/* -*- C++ -*-

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

  *

  * Copyright (C) 2004 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

  * (Egervary Combinatorial Optimization Research Group, 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_MAPS_H

 #define LEMON_MAPS_H

 #include<math.h>

 ///\file

 ///\ingroup maps

 ///\brief Miscellaneous property maps

 ///

 ///\todo This file has the same name as the concept file in concept/,

 /// and this is not easily detectable in docs...

 #include <map>

 namespace lemon {

   /// \addtogroup maps

   /// @{

   /// Base class of maps.

   /// Base class of maps.

   /// It provides the necessary <tt>typedef</tt>s required by the map concept.

   template<typename K, typename T>

   class MapBase

   {

   public:

     ///\e

     typedef K Key;

     ///\e

     typedef T Value;

   };

   /// Null map. (a.k.a. DoNothingMap)

   /// If you have to provide a map only for its type definitions,

   /// or if you have to provide a writable map, but

   /// data written to it will sent to <tt>/dev/null</tt>...

   template<typename K, typename T>

   class NullMap : public MapBase<K,T>

   {

   public:

     /// Gives back a default constructed element.

     T operator[](const K&) const { return T(); }

     /// Absorbs the value.

     void set(const K&, const T&) {}

   };

   /// Constant map.

   /// This is a readable map which assigns a specified value to each key.

   /// In other aspects it is equivalent to the \ref NullMap.

   /// \todo set could be used to set the value.

   template<typename K, typename T>

   class ConstMap : public MapBase<K,T>

   {

     T v;

   public:

     /// Default constructor

     /// The value of the map will be uninitialized. 

     /// (More exactly it will be default constructed.)

     ConstMap() {}

     ///\e

     /// \param _v The initial value of the map.

     ///

     ConstMap(const T &_v) : v(_v) {}

     T operator[](const K&) const { return v; }

     void set(const K&, const T&) {}

     template<typename T1>

     struct rebind {

       typedef ConstMap<K,T1> other;

     };

     template<typename T1>

     ConstMap(const ConstMap<K,T1> &, const T &_v) : v(_v) {}

   };

   //to document later

   template<typename T, T v>

   struct Const { };

   //to document later

   template<typename K, typename V, V v>

   class ConstMap<K, Const<V, v> > : public MapBase<K, V>

   {

   public:

     ConstMap() { }

     V operator[](const K&) const { return v; }

     void set(const K&, const V&) { }

   };

   /// \c std::map wrapper

   /// This is essentially a wrapper for \c std::map. With addition that

   /// you can specify a default value different from \c Value() .

   ///

   /// \todo Provide allocator parameter...

   template <typename K, typename T, typename Compare = std::less<K> >

   class StdMap : public std::map<K,T,Compare> {

     typedef std::map<K,T,Compare> parent;

     T v;

     typedef typename parent::value_type PairType;

   public:

     typedef K Key;

     typedef T Value;

     typedef T& Reference;

     typedef const T& ConstReference;

     StdMap() : v() {}

     /// Constructor with specified default value

     StdMap(const T& _v) : v(_v) {}

     /// \brief Constructs the map from an appropriate std::map.

     ///

     /// \warning Inefficient: copies the content of \c m !

     StdMap(const parent &m) : parent(m) {}

     /// \brief Constructs the map from an appropriate std::map, and explicitly

     /// specifies a default value.

     ///

     /// \warning Inefficient: copies the content of \c m !

     StdMap(const parent &m, const T& _v) : parent(m), v(_v) {}

     template<typename T1, typename Comp1>

     StdMap(const StdMap<Key,T1,Comp1> &m, const T &_v) { 

       //FIXME; 

     }

     Reference operator[](const Key &k) {

       return insert(PairType(k,v)).first -> second;

     }

     ConstReference operator[](const Key &k) const {

       typename parent::iterator i = lower_bound(k);

       if (i == parent::end() || parent::key_comp()(k, (*i).first))

 	return v;

       return (*i).second;

     }

     void set(const Key &k, const T &t) {

       parent::operator[](k) = t;

     }

     /// Changes the default value of the map.

     /// \return Returns the previous default value.

     ///

     /// \warning The value of some keys (which has already been queried, but

     /// the value has been unchanged from the default) may change!

     T setDefault(const T &_v) { T old=v; v=_v; return old; }

     template<typename T1>

     struct rebind {

       typedef StdMap<Key,T1,Compare> other;

     };

   };

   ///Sum of two maps

   ///This \ref concept::ReadMap "read only map" returns the sum of the two

   ///given maps. Its \c Key and \c Value will be inherited from \c M1.

   ///The \c Key and \c Value of M2 must be convertible to those of \c M1.

   template<class M1,class M2> 

   class AddMap

   {

     const M1 &m1;

     const M2 &m2;

   public:

     typedef typename M1::Key Key;

     typedef typename M1::Value Value;

     ///Constructor

     ///\e

     ///

     AddMap(const M1 &_m1,const M2 &_m2) : m1(_m1), m2(_m2) {};

     Value operator[](Key k) const {return m1[k]+m2[k];}

   };

   ///Returns an \ref AddMap class

   ///This function just returns an \ref AddMap class.

   ///\todo How to call these type of functions?

   ///

   ///\relates AddMap

   ///\todo Wrong scope in Doxygen when \c \\relates is used

   template<class M1,class M2> 

   inline AddMap<M1,M2> addMap(const M1 &m1,const M2 &m2) 

   {

     return AddMap<M1,M2>(m1,m2);

   }

   ///Shift a maps with a constant.

   ///This \ref concept::ReadMap "read only map" returns the sum of the

   ///given map and a constant value.

   ///Its \c Key and \c Value is inherited from \c M.

   ///

   ///Actually,

   ///\code

   ///  ShiftMap<X> sh(x,v);

   ///\endcode

   ///it is equivalent with

   ///\code

   ///  ConstMap<X::Key, X::Value> c_tmp(v);

   ///  AddMap<X, ConstMap<X::Key, X::Value> > sh(x,v);

   ///\endcode

   template<class M> 

   class ShiftMap

   {

     const M &m;

     typename M::Value v;

   public:

     typedef typename M::Key Key;

     typedef typename M::Value Value;

     ///Constructor

     ///Constructor

     ///\param _m is the undelying map

     ///\param _v is the shift value

     ShiftMap(const M &_m,const Value &_v ) : m(_m), v(_v) {};

     Value operator[](Key k) const {return m[k]+v;}

   };

   ///Returns an \ref ShiftMap class

   ///This function just returns an \ref ShiftMap class.

   ///\relates ShiftMap

   ///\todo A better name is required.

   template<class M> 

   inline ShiftMap<M> shiftMap(const M &m,const typename M::Value &v) 

   {

     return ShiftMap<M>(m,v);

   }

   ///Difference of two maps

   ///This \ref concept::ReadMap "read only map" returns the difference

   ///of the values returned by the two

   ///given maps. Its \c Key and \c Value will be inherited from \c M1.

   ///The \c Key and \c Value of \c M2 must be convertible to those of \c M1.

   template<class M1,class M2> 

   class SubMap

   {

     const M1 &m1;

     const M2 &m2;

   public:

     typedef typename M1::Key Key;

     typedef typename M1::Value Value;

     ///Constructor

     ///\e

     ///

     SubMap(const M1 &_m1,const M2 &_m2) : m1(_m1), m2(_m2) {};

     Value operator[](Key k) const {return m1[k]-m2[k];}

   };

   ///Returns a \ref SubMap class

   ///This function just returns a \ref SubMap class.

   ///

   ///\relates SubMap

   template<class M1,class M2> 

   inline SubMap<M1,M2> subMap(const M1 &m1,const M2 &m2) 

   {

     return SubMap<M1,M2>(m1,m2);

   }

   ///Product of two maps

   ///This \ref concept::ReadMap "read only map" returns the product of the

   ///values returned by the two

   ///given

   ///maps. Its \c Key and \c Value will be inherited from \c M1.

   ///The \c Key and \c Value of \c M2 must be convertible to those of \c M1.

   template<class M1,class M2> 

   class MulMap

   {

     const M1 &m1;

     const M2 &m2;

   public:

     typedef typename M1::Key Key;

     typedef typename M1::Value Value;

     ///Constructor

     ///\e

     ///

     MulMap(const M1 &_m1,const M2 &_m2) : m1(_m1), m2(_m2) {};

     Value operator[](Key k) const {return m1[k]*m2[k];}

   };

   ///Returns a \ref MulMap class

   ///This function just returns a \ref MulMap class.

   ///\relates MulMap

   template<class M1,class M2> 

   inline MulMap<M1,M2> mulMap(const M1 &m1,const M2 &m2) 

   {

     return MulMap<M1,M2>(m1,m2);

   }

   ///Scale a maps with a constant.

   ///This \ref concept::ReadMap "read only map" returns the value of the

   ///given map multipied with a constant value.

   ///Its \c Key and \c Value is inherited from \c M.

   ///

   ///Actually,

   ///\code

   ///  ScaleMap<X> sc(x,v);

   ///\endcode

   ///it is equivalent with

   ///\code

   ///  ConstMap<X::Key, X::Value> c_tmp(v);

   ///  MulMap<X, ConstMap<X::Key, X::Value> > sc(x,v);

   ///\endcode

   template<class M> 

   class ScaleMap

   {

     const M &m;

     typename M::Value v;

   public:

     typedef typename M::Key Key;

     typedef typename M::Value Value;

     ///Constructor

     ///Constructor

     ///\param _m is the undelying map

     ///\param _v is the scaling value

     ScaleMap(const M &_m,const Value &_v ) : m(_m), v(_v) {};

     Value operator[](Key k) const {return m[k]*v;}

   };

   ///Returns an \ref ScaleMap class

   ///This function just returns an \ref ScaleMap class.

   ///\relates ScaleMap

   ///\todo A better name is required.

   template<class M> 

   inline ScaleMap<M> scaleMap(const M &m,const typename M::Value &v) 

   {

     return ScaleMap<M>(m,v);

   }

   ///Quotient of two maps

   ///This \ref concept::ReadMap "read only map" returns the quotient of the

   ///values returned by the two

   ///given maps. Its \c Key and \c Value will be inherited from \c M1.

   ///The \c Key and \c Value of \c M2 must be convertible to those of \c M1.

   template<class M1,class M2> 

   class DivMap

   {

     const M1 &m1;

     const M2 &m2;

   public:

     typedef typename M1::Key Key;

     typedef typename M1::Value Value;

     ///Constructor

     ///\e

     ///

     DivMap(const M1 &_m1,const M2 &_m2) : m1(_m1), m2(_m2) {};

     Value operator[](Key k) const {return m1[k]/m2[k];}

   };

   ///Returns a \ref DivMap class

   ///This function just returns a \ref DivMap class.

   ///\relates DivMap

   template<class M1,class M2> 

   inline DivMap<M1,M2> divMap(const M1 &m1,const M2 &m2) 

   {

     return DivMap<M1,M2>(m1,m2);

   }

   ///Composition of two maps

   ///This \ref concept::ReadMap "read only map" returns the composition of

   ///two

   ///given maps. That is to say, if \c m1 is of type \c M1 and \c m2 is

   ///of \c M2,

   ///then for

   ///\code

   ///  ComposeMap<M1,M2> cm(m1,m2);

   ///\endcode

   /// <tt>cm[x]</tt> will be equal to <tt>m1[m2[x]]</tt>

   ///

   ///Its \c Key is inherited from \c M2 and its \c Value is from

   ///\c M1.

   ///The \c M2::Value must be convertible to \c M1::Key.

   ///\todo Check the requirements.

   template<class M1,class M2> 

   class ComposeMap

   {

     const M1 &m1;

     const M2 &m2;

   public:

     typedef typename M2::Key Key;

     typedef typename M1::Value Value;

     ///Constructor

     ///\e

     ///

     ComposeMap(const M1 &_m1,const M2 &_m2) : m1(_m1), m2(_m2) {};

     Value operator[](Key k) const {return m1[m2[k]];}

   };

   ///Returns a \ref ComposeMap class

   ///This function just returns a \ref ComposeMap class.

   ///\relates ComposeMap

   template<class M1,class M2> 

   inline ComposeMap<M1,M2> composeMap(const M1 &m1,const M2 &m2) 

   {

     return ComposeMap<M1,M2>(m1,m2);

   }

   ///Negative value of a map

   ///This \ref concept::ReadMap "read only map" returns the negative

   ///value of the

   ///value returned by the

   ///given map. Its \c Key and \c Value will be inherited from \c M.

   ///The unary \c - operator must be defined for \c Value, of course.

   template<class M> 

   class NegMap

   {

     const M &m;

   public:

     typedef typename M::Key Key;

     typedef typename M::Value Value;

     ///Constructor

     ///\e

     ///

     NegMap(const M &_m) : m(_m) {};

     Value operator[](Key k) const {return -m[k];}

   };

   ///Returns a \ref NegMap class

   ///This function just returns a \ref NegMap class.

   ///\relates NegMap

   template<class M> 

   inline NegMap<M> negMap(const M &m) 

   {

     return NegMap<M>(m);

   }

   ///Absolute value of a map

   ///This \ref concept::ReadMap "read only map" returns the absolute value

   ///of the

   ///value returned by the

   ///given map. Its \c Key and \c Value will be inherited

   ///from <tt>M</tt>. <tt>Value</tt>

   ///must be comparable to <tt>0</tt> and the unary <tt>-</tt>

   ///operator must be defined for it, of course.

   ///

   ///\bug We need a unified way to handle the situation below:

   ///\code

   ///  struct _UnConvertible {};

   ///  template<class A> inline A t_abs(A a) {return _UnConvertible();}

   ///  template<> inline int t_abs<>(int n) {return abs(n);}

   ///  template<> inline long int t_abs<>(long int n) {return labs(n);}

   ///  template<> inline long long int t_abs<>(long long int n) {return ::llabs(n);}

   ///  template<> inline float t_abs<>(float n) {return fabsf(n);}

   ///  template<> inline double t_abs<>(double n) {return fabs(n);}

   ///  template<> inline long double t_abs<>(long double n) {return fabsl(n);}

   ///\endcode

   template<class M> 

   class AbsMap

   {

     const M &m;

   public:

     typedef typename M::Key Key;

     typedef typename M::Value Value;

     ///Constructor

     ///\e

     ///

     AbsMap(const M &_m) : m(_m) {};

     Value operator[](Key k) const {Value tmp=m[k]; return tmp>=0?tmp:-tmp;}

   };

   ///Returns a \ref AbsMap class

   ///This function just returns a \ref AbsMap class.

   ///\relates AbsMap

   template<class M> 

   inline AbsMap<M> absMap(const M &m) 

   {

     return AbsMap<M>(m);

   }

   /// @}

 }

 #endif // LEMON_MAPS_H