moving string to parfait

using parfait::word
also rename builtins string to word

lib/virtual/compiler/basic_expressions.rb

@@ -71,7 +71,7 @@ module Virtual
 
   #    attr_reader  :string
       def self.compile_string expression , method
-        value = StringConstant.new(expression.string)
+        value = Parfait::Word.new(expression.string)
         to = Return.new(Reference , value)
         Machine.instance.space.add_object value
         method.add_code Set.new( to , value )

lib/virtual/compiler/callsite_expression.rb

@@ -8,7 +8,7 @@ module Virtual
       me = Compiler.compile( expession.receiver , method )
       method.add_code NewMessage.new
       method.add_code Set.new(NewSelf.new(me.type), me)
-      method.add_code Set.new(NewName.new(), StringConstant.new(expession.name))
+      method.add_code Set.new(NewName.new(), Parfait::Word.new(expession.name))
       compiled_args = []
       expession.args.each_with_index do |arg , i|
         #compile in the running method, ie before passing control