src/include/symbol.h

   1 // -*- C++ -*-
   2 /* Copyright (C) 1989, 1990, 1991, 1992, 2002, 2004
   3    Free Software Foundation, Inc.
   4      Written by James Clark (jjc@jclark.com)
   5
   6 This file is part of groff.
   7
   8 groff 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 groff 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
  21
  22 #define DONT_STORE 1
  23 #define MUST_ALREADY_EXIST 2
  24
  25 class symbol {
  26   static const char **table;
  27   static int table_used;
  28   static int table_size;
  29   static char *block;
  30   static int block_size;
  31   const char *s;
  32 public:
  33   symbol(const char *p, int how = 0);
  34   symbol();
  35   unsigned long hash() const;
  36   int operator ==(symbol) const;
  37   int operator !=(symbol) const;
  38   const char *contents() const;
  39   int is_null() const;
  40   int is_empty() const;
  41 };
  42
  43
  44 extern const symbol NULL_SYMBOL;
  45 extern const symbol EMPTY_SYMBOL;
  46
  47 inline symbol::symbol() : s(0)
  48 {
  49 }
  50
  51 inline int symbol::operator==(symbol p) const
  52 {
  53   return s == p.s;
  54 }
  55
  56 inline int symbol::operator!=(symbol p) const
  57 {
  58   return s != p.s;
  59 }
  60
  61 inline unsigned long symbol::hash() const
  62 {
  63   return (unsigned long)s;
  64 }
  65
  66 inline const char *symbol::contents() const
  67 {
  68   return s;
  69 }
  70
  71 inline int symbol::is_null() const
  72 {
  73   return s == 0;
  74 }
  75
  76 inline int symbol::is_empty() const
  77 {
  78   return s != 0 && *s == 0;
  79 }
  80
  81 symbol concat(symbol, symbol);
  82
  83 extern symbol default_symbol;