implement message pseudo variable (like self)

too easy
also simplified some tests

lib/soml/compiler/field_access.rb

@@ -18,7 +18,7 @@ module Soml
         add_code move
       when :message
         #message Slot
-        raise "message not yet"
+        value = Register.message_reg
       else
         if( index = @method.has_arg(receiver)) #argument
           value = use_reg @method.arguments[index].type
@@ -31,7 +31,7 @@ module Soml
             add_code Register.get_slot(statement , :message , :frame , frame )
             code = Register.get_slot(statement ,frame , Parfait::Frame.get_indexed(index) , value )
           else
-            raise "Variable not defined #{name}"
+            raise "Variable not defined #{receiver}"
           end
         end
       end

test/compiler/statements/test_fields.rb

@@ -7,13 +7,10 @@ module Register
 
     def test_field_frame
       @string_input = <<HERE
-class Fielded
-  field int one
-end
 class Object
   int main()
-    Fielded f
-    return f.one
+    Message m
+    return m.name
   end
 end
 HERE
@@ -23,16 +20,13 @@ HERE
 
     def test_field_arg
       @string_input = <<HERE
-class Fielded
-  field int one
-end
 class Object
-  int the_one(Fielded f)
-    return f.one
+  int get_name(Message main)
+    return main.name
   end
   int main()
-    Fielded f
-    return the_one(f)
+    Message m
+    return get_name(m)
   end
 end
 HERE
@@ -42,5 +36,33 @@ HERE
                  FunctionReturn]
       check
     end
+
+    def test_self_field
+      @string_input = <<HERE
+class Object
+  int main()
+    Layout l = self.layout
+    return 1
+  end
+end
+HERE
+      @expect =  [Label, GetSlot, GetSlot, GetSlot, SetSlot, LoadConstant, SetSlot ,
+                  Label, FunctionReturn]
+      check
+    end
+
+    def test_message_field
+      @string_input = <<HERE
+class Object
+  int main()
+    Word name = message.name
+    return name
+  end
+end
+HERE
+      @expect =  [Label, GetSlot, SetSlot, GetSlot, GetSlot, SetSlot, Label ,
+                  FunctionReturn]
+      check
+    end
   end
 end