/* -*- C++ -*-

 * lemon/map_iterator.h - Part of LEMON, a generic C++ optimization library

 *

 * Copyright (C) 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/traits.h>

#include <lemon/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

    /// differ from \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 the given value.

    FilterMapIt& operator++() {

      Parent::operator++();

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

    }

  protected:

    const Map& map;

    Value value;

  };

}

#endif