Changeset 1565:96244ea562a3 in lemon-0.x

Timestamp:

07/18/05 17:07:28 (20 years ago)

Author:

Balazs Dezso

Branch:

default

Phase:

public

Convert:

svn:c9d7d8f5-90d6-0310-b91f-818b3a526b0e/lemon/trunk@2064

Message:

Improve findEdge interface
ConEdgeIt? is a high level replacement of findEdge

File:

• lemon/graph_utils.h (modified) (2 diffs)

lemon/graph_utils.h

@@ -161 +161 @@
 
 
-  /// Finds an edge between two nodes of a graph.
-
+  template <typename Graph>
+  inline
+  typename enable_if<typename Graph::FindEdgeTag, typename Graph::Edge>::type 
+  _findEdge(const Graph &g,
+            typename Graph::Node u, typename Graph::Node v,
+            typename Graph::Edge prev = INVALID) {
+    return g.findEdge(u, v, prev);
+  }
+
+  template <typename Graph>
+  inline typename Graph::Edge 
+  _findEdge(Wrap<Graph> w,
+            typename Graph::Node u, 
+            typename Graph::Node v,
+            typename Graph::Edge prev = INVALID) {
+    const Graph& g = w.value;
+    if (prev == INVALID) {
+      typename Graph::OutEdgeIt e(g, u);
+      while (e != INVALID && g.target(e) != v) ++e;
+      return e;
+    } else {
+      typename Graph::OutEdgeIt e(g, prev); ++e;
+      while (e != INVALID && g.target(e) != v) ++e;
+      return e;
+    }
+  }
+
+  /// \brief Finds an edge between two nodes of a graph.
+  ///
   /// Finds an edge from node \c u to node \c v in graph \c g.
   ///
@@ -176 +203 @@
   /// }
   /// \endcode
-  /// \todo We may want to use the "GraphBase"
-  /// interface here...
-  /// \bug Untested ...
-  template <typename Graph>
-  typename Graph::Edge findEdge(const Graph &g,
-                                typename Graph::Node u, typename Graph::Node v,
-                                typename Graph::Edge prev = INVALID) 
-  {
-    typename Graph::OutEdgeIt e(g,prev);
-    //    if(prev==INVALID) g.first(e,u);
-    if(prev==INVALID) e=typename Graph::OutEdgeIt(g,u);
-    else ++e;
-    while(e!=INVALID && g.target(e)!=v) ++e;
-    return e;
-  }
+  // /// \todo We may want to use the "GraphBase" 
+  // /// interface here...
+  // /// It would not work with the undirected graphs.
+  template <typename Graph>
+  inline typename Graph::Edge findEdge(const Graph &g,
+                                       typename Graph::Node u, 
+                                       typename Graph::Node v,
+                                       typename Graph::Edge prev = INVALID) {
+    return _findEdge<Graph>(g, u, v, prev);
+  }
+
+  /// \brief Iterator for iterating on edges connected the same nodes.
+  ///
+  /// Iterator for iterating on edges connected the same nodes. It is 
+  /// higher level interface for the findEdge() function. You can
+  /// use it the next way:
+  /// \code
+  /// for (ConEdgeIt<Graph> it(g, src, trg); it != INVALID; ++it) {
+  ///   ...
+  /// }
+  /// \endcode
+  ///
+  /// \author Balazs Dezso 
+  template <typename _Graph>
+  class ConEdgeIt : public _Graph::Edge {
+  public:
+
+    typedef _Graph Graph;
+    typedef typename Graph::Edge Parent;
+
+    typedef typename Graph::Edge Edge;
+    typedef typename Graph::Node Node;
+
+    /// \brief Constructor.
+    ///
+    /// Construct a new ConEdgeIt iterating on the edges which
+    /// connects the \c u and \c v node.
+    ConEdgeIt(const Graph& g, Node u, Node v) : graph(g) {
+      Parent::operator=(findEdge(graph, u, v));
+    }
+
+    /// \brief Constructor.
+    ///
+    /// Construct a new ConEdgeIt which continues the iterating from 
+    /// the \c e edge.
+    ConEdgeIt(const Graph& g, Edge e) : Parent(e), graph(g) {}
+    
+    /// \brief Increment operator.
+    ///
+    /// It increments the iterator and gives back the next edge.
+    ConEdgeIt& operator++() {
+      Parent::operator=(findEdge(graph, graph.source(*this), 
+                                 graph.target(*this), *this));
+      return *this;
+    }
+  private:
+    const Graph& graph;
+  };
 
   /// \brief Copy a map.