regex.h

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{
  REG_NOERROR = 0,	/* Success.  */
  REG_NOMATCH,		/* Didn't find a match (for regexec).  */

  /* POSIX regcomp return error codes.  (In the order listed in the
     standard.)  */
  REG_BADPAT,		/* Invalid pattern.  */
  REG_ECOLLATE,		/* Not implemented.  */
  REG_ECTYPE,		/* Invalid character class name.  */
  REG_EESCAPE,		/* Trailing backslash.  */
  REG_ESUBREG,		/* Invalid back reference.  */
  REG_EBRACK,		/* Unmatched left bracket.  */
  REG_EPAREN,		/* Parenthesis imbalance.  */ 
  REG_EBRACE,		/* Unmatched \{.  */
  REG_BADBR,		/* Invalid contents of \{\}.  */
  REG_ERANGE,		/* Invalid range end.  */
  REG_ESPACE,		/* Ran out of memory.  */
  REG_BADRPT,		/* No preceding re for repetition op.  */

  /* Error codes we've added.  */
  REG_EEND,		/* Premature end.  */
  REG_ESIZE,		/* Compiled pattern bigger than 2^16 bytes.  */
  REG_ERPAREN		/* Unmatched ) or \); not returned from regcomp.  */
} reg_errcode_t;

/* This data structure represents a compiled pattern.  Before calling
   the pattern compiler, the fields `buffer', `allocated', `fastmap',
   `translate', and `no_sub' can be set.  After the pattern has been
   compiled, the `re_nsub' field is available.  All other fields are
   private to the regex routines.  */

struct re_pattern_buffer
{
/* [[[begin pattern_buffer]]] */
	/* Space that holds the compiled pattern.  It is declared as
          `unsigned char *' because its elements are
           sometimes used as array indexes.  */
  unsigned char *buffer;

	/* Number of bytes to which `buffer' points.  */
  unsigned long allocated;

	/* Number of bytes actually used in `buffer'.  */
  unsigned long used;	

        /* Syntax setting with which the pattern was compiled.  */
  reg_syntax_t syntax;

        /* Pointer to a fastmap, if any, otherwise zero.  re_search uses
           the fastmap, if there is one, to skip over impossible
           starting points for matches.  */
  char *fastmap;

        /* Either a translate table to apply to all characters before
           comparing them, or zero for no translation.  The translation
           is applied to a pattern when it is compiled and to a string
           when it is matched.  */
  char *translate;

	/* Number of subexpressions found by the compiler.  */
  size_t re_nsub;

        /* Zero if this pattern cannot match the empty string, one else.
           Well, in truth it's used only in `re_search_2', to see
           whether or not we should use the fastmap, so we don't set
           this absolutely perfectly; see `re_compile_fastmap' (the
           `duplicate' case).  */
  unsigned can_be_null : 1;

        /* If REGS_UNALLOCATED, allocate space in the `regs' structure
             for `max (RE_NREGS, re_nsub + 1)' groups.
           If REGS_REALLOCATE, reallocate space if necessary.
           If REGS_FIXED, use what's there.  */
#define REGS_UNALLOCATED 0
#define REGS_REALLOCATE 1
#define REGS_FIXED 2
  unsigned regs_allocated : 2;

        /* Set to zero when `regex_compile' compiles a pattern; set to one
           by `re_compile_fastmap' if it updates the fastmap.  */
  unsigned fastmap_accurate : 1;

        /* If set, `re_match_2' does not return information about
           subexpressions.  */
  unsigned no_sub : 1;

        /* If set, a beginning-of-line anchor doesn't match at the
           beginning of the string.  */ 
  unsigned not_bol : 1;

        /* Similarly for an end-of-line anchor.  */
  unsigned not_eol : 1;

        /* If true, an anchor at a newline matches.  */
  unsigned newline_anchor : 1;

/* [[[end pattern_buffer]]] */
};

typedef struct re_pattern_buffer regex_t;


/* search.c (search_buffer) in Emacs needs this one opcode value.  It is
   defined both in `regex.c' and here.  */
#define RE_EXACTN_VALUE 1

/* Type for byte offsets within the string.  POSIX mandates this.  */
typedef int regoff_t;


/* This is the structure we store register match data in.  See
   regex.texinfo for a full description of what registers match.  */
struct re_registers
{
  unsigned num_regs;
  regoff_t *start;
  regoff_t *end;
};


/* If `regs_allocated' is REGS_UNALLOCATED in the pattern buffer,
   `re_match_2' returns information about at least this many registers
   the first time a `regs' structure is passed.  */
#ifndef RE_NREGS
#define RE_NREGS 30
#endif


/* POSIX specification for registers.  Aside from the different names than
   `re_registers', POSIX uses an array of structures, instead of a
   structure of arrays.  */
typedef struct
{
  regoff_t rm_so;  /* Byte offset from string's start to substring's start.  */
  regoff_t rm_eo;  /* Byte offset from string's start to substring's end.  */
} regmatch_t;

/* Declarations for routines.  */

/* To avoid duplicating every routine declaration -- once with a
   prototype (if we are ANSI), and once without (if we aren't) -- we
   use the following macro to declare argument types.  This
   unfortunately clutters up the declarations a bit, but I think it's
   worth it.  */

#if __STDC__

#define _RE_ARGS(args) args

#else /* not __STDC__ */

#define _RE_ARGS(args) ()

#endif /* not __STDC__ */

/* Sets the current default syntax to SYNTAX, and return the old syntax.
   You can also simply assign to the `re_syntax_options' variable.  */
extern reg_syntax_t re_set_syntax _RE_ARGS ((reg_syntax_t syntax));

/* Compile the regular expression PATTERN, with length LENGTH
   and syntax given by the global `re_syntax_options', into the buffer
   BUFFER.  Return NULL if successful, and an error string if not.  */
extern const char *re_compile_pattern
  _RE_ARGS ((const char *pattern, int length,
             struct re_pattern_buffer *buffer));


/* Compile a fastmap for the compiled pattern in BUFFER; used to
   accelerate searches.  Return 0 if successful and -2 if was an
   internal error.  */
extern int re_compile_fastmap _RE_ARGS ((struct re_pattern_buffer *buffer));


/* Search in the string STRING (with length LENGTH) for the pattern
   compiled into BUFFER.  Start searching at position START, for RANGE
   characters.  Return the starting position of the match, -1 for no
   match, or -2 for an internal error.  Also return register
   information in REGS (if REGS and BUFFER->no_sub are nonzero).  */
extern int re_search
  _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string,
            int length, int start, int range, struct re_registers *regs));


/* Like `re_search', but search in the concatenation of STRING1 and
   STRING2.  Also, stop searching at index START + STOP.  */
extern int re_search_2
  _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string1,
             int length1, const char *string2, int length2,
             int start, int range, struct re_registers *regs, int stop));


/* Like `re_search', but return how many characters in STRING the regexp
   in BUFFER matched, starting at position START.  */
extern int re_match
  _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string,
             int length, int start, struct re_registers *regs));


/* Relates to `re_match' as `re_search_2' relates to `re_search'.  */
extern int re_match_2 
  _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string1,
             int length1, const char *string2, int length2,
             int start, struct re_registers *regs, int stop));


/* Set REGS to hold NUM_REGS registers, storing them in STARTS and
   ENDS.  Subsequent matches using BUFFER and REGS will use this memory
   for recording register information.  STARTS and ENDS must be
   allocated with malloc, and must each be at least `NUM_REGS * sizeof
   (regoff_t)' bytes long.

   If NUM_REGS == 0, then subsequent matches should allocate their own
   register data.

   Unless this function is called, the first search or match using
   PATTERN_BUFFER will allocate its own register data, without
   freeing the old data.  */
extern void re_set_registers
  _RE_ARGS ((struct re_pattern_buffer *buffer, struct re_registers *regs,
             unsigned num_regs, regoff_t *starts, regoff_t *ends));

/* 4.2 bsd compatibility.  */
extern char *re_comp _RE_ARGS ((const char *));
extern int re_exec _RE_ARGS ((const char *));

/* POSIX compatibility.  */
extern int regcomp _RE_ARGS ((regex_t *preg, const char *pattern, int cflags));
extern int regexec
  _RE_ARGS ((const regex_t *preg, const char *string, size_t nmatch,
             regmatch_t pmatch[], int eflags));
extern size_t regerror
  _RE_ARGS ((int errcode, const regex_t *preg, char *errbuf,
             size_t errbuf_size));
extern void regfree _RE_ARGS ((regex_t *preg));

#endif /* not __REGEXP_LIBRARY_H__ */

/*
Local variables:
make-backup-files: t
version-control: t
trim-versions-without-asking: nil
End:
*/