Renaming Vool exppressions rightly

Class, Method and Lambda (was block) are expressions.
Just making things clearer, especially for the blocks (ahem, lambdas) is matters.
wip

lib/parfait/data_object.rb

@@ -19,11 +19,10 @@
 # DataObjects still have a type, and so can have objects before the data starts
 #
 # A marker class
-module Parfait
   class DataObject < Object
 
     def self.type_length
-      raise "called #{self}"
+      raise "called " + self.to_s
     end
     def padded_length
       self.class.memory_size * 4
@@ -53,4 +52,3 @@ module Parfait
       32
     end
   end
-end

lib/parfait/integer.rb

@@ -1,4 +1,3 @@
-module Parfait
   # Integer class for representing maths on Integers
   # Integers are Objects, specifically DataObjects
   # - they have fixed value
@@ -92,4 +91,3 @@ module Parfait
       1    # 0 type
     end
   end
-end

lib/parfait/vool_method.rb

@@ -23,7 +23,7 @@ module Parfait
       raise "Name must be symbol" unless name.is_a?(Symbol)
       raise "args_type must be type" unless args_type.is_a?(Parfait::Type)
       raise "frame_type must be type" unless frame_type.is_a?(Parfait::Type)
-      raise "source must be vool" unless source.is_a?(Vool::Statement)
+      raise "source must be vool not#{source.class}" unless source.is_a?(Vool::Statement)
       raise "Empty bod" if(@source.is_a?(Vool::Statements) and @source.empty?)
     end