[Python-Dev] PEP 3152 and yield from Future()

[andrew.svetlov at gmail.com]

I can live with `cocall fut()` but the difference between `data = yield from loop.sock_recv(sock, 1024)` and `data = cocall (loop.sock_recv(sock, 1024))()` frustrates me very much.



—
Sent from Mailbox

On Thu, Apr 23, 2015 at 4:09 PM, Victor Stinner <victor.stinner at gmail.com>
wrote:

> (I prefer to start a new thread, the previous one is too long for me :-))
> Hi,
> I'm still trying to understand how the PEP 3152 would impact asyncio.
> Guido suggests to replace "yield from fut" with "cocall fut()" (add
> parenthesis) and so add a __cocall__() method to asyncio.Future.
> Problem: PEP 3152 says "A cofunction (...) does not contain any yield
> or yield from expressions". Currently, Future.__iter__() is
> implemented using yield:
>     def __iter__(self):
>         if not self.done():
>             self._blocking = True
>             yield self  # This tells Task to wait for completion.
>         assert self.done(), "yield from wasn't used with future"
>         return self.result()  # May raise too.
> From my understanding, the PEP 3151 simply does not support
> asyncio.Future. Am I right?
> How is it possible to suspend a cofunction if it's not possible to use yield?
> If waiting for a future in a cofunction is not supported, the PEP 3151
> is useless for asyncio, since asyncio completly relies on futures.
> Victor
> _______________________________________________
> Python-Dev mailing list
> Python-Dev at python.org
> https://mail.python.org/mailman/listinfo/python-dev
> Unsubscribe: https://mail.python.org/mailman/options/python-dev/andrew.svetlov%40gmail.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-dev/attachments/20150423/faaea7ec/attachment.html>