On Thu, Jun 16, 2016 at 3:36 PM, Nick Coghlan <ncogh...@gmail.com> wrote: > I don't think that's a side note, I think it's an important point (and > relates to one of Nikita's questions as well): we have the option of > carving out certain aspects of PEP 520 as CPython implementation > details. > > In particular, the language level guarantee can be that "class > statements set __definition_order__ by default, but may not do so when > using a metaclass that returns a custom namespace from __prepare__", > with the implementation detail that CPython does that by using > collection.OrderedDict for the class namespace by default. > > An implementation like PyPy, with an inherently ordered standard dict > implementation, can just rely on that rather than being obliged to > switch to their full collections.OrderedDict type.
Excellent point from you both. :) I'll rework PEP 520 accordingly (to focus on __definition_order__). At that point I expect the definition order part of PEP 487 could be dropped (as redundant). > > However, I don't think we should leave the compile-time vs runtime > definition order question as an implementation detail - I think we > should be explicit that the definition order attribute captures the > runtime definition order, with conditionals, loops and reassignment > being handled accordingly. Yeah, I'll make that clear. We can discuss these changes in a separate thread once I've updated PEP 520. So let's focus back on the rest of PEP 487! :) -eric _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
