text: // -*- C++ -*-
  /* Copyright (C) 1989, 1990, 1991, 1992, 2009
       Free Software Foundation, Inc.
       Written by James Clark (jjc@jclark.com)
  
  This file is part of groff.
  
  groff 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 3 of the License, or
  (at your option) any later version.
  
  groff 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, see <http://www.gnu.org/licenses/>. */
  
  
  
  // there is no distinction between name with no value and name with NULL value
  // null names are not permitted (they will be ignored).
  
  struct association {
    symbol s;
    void *v;
    association() :  v(0) {}
  };
  
  class dictionary;
  
  class dictionary_iterator {
    dictionary *dict;
    int i;
  public:
    dictionary_iterator(dictionary &);
    int get(symbol *, void **);
  };
  
  class dictionary {
    int size;
    int used;
    double threshold;
    double factor;
    association *table;
    void rehash(int);
  public:
    dictionary(int);
    void *lookup(symbol s, void *v=0); // returns value associated with key
    void *lookup(const char *);
    // if second parameter not NULL, value will be replaced
    void *remove(symbol);
    friend class dictionary_iterator;
  };
  
  class object {
    int rcount;
   public:
    object();
    virtual ~object();
    void add_reference();
    void remove_reference();
  };
  
  class object_dictionary;
  
  class object_dictionary_iterator {
    dictionary_iterator di;
  public:
    object_dictionary_iterator(object_dictionary &);
    int get(symbol *, object **);
  };
  
  class object_dictionary {
    dictionary d;
  public:
    object_dictionary(int);
    object *lookup(symbol nm);
    void define(symbol nm, object *obj);
    void rename(symbol oldnm, symbol newnm);
    void remove(symbol nm);
    int alias(symbol newnm, symbol oldnm);
    friend class object_dictionary_iterator;
  };
  
  
  inline int object_dictionary_iterator::get(symbol *sp, object **op)
  {
    return di.get(sp, (void **)op);
  }
  