/* -*- C++ -*-

  *

  * This file is a part of LEMON, a generic C++ optimization library

  *

  * Copyright (C) 2003-2006

  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

  * (Egervary Research Group on Combinatorial Optimization, EGRES).

  *

  * Permission to use, modify and distribute this software is granted

  * provided that this copyright notice appears in all copies. For

  * precise terms see the accompanying LICENSE file.

  *

  * This software is provided "AS IS" with no warranty of any kind,

  * express or implied, and with no claim as to its suitability for any

  * purpose.

  *

  */

 #ifndef LEMON_MAP_ITERATOR_H

 #define LEMON_MAP_ITERATOR_H

 #include <lemon/bits/traits.h>

 #include <lemon/bits/utility.h>

 /// \ingroup gutils

 /// \file

 /// \brief Iterators on the maps.

 namespace lemon {

   /// \ingroup gutils

   ///

   /// \brief Iterator for maps with possibility of changing values.

   ///

   /// Iterator for maps with possibility of changing values.

   template <typename Graph, typename Item, typename Map>

   class MapIt : public ItemSetTraits<Graph, Item>::ItemIt {

   public:

     typedef typename ItemSetTraits<Graph, Item>::ItemIt Parent;

     typedef typename Map::Value Value;

     /// \brief Creates an iterator

     ///

     /// Creates an iterator for the map, which iterates on the

     /// given graph item set.

     MapIt(const Graph& _graph, Map& _map) : Parent(_graph), map(_map) {}

     /// \brief Gives back the map's value on the current position.

     ///

     /// Gives back the map's value on the current position.

     typename MapTraits<Map>::ConstReturnValue operator*() const {

       return map[*this];

     }

     /// \brief Gives back a reference to the map's value.

     ///

     /// Gives back a reference to the map's value on the current position.

     typename MapTraits<Map>::ReturnValue operator*() {

       return map[*this];

     }

     /// \brief Sets the value on the current position

     ///

     /// Sets the value on the current position.

     void set(const Value& value) {

       map.set(*this, value);

     }

   protected:

     Map& map;

   };

   /// \ingroup gutils

   ///

   /// \brief Iterator for maps with possibility of getting values.

   ///

   /// Iterator for maps with possibility of getting values.

   template <typename Graph, typename Item, typename Map>

   class ConstMapIt : public ItemSetTraits<Graph, Item>::ItemIt {

   public:

     typedef typename ItemSetTraits<Graph, Item>::ItemIt Parent;

     typedef typename Map::Value Value;

     /// \brief Creates an iterator

     ///

     /// Creates an iterator for the map, which iterates on the

     /// given graph item set.

     ConstMapIt(const Graph& _graph, const Map& _map) 

       : Parent(_graph), map(_map) {}

     /// \brief Gives back the map's value on the current position.

     ///

     /// Gives back the map's value on the current position.

     typename MapTraits<Map>::ConstReturnValue operator*() const {

       return map[*this];

     }

   protected:

     const Map& map;

   };

   /// \ingroup gutils

   ///

   /// \brief Iterator for maps which filters items by the values.

   ///

   /// Iterator for maps which gives back only that items which mapped

   /// to an given value.

   template <typename Graph, typename Item, typename Map>

   class FilterMapIt 

     : public ItemSetTraits<Graph, Item>::ItemIt {

   public:

     typedef typename ItemSetTraits<Graph, Item>::ItemIt Parent;

     typedef typename Map::Value Value;

     /// \brief Creates an iterator

     ///

     /// Creates an iterator for the map, which iterates on the

     /// given graph item set and filters all items which mapped value

     /// is not equal to the \c _value.

     FilterMapIt(const Graph& _graph, const Map& _map, const Value& _value) 

       : Parent(_graph), map(_map), value(_value) {}

     /// \brief Increment operator

     ///

     /// Skips items which has not mapped to the given value.

     FilterMapIt& operator++() {

       Parent::operator++();

       while (*this != INVALID && map[*this] != value) Parent::operator++();

     }

   protected:

     const Map& map;

     Value value;

   };

 }

 #endif