Serhiy Storchaka <storchaka+cpyt...@gmail.com> added the comment:
> Alias = C[T, *Ts] > Alias2 = Alias[*tuple[int, ...]] > # Alias2 should be C[int, *tuple[int, ...]] tuple[int, ...] includes also an empty tuple, and in this case there is no value for T. > Oh, also interesting - I didn't know about this one either. Could you give an > example? If __origin__, __parameters__, __args__ are a mess, it will definitely break a code which use them. > We actually deliberately chose not to unpack concrete tuple types - see the > description of https://github.com/python/cpython/pull/30398, under the > heading 'Starred tuple types'. (If you see another way around it, though, let > me know.) You assumed that *tuple[str, bool] in def foo(*args: *tuple[str, bool]) should give foo.__annotations__['args'] = tuple[str, bool], but it should rather give (str, bool). No confusion with tuple[str, bool]. And one of PEP 646 options is to implement star-syntax only in subscription, not in var-parameter type annotations. > I'm also not sure about this one; disallowing unpacked TypeVarTuples in > argument lists to generic aliases completely (if I've understood right?) No, it will only be disallowed in substitution of a VarType. Tuple[T][*Ts] -- error. Tuple[*Ts][*Ts2] -- ok. I propose to implement simple and strict rules, and later add support of new cases where it makes sense. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue47006> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
