include/symbol.h

   1 /*@
   2  * Copyright (c) 2014 - 2017 Steffen (Daode) Nurpmeso <steffen@sdaoden.eu>.
   3  *
   4  * Copyright (C) 1989 - 1992, 2002, 2004
   5  *    Free Software Foundation, Inc.
   6  *      Written by James Clark (jjc@jclark.com)
   7  *
   8  * This is free software; you can redistribute it and/or modify it under
   9  * the terms of the GNU General Public License as published by the Free
  10  * Software Foundation; either version 2, or (at your option) any later
  11  * version.
  12  *
  13  * This is distributed in the hope that it will be useful, but WITHOUT ANY
  14  * WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16  * for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with groff; see the file COPYING.  If not, write to the Free Software
  20  * Foundation, 51 Franklin St - Fifth Floor, Boston, MA 02110-1301, USA.
  21  */
  22 #ifndef _SYMBOL_H
  23 #define _SYMBOL_H
  24
  25 #include "config.h"
  26
  27 #define DONT_STORE 1
  28 #define MUST_ALREADY_EXIST 2
  29
  30 class symbol
  31 {
  32   static const char **table;
  33   static int table_used;
  34   static int table_size;
  35   static char *block;
  36   static int block_size;
  37
  38   const char *s;
  39
  40 public:
  41   symbol(const char *p, int how = 0);
  42   symbol();
  43   unsigned long hash() const;
  44   int operator ==(symbol) const;
  45   int operator !=(symbol) const;
  46   const char *contents() const;
  47   int is_null() const;
  48   int is_empty() const;
  49 };
  50
  51 extern const symbol NULL_SYMBOL;
  52 extern const symbol EMPTY_SYMBOL;
  53
  54 inline symbol::symbol() : s(0)
  55 {
  56 }
  57
  58 inline int symbol::operator==(symbol p) const
  59 {
  60   return s == p.s;
  61 }
  62
  63 inline int symbol::operator!=(symbol p) const
  64 {
  65   return s != p.s;
  66 }
  67
  68 inline unsigned long symbol::hash() const
  69 {
  70   return (unsigned long)s;
  71 }
  72
  73 inline const char *symbol::contents() const
  74 {
  75   return s;
  76 }
  77
  78 inline int symbol::is_null() const
  79 {
  80   return s == 0;
  81 }
  82
  83 inline int symbol::is_empty() const
  84 {
  85   return s != 0 && *s == 0;
  86 }
  87
  88 symbol concat(symbol, symbol);
  89
  90 extern symbol default_symbol;
  91
  92 #endif // _SYMBOL_H
  93 // s-it2-mode