On Sun, Apr 24, 2022 at 10:20 AM Joao S. O. Bueno <gwid...@gmail.com> wrote: > > I am not worried about the bikeshed part of which syntax to use - > and more worried with the possible breaking of a lot of stuff, unless > we work with creation of a non-identical "forward object" that is > rebound, as in plain name binding, when the second part > is declared. I've stated that amidst my ramblings, > but Nick Coghlan managed to keep it suscint at > https://mail.python.org/archives/list/python-dev@python.org/message/DMITVTUIQKJW6RYVOPQXHD54VSYE7QHA/
I don't think name rebinding works. That means that if we have `forward class Bar` in module `foo` and `continue class Bar: ...` in module `foo.impl`, if module `baz` does `from foo import Bar`, it will forever have either the forward reference object or the real class, and which one it has is entirely unpredictable (depends on import ordering accidents of the rest of the codebase.) If `baz` happens to be imported before `foo.impl`, the name `Bar` in the `baz` namespace will never be resolved to the real class, and isn't resolvable to the real class without some outside intervention. > """ > Something worth considering: whether forward references need to be > *transparent* at runtime. If they can just be regular ForwardRef objects > then much of the runtime complexity will go away (at the cost of some > potentially confusing identity check failures between forward references > and the actual class objects). > > ForwardRef's constructor could also potentially be enhanced to accept a > "resolve" callable, and a "resolve()" method added to its public API, > although the extra complexity that would bring may not be worth it. > """ I'm not sure how this `resolve()` method is even possible under the proposed syntax. If `forward class Bar` and `continue class Bar` are in different modules, then how can `forward class Bar` (which must create the "forward reference" object) possibly know which module `continue class Bar: ...` exists in? How can it know how to resolve itself? Carl _______________________________________________ Python-Dev mailing list -- python-dev@python.org To unsubscribe send an email to python-dev-le...@python.org https://mail.python.org/mailman3/lists/python-dev.python.org/ Message archived at https://mail.python.org/archives/list/python-dev@python.org/message/WLZRZIMPRST52UMINB5VB57TOIQVTYQH/ Code of Conduct: http://python.org/psf/codeofconduct/
