int64 | number_integer | `L` + string | string | `S` + char | string | `C` + array | array (optimized values are supported) | `[` + object | object (optimized values are supported) | `{` + + @note The mapping is **complete** in the sense that any UBJSON value can + be converted to a JSON value. + + @param[in] i an input in UBJSON format convertible to an input adapter + @param[in] strict whether to expect the input to be consumed until EOF + (true by default) + + @throw parse_error.110 if the given input ends prematurely or the end of + file was not reached when @a strict was set to true + @throw parse_error.112 if a parse error occurs + @throw parse_error.113 if a string could not be parsed successfully + + @complexity Linear in the size of the input @a i. - return result; - } + @liveexample{The example shows the deserialization of a byte vector in + UBJSON format to a JSON value.,from_ubjson} - friend bool operator==(json_pointer const& lhs, - json_pointer const& rhs) noexcept - { - return lhs.reference_tokens == rhs.reference_tokens; - } + @sa http://ubjson.org + @sa @ref to_ubjson(const basic_json&, const bool, const bool) for the + analogous serialization + @sa @ref from_cbor(detail::input_adapter, const bool) for the related CBOR + format + @sa @ref from_msgpack(detail::input_adapter, const bool) for the related + MessagePack format - friend bool operator!=(json_pointer const& lhs, - json_pointer const& rhs) noexcept - { - return !(lhs == rhs); - } + @since version 3.1.0 + */ + static basic_json from_ubjson(detail::input_adapter i, + const bool strict = true) + { + return binary_reader(i).parse_ubjson(strict); + } - /// the reference tokens - std::vector reference_tokens {}; - }; + template::value, int> = 0> + static basic_json from_ubjson(A1 && a1, A2 && a2, const bool strict = true) + { + return binary_reader(detail::input_adapter(std::forward(a1), std::forward(a2))).parse_ubjson(strict); + } + + /// @} ////////////////////////// // JSON Pointer support // @@ -13854,6 +16381,9 @@ scan_number_done: pointer @a ptr. As `at` provides checked access (and no elements are implicitly inserted), the index '-' is always invalid. See example below. + @throw out_of_range.403 if the JSON pointer describes a key of an object + which cannot be found. See example below. + @throw out_of_range.404 if the JSON pointer @a ptr can not be resolved. See example below. @@ -13894,6 +16424,9 @@ scan_number_done: pointer @a ptr. As `at` provides checked access (and no elements are implicitly inserted), the index '-' is always invalid. See example below. + @throw out_of_range.403 if the JSON pointer describes a key of an object + which cannot be found. See example below. + @throw out_of_range.404 if the JSON pointer @a ptr can not be resolved. See example below. @@ -13961,7 +16494,7 @@ scan_number_done: @complexity Linear in the size the JSON value. @throw type_error.314 if value is not an object - @throw type_error.315 if object values are not primitve + @throw type_error.315 if object values are not primitive @liveexample{The following code shows how a flattened JSON object is unflattened into the original nested JSON object.,unflatten} @@ -14109,8 +16642,8 @@ scan_number_done: } else { - const auto idx = std::stoi(last_path); - if (static_cast(idx) > parent.size()) + const auto idx = json_pointer::array_index(last_path); + if (JSON_UNLIKELY(static_cast(idx) > parent.size())) { // avoid undefined behavior JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range")); @@ -14145,7 +16678,7 @@ scan_number_done: { // perform range check auto it = parent.find(last_path); - if (it != parent.end()) + if (JSON_LIKELY(it != parent.end())) { parent.erase(it); } @@ -14157,12 +16690,12 @@ scan_number_done: else if (parent.is_array()) { // note erase performs range check - parent.erase(static_cast(std::stoi(last_path))); + parent.erase(static_cast(json_pointer::array_index(last_path))); } }; // type check: top level value must be an array - if (not json_patch.is_array()) + if (JSON_UNLIKELY(not json_patch.is_array())) { JSON_THROW(parse_error::create(104, 0, "JSON patch must be an array of objects")); } @@ -14173,7 +16706,7 @@ scan_number_done: // wrapper to get a value for an operation const auto get_value = [&val](const std::string & op, const std::string & member, - bool string_type) -> basic_json& + bool string_type) -> basic_json & { // find value auto it = val.m_value.object->find(member); @@ -14182,13 +16715,13 @@ scan_number_done: const auto error_msg = (op == "op") ? "operation" : "operation '" + op + "'"; // check if desired value is present - if (it == val.m_value.object->end()) + if (JSON_UNLIKELY(it == val.m_value.object->end())) { JSON_THROW(parse_error::create(105, 0, error_msg + " must have member '" + member + "'")); } // check if result is of type string - if (string_type and not it->second.is_string()) + if (JSON_UNLIKELY(string_type and not it->second.is_string())) { JSON_THROW(parse_error::create(105, 0, error_msg + " must have string member '" + member + "'")); } @@ -14198,7 +16731,7 @@ scan_number_done: }; // type check: every element of the array must be an object - if (not val.is_object()) + if (JSON_UNLIKELY(not val.is_object())) { JSON_THROW(parse_error::create(104, 0, "JSON patch must be an array of objects")); } @@ -14252,7 +16785,12 @@ scan_number_done: const json_pointer from_ptr(from_path); // the "from" location must exist - use at() - result[ptr] = result.at(from_ptr); + basic_json v = result.at(from_ptr); + + // The copy is functionally identical to an "add" + // operation at the target location using the value + // specified in the "from" member. + operation_add(ptr, v); break; } @@ -14271,7 +16809,7 @@ scan_number_done: } // throw an exception if test fails - if (not success) + if (JSON_UNLIKELY(not success)) { JSON_THROW(other_error::create(501, "unsuccessful: " + val.dump())); } @@ -14318,13 +16856,13 @@ scan_number_done: diff for two JSON values.,diff} @sa @ref patch -- apply a JSON patch + @sa @ref merge_patch -- apply a JSON Merge Patch @sa [RFC 6902 (JSON Patch)](https://tools.ietf.org/html/rfc6902) @since version 2.0.0 */ - static basic_json diff(const basic_json& source, - const basic_json& target, + static basic_json diff(const basic_json& source, const basic_json& target, const std::string& path = "") { // the patch @@ -14341,9 +16879,7 @@ scan_number_done: // different types: replace value result.push_back( { - {"op", "replace"}, - {"path", path}, - {"value", target} + {"op", "replace"}, {"path", path}, {"value", target} }); } else @@ -14353,7 +16889,7 @@ scan_number_done: case value_t::array: { // first pass: traverse common elements - size_t i = 0; + std::size_t i = 0; while (i < source.size() and i < target.size()) { // recursive call to compare array values at index i @@ -14397,7 +16933,7 @@ scan_number_done: case value_t::object: { // first pass: traverse this object's elements - for (auto it = source.begin(); it != source.end(); ++it) + for (auto it = source.cbegin(); it != source.cend(); ++it) { // escape the key name to be used in a JSON patch const auto key = json_pointer::escape(it.key()); @@ -14413,14 +16949,13 @@ scan_number_done: // found a key that is not in o -> remove it result.push_back(object( { - {"op", "remove"}, - {"path", path + "/" + key} + {"op", "remove"}, {"path", path + "/" + key} })); } } // second pass: traverse other object's elements - for (auto it = target.begin(); it != target.end(); ++it) + for (auto it = target.cbegin(); it != target.cend(); ++it) { if (source.find(it.key()) == source.end()) { @@ -14428,8 +16963,7 @@ scan_number_done: const auto key = json_pointer::escape(it.key()); result.push_back( { - {"op", "add"}, - {"path", path + "/" + key}, + {"op", "add"}, {"path", path + "/" + key}, {"value", it.value()} }); } @@ -14443,9 +16977,7 @@ scan_number_done: // both primitive type: replace value result.push_back( { - {"op", "replace"}, - {"path", path}, - {"value", target} + {"op", "replace"}, {"path", path}, {"value", target} }); break; } @@ -14456,23 +16988,85 @@ scan_number_done: } /// @} -}; -///////////// -// presets // -///////////// + //////////////////////////////// + // JSON Merge Patch functions // + //////////////////////////////// -/*! -@brief default JSON class + /// @name JSON Merge Patch functions + /// @{ -This type is the default specialization of the @ref basic_json class which -uses the standard template types. + /*! + @brief applies a JSON Merge Patch + + The merge patch format is primarily intended for use with the HTTP PATCH + method as a means of describing a set of modifications to a target + resource's content. This function applies a merge patch to the current + JSON value. + + The function implements the following algorithm from Section 2 of + [RFC 7396 (JSON Merge Patch)](https://tools.ietf.org/html/rfc7396): + + ``` + define MergePatch(Target, Patch): + if Patch is an Object: + if Target is not an Object: + Target = {} // Ignore the contents and set it to an empty Object + for each Name/Value pair in Patch: + if Value is null: + if Name exists in Target: + remove the Name/Value pair from Target + else: + Target[Name] = MergePatch(Target[Name], Value) + return Target + else: + return Patch + ``` + + Thereby, `Target` is the current object; that is, the patch is applied to + the current value. + + @param[in] patch the patch to apply + + @complexity Linear in the lengths of @a patch. + + @liveexample{The following code shows how a JSON Merge Patch is applied to + a JSON document.,merge_patch} -@since version 1.0.0 -*/ -using json = basic_json<>; -} // namespace nlohmann + @sa @ref patch -- apply a JSON patch + @sa [RFC 7396 (JSON Merge Patch)](https://tools.ietf.org/html/rfc7396) + + @since version 3.0.0 + */ + void merge_patch(const basic_json& patch) + { + if (patch.is_object()) + { + if (not is_object()) + { + *this = object(); + } + for (auto it = patch.begin(); it != patch.end(); ++it) + { + if (it.value().is_null()) + { + erase(it.key()); + } + else + { + operator[](it.key()).merge_patch(it.value()); + } + } + } + else + { + *this = patch; + } + } + /// @} +}; +} // namespace nlohmann /////////////////////// // nonmember support // @@ -14514,8 +17108,10 @@ struct hash }; /// specialization for std::less -template <> -struct less<::nlohmann::detail::value_t> +/// @note: do not remove the space after '<', +/// see https://github.com/nlohmann/json/pull/679 +template<> +struct less< ::nlohmann::detail::value_t> { /*! @brief compare two value_t enum values @@ -14566,13 +17162,16 @@ inline nlohmann::json::json_pointer operator "" _json_pointer(const char* s, std return nlohmann::json::json_pointer(std::string(s, n)); } +// #include + + // restore GCC/clang diagnostic settings -#if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__) - #pragma GCC diagnostic pop -#endif -#if defined(__clang__) - #pragma GCC diagnostic pop -#endif +// #if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__) +// #pragma GCC diagnostic pop +// #endif +// #if defined(__clang__) +// #pragma GCC diagnostic pop +// #endif // clean up #undef JSON_CATCH @@ -14581,5 +17180,11 @@ inline nlohmann::json::json_pointer operator "" _json_pointer(const char* s, std #undef JSON_LIKELY #undef JSON_UNLIKELY #undef JSON_DEPRECATED +#undef JSON_HAS_CPP_14 +#undef JSON_HAS_CPP_17 +#undef NLOHMANN_BASIC_JSON_TPL_DECLARATION +#undef NLOHMANN_BASIC_JSON_TPL +#undef NLOHMANN_JSON_HAS_HELPER + #endif diff --git a/src/ndjson.cpp b/src/ndjson.cpp index 10769f4..e761ccb 100644 --- a/src/ndjson.cpp +++ b/src/ndjson.cpp @@ -94,7 +94,7 @@ List gz_stream_in(const std::string &path) { } // [[Rcpp::export]] -List internal_flatten(CharacterVector lines) { +List flatten_int(CharacterVector lines) { R_xlen_t num_lines = lines.size(); List container(num_lines); @@ -230,7 +230,7 @@ List j_stream_in(const std::string &path) { } // [[Rcpp::export]] -List internal_stream_in(const std::string &path) { +List stream_in_int(const std::string &path) { if (ends_with(path, ".gz")) { return(gz_stream_in(path)); @@ -241,7 +241,7 @@ List internal_stream_in(const std::string &path) { } // [[Rcpp::export]] -bool internal_validate(std::string path, bool verbose) { +bool validate_int(std::string path, bool verbose) { bool ok = true; std::string line; diff --git a/tests/testthat/test-ndjson.R b/tests/testthat/test-ndjson.R index 1d934c2..5797fe1 100644 --- a/tests/testthat/test-ndjson.R +++ b/tests/testthat/test-ndjson.R @@ -1,5 +1,5 @@ -context("basic functionality") -test_that("we can do something", { +context("uncompressed files (validation and streaming)") +test_that("validation and streaming works in uncompressed files (validation and streaming)", { f <- system.file("extdata", "test.json", package="ndjson") expect_that(validate(f), equals(TRUE)) @@ -7,6 +7,11 @@ test_that("we can do something", { expect_that(stream_in(f), is_a("tbl_dt")) expect_that(stream_in(f, "tbl"), is_a("tbl_df")) +}) + +context("compressed files (validation and streaming)") +test_that("validation and streaming works in compressed files", { + gzf <- system.file("extdata", "testgz.json.gz", package="ndjson") expect_that(validate(gzf), equals(TRUE)) expect_that(nrow(stream_in(gzf)), equals(100))