On Wed, Apr 29, 2015 at 2:26 PM, Paul Moore
On 29 April 2015 at 18:43, Jim J. Jewett
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