On Wed, Apr 29, 2015 at 2:26 PM, Paul Moore <p.f.mo...@gmail.com> wrote: > On 29 April 2015 at 18:43, Jim J. Jewett <jimjjew...@gmail.com> wrote:
>> So? PEP 492 never says what coroutines *are* in a way that explains >> why it matters that they are different from generators. ... > Looking at the Wikipedia article on coroutines, I see an example of > how a producer/consumer process might be written with coroutines: > > var q := new queue > > coroutine produce > loop > while q is not full > create some new items > add the items to q > yield to consume > > coroutine consume > loop > while q is not empty > remove some items from q > use the items > yield to produce > > (To start everything off, you'd just run "produce"). > > I can't even see how to relate that to PEP 429 syntax. I'm not allowed > to use "yield", so should I use "await consume" in produce (and vice > versa)? I think so ... but the fact that nothing is actually coming via the await channel makes it awkward. I also worry that it would end up with an infinite stack depth, unless the await were actually replaced with some sort of framework-specific scheduling primitive, or one of them were rewritten differently to ensure it returned to the other instead of calling it anew. I suspect the real problem is that the PEP is really only concerned with a very specific subtype of coroutine, and these don't quite fit. (Though it could be done by somehow making them both await on the queue status, instead of on each other.) -jJ _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
