[Python-Dev] semantics of subclassing things from itertools

[Maciej Fijalkowski]

Hi

I would like to know what are the semantics if you subclass something
from itertools (e.g. islice).

Right now it's allowed and people do it, which is why the
documentation is incorrect. It states "equivalent to: a function-or a
generator", but you can't subclass whatever it is equivalent to, which
is why in PyPy we're unable to make it work in pure python.

I would like some clarification on that.

Cheers,
fijal