On 27 June 2015 at 04:06, Ron Adam <ron3200@gmail.com> wrote:
It seems that those points are defined by other means outside of a function defined with "async def". From the PEP...
* It is a SyntaxError to have yield or yield from expressions in an async function.
So somewhere in an async function, it needs to "await something" with a yield in it that isn't an async function.
This isn't the case - it can be async functions and C level coroutines all the way down. Using a generator or other iterable instead requires adaptation to the awaitable protocol (which makes it possible to tap into all the work that has been done for the generator-based coroutines used previously, rather than having to rewrite it to use native coroutines). This isn't very clear in the currently released beta as we made some decisions to simplify the original implementation that we thought would also be OK from an API design perspective, but turned out to pose significant problems once folks actually started trying to integrate native coroutines with other async systems beyond asyncio. Yury fixed those underlying object model limitations as part of addressing Ben Darnell's report of problems attempting to integrate native coroutine support into Tornado (https://hg.python.org/cpython/rev/7a0a1a4ac639). Yury had already updated the PEP to account for those changes, but I've now also added a specific note regarding the API design change in response to beta feedback: https://hg.python.org/peps/rev/0c963fa25db8 Cheers, Nick. -- Nick Coghlan | ncoghlan@gmail.com | Brisbane, Australia