[Python-Dev] PEP 492 vs. PEP 3152, new round

[Yury Selivanov]

Hi Ethan,

On 2015-04-29 2:32 PM, Ethan Furman wrote:
> On 04/29, Yury Selivanov wrote:
>> On 2015-04-29 1:25 PM, Ethan Furman wrote:
>>> cannot also just work and be the same as the parenthesized
>>> version.
>> Because it does not make any sense.
> I obviously don't understand your position that "it does not make
> any sense" -- perhaps you could explain a bit?
>
> What I see is a suspension point that is waiting for the results of
> coro(), which will be negated (and returned/assigned/whatever).
> What part of that doesn't make sense?
>

Because you want operators to be resolved in the
order you see them, generally.

You want '(await -fut)' to:

1. Suspend on fut;
2. Get the result;
3. Negate it.

This is a non-obvious thing. I would myself interpret it
as:

1. Get fut.__neg__();
2. await on it.

So I want to make this syntactically incorrect:

'await -fut' would throw a SyntaxError. To do what you
want, write a pythonic '- await fut'.


Yury