start a new ruby layer to do the to_vool conversion

the "normalization" is getting more and more complicated and is not tested
And it seems i really don't like working with the untyped ast

lib/ruby/method_statement.rb

@@ -0,0 +1,27 @@
+module Ruby
+  class MethodStatement < Statement
+    attr_reader :name, :args , :body , :clazz
+
+    def initialize( name , args , body , clazz = nil)
+      @name , @args , @body = name , args , body
+      raise "no bod" unless @body
+      @clazz = clazz
+    end
+
+
+    def normalize
+      MethodStatement.new( @name , @args , @body.normalize)
+    end
+
+    def has_yield?
+      each{|statement| return true if statement.is_a?(YieldStatement)}
+      return false
+    end
+
+    def to_s(depth = 0)
+      arg_str = @args.collect{|a| a.to_s}.join(', ')
+      at_depth(depth , "def #{name}(#{arg_str})" , @body.to_s(depth + 1) , "end")
+    end
+
+  end
+end