(original) (raw)

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@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@python.org
https://mail.python.org/mailman/listinfo/python-dev
Unsubscribe: https://mail.python.org/mailman/options/python-dev/andrew.svetlov%40gmail.com