From: "Alex Martelli" <aleax@aleax.it>

PEP 246 cannot in any way impede "something" (or more likely "somebody") from writing inappropriate or totally incorrect code, nor will it even try. Maybe I'm missing your point...?

Maybe, or maybe not. I guess if the reiterable sequence adapter says "list(x)", nobody should be using it to find out whether a thing is reiterable. Or maybe the reiterable sequence adapter shouldn't say "list(x)" because that's destructive -- though that begs the question of finding out whether x is reiterable. Maybe the PEP is just a red herring as far as the iterator problem is concerned. As long as the language has built-in facilities like 'for' and 'in' which use iteration protocols at the core of the language, re-iterability ought to be expressible likewise, in core language terms, regardless of the more-extensible mechanisms of PEP 246. whole-pile-of-maybes-ly y'rs, dave