self is just a built-in function returning the invocant. If you want a different name for it, you can always declare it explicitly.

Also, it's probably bogus to say any(self). It should probably be a function that is not context sensitive, in which case we'd have to say any(self[]) or some such to pull out the elements.

Finally, I think the failure of the multi form is just hitting some things that aren't completely implemented in pugs yet.