I agree with Ara. What's being presented here looks like it may be s
simple name "hack", i.e.

  define_method( "jcode$chop" ) { ... }

'using' just auto prefixes all method calls.  This isn't true namespace
selectors, is it?

What we need is as Ara suggests and my expiremention confirms, are
module/module-like constructs.

  class String

    namespace JCode ; end

    def JCode.chop
      ...
    end

  end

In fact modules themselves can be used here with the concept of
self-shimmying, which has been disccussed a good deal on suby mailing
list. (I'll resue $ here for demonstration purposes):

  class X

    module M
      def x
        self
      end
    end

    def show_em_how_you_shimmy
      M$x
    end

  end

  X.new.show_em_how_you_shimmy  #=> #<X ...>

Which is the simplified essence of namespace selector.

T.