Fix #3144: more aggressively check unreachability #3891
Merged
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
|
Regarding (2), I think we should keep the old behavior under scala2 mode. Related #3208 |
|
@allanrenucci Thanks for the pointer. The intersect in this PR is different from the issues discussed in #3208. Current PR only changes exhaustivity check, type checking of patmat remains the same. |
OlivierBlanvillain
approved these changes
Jan 26, 2018
|
|
||
| // starts from the second, the first can't be redundant | ||
| (1 until cases.length).foreach { i => | ||
| (0 until cases.length).foreach { i => |
There was a problem hiding this comment.
Maybe you could iterate over cases.inits instead?
There was a problem hiding this comment.
Thanks, I didn't know inits before, I'll consider use it later. In the current case, I do need i to get the current clause, init doesn't help much here.
Sealed classes and traits are effectively inhabited in practice. By treating them as inhabited by default, we avoid spurious warnings that ignore anonymous classes. When we have a mechanism to track anonymous children or disallow anonymous children for sealed classes, we could revert this change to make the check stronger.
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Outdated suggestions cannot be applied.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.
Fix #3144: more aggressively check unreachability.
Previously, we optimise by (1) skipping the check for the first clause; (2) don't intersect with the scrutinee type.
Based on #3888.