Fix #18769: Allow HK type args in Java signatures. #18883
Merged
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Outdated suggestions cannot be applied.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.
Contrary to what an earlier comment said, we do emit HK type parameters in Java signatures. They are always unbounded and never the type of values.
However, they can appear as type arguments to other higher-kinded types. Previously, an assertion error would trigger in that situation. We relax the assertion to allow this situation and emit a correct Java signature.
I manually verified that the generated Java signatures are consistent with what Scala 2 emits for the same code snippet.
fixes #18769