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Diffstat (limited to 'pjlib-util/include/pjlib-util/scanner.h')
-rw-r--r-- | pjlib-util/include/pjlib-util/scanner.h | 456 |
1 files changed, 456 insertions, 0 deletions
diff --git a/pjlib-util/include/pjlib-util/scanner.h b/pjlib-util/include/pjlib-util/scanner.h new file mode 100644 index 00000000..f1b0b133 --- /dev/null +++ b/pjlib-util/include/pjlib-util/scanner.h @@ -0,0 +1,456 @@ +/* $Id$ + * + */ + +#ifndef __PJ_PARSER_H__ +#define __PJ_PARSER_H__ + +/** + * @file scanner.h + * @brief Text Scanning. + */ + +#include <pj/types.h> + +PJ_BEGIN_DECL + +/** + * @defgroup PJ_SCAN Text Scanning + * @ingroup PJ_MISC + * @brief + * Text scanning utility. + */ + +/** + * @defgroup PJ_CHARSPEC Character Filter Specification + * @ingroup PJ_SCAN + * @brief + * The type pj_char_spec is a specification of character set used in + * scanner. Application can define multiple character specs, such as to + * scan alpha numerics, numbers, tokens, etc. + * @{ + */ + +/** + * This describes the type of individual character specification in + * #pj_char_spec. + */ +typedef pj_uint8_t pj_char_spec_element_t; + +/** + * The character specification is implemented as array of boolean flags. Each + * flag indicates the membership of the character in the spec. If the flag + * at one position is non-zero, then the character at that position belongs + * to the specification, and vice versa. + */ +typedef pj_char_spec_element_t pj_char_spec[256]; +// Note: it's got to be 256 (not 128) to cater for extended character in input. + +/** + * Initialize character spec. + * @param cs the scanner character specification. + */ +PJ_DECL(void) pj_cs_init( pj_char_spec cs); + +/** + * Set the membership of the specified character to TRUE. + * @param cs the scanner character specification. + * @param c the character. + */ +PJ_DECL(void) pj_cs_set( pj_char_spec cs, int c); + +/** + * Add the characters in the specified range '[cstart, cend)' to the + * specification (the last character itself ('cend') is not added). + * @param cs the scanner character specification. + * @param cstart the first character in the range. + * @param cend the next character after the last character in the range. + */ +PJ_DECL(void) pj_cs_add_range( pj_char_spec cs, int cstart, int cend); + +/** + * Add alphabetic characters to the specification. + * @param cs the scanner character specification. + */ +PJ_DECL(void) pj_cs_add_alpha( pj_char_spec cs); + +/** + * Add numeric characters to the specification. + * @param cs the scanner character specification. + */ +PJ_DECL(void) pj_cs_add_num( pj_char_spec cs); + +/** + * Add the characters in the string to the specification. + * @param cs the scanner character specification. + * @param str the string. + */ +PJ_DECL(void) pj_cs_add_str( pj_char_spec cs, const char *str); + +/** + * Delete characters in the specified range from the specification. + * @param cs the scanner character specification. + * @param cstart the first character in the range. + * @param cend the next character after the last character in the range. + */ +PJ_DECL(void) pj_cs_del_range( pj_char_spec cs, int cstart, int cend); + +/** + * Delete characters in the specified string from the specification. + * @param cs the scanner character specification. + * @param str the string. + */ +PJ_DECL(void) pj_cs_del_str( pj_char_spec cs, const char *str); + +/** + * Invert specification. + * @param cs the scanner character specification. + */ +PJ_DECL(void) pj_cs_invert( pj_char_spec cs ); + +/** + * Check whether the specified character belongs to the specification. + * @param cs the scanner character specification. + * @param c the character to check for matching. + */ +PJ_INLINE(int) pj_cs_match( const pj_char_spec cs, int c ) +{ + return cs[c]; +} + +/** + * @} + */ + +/** + * @defgroup PJ_SCANNER Text Scanner + * @ingroup PJ_SCAN + * @{ + */ + +/** + * Flags for scanner. + */ +enum +{ + /** This flags specifies that the scanner should automatically skip + whitespaces + */ + PJ_SCAN_AUTOSKIP_WS = 1, + + /** This flags specifies that the scanner should automatically skip + SIP header continuation. This flag implies PJ_SCAN_AUTOSKIP_WS. + */ + PJ_SCAN_AUTOSKIP_WS_HEADER = 3, + + /** Auto-skip new lines. + */ + PJ_SCAN_AUTOSKIP_NEWLINE = 4, +}; + + +/* Forward decl. */ +struct pj_scanner; + + +/** + * The callback function type to be called by the scanner when it encounters + * syntax error. + * @param scanner The scanner instance that calls the callback . + */ +typedef void (*pj_syn_err_func_ptr)(struct pj_scanner *scanner); + + +/** + * The text scanner structure. + */ +typedef struct pj_scanner +{ + char *begin; /**< Start of input buffer. */ + char *end; /**< End of input buffer. */ + char *curptr; /**< Current pointer. */ + int line; /**< Current line. */ + int col; /**< Current column. */ + int skip_ws; /**< Skip whitespace flag. */ + pj_syn_err_func_ptr callback; /**< Syntax error callback. */ +} pj_scanner; + + +/** + * This structure can be used by application to store the state of the parser, + * so that the scanner state can be rollback to this state when necessary. + */ +typedef struct pj_scan_state +{ + char *curptr; /**< Current scanner's pointer. */ + int line; /**< Current line. */ + int col; /**< Current column. */ +} pj_scan_state; + + +/** + * Initialize the scanner. Note that the input string buffer must have + * length at least buflen+1 because the scanner will NULL terminate the + * string during initialization. + * + * @param scanner The scanner to be initialized. + * @param bufstart The input buffer to scan. Note that buffer[buflen] will be + * filled with NULL char until scanner is destroyed, so + * the actual buffer length must be at least buflen+1. + * @param buflen The length of the input buffer, which normally is + * strlen(bufstart). + * @param options Zero, or combination of PJ_SCAN_AUTOSKIP_WS or + * PJ_SCAN_AUTOSKIP_WS_HEADER + * @param callback Callback to be called when the scanner encounters syntax + * error condition. + */ +PJ_DECL(void) pj_scan_init( pj_scanner *scanner, char *bufstart, int buflen, + unsigned options, + pj_syn_err_func_ptr callback ); + + +/** + * Call this function when application has finished using the scanner. + * + * @param scanner The scanner. + */ +PJ_DECL(void) pj_scan_fini( pj_scanner *scanner ); + + +/** + * Determine whether the EOF condition for the scanner has been met. + * + * @param scanner The scanner. + * + * @return Non-zero if scanner is EOF. + */ +PJ_INLINE(int) pj_scan_is_eof( const pj_scanner *scanner) +{ + return scanner->curptr >= scanner->end; +} + + +/** + * Peek strings in current position according to parameter spec, and return + * the strings in parameter out. The current scanner position will not be + * moved. If the scanner is already in EOF state, syntax error callback will + * be called thrown. + * + * @param scanner The scanner. + * @param spec The spec to match input string. + * @param out String to store the result. + * + * @return the character right after the peek-ed position or zero if there's + * no more characters. + */ +PJ_DECL(int) pj_scan_peek( pj_scanner *scanner, + const pj_char_spec spec, pj_str_t *out); + + +/** + * Peek len characters in current position, and return them in out parameter. + * Note that whitespaces or newlines will be returned as it is, regardless + * of PJ_SCAN_AUTOSKIP_WS settings. If the character left is less than len, + * syntax error callback will be called. + * + * @param scanner The scanner. + * @param len Length to peek. + * @param out String to store the result. + * + * @return the character right after the peek-ed position or zero if there's + * no more characters. + */ +PJ_DECL(int) pj_scan_peek_n( pj_scanner *scanner, + pj_size_t len, pj_str_t *out); + + +/** + * Peek strings in current position until spec is matched, and return + * the strings in parameter out. The current scanner position will not be + * moved. If the scanner is already in EOF state, syntax error callback will + * be called. + * + * @param scanner The scanner. + * @param spec The peeking will stop when the input match this spec. + * @param out String to store the result. + * + * @return the character right after the peek-ed position. + */ +PJ_DECL(int) pj_scan_peek_until( pj_scanner *scanner, + const pj_char_spec spec, + pj_str_t *out); + + +/** + * Get characters from the buffer according to the spec, and return them + * in out parameter. The scanner will attempt to get as many characters as + * possible as long as the spec matches. If the first character doesn't + * match the spec, or scanner is already in EOF when this function is called, + * an exception will be thrown. + * + * @param scanner The scanner. + * @param spec The spec to match input string. + * @param out String to store the result. + */ +PJ_DECL(void) pj_scan_get( pj_scanner *scanner, + const pj_char_spec spec, pj_str_t *out); + + +/** + * Get characters between quotes. If current input doesn't match begin_quote, + * syntax error will be thrown. + * + * @param scanner The scanner. + * @param begin_quote The character to begin the quote. + * @param end_quote The character to end the quote. + * @param out String to store the result. + */ +PJ_DECL(void) pj_scan_get_quote( pj_scanner *scanner, + int begin_quote, int end_quote, + pj_str_t *out); + +/** + * Get N characters from the scanner. + * + * @param scanner The scanner. + * @param N Number of characters to get. + * @param out String to store the result. + */ +PJ_DECL(void) pj_scan_get_n( pj_scanner *scanner, + unsigned N, pj_str_t *out); + + +/** + * Get one character from the scanner. + * + * @param scanner The scanner. + * + * @return (unknown) + */ +PJ_DECL(int) pj_scan_get_char( pj_scanner *scanner ); + + +/** + * Get a newline from the scanner. A newline is defined as '\\n', or '\\r', or + * "\\r\\n". If current input is not newline, syntax error will be thrown. + * + * @param scanner The scanner. + */ +PJ_DECL(void) pj_scan_get_newline( pj_scanner *scanner ); + + +/** + * Get characters from the scanner and move the scanner position until the + * current character matches the spec. + * + * @param scanner The scanner. + * @param spec Get until the input match this spec. + * @param out String to store the result. + */ +PJ_DECL(void) pj_scan_get_until( pj_scanner *scanner, + const pj_char_spec spec, pj_str_t *out); + + +/** + * Get characters from the scanner and move the scanner position until the + * current character matches until_char. + * + * @param scanner The scanner. + * @param until_char Get until the input match this character. + * @param out String to store the result. + */ +PJ_DECL(void) pj_scan_get_until_ch( pj_scanner *scanner, + int until_char, pj_str_t *out); + + +/** + * Get characters from the scanner and move the scanner position until the + * current character matches until_char. + * + * @param scanner The scanner. + * @param until_spec Get until the input match any of these characters. + * @param out String to store the result. + */ +PJ_DECL(void) pj_scan_get_until_chr( pj_scanner *scanner, + const char *until_spec, pj_str_t *out); + +/** + * Advance the scanner N characters, and skip whitespace + * if necessary. + * + * @param scanner The scanner. + * @param N Number of characters to skip. + * @param skip Flag to specify whether whitespace should be skipped + * after skipping the characters. + */ +PJ_DECL(void) pj_scan_advance_n( pj_scanner *scanner, + unsigned N, pj_bool_t skip); + + +/** + * Compare string in current position with the specified string. + * + * @param scanner The scanner. + * @param s The string to compare with. + * @param len Length of the string to compare. + * + * @return zero, <0, or >0 (just like strcmp()). + */ +PJ_DECL(int) pj_scan_strcmp( pj_scanner *scanner, const char *s, int len); + + +/** + * Case-less string comparison of current position with the specified + * string. + * + * @param scanner The scanner. + * @param s The string to compare with. + * @param len Length of the string to compare with. + * + * @return zero, <0, or >0 (just like strcmp()). + */ +PJ_DECL(int) pj_scan_stricmp( pj_scanner *scanner, const char *s, int len); + + +/** + * Manually skip whitespaces according to flag that was specified when + * the scanner was initialized. + * + * @param scanner The scanner. + */ +PJ_DECL(void) pj_scan_skip_whitespace( pj_scanner *scanner ); + + +/** + * Save the full scanner state. + * + * @param scanner The scanner. + * @param state Variable to store scanner's state. + */ +PJ_DECL(void) pj_scan_save_state( pj_scanner *scanner, pj_scan_state *state); + + +/** + * Restore the full scanner state. + * Note that this would not restore the string if application has modified + * it. This will only restore the scanner scanning position. + * + * @param scanner The scanner. + * @param state State of the scanner. + */ +PJ_DECL(void) pj_scan_restore_state( pj_scanner *scanner, + pj_scan_state *state); + +/** + * @} + */ + +#if PJ_FUNCTIONS_ARE_INLINED +# include "scanner_i.h" +#endif + + +PJ_END_DECL + +#endif + |