It occurs to me that there's one other attribute that makes `tuple` special. It accepts zero-length lists (i.e. `tuple[()]`). Would the proposed variadic TypeVar mechanism also support this? For example, would `Tensor[()]` be legal?
Yes, zero-length Tuples are valid as arguments for Ts. That is the case, for example, when we have def foo(*args: *Ts) -> Ts: ... and we call it with no arguments: foo(). Ts would then resolve to Tuple[()]. Likewise, Tensor[()] is also legal.
-- Pradeep
________________________________ From: Eric Traut eric@traut.com Sent: Monday, December 14, 2020 9:38 AM To: typing-sig@python.org typing-sig@python.org Subject: [Typing-sig] Re: Variadic generics PEP draft
Perhaps my choice of the term "arbitrary length" was confusing here. Alternatives might be "unknown length" or "unspecified length".
It occurs to me that there's one other attribute that makes `tuple` special. It accepts zero-length lists (i.e. `tuple[()]`). Would the proposed variadic TypeVar mechanism also support this? For example, would `Tensor[()]` be legal?
Perhaps `tuple` is just too much of an oddity for us to model using the proposed variadic TypeVar mechanism. I figured it was at least worth exploring the idea, so thanks for the discussion.
-Eric _______________________________________________ Typing-sig mailing list -- typing-sig@python.org To unsubscribe send an email to typing-sig-leave@python.org https://mail.python.org/mailman3/lists/typing-sig.python.org/ Member address: gohanpra@gmail.com