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/statement.rb

@@ -0,0 +1,25 @@
+module Ruby
+
+  # Base class for all statements in the tree. Derived classes correspond to known language
+  # constructs
+  #
+  # Compilers or compiler passes are written by implementing methods.
+  #
+  class Statement
+
+    def at_depth(depth , *strings)
+      prefix = " " * 2 * depth
+      strings.collect{|str| prefix + str}.join("\n")
+    end
+
+  end
+
+  class Expression
+
+    def normalize
+      raise "should not be normalized #{self}"
+    end
+
+  end
+
+end