[string] Wean off of non-String-API. #1476
Conversation
String._fromCodeUnits is about to disappear; use already existing String.init calls instead.
|
@swift-ci please test linux platform |
|
@phausler who is the right person to review this change? |
|
@itaiferber can you review? |
| var uintValue = value.unicodeScalar.value | ||
| super.init(String._fromWellFormedCodeUnitSequence(UTF32.self, input: UnsafeBufferPointer(start: &uintValue, count: 1))) | ||
| } | ||
| super.init(value.description) |
There was a problem hiding this comment.
Does value.description just return a String representing StaticString? Is there a performance hit to not initializing directly from the contents?
There was a problem hiding this comment.
value.description is direct initialization of a String with the same contents. It will be faster in the future than trying to do it yourself, as StaticString can poke at String's innards.
Currently, it will encode a single scalar as UTF-8 prior to initialization, and then allocate storage on the heap to store it. We could try to skip that transcoding temporarily, however, I'm about to land small strings and plan on supporting UTF-8 in them. In this case, we still want to encode as UTF-8 there, so we'd do a encoding anyways and skip the heap allocation. This will be better than what this code was doing before: before, even a single scalar gets a heap allocation.
It is equivalent for non-scalar StaticString.
There was a problem hiding this comment.
Okay, sounds reasonable, then!
Foundation/NSString.swift
Outdated
| @@ -273,7 +273,7 @@ open class NSString : NSObject, NSCopying, NSMutableCopying, NSSecureCoding, NSC | |||
| } | |||
|
|
|||
| public init(characters: UnsafePointer<unichar>, length: Int) { | |||
| _storage = String._fromWellFormedCodeUnitSequence(UTF16.self, input: UnsafeBufferPointer(start: characters, count: length)) | |||
| _storage = String.init(decoding: UnsafeBufferPointer(start: characters, count: length), as: UTF16.self) | |||
There was a problem hiding this comment.
We can drop .init for brevity, no?
|
@swift-ci please test |
|
@swift-ci please test |
String._fromCodeUnits is about to disappear; use already existing
String.init calls instead.