> The thrust of duck typing, as I
> understand it, is that you just ask an object to do something --
> without regard to its class, and quite likely without doing a
> respond_to? call first.

I've pondered if duck typing is about an object being able to respond
to a specific method or if it is about a set of methods.   I also
wonder if a mechanism like Objective-C's  'protocol' would be useful
in Ruby.

- Mark