[Python-Dev] PEP 492 vs. PEP 3152, new round (original) (raw)

Yury Selivanov yselivanov.ml at gmail.com
Fri Apr 24 23:36:49 CEST 2015

Victor,

On 2015-04-24 5:32 PM, Victor Stinner wrote:

7. compatibility with asyncio and existing users of it The current state of the PEP makes types.coroutine() mandatory. If a generator-based coroutine is not modified with types.coroutine, await cannot be used on it. To be more concrete: asyncio coroutines not declared with @asyncio.coroutine cannot be used with await. Would it be crazy to allow waiting on a generator-based coroutine (current asyncio coroutines) without having to call types.coroutine() on it?

I'd be big -1 on that. The current PEP design is all about strictly prohibiting users from calling regular generators with 'await' expression. And if a generator isn't decorated with @coroutine - then it's a regular generator for us.

Maybe I just missed the purpose of disallow this. It's also possible to modify asyncio to detect at runtime when an asyncio coroutine is not decorated by @asyncio.coroutine (emit a warning or even raise an exception).

I'd be +1 to add a warning to Task and other places where we accept generator-based coroutines.

Thanks! Yury

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