/* fsaparse -- Build a structure naming relationships (sequences, alternatives, options and precedence) of tokens

   Copyright (C) 1988, 1998, 2000, 2002, 2004-2005, 2007-2014 Free Software
   Foundation, Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3, or (at your option)
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc.,
   51 Franklin Street - Fifth Floor, Boston, MA  02110-1301, USA */

/* Written June, 1988 by Mike Haertel
   Modified July, 1988 by Arthur David Olson to assist BMG speedups  */

/* 2014: Repackaged by "untangle" script, written by behoffski.  */

/* This function receives a stream of tokens from fsalex, and processes
   them to impose precedence rules and to describe complex pattern elements
   that are beyond the capability of the simple lexer.  In addition to the
   cases explicit in the syntax (e.g."(ab|c)", variable-length multibyte
   encodings (UTF-8; codesets including modifiers and/or shift items) also
   require these enhanced facilities.  */


#ifndef FSAPARSE_H
#define FSAPARSE_H 1

/* Always import environment-specific configuration items first.  */
#include <config.h>

#include "fsatoken.h"
#include "proto-lexparse.h"

/* Multiple parser instances can exist in parallel, so define an opaque
   type to collect together all the context relating to each instance.  */
typedef struct fsaparse_ctxt_struct fsaparse_ctxt_t;

/* Allow configurable parser/lexer combinations by using a plugin interface
   for lexer invocation.  */
typedef fsatoken_token_t
fsaparse_lexer_fn_t (void *lexer_context);

/* Generate a new instance of an FSA parser.  */
extern fsaparse_ctxt_t *
fsaparse_new (void);

/* Receiver a lexer function, plus lexer instance context pointer, for use by
   the parser.  Although not needed initially, this plug-in architecture may
   be useful in the future, and it breaks up some of the intricate
   connections that made the original dfa.c code so daunting.  */
extern void
fsaparse_lexer (fsaparse_ctxt_t *parser,
                void *lexer_context,
                proto_lexparse_lex_fn_t *lex_fn,
                proto_lexparse_exchange_fn_t *lex_exchange_fn);

/* Define function prototypes for warning and error callbacks.  */
typedef void
fsaparse_warn_callback_fn (const char *);
typedef void /* ?? _Noreturn? */
fsaparse_error_callback_fn (const char *);

/* Receive functions to deal with exceptions detected by the parser:
   Warnings and errors.  Internally, we add the _Noreturn attribute
   to the error callback, to help the compiler with code flow
   analysis.  */
extern void
fsaparse_exception_fns (fsaparse_ctxt_t *parser,
                      fsaparse_warn_callback_fn *warningfn,
                      fsaparse_error_callback_fn *errorfn);

/* Main entry point for the parser.  Parser is a pointer to a parser
   context struct created by fsaparse_new.  Before calling this function,
   the parser instance must be supplied with a lexer (fsaparse_lexer), and
   also with callback functions to receive warning and error reports
   (fsaparse_esception_fns).  */
extern void
fsaparse_parse (fsaparse_ctxt_t *parser);

/* After parsing, report a list of tokens describing the pattern.  Complex
   structures such as alternation, backreferences, and locale-induced
   complexity such as variable-length utf8 sequences are described here by
   appending operators that apply to the preceding item(s) (postfix
   notation).  */
extern void
fsaparse_get_token_list (fsaparse_ctxt_t *parser,
                         size_t *nr_tokens,
                         fsatoken_token_t **token_list);

#endif /* FSAPARSE_H */

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