Make Arrays mutable types under separation checking#24649
Merged
odersky merged 7 commits intoscala:mainfrom Dec 19, 2025
Merged
Make Arrays mutable types under separation checking#24649odersky merged 7 commits intoscala:mainfrom
odersky merged 7 commits intoscala:mainfrom
Conversation
In capture checking, a type mismatch might happen for a synthesized tree (say from implicit search). It can be helpful to show this tree. Before capture checking a helpful message is less likely since we don't synthesize implicit trees that then don't match under the standard typing rules.
Fields are only allowed in stateful classes unless marked with @untrackedCaptures.
bracevac
approved these changes
Dec 18, 2025
| && !sym.field.hasAnnotation(defn.UntrackedCapturesAnnot) | ||
| else true | ||
| ) | ||
| || ccConfig.strictMutability && sym.name == nme.update && sym == defn.Array_update |
Contributor
There was a problem hiding this comment.
Suggested change
| || ccConfig.strictMutability && sym.name == nme.update && sym == defn.Array_update | |
| || ccConfig.strictMutability && sym == defn.Array_update |
Isn't this enough?
Contributor
Author
There was a problem hiding this comment.
It might force too much (i.e. complete the Array class to find its update method). That's why we defensively test the name first.
Co-authored-by: Oliver Bračevac <bracevac@users.noreply.github.com>
He-Pin
reviewed
Dec 19, 2025
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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
6 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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Also: enforce that mutable fields can only be declared in
Statefulclasses, unless they are annotated withuntrackedCaptures.