[6.0] Allow captures in lookahead and atomic groups #736
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
This fixes an issue where capture groups inside a positive lookahead
were being reset even upon successful matching of the lookahead. For
example, with the pattern `/(?=(\d))/`, matching against a string like
`"abc1"` should result in the output `("", "1")`. However, accessing
the output traps instead, since the range data for capture 1 is
missing even on success.
This change resolves the issue by adding a boolean payload to the
`fail` instruction that indicates whether to preserve captures when
resetting the matching state, which allows any captures inside a
lookahead to persist after success.
Fixes #713.
|
@swift-ci Please test |
stephentyrone
approved these changes
Apr 17, 2024
# for free
to join this conversation on GitHub.
Already have an account?
# 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Outdated suggestions cannot be applied.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.
Explanation: This resolves an issue where matching a pattern that includes a capture group inside a positive lookahead or an atomic group results in a runtime error.
Scope: All the changes are internal implementation within the
_StringProcessingmodule.Issue: rdar://126009544
Original PR: #723
Risk: Low. There's no API or ABI impact of this change.
Testing: This change adds tests that verify that the previously failing patterns are working correctly, and continues to pass the existing compilation and pattern-matching tests.
Reviewer: @stephentyrone
Cherry pick to
swift/release/6.0of #723.