moving string to parfait

using parfait::word
also rename builtins string to word

lib/parfait/word.rb

@@ -8,5 +8,28 @@ module Parfait
   # Words are constant, maybe like js strings, ruby symbols
   # Words are short, but may have spaces
   class Word < Object
+    def initialize str
+      @string = str
+    end
+    attr_reader :string
+
+    def result= value
+      raise "called"
+      class_for(MoveInstruction).new(value , self , :opcode => :mov)
+    end
+    def clazz
+      Space.space.get_or_create_class(:Word)
+    end
+    def layout
+      Virtual::Object.layout
+    end
+    def mem_length
+      padded(1 + string.length)
+    end
+    def position
+      return @position if @position
+      return @string.position if @string.position
+      super
+    end
   end
 end