455 lines
12 KiB
C
455 lines
12 KiB
C
/* $Header: /pjproject-0.3/pjlib/include/pj/scanner.h 10 10/14/05 12:26a Bennylp $ */
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#ifndef __PJ_PARSER_H__
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#define __PJ_PARSER_H__
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/**
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* @file scanner.h
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* @brief Text Scanning.
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*/
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#include <pj/types.h>
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PJ_BEGIN_DECL
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/**
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* @defgroup PJ_SCAN Text Scanning
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* @ingroup PJ_MISC
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* @brief
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* Text scanning utility.
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*/
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/**
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* @defgroup PJ_CHARSPEC Character Filter Specification
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* @ingroup PJ_SCAN
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* @brief
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* The type pj_char_spec is a specification of character set used in
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* scanner. Application can define multiple character specs, such as to
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* scan alpha numerics, numbers, tokens, etc.
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* @{
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*/
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/**
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* This describes the type of individual character specification in
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* #pj_char_spec.
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*/
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typedef pj_uint8_t pj_char_spec_element_t;
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/**
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* The character specification is implemented as array of boolean flags. Each
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* flag indicates the membership of the character in the spec. If the flag
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* at one position is non-zero, then the character at that position belongs
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* to the specification, and vice versa.
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*/
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typedef pj_char_spec_element_t pj_char_spec[256];
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// Note: it's got to be 256 (not 128) to cater for extended character in input.
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/**
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* Initialize character spec.
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* @param cs the scanner character specification.
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*/
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PJ_DECL(void) pj_cs_init( pj_char_spec cs);
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/**
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* Set the membership of the specified character to TRUE.
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* @param cs the scanner character specification.
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* @param c the character.
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*/
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PJ_DECL(void) pj_cs_set( pj_char_spec cs, int c);
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/**
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* Add the characters in the specified range '[cstart, cend)' to the
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* specification (the last character itself ('cend') is not added).
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* @param cs the scanner character specification.
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* @param cstart the first character in the range.
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* @param cend the next character after the last character in the range.
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*/
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PJ_DECL(void) pj_cs_add_range( pj_char_spec cs, int cstart, int cend);
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/**
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* Add alphabetic characters to the specification.
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* @param cs the scanner character specification.
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*/
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PJ_DECL(void) pj_cs_add_alpha( pj_char_spec cs);
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/**
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* Add numeric characters to the specification.
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* @param cs the scanner character specification.
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*/
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PJ_DECL(void) pj_cs_add_num( pj_char_spec cs);
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/**
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* Add the characters in the string to the specification.
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* @param cs the scanner character specification.
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* @param str the string.
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*/
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PJ_DECL(void) pj_cs_add_str( pj_char_spec cs, const char *str);
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/**
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* Delete characters in the specified range from the specification.
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* @param cs the scanner character specification.
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* @param cstart the first character in the range.
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* @param cend the next character after the last character in the range.
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*/
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PJ_DECL(void) pj_cs_del_range( pj_char_spec cs, int cstart, int cend);
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/**
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* Delete characters in the specified string from the specification.
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* @param cs the scanner character specification.
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* @param str the string.
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*/
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PJ_DECL(void) pj_cs_del_str( pj_char_spec cs, const char *str);
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/**
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* Invert specification.
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* @param cs the scanner character specification.
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*/
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PJ_DECL(void) pj_cs_invert( pj_char_spec cs );
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/**
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* Check whether the specified character belongs to the specification.
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* @param cs the scanner character specification.
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* @param c the character to check for matching.
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*/
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PJ_INLINE(int) pj_cs_match( const pj_char_spec cs, int c )
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{
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return cs[c];
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}
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/**
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* @}
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*/
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/**
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* @defgroup PJ_SCANNER Text Scanner
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* @ingroup PJ_SCAN
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* @{
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*/
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/**
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* Flags for scanner.
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*/
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enum
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{
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/** This flags specifies that the scanner should automatically skip
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whitespaces
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*/
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PJ_SCAN_AUTOSKIP_WS = 1,
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/** This flags specifies that the scanner should automatically skip
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SIP header continuation. This flag implies PJ_SCAN_AUTOSKIP_WS.
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*/
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PJ_SCAN_AUTOSKIP_WS_HEADER = 3,
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/** Auto-skip new lines.
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*/
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PJ_SCAN_AUTOSKIP_NEWLINE = 4,
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};
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/* Forward decl. */
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struct pj_scanner;
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/**
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* The callback function type to be called by the scanner when it encounters
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* syntax error.
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* @param scanner The scanner instance that calls the callback .
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*/
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typedef void (*pj_syn_err_func_ptr)(struct pj_scanner *scanner);
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/**
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* The text scanner structure.
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*/
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typedef struct pj_scanner
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{
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char *begin; /**< Start of input buffer. */
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char *end; /**< End of input buffer. */
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char *curptr; /**< Current pointer. */
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int line; /**< Current line. */
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int col; /**< Current column. */
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int skip_ws; /**< Skip whitespace flag. */
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pj_syn_err_func_ptr callback; /**< Syntax error callback. */
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} pj_scanner;
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/**
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* This structure can be used by application to store the state of the parser,
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* so that the scanner state can be rollback to this state when necessary.
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*/
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typedef struct pj_scan_state
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{
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char *curptr; /**< Current scanner's pointer. */
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int line; /**< Current line. */
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int col; /**< Current column. */
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} pj_scan_state;
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/**
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* Initialize the scanner. Note that the input string buffer must have
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* length at least buflen+1 because the scanner will NULL terminate the
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* string during initialization.
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*
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* @param scanner The scanner to be initialized.
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* @param bufstart The input buffer to scan. Note that buffer[buflen] will be
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* filled with NULL char until scanner is destroyed, so
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* the actual buffer length must be at least buflen+1.
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* @param buflen The length of the input buffer, which normally is
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* strlen(bufstart).
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* @param options Zero, or combination of PJ_SCAN_AUTOSKIP_WS or
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* PJ_SCAN_AUTOSKIP_WS_HEADER
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* @param callback Callback to be called when the scanner encounters syntax
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* error condition.
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*/
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PJ_DECL(void) pj_scan_init( pj_scanner *scanner, char *bufstart, int buflen,
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unsigned options,
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pj_syn_err_func_ptr callback );
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/**
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* Call this function when application has finished using the scanner.
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*
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* @param scanner The scanner.
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*/
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PJ_DECL(void) pj_scan_fini( pj_scanner *scanner );
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/**
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* Determine whether the EOF condition for the scanner has been met.
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*
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* @param scanner The scanner.
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*
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* @return Non-zero if scanner is EOF.
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*/
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PJ_INLINE(int) pj_scan_is_eof( const pj_scanner *scanner)
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{
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return scanner->curptr >= scanner->end;
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}
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/**
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* Peek strings in current position according to parameter spec, and return
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* the strings in parameter out. The current scanner position will not be
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* moved. If the scanner is already in EOF state, syntax error callback will
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* be called thrown.
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*
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* @param scanner The scanner.
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* @param spec The spec to match input string.
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* @param out String to store the result.
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*
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* @return the character right after the peek-ed position or zero if there's
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* no more characters.
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*/
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PJ_DECL(int) pj_scan_peek( pj_scanner *scanner,
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const pj_char_spec spec, pj_str_t *out);
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/**
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* Peek len characters in current position, and return them in out parameter.
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* Note that whitespaces or newlines will be returned as it is, regardless
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* of PJ_SCAN_AUTOSKIP_WS settings. If the character left is less than len,
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* syntax error callback will be called.
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*
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* @param scanner The scanner.
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* @param len Length to peek.
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* @param out String to store the result.
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*
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* @return the character right after the peek-ed position or zero if there's
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* no more characters.
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*/
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PJ_DECL(int) pj_scan_peek_n( pj_scanner *scanner,
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pj_size_t len, pj_str_t *out);
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/**
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* Peek strings in current position until spec is matched, and return
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* the strings in parameter out. The current scanner position will not be
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* moved. If the scanner is already in EOF state, syntax error callback will
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* be called.
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*
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* @param scanner The scanner.
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* @param spec The peeking will stop when the input match this spec.
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* @param out String to store the result.
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*
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* @return the character right after the peek-ed position.
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*/
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PJ_DECL(int) pj_scan_peek_until( pj_scanner *scanner,
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const pj_char_spec spec,
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pj_str_t *out);
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/**
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* Get characters from the buffer according to the spec, and return them
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* in out parameter. The scanner will attempt to get as many characters as
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* possible as long as the spec matches. If the first character doesn't
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* match the spec, or scanner is already in EOF when this function is called,
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* an exception will be thrown.
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*
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* @param scanner The scanner.
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* @param spec The spec to match input string.
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* @param out String to store the result.
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*/
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PJ_DECL(void) pj_scan_get( pj_scanner *scanner,
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const pj_char_spec spec, pj_str_t *out);
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/**
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* Get characters between quotes. If current input doesn't match begin_quote,
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* syntax error will be thrown.
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*
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* @param scanner The scanner.
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* @param begin_quote The character to begin the quote.
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* @param end_quote The character to end the quote.
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* @param out String to store the result.
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*/
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PJ_DECL(void) pj_scan_get_quote( pj_scanner *scanner,
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int begin_quote, int end_quote,
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pj_str_t *out);
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/**
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* Get N characters from the scanner.
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*
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* @param scanner The scanner.
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* @param N Number of characters to get.
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* @param out String to store the result.
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*/
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PJ_DECL(void) pj_scan_get_n( pj_scanner *scanner,
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unsigned N, pj_str_t *out);
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/**
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* Get one character from the scanner.
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*
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* @param scanner The scanner.
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*
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* @return (unknown)
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*/
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PJ_DECL(int) pj_scan_get_char( pj_scanner *scanner );
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/**
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* Get a newline from the scanner. A newline is defined as '\\n', or '\\r', or
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* "\\r\\n". If current input is not newline, syntax error will be thrown.
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*
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* @param scanner The scanner.
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*/
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PJ_DECL(void) pj_scan_get_newline( pj_scanner *scanner );
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/**
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* Get characters from the scanner and move the scanner position until the
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* current character matches the spec.
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*
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* @param scanner The scanner.
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* @param spec Get until the input match this spec.
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* @param out String to store the result.
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*/
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PJ_DECL(void) pj_scan_get_until( pj_scanner *scanner,
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const pj_char_spec spec, pj_str_t *out);
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/**
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* Get characters from the scanner and move the scanner position until the
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* current character matches until_char.
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*
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* @param scanner The scanner.
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* @param until_char Get until the input match this character.
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* @param out String to store the result.
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*/
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PJ_DECL(void) pj_scan_get_until_ch( pj_scanner *scanner,
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int until_char, pj_str_t *out);
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/**
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* Get characters from the scanner and move the scanner position until the
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* current character matches until_char.
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*
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* @param scanner The scanner.
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* @param until_spec Get until the input match any of these characters.
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* @param out String to store the result.
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*/
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PJ_DECL(void) pj_scan_get_until_chr( pj_scanner *scanner,
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const char *until_spec, pj_str_t *out);
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/**
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* Advance the scanner N characters, and skip whitespace
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* if necessary.
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*
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* @param scanner The scanner.
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* @param N Number of characters to skip.
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* @param skip Flag to specify whether whitespace should be skipped
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* after skipping the characters.
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*/
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PJ_DECL(void) pj_scan_advance_n( pj_scanner *scanner,
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unsigned N, pj_bool_t skip);
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/**
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* Compare string in current position with the specified string.
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*
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* @param scanner The scanner.
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* @param s The string to compare with.
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* @param len Length of the string to compare.
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*
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* @return zero, <0, or >0 (just like strcmp()).
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*/
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PJ_DECL(int) pj_scan_strcmp( pj_scanner *scanner, const char *s, int len);
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/**
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* Case-less string comparison of current position with the specified
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* string.
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*
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* @param scanner The scanner.
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* @param s The string to compare with.
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* @param len Length of the string to compare with.
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*
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* @return zero, <0, or >0 (just like strcmp()).
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*/
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PJ_DECL(int) pj_scan_stricmp( pj_scanner *scanner, const char *s, int len);
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/**
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* Manually skip whitespaces according to flag that was specified when
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* the scanner was initialized.
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*
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* @param scanner The scanner.
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*/
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PJ_DECL(void) pj_scan_skip_whitespace( pj_scanner *scanner );
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/**
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* Save the full scanner state.
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*
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* @param scanner The scanner.
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* @param state Variable to store scanner's state.
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*/
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PJ_DECL(void) pj_scan_save_state( pj_scanner *scanner, pj_scan_state *state);
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/**
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* Restore the full scanner state.
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* Note that this would not restore the string if application has modified
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* it. This will only restore the scanner scanning position.
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*
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* @param scanner The scanner.
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* @param state State of the scanner.
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*/
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PJ_DECL(void) pj_scan_restore_state( pj_scanner *scanner,
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pj_scan_state *state);
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/**
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* @}
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*/
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#if PJ_FUNCTIONS_ARE_INLINED
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# include "scanner_i.h"
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#endif
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PJ_END_DECL
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#endif
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