troff/symbol.h

   1 // -*- C++ -*-
   2 /* Copyright (C) 1989, 1990, 1991, 1992 Free Software Foundation, Inc.
   3      Written by James Clark (jjc@jclark.com)
   4
   5 This file is part of groff.
   6
   7 groff is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 2, or (at your option) any later
  10 version.
  11
  12 groff is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License along
  18 with groff; see the file COPYING.  If not, write to the Free Software
  19 Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
  20
  21 #define DONT_STORE 1
  22 #define MUST_ALREADY_EXIST 2
  23
  24 class symbol {
  25   static const char **table;
  26   static int table_used;
  27   static int table_size;
  28   static char *block;
  29   static int block_size;
  30   const char *s;
  31 public:
  32   symbol(const char *p, int how = 0);
  33   symbol();
  34   int hash() const;
  35   operator ==(symbol) const;
  36   operator !=(symbol) const;
  37   const char *contents() const;
  38   int is_null() const;
  39 };
  40
  41
  42 extern const symbol NULL_SYMBOL;
  43
  44 inline symbol::symbol() : s(0)
  45 {
  46 }
  47
  48 inline int symbol::operator==(symbol p) const
  49 {
  50   return s == p.s;
  51 }
  52
  53 inline int symbol::operator!=(symbol p) const
  54 {
  55   return s != p.s;
  56 }
  57
  58 // guaranteed to return a positive integer
  59
  60 inline int symbol::hash() const
  61 {
  62   int i = int(s);
  63   return i < 0 ? -i : i;
  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 symbol concat(symbol, symbol);