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#ifndef __LEXER_H__
#define __LEXER_H__
/* lexer.h -- Lexer for html parser
(c) 1998-2008 (W3C) MIT, ERCIM, Keio University
See tidy.h for the copyright notice.
Given an input source, it returns a sequence of tokens.
GetToken(source) gets the next token
UngetToken(source) provides one level undo
The tags include an attribute list:
- linked list of attribute/value nodes
- each node has 2 NULL-terminated strings.
- entities are replaced in attribute values
white space is compacted if not in preformatted mode
If not in preformatted mode then leading white space
is discarded and subsequent white space sequences
compacted to single space characters.
If XmlTags is no then Tag names are folded to upper
case and attribute names to lower case.
Not yet done:
- Doctype subset and marked sections
#ifdef __cplusplus
extern "C" {
#include "forward.h"
/* lexer character types
#define digit 1u
#define letter 2u
#define namechar 4u
#define white 8u
#define newline 16u
#define lowercase 32u
#define uppercase 64u
#define digithex 128u
/* node->type is one of these values
typedef enum
} NodeType;
/* lexer GetToken states
typedef enum
} LexerState;
/* ParseDocTypeDecl state constants */
typedef enum
} ParseDocTypeDeclState;
/* content model shortcut encoding
Descriptions are tentative.
#define CM_UNKNOWN 0
/* Elements with no content. Map to HTML specification. */
#define CM_EMPTY (1 << 0)
/* Elements that appear outside of "BODY". */
#define CM_HTML (1 << 1)
/* Elements that can appear within HEAD. */
#define CM_HEAD (1 << 2)
/* HTML "block" elements. */
#define CM_BLOCK (1 << 3)
/* HTML "inline" elements. */
#define CM_INLINE (1 << 4)
/* Elements that mark list item ("LI"). */
#define CM_LIST (1 << 5)
/* Elements that mark definition list item ("DL", "DT"). */
#define CM_DEFLIST (1 << 6)
/* Elements that can appear inside TABLE. */
#define CM_TABLE (1 << 7)
/* Used for "THEAD", "TFOOT" or "TBODY". */
#define CM_ROWGRP (1 << 8)
/* Used for "TD", "TH" */
#define CM_ROW (1 << 9)
/* Elements whose content must be protected against white space movement.
Includes some elements that can found in forms. */
#define CM_FIELD (1 << 10)
/* Used to avoid propagating inline emphasis inside some elements
such as OBJECT or APPLET. */
#define CM_OBJECT (1 << 11)
/* Elements that allows "PARAM". */
#define CM_PARAM (1 << 12)
/* "FRAME", "FRAMESET", "NOFRAMES". Used in ParseFrameSet. */
#define CM_FRAMES (1 << 13)
/* Heading elements (h1, h2, ...). */
#define CM_HEADING (1 << 14)
/* Elements with an optional end tag. */
#define CM_OPT (1 << 15)
/* Elements that use "align" attribute for vertical position. */
#define CM_IMG (1 << 16)
/* Elements with inline and block model. Used to avoid calling InlineDup. */
#define CM_MIXED (1 << 17)
/* Elements whose content needs to be indented only if containing one
CM_BLOCK element. */
#define CM_NO_INDENT (1 << 18)
/* Elements that are obsolete (such as "dir", "menu"). */
#define CM_OBSOLETE (1 << 19)
/* User defined elements. Used to determine how attributes wihout value
should be printed. */
#define CM_NEW (1 << 20)
/* Elements that cannot be omitted. */
#define CM_OMITST (1 << 21)
/* If the document uses just HTML 2.0 tags and attributes described
** it as HTML 2.0 Similarly for HTML 3.2 and the 3 flavors of HTML 4.0.
** If there are proprietary tags and attributes then describe it as
** HTML Proprietary. If it includes the xml-lang or xmlns attributes
** but is otherwise HTML 2.0, 3.2 or 4.0 then describe it as one of the
** flavors of Voyager (strict, loose or frameset).
/* unknown */
#define xxxx 0u
/* W3C defined HTML/XHTML family document types */
#define HT20 1u
#define HT32 2u
#define H40S 4u
#define H40T 8u
#define H40F 16u
#define H41S 32u
#define H41T 64u
#define H41F 128u
#define X10S 256u
#define X10T 512u
#define X10F 1024u
#define XH11 2048u
#define XB10 4096u
/* proprietary stuff */
#define VERS_SUN 8192u
#define VERS_NETSCAPE 16384u
#define VERS_MICROSOFT 32768u
/* special flag */
#define VERS_XML 65536u
/* HTML5 */
#define HT50 131072u
#define XH50 262144u
/* compatibility symbols */
#define VERS_UNKNOWN (xxxx)
#define VERS_HTML20 (HT20)
#define VERS_HTML32 (HT32)
#define VERS_HTML40_STRICT (H40S|H41S|X10S)
#define VERS_HTML40_LOOSE (H40T|H41T|X10T)
#define VERS_FRAMESET (H40F|H41F|X10F)
#define VERS_XHTML11 (XH11)
#define VERS_BASIC (XB10)
/* HTML5 */
#define VERS_HTML5 (HT50|XH50)
/* meta symbols */
#define VERS_XHTML (X10S|X10T|X10F|XH11|XB10|XH50)
/* strict */
/* all W3C defined document types */
/* all proprietary types */
/* Linked list of class names and styles
struct _Style;
typedef struct _Style TagStyle;
struct _Style
tmbstr tag;
tmbstr tag_class;
tmbstr properties;
TagStyle *next;
/* Linked list of style properties
struct _StyleProp;
typedef struct _StyleProp StyleProp;
struct _StyleProp
tmbstr name;
tmbstr value;
StyleProp *next;
/* Attribute/Value linked list node
struct _AttVal
AttVal* next;
const Attribute* dict;
Node* asp;
Node* php;
int delim;
tmbstr attribute;
tmbstr value;
Mosaic handles inlines via a separate stack from other elements
We duplicate this to recover from inline markup errors such as:
<i>italic text
<p>more italic text</b> normal text
which for compatibility with Mosaic is mapped to:
<i>italic text</i>
<p><i>more italic text</i> normal text
Note that any inline end tag pop's the effect of the current
inline start tag, so that </b> pop's <i> in the above example.
struct _IStack
IStack* next;
const Dict* tag; /* tag's dictionary definition */
tmbstr element; /* name (NULL for text nodes) */
AttVal* attributes;
/* HTML/XHTML/XML Element, Comment, PI, DOCTYPE, XML Decl,
** etc. etc.
struct _Node
Node* parent; /* tree structure */
Node* prev;
Node* next;
Node* content;
Node* last;
AttVal* attributes;
const Dict* was; /* old tag when it was changed */
const Dict* tag; /* tag's dictionary definition */
tmbstr element; /* name (NULL for text nodes) */
uint start; /* start of span onto text array */
uint end; /* end of span onto text array */
NodeType type; /* TextNode, StartTag, EndTag etc. */
uint line; /* current line of document */
uint column; /* current column of document */
Bool closed; /* true if closed by explicit end tag */
Bool implicit; /* true if inferred */
Bool linebreak; /* true if followed by a line break */
tmbstr otext;
The following are private to the lexer
Use NewLexer() to create a lexer, and
FreeLexer() to free it.
struct _Lexer
#if 0 /* Move to TidyDocImpl */
StreamIn* in; /* document content input */
StreamOut* errout; /* error output stream */
uint badAccess; /* for accessibility errors */
uint badLayout; /* for bad style errors */
uint badChars; /* for bad character encodings */
uint badForm; /* for mismatched/mispositioned form tags */
uint warnings; /* count of warnings in this document */
uint errors; /* count of errors */
uint lines; /* lines seen */
uint columns; /* at start of current token */
Bool waswhite; /* used to collapse contiguous white space */
Bool pushed; /* true after token has been pushed back */
Bool insertspace; /* when space is moved after end tag */
Bool excludeBlocks; /* Netscape compatibility */
Bool exiled; /* true if moved out of table */
Bool isvoyager; /* true if xmlns attribute on html element */
uint versions; /* bit vector of HTML versions */
uint doctype; /* version as given by doctype (if any) */
uint versionEmitted; /* version of doctype emitted */
Bool bad_doctype; /* e.g. if html or PUBLIC is missing */
uint txtstart; /* start of current node */
uint txtend; /* end of current node */
LexerState state; /* state of lexer's finite state machine */
Node* token; /* last token returned by GetToken() */
Node* itoken; /* last duplicate inline returned by GetToken() */
Node* root; /* remember root node of the document */
Node* parent; /* remember parent node for CDATA elements */
Bool seenEndBody; /* true if a </body> tag has been encountered */
Bool seenEndHtml; /* true if a </html> tag has been encountered */
Lexer character buffer
Parse tree nodes span onto this buffer
which contains the concatenated text
contents of all of the elements.
lexsize must be reset for each file.
tmbstr lexbuf; /* MB character buffer */
uint lexlength; /* allocated */
uint lexsize; /* used */
/* Inline stack for compatibility with Mosaic */
Node* inode; /* for deferring text node */
IStack* insert; /* for inferring inline tags */
IStack* istack;
uint istacklength; /* allocated */
uint istacksize; /* used */
uint istackbase; /* start of frame */
TagStyle *styles; /* used for cleaning up presentation markup */
TidyAllocator* allocator; /* allocator */
#if 0
TidyDocImpl* doc; /* Pointer back to doc for error reporting */
/* Lexer Functions
/* choose what version to use for new doctype */
int TY_(HTMLVersion)( TidyDocImpl* doc );
/* everything is allowed in proprietary version of HTML */
/* this is handled here rather than in the tag/attr dicts */
void TY_(ConstrainVersion)( TidyDocImpl* doc, uint vers );
Bool TY_(IsWhite)(uint c);
Bool TY_(IsDigit)(uint c);
Bool TY_(IsLetter)(uint c);
Bool TY_(IsHTMLSpace)(uint c);
Bool TY_(IsNewline)(uint c);
Bool TY_(IsNamechar)(uint c);
Bool TY_(IsXMLLetter)(uint c);
Bool TY_(IsXMLNamechar)(uint c);
/* Bool IsLower(uint c); */
Bool TY_(IsUpper)(uint c);
uint TY_(ToLower)(uint c);
uint TY_(ToUpper)(uint c);
Lexer* TY_(NewLexer)( TidyDocImpl* doc );
void TY_(FreeLexer)( TidyDocImpl* doc );
/* store character c as UTF-8 encoded byte stream */
void TY_(AddCharToLexer)( Lexer *lexer, uint c );
Used for elements and text nodes
element name is NULL for text nodes
start and end are offsets into lexbuf
which contains the textual content of
all elements in the parse tree.
parent and content allow traversal
of the parse tree in any direction.
attributes are represented as a linked
list of AttVal nodes which hold the
strings for attribute/value pairs.
Node* TY_(NewNode)( TidyAllocator* allocator, Lexer* lexer );
/* used to clone heading nodes when split by an <HR> */
Node* TY_(CloneNode)( TidyDocImpl* doc, Node *element );
/* free node's attributes */
void TY_(FreeAttrs)( TidyDocImpl* doc, Node *node );
/* doesn't repair attribute list linkage */
void TY_(FreeAttribute)( TidyDocImpl* doc, AttVal *av );
/* detach attribute from node */
void TY_(DetachAttribute)( Node *node, AttVal *attr );
/* detach attribute from node then free it
void TY_(RemoveAttribute)( TidyDocImpl* doc, Node *node, AttVal *attr );
Free document nodes by iterating through peers and recursing
through children. Set next to NULL before calling FreeNode()
to avoid freeing peer nodes. Doesn't patch up prev/next links.
void TY_(FreeNode)( TidyDocImpl* doc, Node *node );
Node* TY_(TextToken)( Lexer *lexer );
/* used for creating preformatted text from Word2000 */
Node* TY_(NewLineNode)( Lexer *lexer );
/* used for adding a &nbsp; for Word2000 */
Node* TY_(NewLiteralTextNode)(Lexer *lexer, ctmbstr txt );
void TY_(AddStringLiteral)( Lexer* lexer, ctmbstr str );
/* void AddStringLiteralLen( Lexer* lexer, ctmbstr str, int len ); */
/* find element */
Node* TY_(FindDocType)( TidyDocImpl* doc );
Node* TY_(FindHTML)( TidyDocImpl* doc );
Node* TY_(FindHEAD)( TidyDocImpl* doc );
Node* TY_(FindTITLE)(TidyDocImpl* doc);
Node* TY_(FindBody)( TidyDocImpl* doc );
Node* TY_(FindXmlDecl)(TidyDocImpl* doc);
/* Returns containing block element, if any */
Node* TY_(FindContainer)( Node* node );
/* add meta element for Tidy */
Bool TY_(AddGenerator)( TidyDocImpl* doc );
uint TY_(ApparentVersion)( TidyDocImpl* doc );
ctmbstr TY_(HTMLVersionNameFromCode)( uint vers, Bool isXhtml );
Bool TY_(WarnMissingSIInEmittedDocType)( TidyDocImpl* doc );
Bool TY_(SetXHTMLDocType)( TidyDocImpl* doc );
/* fixup doctype if missing */
Bool TY_(FixDocType)( TidyDocImpl* doc );
/* ensure XML document starts with <?xml version="1.0"?> */
/* add encoding attribute if not using ASCII or UTF-8 output */
Bool TY_(FixXmlDecl)( TidyDocImpl* doc );
Node* TY_(InferredTag)(TidyDocImpl* doc, TidyTagId id);
void TY_(UngetToken)( TidyDocImpl* doc );
modes for GetToken()
MixedContent -- for elements which don't accept PCDATA
Preformatted -- white space preserved as is
IgnoreMarkup -- for CDATA elements such as script, style
typedef enum
} GetTokenMode;
Node* TY_(GetToken)( TidyDocImpl* doc, GetTokenMode mode );
void TY_(InitMap)(void);
/* create a new attribute */
AttVal* TY_(NewAttribute)( TidyDocImpl* doc );
/* create a new attribute with given name and value */
AttVal* TY_(NewAttributeEx)( TidyDocImpl* doc, ctmbstr name, ctmbstr value,
int delim );
/* insert attribute at the end of attribute list of a node */
void TY_(InsertAttributeAtEnd)( Node *node, AttVal *av );
/* insert attribute at the start of attribute list of a node */
void TY_(InsertAttributeAtStart)( Node *node, AttVal *av );
In-line Stack functions
/* duplicate attributes */
AttVal* TY_(DupAttrs)( TidyDocImpl* doc, AttVal* attrs );
push a copy of an inline node onto stack
but don't push if implicit or OBJECT or APPLET
(implicit tags are ones generated from the istack)
One issue arises with pushing inlines when
the tag is already pushed. For instance:
<p><em>more text
Shouldn't be mapped to
<p><em><em>more text</em></em>
void TY_(PushInline)( TidyDocImpl* doc, Node* node );
/* pop inline stack */
void TY_(PopInline)( TidyDocImpl* doc, Node* node );
Bool TY_(IsPushed)( TidyDocImpl* doc, Node* node );
Bool TY_(IsPushedLast)( TidyDocImpl* doc, Node *element, Node *node );
This has the effect of inserting "missing" inline
elements around the contents of blocklevel elements
such as P, TD, TH, DIV, PRE etc. This procedure is
called at the start of ParseBlock. when the inline
stack is not empty, as will be the case in:
<i><h1>italic heading</h1></i>
which is then treated as equivalent to
<h1><i>italic heading</i></h1>
This is implemented by setting the lexer into a mode
where it gets tokens from the inline stack rather than
from the input stream.
int TY_(InlineDup)( TidyDocImpl* doc, Node *node );
defer duplicates when entering a table or other
element where the inlines shouldn't be duplicated
void TY_(DeferDup)( TidyDocImpl* doc );
Node* TY_(InsertedToken)( TidyDocImpl* doc );
/* stack manipulation for inline elements */
Bool TY_(SwitchInline)( TidyDocImpl* doc, Node* element, Node* node );
Bool TY_(InlineDup1)( TidyDocImpl* doc, Node* node, Node* element );
#ifdef __cplusplus
#endif /* __LEXER_H__ */