/*
 * Copyright (c) 1995, 1996 Gunther Schadow.  All rights reserved.
 *
 * 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 2 of the License, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#ifndef PG_HASHCODE_H_
#define PG_HASHCODE_H_

#include <pg_config.h>

#pragma interface

#include <Code.h>

class HashCode : public Code
{
 public:
  const int invalid     = -3;
  const int not_present = -2;
  const int null        = -1;

  void unset();
  void nullify();

  operator const char* () const;
  operator int () const;

  const HashCode& operator = (const HashCode&);
  const HashCode& operator = (const char*);
  const HashCode& operator = (int);

  bool operator == (const HashCode&) const;
  bool operator != (const HashCode&) const;
  bool operator == (const char*)     const;
  bool operator != (const char*)     const;
  bool operator == (int)             const;
  bool operator != (int)             const;

  bool OK() const;

  int  lookup(const char *str) /* const -- gperf problem */;
  bool valid(int i) const;

 protected:
  HashCode(const char *table[], int first, int last);
  HashCode(int val, const char *table[], int first, int last);
  HashCode(const char *s, const char *table[], int first, int last);

  virtual int in_word_set(const char *str, int len) =0;
                                               /* const -- gperf problem */ ;

 private:
  const char **_table;
  int _first;
  int _last;
  int _val;

  void set(const char *);
};

#ifndef OUTLINE
# include "HashCode.icc"
#endif

#endif /* !PG_LINEARCODE_H_ */