fixes the tests after fixing hierarchy

lib/virtual/value.rb

@@ -9,15 +9,65 @@ module Virtual
     def == other
       other.class == self.class
     end
-    def inspect
-      self.class.name + ".new()"
-    end
     def type
-      raise "abstract called"
+      raise "abstract called for #{self.class}"
+    end
+    def attributes
+      raise "abstract called for #{self.class}"
+    end
+    def == other
+      return false unless other.class == self.class 
+      attributes.each do |a|
+        left = send(a)
+        right = other.send(a)
+        return false unless left.class == right.class 
+        return false unless left == right
+      end
+      return true
+    end
+    def inspect
+      self.class.name + ".new(" + attributes.collect{|a| send(a).inspect }.join(",")+ ")"
     end
     private
     def initialize
     end
   end
-  
+
+  class Variable < Value
+
+    def initialize name , type
+      @name = name
+      @type = type
+    end
+    attr_accessor :name , :type
+    def attributes
+      [:name , :type]
+    end
+  end
+  # The subclasses are not strictly speaking neccessary at this def point
+  # i just don't want to destroy the information for later optimizations
+  # 
+  # All variables are stored in frames and quite possibly in order arg,local,tmp
+  class Return < Variable
+    def initialize type
+      super(:return , type)
+    end
+    def attributes
+      [:type]
+    end
+  end
+  class Self < Variable
+    def initialize type
+      super(:self , type)
+    end
+    def attributes
+      [:type]
+    end
+  end
+  class Argument < Variable
+  end
+  class Local < Variable
+  end
+  class Temp < Variable
+  end
 end