lib/society/edge.rb in society-1.1.1 vs lib/society/edge.rb in society-1.2.0

@@ -1,15 +1,41 @@
 module Society
+
+  # The Edge class represents an edge between two nodes in a graph.  An edge is
+  # assumed to represent a direct relationship between two Classes or Modules.
   class Edge
 
-    attr_reader :from, :to
-    attr_accessor :meta
+    attr_reader :to, :weight
 
-    def initialize(from:, to:, meta:nil)
-      @from = from
-      @to = to
-      @meta = meta
+    # Public: Create a new Edge.
+    #
+    # to     - Node to target.
+    # weight - Weight of the edge, representing the number of references to the
+    #          node referenced.  (Default: 1)
+    def initialize(to:, weight: 1)
+      @to     = to
+      @weight = weight
     end
+
+    # Public: Add two Edges' weights, returning a new Edge.
+    #
+    # edge - An Edge.
+    #
+    # Returns a new Edge if both edges target the same node.
+    # Returns nil otherwise.
+    def +(edge)
+      return nil unless edge.to == to
+
+      Edge.new(to: to, weight: weight + edge.weight)
+    end
+
+    # Public: Return the name of the node to which the edge points.
+    #
+    # Returns a string.
+    def to_s
+      to.to_s
+    end
+    alias_method :inspect, :to_s
 
   end
 
 end