On Tue, Nov 25, 2014 at 9:58 AM, Chris Angelico <rosuav@gmail.com> wrote:
On Wed, Nov 26, 2014 at 4:53 AM, Guido van Rossum <guido@python.org> wrote:
> It's not viable. It will break more code than PEP 479, and it will incur a
> larger interpreter overhead (every time any exception bubbles out of any
> frame we'd have to check whether it is (derived from) StopIteration and
> replace it, rather than only when exiting a generator frame. (The check for
> StopIteration is relatively expensive -- it's easy to determine that an
> exception *is* StopIteration, but in order that it doesn't derive from
> StopIteration you have to walk the inheritance tree.)
> Please stop panicking.

Heh. If that last comment was aimed at me, I wasn't panicking... I
just thought it an intellectually curious concept, having a measure of
interpreter support for the "not-a-return-value" concept.

OK, then I will just ignore this thread.

--Guido van Rossum (python.org/~guido)