[3.13] gh-115528: Update language reference for PEP 646 (GH-121181)#124632
Uh oh!
There was an error while loading. Please reload this page.
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
To recap: the objective is to make starred expressions valid in `subscription`, which is used for generics: `Generic[...]`, `list[...]`, etc. What _is_ gramatically valid in such contexts? Seemingly any of the following. (At least, none of the following throw `SyntaxError` in a 3.12.3 REPL.) Generic[x] Generic[*x] Generic[*x, y] Generic[y, *x] Generic[x := 1] Generic[x := 1, y := 2] So introducting flexible_expression: expression | assignment_expression | starred_item end then switching `subscription` to use `flexible_expression` sorts that. But then we need to field `yield` - for which any of the following are apparently valid: yield x yield x, yield x, y yield *x, yield *x, *y Introducing a separate `yield_list` is the simplest way I've been figure out to do this - separating out the special case of `starred_item ,`. (cherry picked from commit 7d3497f) Co-authored-by: Matthew Rahtz <[email protected]> Co-authored-by: Jelle Zijlstra <[email protected]>
This was referenced Sep 26, 2024
JelleZijlstra approved these changes Sep 26, 2024
Sign up for freeto 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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
To recap: the objective is to make starred expressions valid in
subscription,which is used for generics:
Generic[...],list[...], etc.What is gramatically valid in such contexts? Seemingly any of the following.
(At least, none of the following throw
SyntaxErrorin a 3.12.3 REPL.)So introducting
end then switching
subscriptionto useflexible_expressionsorts that.But then we need to field
yield- for which any of the following areapparently valid:
Introducing a separate
yield_listis the simplest way I've been figure out todo this - separating out the special case of
starred_item ,.(cherry picked from commit 7d3497f)
Co-authored-by: Matthew Rahtz [email protected]
Co-authored-by: Jelle Zijlstra [email protected]
📚 Documentation preview 📚: https://cpython-previews--124632.org.readthedocs.build/