Hi ! If my understanding is correct, a type-checker will have to parse the whole annotation payload to decide if it supports it or not. That's seems a bit too complicated, doesn't it ? Shouldn't we add a label (like `Annotated[T, 'feature name', X]`, with type alias to shorten the whole thing if need be) to make this decision easier ?
Le mer. 22 mai 2019 à 21:11, Guido van Rossum email@example.com a écrit :
If it makes it easier, I'd definitely start with >= 3.7. That will be sufficient as a proof of concept and will provide the baseline to include in the 3.8 stdlib typing.py (if the PEP makes it through quickly enough).
But I assume people would want to use this on legacy code as well (several companies I know who are using type checkers have large legacy code bases, for some value of legacy).
On Wed, May 22, 2019 at 11:20 AM Till firstname.lastname@example.org wrote:
Would people object to me implementing this only for `python >= 3.7` in typing_extension? I'm new to that codebase and it seems like this would make it easier to implement (using __class_getitems__...). Otherwise I can aim for a first patch that adds 3.7 and work my way down to older revisions.
-- --Guido van Rossum (python.org/~guido) *Pronouns: he/him/his **(why is my pronoun here?)* http://feministing.com/2015/02/03/how-using-they-as-a-singular-pronoun-can-change-the-world/ _______________________________________________ Typing-sig mailing list -- email@example.com To unsubscribe send an email to firstname.lastname@example.org https://mail.python.org/mailman3/lists/typing-sig.python.org/