On Tue, Sep 5, 2017 at 8:35 AM, Koos Zevenhoven <k7hoven@gmail.com> wrote:
> On Tue, Sep 5, 2017 at 3:49 AM, Nathaniel Smith <njs@pobox.com> wrote:
[..]
>>
>> I think PEP 550 is sufficient to allow implementing all
>> your proposed APIs (and that if it isn't, that's a bug in PEP 550).
>
>
> That's not true either. The LocalContext-based semantics introduces scope
> barriers that affect *all* variables. You might get close by putting just
> one variable in a LogicalContext and then nest them, but PEP 550 does not
> allow this in all cases. With the addition of PEP 521 and some trickery, it
> might.

I think you have a wrong idea about PEP 550 specification.  I
recommend you to reread it carefully, otherwise we can't have a
productive discussion here.