lib/nydp/builtin/to_string.rb in nydp-0.1.15 vs lib/nydp/builtin/to_string.rb in nydp-0.2.0

@@ -1,8 +1,8 @@
 module Nydp::Builtin
   class ToString
-    include Nydp::Builtin::Base
+    include Nydp::Builtin::Base, Singleton
 
     def builtin_invoke vm, args
       arg = args.car
       val = case arg.class
             when Nydp::StringAtom
@@ -13,10 +13,10 @@
       vm.push_arg val
     end
   end
 
   class StringLength
-    include Nydp::Builtin::Base
+    include Nydp::Builtin::Base, Singleton
 
     def builtin_invoke vm, args
       arg = args.car
       val = case arg
             when Nydp::StringAtom