bpo-43224: Add tests for TypeVarTuple substitution in Annotated #31846
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
mrahtz requested review from Fidget-Spinner, JelleZijlstra and gvanrossum as code owners 
Member
JelleZijlstra left a comment
JelleZijlstra left a comment There was a problem hiding this comment.
Thanks! The tests are good but it's a bit unfortunate if we can't use Annotated around a TypeVarTuple at all.
| raise TypeError("Annotated[...] should be used " | ||
| "with at least two arguments (a type and an " | ||
| "annotation).") | ||
| if _is_unpacked_typevartuple(params[0]): |
Member
There was a problem hiding this comment.
I don't think we need to explicitly disallow this at runtime.
Contributor Author
There was a problem hiding this comment.
Hmm, but then how should we handle situations like this?
A = Annotated[Unpack[Ts], "foo"] B = A[int, str]Annotated[int, str, "foo"] wouldn't be valid. We could do some kind of automatic tuple wrapping, Annotated[tuple[int, str], "foo", but that would be inconsistent with how we handle TypeVarTuple substitution elsewhere.
Member
There was a problem hiding this comment.
Good point, and sorry for not responding to this earlier.
JelleZijlstra approved these changes Apr 15, 2022
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
4 participants
Add this suggestion to a batch that can be applied as a single commit. This suggestion is invalid because no changes were made to the code. Suggestions cannot be applied while the pull request is closed. Suggestions cannot be applied while viewing a subset of changes. Only one suggestion per line can be applied in a batch. Add this suggestion to a batch that can be applied as a single commit. Applying suggestions on deleted lines is not supported. You must change the existing code in this line in order to create a valid suggestion. Outdated suggestions cannot be applied. This suggestion has been applied or marked resolved. Suggestions cannot be applied from pending reviews. Suggestions cannot be applied on multi-line comments. Suggestions cannot be applied while the pull request is queued to merge. Suggestion cannot be applied right now. Please check back later.
At some point I guess we should add tests for the native
tupletoo, once #31828 or similar is in.@JelleZijlstra Does this assuage the concerns you mentioned about
Annotatedin #31021 (review)?@@GBeauregard too, since Jelle also mentioned you in that thread - is there anything else we should test for here?
https://bugs.python.org/issue43224