Changeset 1627:3fd1ba6e9872 in lemon-0.x

Timestamp:

08/11/05 17:55:17 (19 years ago)

Author:

Balazs Dezso

Branch:

default

Phase:

public

Convert:

svn:c9d7d8f5-90d6-0310-b91f-818b3a526b0e/lemon/trunk@2135

Message:

Some modification on the undirected graph interface.
Doc improvments

Location:

lemon

Files:

• bits/erasable_graph_extender.h (modified) (1 diff)
• bits/extendable_graph_extender.h (modified) (1 diff)
• bits/iterable_graph_extender.h (modified) (4 diffs)
• bits/undir_graph_extender.h (modified) (4 diffs)
• concept/graph.h (modified) (6 diffs)
• concept/graph_component.h (modified) (5 diffs)
• concept/undir_graph.h (modified) (24 diffs)
• graph_adaptor.h (modified) (3 diffs)
• graph_utils.h (modified) (2 diffs)
• lemon_reader.h (modified) (1 diff)

lemon/bits/erasable_graph_extender.h

@@ -71 +71 @@
     void erase(const UndirEdge& uedge) {
       std::vector<Edge> edges;
-      edges.push_back(Edge(uedge,true));
-      edges.push_back(Edge(uedge,false));
+      edges.push_back(Parent::direct(uedge,true));
+      edges.push_back(Parent::direct(uedge,false));
       Parent::getNotifier(Edge()).erase(edges);
       Parent::getNotifier(UndirEdge()).erase(uedge);

lemon/bits/extendable_graph_extender.h

@@ -52 +52 @@
 
       std::vector<Edge> edges;
-      edges.push_back(Edge(uedge, true));
-      edges.push_back(Edge(uedge, false));
+      edges.push_back(Parent::direct(uedge, true));
+      edges.push_back(Parent::direct(uedge, false));
       Parent::getNotifier(Edge()).add(edges);
 

lemon/bits/iterable_graph_extender.h

@@ -119 +119 @@
     };
 
-    /// Base node of the iterator
+    /// \brief Base node of the iterator
     ///
     /// Returns the base node (ie. the source in this case) of the iterator
-    ///
-    /// \todo Document in the concept!
     Node baseNode(const OutEdgeIt &e) const {
       return Parent::source((Edge)e);
     }
-    /// Running node of the iterator
+    /// \brief Running node of the iterator
     ///
     /// Returns the running node (ie. the target in this case) of the
     /// iterator
-    ///
-    /// \todo Document in the concept!
     Node runningNode(const OutEdgeIt &e) const {
       return Parent::target((Edge)e);
     }
 
-    /// Base node of the iterator
+    /// \brief Base node of the iterator
     ///
     /// Returns the base node (ie. the target in this case) of the iterator
-    ///
-    /// \todo Document in the concept!
     Node baseNode(const InEdgeIt &e) const {
       return Parent::target((Edge)e);
     }
-    /// Running node of the iterator
+    /// \brief Running node of the iterator
     ///
     /// Returns the running node (ie. the source in this case) of the
     /// iterator
-    ///
-    /// \todo Document in the concept!
     Node runningNode(const InEdgeIt &e) const {
       return Parent::source((Edge)e);
@@ -157 +149 @@
     using Parent::first;
 
+    /// \brief The opposite node on the given edge.
+    ///
+    /// Gives back the opposite on the given edge.
+    Node oppositeNode(const Node& n, const Edge& e) const {
+      if (Parent::source(e) == n) {
+        return Parent::target(e);
+      } else {
+        return Parent::source(e);
+      }
+    }
+
   private:
-
-    // /// \todo When (and if) we change the iterators concept to use operator*,
-    // /// then the following shadowed methods will become superfluous.
-    // /// But for now these are important safety measures.
 
     // void first(NodeIt &) const;
@@ -191 +190 @@
     typedef IterableUndirGraphExtender<_Base> Graph;
     typedef typename Parent::Node Node;
-
+    typedef typename Parent::Edge Edge;
     typedef typename Parent::UndirEdge UndirEdge;
 
@@ -262 +261 @@
     }
 
+    /// \brief The opposite node on the given undirected edge.
+    ///
+    /// Gives back the opposite on the given undirected edge.
+    Node oppositeNode(const Node& n, const UndirEdge& e) const {
+      if (Parent::source(e) == n) {
+        return Parent::target(e);
+      } else {
+        return Parent::source(e);
+      }
+    }
+
   };
 }

lemon/bits/undir_graph_extender.h

@@ -43 +43 @@
       bool forward;
 
+      Edge(const UndirEdge &ue, bool _forward) :
+        UndirEdge(ue), forward(_forward) {}
+
     public:
       Edge() {}
-
-      /// \brief Directed edge from undirected edge and a direction.
-      ///
-      /// This constructor is not a part of the concept interface of
-      /// undirected graph, so please avoid using it if possible!
-      Edge(const UndirEdge &ue, bool _forward) :
-        UndirEdge(ue), forward(_forward) {}
-
-      /// \brief Directed edge from undirected edge and a source node.
-      ///
-      /// Constructs a directed edge from undirected edge and a source node.
-      ///
-      /// \note You have to specify the graph for this constructor.
-      Edge(const Graph &g, const UndirEdge &ue, const Node &n) :
-        UndirEdge(ue) { forward = (g.source(ue) == n); }
 
       /// Invalid edge constructor
@@ -80 +68 @@
     ///
     /// Returns the Edge of opposite direction.
-    Edge opposite(const Edge &e) const {
+    Edge oppositeEdge(const Edge &e) const {
       return Edge(e,!e.forward);
     }
@@ -114 +102 @@
       return _dirTarget(e);
     }
-
-    /// Returns whether the given directed edge is same orientation as the
-    /// corresponding undirected edge.
-    ///
-    /// \todo reference to the corresponding point of the undirected graph
-    /// concept. "What does the direction of an undirected edge mean?"
-    bool forward(const Edge &e) const { return e.forward; }
 
     Node oppositeNode(const Node &n, const UndirEdge &e) const {
@@ -131 +112 @@
     }
 
-    /// Directed edge from an undirected edge and a source node.
+    /// \brief Directed edge from an undirected edge and a source node.
     ///
     /// Returns a (directed) Edge corresponding to the specified UndirEdge
     /// and source Node.
     ///
-    ///\todo Do we need this?
-    ///
-    ///\todo Better name...
-    Edge edgeWithSource(const UndirEdge &ue, const Node &s) const {
-      return Edge(*this, ue, s);
-    }
+    Edge direct(const UndirEdge &ue, const Node &s) const {
+      return Edge(ue, s == source(ue));
+    }
+
+    /// \brief Directed edge from an undirected edge.
+    ///
+    /// Returns a directed edge corresponding to the specified UndirEdge.
+    /// If the given bool is true the given undirected edge and the
+    /// returned edge have the same source node.
+    Edge direct(const UndirEdge &ue, bool d) const {
+      return Edge(ue, d);
+    }
+
+    /// Returns whether the given directed edge is same orientation as the
+    /// corresponding undirected edge.
+    ///
+    /// \todo reference to the corresponding point of the undirected graph
+    /// concept. "What does the direction of an undirected edge mean?"
+    bool direction(const Edge &e) const { return e.forward; }
+
 
     using Parent::first;

lemon/concept/graph.h

@@ -480 +480 @@
       ///
       /// Gives back the base node of the iterator.
+      /// It is always the target of the pointed edge.
       Node baseNode(const InEdgeIt&) const { return INVALID; }
 
@@ -485 +486 @@
       ///
       /// Gives back the running node of the iterator.
+      /// It is always the source of the pointed edge.
       Node runningNode(const InEdgeIt&) const { return INVALID; }
 
@@ -490 +492 @@
       ///
       /// Gives back the base node of the iterator.
+      /// It is always the source of the pointed edge.
       Node baseNode(const OutEdgeIt&) const { return INVALID; }
 
@@ -495 +498 @@
       ///
       /// Gives back the running node of the iterator.
+      /// It is always the target of the pointed edge.
       Node runningNode(const OutEdgeIt&) const { return INVALID; }
-      /// Read write map of the nodes to type \c T.
-
-      /// \ingroup concept
+
+      /// \brief The opposite node on the given edge.
+      ///
+      /// Gives back the opposite node on the given edge.
+      Node oppositeNode(const Node&, const Edge&) const { return INVALID; }
+
+      /// \brief Read write map of the nodes to type \c T.
+      /// 
       /// ReadWrite map of the nodes to type \c T.
       /// \sa Reference
@@ -520 +529 @@
       };
 
-      /// Read write map of the edges to type \c T.
-
-      /// \ingroup concept
-      ///Reference map of the edges to type \c T.
+      /// \brief Read write map of the edges to type \c T.
+      ///
+      /// Reference map of the edges to type \c T.
       /// \sa Reference
       /// \warning Making maps that can handle bool type (EdgeMap<bool>)
@@ -611 +619 @@
 
     };
-
-    
-    /************* New GraphBase stuff **************/
-
-
-//     /// A minimal GraphBase concept
-
-//     /// This class describes a minimal concept which can be extended to a
-//     /// full-featured graph with \ref GraphFactory.
-//     class GraphBase {
-//     public:
-
-//       GraphBase() {}
-
-//       /// \bug Should we demand that Node and Edge be subclasses of the
-//       /// Graph class???
-
-//       typedef GraphItem<'n'> Node;
-//       typedef GraphItem<'e'> Edge;
-
-// //       class Node : public BaseGraphItem<'n'> {};
-// //       class Edge : public BaseGraphItem<'e'> {};
-
-//       // Graph operation
-//       void firstNode(Node &n) const { }
-//       void firstEdge(Edge &e) const { }
-
-//       void firstOutEdge(Edge &e, Node) const { }
-//       void firstInEdge(Edge &e, Node) const { }
-
-//       void nextNode(Node &n) const { }
-//       void nextEdge(Edge &e) const { }
-
-
-//       // Question: isn't it reasonable if this methods have a Node
-//       // parameter? Like this:
-//       // Edge& nextOut(Edge &e, Node) const { return e; }
-//       void nextOutEdge(Edge &e) const { }
-//       void nextInEdge(Edge &e) const { }
-
-//       Node target(Edge) const { return Node(); }
-//       Node source(Edge) const { return Node(); }
-      
-
-//       // Do we need id, nodeNum, edgeNum and co. in this basic graphbase
-//       // concept?
-
-
-//       // Maps.
-//       //
-//       // We need a special slimer concept which does not provide maps (it
-//       // wouldn't be strictly slimer, cause for map-factory id() & friends
-//       // a required...)
-
-//       template<typename T>
-//       class NodeMap : public GraphMap<GraphBase, Node, T> {};
-
-//       template<typename T>
-//       class EdgeMap : public GraphMap<GraphBase, Node, T> {};
-//     };
-
+    
     // @}
   } //namespace concept  

lemon/concept/graph_component.h

@@ -679 +679 @@
       ///
       /// Gives back the base node of the iterator.
+      /// It is always the target of the pointed edge.
       Node baseNode(const InEdgeIt&) const { return INVALID; }
 
@@ -684 +685 @@
       ///
       /// Gives back the running node of the iterator.
+      /// It is always the source of the pointed edge.
       Node runningNode(const InEdgeIt&) const { return INVALID; }
 
@@ -689 +691 @@
       ///
       /// Gives back the base node of the iterator.
+      /// It is always the source of the pointed edge.
       Node baseNode(const OutEdgeIt&) const { return INVALID; }
 
@@ -694 +697 @@
       ///
       /// Gives back the running node of the iterator.
+      /// It is always the target of the pointed edge.
       Node runningNode(const OutEdgeIt&) const { return INVALID; }
+
+      /// \brief The opposite node on the given edge.
+      ///
+      /// Gives back the opposite on the given edge.
+      /// \todo It should not be here.
+      Node oppositeNode(const Node&, const Edge&) const { return INVALID; }
 
     
@@ -708 +718 @@
           checkConcept<GraphIncIterator<_Graph>, typename _Graph::InEdgeIt>();
           checkConcept<GraphIncIterator<_Graph>, typename _Graph::OutEdgeIt>();
-        }
+
+          typename _Graph::Node n;
+          typename _Graph::Edge e;
+          n = graph.oppositeNode(n, e);
+        }
+        
+        const _Graph& graph;
+        
       };
     };

lemon/concept/undir_graph.h

@@ -120 +120 @@
 
           bool b;
-          b = graph.forward(e);
+          b = graph.direction(e);
+          Edge e = graph.direct(UndirEdge(), true);
+          e = graph.direct(UndirEdge(), n);
+ 
           ignore_unused_variable_warning(b);
         }
@@ -233 +236 @@
     /// explanation of this and more see also the page \ref undir_graphs,
     /// a tutorial about undirected graphs.
-
-    class UndirGraph : public StaticGraph {
+    ///
+    /// You can assume that all undirected graph can be handled
+    /// as a static directed graph. This way it is fully conform
+    /// to the StaticGraph concept.
+
+    class UndirGraph {
     public:
       ///\e
@@ -242 +249 @@
       typedef True UndirTag;
 
+      /// The base type of node iterators, 
+      /// or in other words, the trivial node iterator.
+
+      /// This is the base type of each node iterator,
+      /// thus each kind of node iterator converts to this.
+      /// More precisely each kind of node iterator should be inherited 
+      /// from the trivial node iterator.
+      class Node {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        Node() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        Node(const Node&) { }
+
+        /// Invalid constructor \& conversion.
+
+        /// This constructor initializes the iterator to be invalid.
+        /// \sa Invalid for more details.
+        Node(Invalid) { }
+        /// Equality operator
+
+        /// Two iterators are equal if and only if they point to the
+        /// same object or both are invalid.
+        bool operator==(Node) const { return true; }
+
+        /// Inequality operator
+        
+        /// \sa operator==(Node n)
+        ///
+        bool operator!=(Node) const { return true; }
+
+        /// Artificial ordering operator.
+        
+        /// To allow the use of graph descriptors as key type in std::map or
+        /// similar associative container we require this.
+        ///
+        /// \note This operator only have to define some strict ordering of
+        /// the items; this order has nothing to do with the iteration
+        /// ordering of the items.
+        ///
+        /// \bug This is a technical requirement. Do we really need this?
+        bool operator<(Node) const { return false; }
+
+      };
+    
+      /// This iterator goes through each node.
+
+      /// This iterator goes through each node.
+      /// Its usage is quite simple, for example you can count the number
+      /// of nodes in graph \c g of type \c Graph like this:
+      /// \code
+      /// int count=0;
+      /// for (Graph::NodeIt n(g); n!=INVALID; ++n) ++count;
+      /// \endcode
+      class NodeIt : public Node {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        NodeIt() { }
+        /// Copy constructor.
+        
+        /// Copy constructor.
+        ///
+        NodeIt(const NodeIt& n) : Node(n) { }
+        /// Invalid constructor \& conversion.
+
+        /// Initialize the iterator to be invalid.
+        /// \sa Invalid for more details.
+        NodeIt(Invalid) { }
+        /// Sets the iterator to the first node.
+
+        /// Sets the iterator to the first node of \c g.
+        ///
+        NodeIt(const UndirGraph&) { }
+        /// Node -> NodeIt conversion.
+
+        /// Sets the iterator to the node of \c the graph pointed by 
+        /// the trivial iterator.
+        /// This feature necessitates that each time we 
+        /// iterate the edge-set, the iteration order is the same.
+        NodeIt(const UndirGraph&, const Node&) { }
+        /// Next node.
+
+        /// Assign the iterator to the next node.
+        ///
+        NodeIt& operator++() { return *this; }
+      };
+    
+    
       /// The base type of the undirected edge iterators.
-      
+
       /// The base type of the undirected edge iterators.
       ///
@@ -258 +362 @@
         ///
         UndirEdge(const UndirEdge&) { }
-        /// Edge -> UndirEdge conversion
-
-        /// Edge -> UndirEdge conversion
-        ///
-        UndirEdge(const Edge&) { }
         /// Initialize the iterator to be invalid.
 
@@ -279 +378 @@
         bool operator!=(UndirEdge) const { return true; }
 
-        ///\e
-
-        ///\todo Do we need this?
+        /// Artificial ordering operator.
+        
+        /// To allow the use of graph descriptors as key type in std::map or
+        /// similar associative container we require this.
         ///
-        bool operator<(const UndirEdge &that) const { return true; }
-      };
-    
+        /// \note This operator only have to define some strict ordering of
+        /// the items; this order has nothing to do with the iteration
+        /// ordering of the items.
+        ///
+        /// \bug This is a technical requirement. Do we really need this?
+        bool operator<(UndirEdge) const { return false; }
+      };
+
       /// This iterator goes through each undirected edge.
 
       /// This iterator goes through each undirected edge of a graph.
       /// Its usage is quite simple, for example you can count the number
-      /// of edges in a graph \c g of type \c Graph as follows:
+      /// of undirected edges in a graph \c g of type \c Graph as follows:
       /// \code
       /// int count=0;
@@ -298 +403 @@
       public:
         /// Default constructor
-        
+
         /// @warning The default constructor sets the iterator
         /// to an undefined value.
         UndirEdgeIt() { }
         /// Copy constructor.
-        
+
         /// Copy constructor.
         ///
@@ -312 +417 @@
         ///
         UndirEdgeIt(Invalid) { }
-        /// This constructor sets the iterator to the first edge.
+        /// This constructor sets the iterator to the first undirected edge.
     
-        /// This constructor sets the iterator to the first edge of \c g.
+        /// This constructor sets the iterator to the first undirected edge.
         UndirEdgeIt(const UndirGraph&) { }
         /// UndirEdge -> UndirEdgeIt conversion
 
-        /// Sets the iterator to the value of the trivial iterator \c e.
-        /// This feature necessitates that each time we 
-        /// iterate the edge-set, the iteration order is the same.
+        /// Sets the iterator to the value of the trivial iterator.
+        /// This feature necessitates that each time we
+        /// iterate the undirected edge-set, the iteration order is the 
+        /// same.
         UndirEdgeIt(const UndirGraph&, const UndirEdge&) { } 
-        ///Next edge
+        /// Next undirected edge
         
-        /// Assign the iterator to the next edge.
+        /// Assign the iterator to the next undirected edge.
         UndirEdgeIt& operator++() { return *this; }
       };
 
-      /// This iterator goes trough the incident undirected edges of a node.
-
+      /// \brief This iterator goes trough the incident undirected 
+      /// edges of a node.
+      ///
       /// This iterator goes trough the incident undirected edges
       /// of a certain node
@@ -376 +483 @@
       };
 
+      /// The directed edge type.
+
+      /// The directed edge type. It can be converted to the
+      /// undirected edge.
+      class Edge : public UndirEdge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        Edge() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        Edge(const Edge& e) : UndirEdge(e) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        Edge(Invalid) { }
+        /// Equality operator
+
+        /// Two iterators are equal if and only if they point to the
+        /// same object or both are invalid.
+        bool operator==(Edge) const { return true; }
+        /// Inequality operator
+
+        /// \sa operator==(Edge n)
+        ///
+        bool operator!=(Edge) const { return true; }
+
+        /// Artificial ordering operator.
+        
+        /// To allow the use of graph descriptors as key type in std::map or
+        /// similar associative container we require this.
+        ///
+        /// \note This operator only have to define some strict ordering of
+        /// the items; this order has nothing to do with the iteration
+        /// ordering of the items.
+        ///
+        /// \bug This is a technical requirement. Do we really need this?
+        bool operator<(Edge) const { return false; }
+        
+      }; 
+      /// This iterator goes through each directed edge.
+
+      /// This iterator goes through each edge of a graph.
+      /// Its usage is quite simple, for example you can count the number
+      /// of edges in a graph \c g of type \c Graph as follows:
+      /// \code
+      /// int count=0;
+      /// for(Graph::EdgeIt e(g); e!=INVALID; ++e) ++count;
+      /// \endcode
+      class EdgeIt : public Edge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        EdgeIt() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        EdgeIt(const EdgeIt& e) : Edge(e) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        EdgeIt(Invalid) { }
+        /// This constructor sets the iterator to the first edge.
+    
+        /// This constructor sets the iterator to the first edge of \c g.
+        ///@param g the graph
+        EdgeIt(const UndirGraph&) { }
+        /// Edge -> EdgeIt conversion
+
+        /// Sets the iterator to the value of the trivial iterator \c e.
+        /// This feature necessitates that each time we 
+        /// iterate the edge-set, the iteration order is the same.
+        EdgeIt(const UndirGraph&, const Edge&) { } 
+        ///Next edge
+        
+        /// Assign the iterator to the next edge.
+        EdgeIt& operator++() { return *this; }
+      };
+   
+      /// This iterator goes trough the outgoing directed edges of a node.
+
+      /// This iterator goes trough the \e outgoing edges of a certain node
+      /// of a graph.
+      /// Its usage is quite simple, for example you can count the number
+      /// of outgoing edges of a node \c n
+      /// in graph \c g of type \c Graph as follows.
+      /// \code
+      /// int count=0;
+      /// for (Graph::OutEdgeIt e(g, n); e!=INVALID; ++e) ++count;
+      /// \endcode
+    
+      class OutEdgeIt : public Edge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        OutEdgeIt() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        OutEdgeIt(const OutEdgeIt& e) : Edge(e) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        OutEdgeIt(Invalid) { }
+        /// This constructor sets the iterator to the first outgoing edge.
+    
+        /// This constructor sets the iterator to the first outgoing edge of
+        /// the node.
+        ///@param n the node
+        ///@param g the graph
+        OutEdgeIt(const UndirGraph&, const Node&) { }
+        /// Edge -> OutEdgeIt conversion
+
+        /// Sets the iterator to the value of the trivial iterator.
+        /// This feature necessitates that each time we 
+        /// iterate the edge-set, the iteration order is the same.
+        OutEdgeIt(const UndirGraph&, const Edge&) { }
+        ///Next outgoing edge
+        
+        /// Assign the iterator to the next 
+        /// outgoing edge of the corresponding node.
+        OutEdgeIt& operator++() { return *this; }
+      };
+
+      /// This iterator goes trough the incoming directed edges of a node.
+
+      /// This iterator goes trough the \e incoming edges of a certain node
+      /// of a graph.
+      /// Its usage is quite simple, for example you can count the number
+      /// of outgoing edges of a node \c n
+      /// in graph \c g of type \c Graph as follows.
+      /// \code
+      /// int count=0;
+      /// for(Graph::InEdgeIt e(g, n); e!=INVALID; ++e) ++count;
+      /// \endcode
+
+      class InEdgeIt : public Edge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        InEdgeIt() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        InEdgeIt(const InEdgeIt& e) : Edge(e) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        InEdgeIt(Invalid) { }
+        /// This constructor sets the iterator to first incoming edge.
+    
+        /// This constructor set the iterator to the first incoming edge of
+        /// the node.
+        ///@param n the node
+        ///@param g the graph
+        InEdgeIt(const UndirGraph&, const Node&) { }
+        /// Edge -> InEdgeIt conversion
+
+        /// Sets the iterator to the value of the trivial iterator \c e.
+        /// This feature necessitates that each time we 
+        /// iterate the edge-set, the iteration order is the same.
+        InEdgeIt(const UndirGraph&, const Edge&) { }
+        /// Next incoming edge
+
+        /// Assign the iterator to the next inedge of the corresponding node.
+        ///
+        InEdgeIt& operator++() { return *this; }
+      };
+
+      /// \brief Read write map of the nodes to type \c T.
+      /// 
+      /// ReadWrite map of the nodes to type \c T.
+      /// \sa Reference
+      /// \warning Making maps that can handle bool type (NodeMap<bool>)
+      /// needs some extra attention!
+      template<class T> 
+      class NodeMap : public ReadWriteMap< Node, T >
+      {
+      public:
+
+        ///\e
+        NodeMap(const UndirGraph&) { }
+        ///\e
+        NodeMap(const UndirGraph&, T) { }
+
+        ///Copy constructor
+        NodeMap(const NodeMap& nm) : ReadWriteMap< Node, T >(nm) { }
+        ///Assignment operator
+        NodeMap& operator=(const NodeMap&) { return *this; }
+        // \todo fix this concept
+      };
+
+      /// \brief Read write map of the directed edges to type \c T.
+      ///
+      /// Reference map of the directed edges to type \c T.
+      /// \sa Reference
+      /// \warning Making maps that can handle bool type (EdgeMap<bool>)
+      /// needs some extra attention!
+      template<class T> 
+      class EdgeMap : public ReadWriteMap<Edge,T>
+      {
+      public:
+
+        ///\e
+        EdgeMap(const UndirGraph&) { }
+        ///\e
+        EdgeMap(const UndirGraph&, T) { }
+        ///Copy constructor
+        EdgeMap(const EdgeMap& em) : ReadWriteMap<Edge,T>(em) { }
+        ///Assignment operator
+        EdgeMap& operator=(const EdgeMap&) { return *this; }
+        // \todo fix this concept    
+      };
+
       /// Read write map of the undirected edges to type \c T.
 
@@ -392 +730 @@
         UndirEdgeMap(const UndirGraph&, T) { }
         ///Copy constructor
-        UndirEdgeMap(const UndirEdgeMap& em) : ReadWriteMap<UndirEdge,T>(em) { }
+        UndirEdgeMap(const UndirEdgeMap& em) : ReadWriteMap<UndirEdge,T>(em) {}
         ///Assignment operator
         UndirEdgeMap &operator=(const UndirEdgeMap&) { return *this; }
@@ -398 +736 @@
       };
 
-      /// Is the Edge oriented "forward"?
-
+      /// \brief Direct the given undirected edge.
+      ///
+      /// Direct the given undirected edge. The returned edge source
+      /// will be the given edge.
+      Edge direct(const UndirEdge&, const Node&) const {
+        return INVALID;
+      }
+
+      /// \brief Direct the given undirected edge.
+      ///
+      /// Direct the given undirected edge. The returned edge source
+      /// will be the source of the undirected edge if the given bool
+      /// is true.
+      Edge direct(const UndirEdge&, bool) const {
+        return INVALID;
+      }
+
+      /// \brief Returns true if the edge has default orientation.
+      ///
       /// Returns whether the given directed edge is same orientation as
       /// the corresponding undirected edge.
-      ///
-      /// \todo "What does the direction of an undirected edge mean?"
-      bool forward(Edge) const { return true; }
-
-      /// Opposite node on an edge
-
+      bool direction(Edge) const { return true; }
+
+      /// \brief Returns the opposite directed edge.
+      ///
+      /// Returns the opposite directed edge.
+      Edge oppositeEdge(Edge) const { return INVALID; }
+
+      /// \brief Opposite node on an edge
+      ///
       /// \return the opposite of the given Node on the given Edge
-      ///
-      /// \todo What should we do if given Node and Edge are not incident?
       Node oppositeNode(Node, UndirEdge) const { return INVALID; }
 
-      /// First node of the undirected edge.
-
+      /// \brief First node of the undirected edge.
+      ///
       /// \return the first node of the given UndirEdge.
       ///
@@ -421 +777 @@
       /// to query the two endnodes of the edge. The direction of the edge
       /// which arises this way is called the inherent direction of the
-      /// undirected edge, and is used to define the "forward" direction
+      /// undirected edge, and is used to define the "default" direction
       /// of the directed versions of the edges.
-      /// \sa forward
+      /// \sa direction
       Node source(UndirEdge) const { return INVALID; }
 
-      /// Second node of the undirected edge.
+      /// \brief Second node of the undirected edge.
       Node target(UndirEdge) const { return INVALID; }
 
-      /// Source node of the directed edge.
+      /// \brief Source node of the directed edge.
       Node source(Edge) const { return INVALID; }
 
-      /// Target node of the directed edge.
+      /// \brief Target node of the directed edge.
       Node target(Edge) const { return INVALID; }
 
-      /// First node of the graph
-
+      /// \brief First node of the graph
+      ///
       /// \note This method is part of so called \ref
       /// developpers_interface "Developpers' interface", so it shouldn't
       /// be used in an end-user program.
       void first(Node&) const {}
-      /// Next node of the graph
-
+      /// \brief Next node of the graph
+      ///
       /// \note This method is part of so called \ref
       /// developpers_interface "Developpers' interface", so it shouldn't
@@ -448 +804 @@
       void next(Node&) const {}
 
-      /// First undirected edge of the graph
-
+      /// \brief First undirected edge of the graph
+      ///
       /// \note This method is part of so called \ref
       /// developpers_interface "Developpers' interface", so it shouldn't
       /// be used in an end-user program.
       void first(UndirEdge&) const {}
-      /// Next undirected edge of the graph
-
+      /// \brief Next undirected edge of the graph
+      ///
       /// \note This method is part of so called \ref
       /// developpers_interface "Developpers' interface", so it shouldn't
@@ -461 +817 @@
       void next(UndirEdge&) const {}
 
-      /// First directed edge of the graph
-
+      /// \brief First directed edge of the graph
+      ///
       /// \note This method is part of so called \ref
       /// developpers_interface "Developpers' interface", so it shouldn't
       /// be used in an end-user program.
       void first(Edge&) const {}
-      /// Next directed edge of the graph
-
+      /// \brief Next directed edge of the graph
+      ///
       /// \note This method is part of so called \ref
       /// developpers_interface "Developpers' interface", so it shouldn't
@@ -474 +830 @@
       void next(Edge&) const {}
 
-      /// First outgoing edge from a given node
-
+      /// \brief First outgoing edge from a given node
+      ///
       /// \note This method is part of so called \ref
       /// developpers_interface "Developpers' interface", so it shouldn't
       /// be used in an end-user program.
       void firstOut(Edge&, Node) const {}
-      /// Next outgoing edge to a node
-
+      /// \brief Next outgoing edge to a node
+      ///
       /// \note This method is part of so called \ref
       /// developpers_interface "Developpers' interface", so it shouldn't
@@ -487 +843 @@
       void nextOut(Edge&) const {}
 
-      /// First incoming edge to a given node
-
+      /// \brief First incoming edge to a given node
+      ///
       /// \note This method is part of so called \ref
       /// developpers_interface "Developpers' interface", so it shouldn't
       /// be used in an end-user program.
       void firstIn(Edge&, Node) const {}
-      /// Next incoming edge to a node
-
+      /// \brief Next incoming edge to a node
+      ///
       /// \note This method is part of so called \ref
       /// developpers_interface "Developpers' interface", so it shouldn't
@@ -501 +857 @@
 
 
-      /// Base node of the iterator
+      /// \brief Base node of the iterator
       ///
       /// Returns the base node (the source in this case) of the iterator
@@ -507 +863 @@
         return source(e);
       }
-      /// Running node of the iterator
+      /// \brief Running node of the iterator
       ///
       /// Returns the running node (the target in this case) of the
@@ -515 +871 @@
       }
 
-      /// Base node of the iterator
+      /// \brief Base node of the iterator
       ///
       /// Returns the base node (the target in this case) of the iterator
@@ -521 +877 @@
         return target(e);
       }
-      /// Running node of the iterator
+      /// \brief Running node of the iterator
       ///
       /// Returns the running node (the source in this case) of the
@@ -529 +885 @@
       }
 
-      /// Base node of the iterator
+      /// \brief Base node of the iterator
       ///
       /// Returns the base node of the iterator
@@ -535 +891 @@
         return INVALID;
       }
-      /// Running node of the iterator
+      
+      /// \brief Running node of the iterator
       ///
       /// Returns the running node of the iterator
@@ -541 +898 @@
         return INVALID;
       }
-
 
       template <typename Graph>
@@ -554 +910 @@
     };
 
+    /// \brief An empty non-static undirected graph class.
+    ///    
+    /// This class provides everything that \ref UndirGraph does.
+    /// Additionally it enables building graphs from scratch.
     class ExtendableUndirGraph : public UndirGraph {
     public:
+      
+      /// \brief Add a new node to the graph.
+      ///
+      /// Add a new node to the graph.
+      /// \return the new node.
+      Node addNode();
+
+      /// \brief Add a new undirected edge to the graph.
+      ///
+      /// Add a new undirected edge to the graph.
+      /// \return the new edge.
+      UndirEdge addEdge(const Node& from, const Node& to);
+
+      /// \brief Resets the graph.
+      ///
+      /// This function deletes all undirected edges and nodes of the graph.
+      /// It also frees the memory allocated to store them.
+      void clear() { }
 
       template <typename Graph>
@@ -572 +950 @@
     };
 
+    /// \brief An empty erasable undirected graph class.
+    ///
+    /// This class is an extension of \ref ExtendableUndirGraph. It makes it
+    /// possible to erase undirected edges or nodes.
     class ErasableUndirGraph : public ExtendableUndirGraph {
     public:
+
+      /// \brief Deletes a node.
+      ///
+      /// Deletes a node.
+      ///
+      void erase(Node) { }
+      /// \brief Deletes an undirected edge.
+      ///
+      /// Deletes an undirected edge.
+      ///
+      void erase(UndirEdge) { }
 
       template <typename Graph>

lemon/graph_adaptor.h

@@ -106 +106 @@
     void clear() const { graph->clear(); }
     
-    bool forward(const Edge& e) const { return graph->forward(e); }
-    bool backward(const Edge& e) const { return graph->backward(e); }
-
     int id(const Node& v) const { return graph->id(v); }
     int id(const Edge& e) const { return graph->id(e); }
     
-    Edge opposite(const Edge& e) const { return Edge(graph->opposite(e)); }
+    Edge oppositeNode(const Edge& e) const { 
+      return Edge(graph->opposite(e)); 
+    }
 
     template <typename _Value>
@@ -609 +608 @@
       
       void set(Edge e, T a) { 
-        if (g->forward(e)) 
+        if (g->direction(e)) 
           forward_map.set(e, a); 
         else 
@@ -616 +615 @@
 
       T operator[](Edge e) const { 
-        if (g->forward(e)) 
+        if (g->direction(e)) 
           return forward_map[e]; 
         else 

lemon/graph_utils.h

@@ -996 +996 @@
     /// \return The "forward" directed edge view of undirected edge 
     Value operator[](const Key& key) const {
-      return graph.edgeWithSource(key, graph.source(key));
+      return graph.direct(key, true);
     }
 
@@ -1036 +1036 @@
     /// \return The "backward" directed edge view of undirected edge 
     Value operator[](const Key& key) const {
-      return graph.edgeWithSource(key, graph.target(key));
+      return graph.direct(key, false);
     }
 

lemon/lemon_reader.h

@@ -1323 +1323 @@
       UndirEdge undirEdge = inverter->read(is);
       if (c == '+') {
-        edge = graph.edgeWithSource(undirEdge, graph.source(undirEdge));
+        edge = graph.direct(undirEdge, true);
       } else if (c == '-') {
-        edge = graph.edgeWithSource(undirEdge, graph.target(undirEdge));
+        edge = graph.direct(undirEdge, false);
       } else {
         throw DataFormatError("Wrong id format for edge "