Allow eta-expansion of inline defs #18249
Merged
Conversation
This file contains 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
nicolasstucki
approved these changes
Jul 19, 2023
The fact that this wasn't allowed before seems to be a bug and not an intentional restriction: the check was originally introduced in a019a4e for "typelevel methods" which are only vaguely related to today's inline methods.
nicolasstucki
approved these changes
Jul 19, 2023
Kordyjan
added a commit
that referenced
this pull request
Dec 8, 2023
Backports #18249 to the LTS branch. PR submitted by the release tooling. [skip ci]
smarter
added a commit
to dotty-staging/dotty
that referenced
this pull request
Mar 4, 2024
`inline implicit def` is not really a supported feature since it combines Scala 3's `inline` with Scala 2's `implicit` where the latter should eventually be deprecated. This however didn't prevent at least one project from using this combination in a way that was broken by scala#18249, see scala#19862 for the details. The issue is that when definining: implicit def foo(x: A): B = ... Then `foo` is a valid implicit search candidate when looking up an implicit `Function1[A, B]`. However, before scala#18249 if instead we wrote: inline implicit def foo(x: A): B = ... Then `foo` would be considered as an implicit search candidate but discarded because eta-expansion was disabled. There is no particular reason for `inline implicit def` to behave differently from `implicit def` here, but since `implicit def` is a legacy feature and since Scala 3.3 is an LTS release, we choose to restore the pre-scala#18249 behavior for compatibility reasons. Fixes scala#19862.
smarter
added a commit
to dotty-staging/dotty
that referenced
this pull request
Mar 5, 2024
`inline implicit def` is not really a supported feature since it combines Scala 3's `inline` with Scala 2's `implicit` where the latter should eventually be deprecated. This however didn't prevent at least one project from using this combination in a way that was broken by scala#18249, see scala#19862 for the details. The issue is that when definining: implicit def foo(x: A): B = ... Then `foo` is a valid implicit search candidate when looking up an implicit `Function1[A, B]`. However, before scala#18249 if instead we wrote: inline implicit def foo(x: A): B = ... Then `foo` would be considered as an implicit search candidate but discarded because eta-expansion was disabled. There is no particular reason for `inline implicit def` to behave differently from `implicit def` here, but since `implicit def` is a legacy feature and since Scala 3.3 is an LTS release, we choose to restore the pre-scala#18249 behavior for compatibility reasons. Fixes scala#19862.
nicolasstucki
added a commit
that referenced
this pull request
Mar 5, 2024
`inline implicit def` is not really a supported feature since it combines Scala 3's `inline` with Scala 2's `implicit` where the latter should eventually be deprecated. This however didn't prevent at least one project from using this combination in a way that was broken by #18249, see #19862 for the details. The issue is that when definining: implicit def foo(x: A): B = ... Then `foo` is a valid implicit search candidate when looking up an implicit `Function1[A, B]`. However, before #18249 if instead we wrote: inline implicit def foo(x: A): B = ... Then `foo` would be considered as an implicit search candidate but discarded because eta-expansion was disabled. There is no particular reason for `inline implicit def` to behave differently from `implicit def` here, but since `implicit def` is a legacy feature and since Scala 3.3 is an LTS release, we choose to restore the pre-#18249 behavior for compatibility reasons. Fixes #19862.
WojciechMazur
pushed a commit
that referenced
this pull request
Jul 2, 2024
`inline implicit def` is not really a supported feature since it combines Scala 3's `inline` with Scala 2's `implicit` where the latter should eventually be deprecated. This however didn't prevent at least one project from using this combination in a way that was broken by #18249, see #19862 for the details. The issue is that when definining: implicit def foo(x: A): B = ... Then `foo` is a valid implicit search candidate when looking up an implicit `Function1[A, B]`. However, before #18249 if instead we wrote: inline implicit def foo(x: A): B = ... Then `foo` would be considered as an implicit search candidate but discarded because eta-expansion was disabled. There is no particular reason for `inline implicit def` to behave differently from `implicit def` here, but since `implicit def` is a legacy feature and since Scala 3.3 is an LTS release, we choose to restore the pre-#18249 behavior for compatibility reasons. Fixes #19862. [Cherry-picked af69895]
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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.
The fact that this wasn't allowed before seems to be a bug and not an intentional restriction: the check was originally introduced in a019a4e for "typelevel methods" which are only vaguely related to today's inline methods.