/*
 * 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_LINEARCODE_H_
#define PG_LINEARCODE_H_

#include <pg_config.h>

#pragma interface

#include <Code.h>
#include <sys/types.h>

/*
 * Linear Code are simple arrays. Code is looked up by a linear searching
 * through the array. Thus, each code is mapped to a consecutive integer
 * number. The first code is mapped to `first' and the last code i mapped
 * to `last' (which is equal to `size' - 1). Additional mappings are:
 * 
 *                           (int)       (const char*)
 * invalid code string       `invalid'   `'
 * code data was not given   `not_set'   `'
 * code data is null         `null'      `""'
 */

class LinearCode : public Code
{
 public:
  const invalid     = -3;
  const not_present = -2;
  const null        = -1;
  const first       =  0;

  void unset();
  void nullify();

  const LinearCode& operator = (int val);
  const LinearCode& operator = (const char *s);
  const LinearCode& operator = (const LinearCode&);

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

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

  bool OK() const;

  int  lookup(const char *str) const;
  bool valid(int) const;

 protected:
  LinearCode(const char *table[], size_t size);
  LinearCode(int val, const char *table[], size_t size);
  LinearCode(const char *s, const char *table[], size_t size);

 private:
  int          _val;
  const char **_table;
  int          _size;

  void set(const char *);
};

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

#endif /* !PG_LINEARCODE_H_ */