dot.rb in rgl-0.5.1

- old
+ new

@@ -10,10 +10,15 @@
 
 module RGL
 
   module Graph
 
+    # Returns a label for vertex v. Default is v.to_s
+    def vertex_label(v)
+      v.to_s
+    end
+
     # Return a RGL::DOT::Digraph for directed graphs or a DOT::Graph for an
     # undirected Graph. _params_ can contain any graph property specified in
     # rdot.rb.
     #
     def to_dot_graph(params = {})
@@ -21,21 +26,20 @@
       fontsize       = params['fontsize'] ? params['fontsize'] : '8'
       graph          = (directed? ? DOT::Digraph : DOT::Graph).new(params)
       edge_class     = directed? ? DOT::DirectedEdge : DOT::Edge
 
       each_vertex do |v|
-        name = v.to_s
         graph << DOT::Node.new(
-            'name'     => name,
+            'name'     => v.object_id,
             'fontsize' => fontsize,
-            'label'    => name
+            'label'    => vertex_label(v)
         )
       end
 
       each_edge do |u, v|
         graph << edge_class.new(
-            'from'     => u.to_s,
-            'to'       => v.to_s,
+            'from'     => u.object_id,
+            'to'       => v.object_id,
             'fontsize' => fontsize
         )
       end
 
       graph