[5.0][String.Index] Deprecate encodedOffset var/init #22695
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
String.Index has an encodedOffset-based initializer and computed property that exists for serialization purposes. It was documented as UTF-16 in the SE proposal introducing it, which was String's underlying encoding at the time, but the dream of String even then was to abstract away whatever encoding happend to be used. Serialization needs an explicit encoding for serialized indices to make sense: the offsets need to align with the view. With String utilizing UTF-8 encoding for native contents in Swift 5, serialization isn't necessarily the most efficient in UTF-16. Furthermore, the majority of usage of encodedOffset in the wild is buggy and operates under the assumption that a UTF-16 code unit was a Swift Character, which isn't even valid if the String is known to be all-ASCII (because CR-LF). This change introduces a pair of semantics-preserving alternatives to encodedOffset that explicitly call out the UTF-16 assumption. These serve as a gentle off-ramp for current mis-uses of encodedOffset.
|
@swift-ci please test |
|
Build failed |
|
@swift-ci please test os x platform |
|
Build failed |
|
@swift-ci please test os x platform |
airspeedswift
approved these changes
Feb 22, 2019
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Outdated suggestions cannot be applied.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.
Cherry-pick of #22108 for SE-0241