lex.c File Reference

#include <assert.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <parserutils/charset/utf8.h>
#include <parserutils/input/inputstream.h>
#include <parserutils/utils/buffer.h>
#include <libcss/errors.h>
#include "lex/lex.h"
#include "utils/parserutilserror.h"
#include "utils/utils.h"

Classes
struct	css_lexer

Macros
#define	APPEND(lexer, data, len)

Enumerations
enum	{   sSTART = 0 , sATKEYWORD = 1 , sSTRING = 2 , sHASH = 3 ,   sNUMBER = 4 , sCDO = 5 , sCDC = 6 , sS = 7 ,   sCOMMENT = 8 , sMATCH = 9 , sURI = 10 , sIDENT = 11 ,   sESCAPEDIDENT = 12 , sURL = 13 , sUCR = 14 }

Functions
css_error	css__lexer_create (parserutils_inputstream *input, css_lexer **lexer)
css_error	css__lexer_destroy (css_lexer *lexer)
css_error	css__lexer_setopt (css_lexer *lexer, css_lexer_opttype type, css_lexer_optparams *params)
css_error	css__lexer_get_token (css_lexer *lexer, css_token **token)

Macro Definition Documentation

APPEND

#define APPEND	(		lexer,
			data,
			len
	)

Value:

do {                                                                    \
        css_error error;                                                \
        error = appendToTokenData((lexer),                              \
                        (const uint8_t *) (data), (len));               \
        if (error != CSS_OK)                                            \
                return error;                                           \
        (lexer)->bytesReadForToken += (len);                            \
        (lexer)->currentCol += (len);                                   \
} while(0)                                                              \

Enumeration Type Documentation

anonymous enum

anonymous enum

Todo:

Optimisation – we're currently revisiting a bunch of input characters (Currently, we're calling parserutils_inputstream_peek about 1.5x the number of characters in the input stream). Ideally, we'll visit each character in the input exactly once. In reality, the upper bound is twice, due to the need, in some cases, to read one character beyond the end of a token's input to detect the end of the token. Resumability adds a little overhead here, unless we're somewhat more clever when it comes to having support for restarting mid-escape sequence. Currently, we rewind back to the start of the sequence and process the whole thing again.

Enumerator
sSTART
sATKEYWORD
sSTRING
sHASH
sNUMBER
sCDO
sCDC
sS
sCOMMENT
sMATCH
sURI
sIDENT
sESCAPEDIDENT
sURL
sUCR

Function Documentation

css__lexer_create()

css_error css__lexer_create	(	parserutils_inputstream *	input,
		css_lexer **	lexer
	)

Create a lexer instance

Parameters

input	The inputstream to read from
lexer	Pointer to location to receive lexer instance

Returns

CSS_OK on success, CSS_BADPARM on bad parameters, CSS_NOMEM on memory exhaustion

css__lexer_destroy()

css_error css__lexer_destroy

(

css_lexer *

lexer

)

Destroy a lexer instance

Parameters

lexer

The instance to destroy

Returns

CSS_OK on success, appropriate error otherwise

css__lexer_get_token()

css_error css__lexer_get_token	(	css_lexer *	lexer,
		css_token **	token
	)

Retrieve a token from a lexer

Parameters

lexer	The lexer instance to read from
token	Pointer to location to receive pointer to token

Returns

CSS_OK on success, appropriate error otherwise

The returned token object is owned by the lexer. However, the client is permitted to modify the data members of the token. The token must not be freed by the client (it may not have been allocated in the first place), nor may any of the pointers contained within it. The client may, if they wish, overwrite any data member of the returned token object – the lexer does not depend on these remaining constant. This allows the client code to efficiently implement a push-back buffer with interned string data.

css__lexer_setopt()

css_error css__lexer_setopt	(	css_lexer *	lexer,
		css_lexer_opttype	type,
		css_lexer_optparams *	params
	)

Configure a lexer instance

Parameters

lexer	The lexer to configure
type	The option type to modify
params	Option-specific parameters

Returns

CSS_OK on success, appropriate error otherwise