/*
 * -*- mode: c-mode; c-file-style: python -*-
 */

#ifndef Py_REGEXPR_H
#define Py_REGEXPR_H
#ifdef __cplusplus
extern "C" {
#endif

/*
 * regexpr.h
 *
 * Author: Tatu Ylonen <ylo@ngs.fi>
 *
 * Copyright (c) 1991 Tatu Ylonen, Espoo, Finland
 *
 * Permission to use, copy, modify, distribute, and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies.  This
 * software is provided "as is" without express or implied warranty.
 *
 * Created: Thu Sep 26 17:15:36 1991 ylo
 * Last modified: Mon Nov  4 15:49:46 1991 ylo
 */

/* $Id$ */

#ifndef REGEXPR_H
#define REGEXPR_H

#define RE_NREGS	100  /* number of registers available */

typedef struct re_pattern_buffer
{
	unsigned char *buffer;          /* compiled pattern */
	int allocated;         /* allocated size of compiled pattern */
	int used;              /* actual length of compiled pattern */
	unsigned char *fastmap;         /* fastmap[ch] is true if ch can start pattern */
	unsigned char *translate;       /* translation to apply during compilation/matching */
	unsigned char fastmap_accurate; /* true if fastmap is valid */
	unsigned char can_be_null;      /* true if can match empty string */
	unsigned char uses_registers;   /* registers are used and need to be initialized */
	int num_registers;     /* number of registers used */
	unsigned char anchor;           /* anchor: 0=none 1=begline 2=begbuf */
} *regexp_t;

typedef struct re_registers
{
	int start[RE_NREGS];  /* start offset of region */
	int end[RE_NREGS];    /* end offset of region */
} *regexp_registers_t;

/* bit definitions for syntax */
#define RE_NO_BK_PARENS		1    /* no quoting for parentheses */
#define RE_NO_BK_VBAR		2    /* no quoting for vertical bar */
#define RE_BK_PLUS_QM		4    /* quoting needed for + and ? */
#define RE_TIGHT_VBAR		8    /* | binds tighter than ^ and $ */
#define RE_NEWLINE_OR		16   /* treat newline as or */
#define RE_CONTEXT_INDEP_OPS	32   /* ^$?*+ are special in all contexts */
#define RE_ANSI_HEX		64   /* ansi sequences (\n etc) and \xhh */
#define RE_NO_GNU_EXTENSIONS   128   /* no gnu extensions */

/* definitions for some common regexp styles */
#define RE_SYNTAX_AWK	(RE_NO_BK_PARENS|RE_NO_BK_VBAR|RE_CONTEXT_INDEP_OPS)
#define RE_SYNTAX_EGREP	(RE_SYNTAX_AWK|RE_NEWLINE_OR)
#define RE_SYNTAX_GREP	(RE_BK_PLUS_QM|RE_NEWLINE_OR)
#define RE_SYNTAX_EMACS	0

#define Sword       1
#define Swhitespace 2
#define Sdigit      4
#define Soctaldigit 8
#define Shexdigit   16

/* Rename all exported symbols to avoid conflicts with similarly named
   symbols in some systems' standard C libraries... */

#define re_syntax _Py_re_syntax
#define re_syntax_table _Py_re_syntax_table
#define re_compile_initialize _Py_re_compile_initialize
#define re_set_syntax _Py_re_set_syntax
#define re_compile_pattern _Py_re_compile_pattern
#define re_match _Py_re_match
#define re_search _Py_re_search
#define re_compile_fastmap _Py_re_compile_fastmap
#define re_comp _Py_re_comp
#define re_exec _Py_re_exec

#ifdef HAVE_PROTOTYPES

extern int re_syntax;
/* This is the actual syntax mask.  It was added so that Python could do
 * syntax-dependent munging of patterns before compilation. */

extern unsigned char re_syntax_table[256];

void re_compile_initialize(void);

int re_set_syntax(int syntax);
/* This sets the syntax to use and returns the previous syntax.  The
 * syntax is specified by a bit mask of the above defined bits. */

char *re_compile_pattern(unsigned char *regex, int regex_size, regexp_t compiled);
/* This compiles the regexp (given in regex and length in regex_size).
 * This returns NULL if the regexp compiled successfully, and an error
 * message if an error was encountered.  The buffer field must be
 * initialized to a memory area allocated by malloc (or to NULL) before
 * use, and the allocated field must be set to its length (or 0 if
 * buffer is NULL).  Also, the translate field must be set to point to a
 * valid translation table, or NULL if it is not used. */

int re_match(regexp_t compiled, unsigned char *string, int size, int pos,
	     regexp_registers_t old_regs);
/* This tries to match the regexp against the string.  This returns the
 * length of the matched portion, or -1 if the pattern could not be
 * matched and -2 if an error (such as failure stack overflow) is
 * encountered. */

int re_search(regexp_t compiled, unsigned char *string, int size, int startpos,
	      int range, regexp_registers_t regs);
/* This searches for a substring matching the regexp.  This returns the
 * first index at which a match is found.  range specifies at how many
 * positions to try matching; positive values indicate searching
 * forwards, and negative values indicate searching backwards.  mstop
 * specifies the offset beyond which a match must not go.  This returns
 * -1 if no match is found, and -2 if an error (such as failure stack
 * overflow) is encountered. */

void re_compile_fastmap(regexp_t compiled);
/* This computes the fastmap for the regexp.  For this to have any effect,
 * the calling program must have initialized the fastmap field to point
 * to an array of 256 characters. */

#else /* HAVE_PROTOTYPES */

extern int re_syntax;
extern unsigned char re_syntax_table[256];
void re_compile_initialize();
int re_set_syntax();
char *re_compile_pattern();
int re_match();
int re_search();
void re_compile_fastmap();

#endif /* HAVE_PROTOTYPES */

#endif /* REGEXPR_H */


#ifdef __cplusplus
}
#endif
#endif /* !Py_REGEXPR_H */