[Python-Dev] async/await in Python; v2

[Greg Ewing]

Yury Selivanov wrote:

> On the other hand, I hate the idea
> of grammatically requiring parentheses for 'await'
> expressions.  That feels non-pytonic to me.

How is it any different from grammatically requiring
parens in an ordinary function call? Nobody ever
complained about that.

In the PEP 3152 way of thinking, a cocall is just
a function call that happens to be suspendable.
The fact that there is an iterator object involved
behind the scenes is an implementation detail. You
don't have to think about it or even know about it
in order to write or understand suspendable code.

It's possible to think about "yield from f(x)" or
"await f(x)" that way, but only by exploiting a kind
of pun in the code, where you think of f(x) as doing
all the work and the rest as a syntactic marker
indicating that the call is suspendable. PEP 3152
removes the pun by making this the *actual*
interpretation of "cocall f(x)".

-- 
Greg