Hello, On 2015年4月22日 13:31:18 -0700 Guido van Rossum <[email protected]> wrote:
> On Wed, Apr 22, 2015 at 1:10 PM, Andrew Svetlov > <[email protected]> wrote: > > > On Wed, Apr 22, 2015 at 10:44 PM, PJ Eby <[email protected]> > > wrote: > > > On Tue, Apr 21, 2015 at 1:26 PM, Yury Selivanov > > > <[email protected]> > > wrote: > > >> It is an error to pass a regular context manager without > > >> ``__aenter__`` and ``__aexit__`` methods to ``async with``. It > > >> is a ``SyntaxError`` to use ``async with`` outside of a > > >> coroutine. > > > > > > I find this a little weird. Why not just have `with` and `for` > > > inside a coroutine dynamically check the iterator or context > > > manager, and either behave sync or async accordingly? Why must > > > there be a *syntactic* difference? > > > > IIRC Guido always like to have different syntax for calling regular > > functions and coroutines. > > That's why we need explicit syntax for asynchronous context managers > > and iterators. > > > > To clarify: the philosophy behind asyncio coroutines is that you > should be able to tell statically where a task may be suspended > simply by looking for `yield from`. This means that *no* implicit > suspend points may exist, and it rules out gevent, stackless and > similar microthreading frameworks. I always wanted to ask - does that mean that Python could have symmetric coroutines (in a sense that it would be Pythonic feature), as long as the call syntax is different from a function call? E.g.: sym def coro1(val): while True: val = coro2.corocall(val) sym def coro2(val): while True: val = coro1.corocall(val) coro1.call(1) -- Best regards, Paul mailto:[email protected] _______________________________________________ Python-Dev mailing list [email protected] https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com