flex-lexer.hh

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// -*-C++-*-
// FlexLexer.h -- define interfaces for lexical analyzer classes generated
// by flex

// Copyright (c) 1993 The Regents of the University of California.
// All rights reserved.
//
// This code is derived from software contributed to Berkeley by
// Kent Williams and Tom Epperly.
//
//  Redistribution and use in source and binary forms, with or without
//  modification, are permitted provided that the following conditions
//  are met:

//  1. Redistributions of source code must retain the above copyright
//  notice, this list of conditions and the following disclaimer.
//  2. Redistributions in binary form must reproduce the above copyright
//  notice, this list of conditions and the following disclaimer in the
//  documentation and/or other materials provided with the distribution.

//  Neither the name of the University nor the names of its contributors
//  may be used to endorse or promote products derived from this software
//  without specific prior written permission.

//  THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
//  IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
//  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
//  PURPOSE.

// This file defines FlexLexer, an abstract class which specifies the
// external interface provided to flex C++ lexer objects, and yyFlexLexer,
// which defines a particular lexer class.
//
// If you want to create multiple lexer classes, you use the -P flag
// to rename each yyFlexLexer to some other xxFlexLexer.  You then
// include <FlexLexer.h> in your other sources once per lexer class:
//
//      #undef yyFlexLexer
//      #define yyFlexLexer xxFlexLexer
//      #include <FlexLexer.h>
//
//      #undef yyFlexLexer
//      #define yyFlexLexer zzFlexLexer
//      #include <FlexLexer.h>
//      ...

#ifndef VCSN_MISC_FLEX_LEXER_HH
# define VCSN_MISC_FLEX_LEXER_HH

struct yy_buffer_state;
typedef int yy_state_type;

class FlexLexer
{
public:
  virtual ~FlexLexer()  { }

  const char* YYText() const    { return yytext; }
  int YYLeng()  const   { return yyleng; }

  virtual void
  yy_switch_to_buffer( struct yy_buffer_state* new_buffer ) = 0;
  virtual struct yy_buffer_state*
  yy_create_buffer( std::istream* s, int size ) = 0;
  virtual void yy_delete_buffer( struct yy_buffer_state* b ) = 0;
  virtual void yyrestart( std::istream* s ) = 0;

  // Switch to new input/output streams.  A nil stream pointer
  // indicates "keep the current one".
  virtual void switch_streams( std::istream* new_in = nullptr,
                               std::ostream* new_out = nullptr ) = 0;
  int lineno() const            { return yylineno; }

  int debug() const             { return yy_flex_debug; }
  void set_debug( int flag )    { yy_flex_debug = flag; }

protected:
  char* yytext;
  int yyleng;
  int yylineno;                 // only maintained if you use %option yylineno
  int yy_flex_debug;    // only has effect with -d or "%option debug"
};

YY_FLEX_NAMESPACE_BEGIN

void *yyalloc (size_t);
void *yyrealloc (void *, size_t);
void yyfree (void *);

class yyFlexLexer : public FlexLexer
{
public:
  // arg_yyin and arg_yyout default to the cin and cout, but we
  // only make that assignment when initializing in yylex().
  yyFlexLexer( std::istream* arg_yyin = nullptr, std::ostream* arg_yyout = nullptr );

  virtual ~yyFlexLexer();

  void yy_switch_to_buffer( struct yy_buffer_state* new_buffer );
  struct yy_buffer_state* yy_create_buffer( std::istream* s, int size );
  void yy_delete_buffer( struct yy_buffer_state* b );
  void yyrestart( std::istream* s );

  void yypush_buffer_state( struct yy_buffer_state* new_buffer );
  void yypop_buffer_state();

  // The signature of yylex.
  YY_DECL_();

  void scan_open_(std::istream& f);

  void scan_close_();

  location loc;

  virtual void switch_streams(std::istream* new_in,
                              std::ostream* new_out = nullptr );
  virtual int yywrap();

  std::istream* yyin;   // input source for default LexerInput

protected:
  virtual int LexerInput( char* buf, int max_size );
  virtual void LexerOutput( const char* buf, int size );
  virtual void LexerError( const char* msg );

  void yyunput( int c, char* buf_ptr );
  int yyinput();

  void yy_load_buffer_state();
  void yy_init_buffer( struct yy_buffer_state* b, std::istream* s );
  void yy_flush_buffer( struct yy_buffer_state* b );

  int yy_start_stack_ptr;
  int yy_start_stack_depth;
  int* yy_start_stack;

  void yy_push_state( int new_state );
  void yy_pop_state();
  int yy_top_state();

  yy_state_type yy_get_previous_state();
  yy_state_type yy_try_NUL_trans( yy_state_type current_state );
  int yy_get_next_buffer();

  std::ostream* yyout;  // output sink for default LexerOutput

  // yy_hold_char holds the character lost when yytext is formed.
  char yy_hold_char;

  // Number of characters read into yy_ch_buf.
  int yy_n_chars;

  // Points to current character in buffer.
  char* yy_c_buf_p;

  int yy_init;          // whether we need to initialize
  int yy_start;                 // start state number

  // Flag which is used to allow yywrap()'s to do buffer switches
  // instead of setting up a fresh yyin.  A bit of a hack ...
  int yy_did_buffer_switch_on_eof;


  size_t yy_buffer_stack_top; 
  size_t yy_buffer_stack_max; 
  struct yy_buffer_state ** yy_buffer_stack; 
  void yyensure_buffer_stack(void);

  // The following are not always needed, but may be depending
  // on use of certain flex features (like REJECT or yymore()).

  yy_state_type yy_last_accepting_state;
  char* yy_last_accepting_cpos;

  yy_state_type* yy_state_buf;
  yy_state_type* yy_state_ptr;

  char* yy_full_match;
  int* yy_full_state;
  int yy_full_lp;

  int yy_lp;
  int yy_looking_for_trail_begin;

  int yy_more_flag;
  int yy_more_len;
  int yy_more_offset;
  int yy_prev_more_offset;
};

YY_FLEX_NAMESPACE_END

#endif // !VCSN_MISC_FLEX_LEXER_HH