lib/rgl/adjacency.rb in rgl-0.2.3 vs lib/rgl/adjacency.rb in rgl-0.3.0

@@ -1,8 +1,8 @@
 # adjacency.rb
 # 
-# $Id: adjacency.rb,v 1.7 2005/03/30 21:25:34 monora Exp $
+# $Id: adjacency.rb,v 1.11 2008/03/02 13:45:43 monora Exp $
 # 
 # The DirectedAdjacencyGraph class implements a generalized adjacency list
 # graph structure.  An AdjacencyGraph is basically a two-dimensional structure
 # (ie, a list of lists).  Each element of the first dimension represents a
 # vertex.  Each of the vertices contains a one-dimensional structure that is
@@ -33,25 +33,39 @@
     end
 
     # Returns a new empty DirectedAdjacencyGraph which has as its edgelist
     # class the given class.  The default edgelist class is Set, to ensure
     # set semantics for edges and vertices.
-
-    def initialize (edgelist_class = Set)
+    #
+    # If other graphs are passed as parameters their vertices and edges are
+    # added to the new graph.
+    def initialize (edgelist_class = Set, *other_graphs)
       @edgelist_class = edgelist_class
       @vertice_dict   = Hash.new
+      other_graphs.each do |g|
+        g.each_vertex {|v| add_vertex v}
+        g.each_edge {|v,w| add_edge v,w}
+      end
     end
 
+    # Copy internal vertice_dict
+    def initialize_copy(orig)
+      @vertice_dict = orig.instance_eval{@vertice_dict}.dup
+      @vertice_dict.keys.each do |v|
+        @vertice_dict[v] = @vertice_dict[v].dup
+      end
+    end
+
     # Iterator for the keys of the vertice list hash.
 
     def each_vertex (&b)
       @vertice_dict.each_key(&b)
     end
 
     def each_adjacent (v, &b)			# :nodoc:
-      adjacency_list = @vertice_dict[v] or
-        raise NoVertexError, "No vertex #{v}."
+      adjacency_list = (@vertice_dict[v] or
+        raise NoVertexError, "No vertex #{v}.")
       adjacency_list.each(&b)
     end
 
     # Returns true.
 
@@ -107,10 +121,19 @@
 
     def remove_edge (u, v)
       @vertice_dict[u].delete(v) unless @vertice_dict[u].nil?
     end
 
+    # Converts the adjacency list of each vertex to be of type _klass_. The
+    # class is expected to have a new contructor which accepts an enumerable as
+    # parameter.
+    def edgelist_class=(klass)
+      @vertice_dict.keys.each do |v|
+         @vertice_dict[v] = klass.new @vertice_dict[v].to_a
+      end
+    end
+
     protected
 
     def basic_add_edge (u, v)
       @vertice_dict[u].add(v)
     end
@@ -173,12 +196,10 @@
     #
     # If the graph is undirected, the result is self.
 
     def to_undirected
       return self unless directed?
-      result = AdjacencyGraph.new
-      each_edge { |u,v| result.add_edge(u, v) }
-      result
+      AdjacencyGraph.new(Set, self)
     end
 
   end		# module Graph
 end		# module RGL