[Python-Dev] PEP 550 v4

Koos Zevenhoven k7hoven at gmail.com
Wed Aug 30 08:19:16 EDT 2017

On Wed, Aug 30, 2017 at 2:36 AM, Greg Ewing <greg.ewing at canterbury.ac.nz>

> Yury Selivanov wrote:
>> While we want "yield from" to have semantics close to a function call,
> That's not what I said! I said that "yield from foo()" should
> have semantics close to a function call. If you separate the
> "yield from" from the "foo()", then of course you can get
> different behaviours.
> But that's beside the point, because I'm not suggesting
> that generators should behave differently depending on when
> or if you use "yield from" on them.
> For (1) we want the context change to be isolated.  For (2) you say
>> that the context change should propagate to the caller.
> No, I'm saying that the context change should *always*
> propagate to the caller, unless you do something explicit
> within the generator to prevent it.
> I have some ideas on what that something might be, which
> I'll post later.
​FYI, I've been sketching an alternative solution that addresses these
kinds of things. I've been hesitant to post ​about it, partly because of
the PEP550-based workarounds that Nick, Nathaniel, Yury etc. have been
describing, and partly because that might be a major distraction from other
useful discussions, especially because I wasn't completely sure yet about
whether my approach has some fatal flaw compared to PEP 550 ;).


+ Koos Zevenhoven + http://twitter.com/k7hoven +
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