averello/swift-mirror
1
0
Fork 0
mirror of https://github.com/apple/swift.git synced 2025-12-21 12:14:44 +01:00
Code Issues Packages Projects Releases Wiki Activity

[String] NFC iterator fast-paths

Browse Source 
Refactor and rename _StringGutsSlice, apply NFC-aware fast paths to a
new buffered iterator.

Also, fix bug in _typeName which used to assume ASCIIness and better
SIL optimizations on StringObject.
This commit is contained in:
Michael Ilseman
2018-10-28 15:47:49 -07:00
parent 7376009ccc
commit 7aea40680d
27 changed files with 716 additions and 285 deletions
Download Patch File Download Diff File Expand all files Collapse all files

20
stdlib/public/core/StringUTF16View.swift
View File

@@ -53,9 +53,9 @@ extension String.UTF16View: BidirectionalCollection {
// scalar, use a transcoded offset first.
let len = _guts.fastUTF8ScalarLength(startingAt: i.encodedOffset)
if len == 4 && i.transcodedOffset == 0 {
return Index(transcodedAfter: i)
return i.nextTranscoded
}
return Index(encodedOffset: i.encodedOffset &+ len)
return i.strippingTranscoding.encoded(offsetBy: len)
}
@inlinable @inline(__always)
@@ -68,21 +68,19 @@ extension String.UTF16View: BidirectionalCollection {
if i.transcodedOffset != 0 {
_sanityCheck(i.transcodedOffset == 1)
return Index(encodedOffset: i.encodedOffset)
return i.strippingTranscoding
}
let len = _guts.fastUTF8ScalarLength(endingAt: i.encodedOffset)
if len == 4 {
// 2 UTF-16 code units comprise this scalar; advance to the beginning and
// start mid-scalar transcoding
return Index(
encodedOffset: i.encodedOffset &- len,
transcodedOffset: 1)
return i.encoded(offsetBy: -len).nextTranscoded
}
// Single UTF-16 code unit
_sanityCheck((1...3) ~= len)
return Index(encodedOffset: i.encodedOffset &- len)
return i.encoded(offsetBy: -len)
}
public func index(_ i: Index, offsetBy n: Int) -> Index {
@@ -295,14 +293,14 @@ extension String.UTF16View {
@_effects(releasenone)
internal func _foreignIndex(after i: Index) -> Index {
_sanityCheck(_guts.isForeign)
return Index(encodedOffset: i.encodedOffset + 1)
return i.nextEncoded
}
@usableFromInline @inline(never)
@_effects(releasenone)
internal func _foreignIndex(before i: Index) -> Index {
_sanityCheck(_guts.isForeign)
return Index(encodedOffset: i.encodedOffset - 1)
return i.priorEncoded
}
@usableFromInline @inline(never)
@@ -329,14 +327,14 @@ extension String.UTF16View {
if n > 0 ? l >= 0 && l < n : l <= 0 && n < l {
return nil
}
return Index(encodedOffset: i.encodedOffset + n)
return i.encoded(offsetBy: n)
}
@usableFromInline @inline(never)
@_effects(releasenone)
internal func _foreignIndex(_ i: Index, offsetBy n: Int) -> Index {
_sanityCheck(_guts.isForeign)
return Index(encodedOffset: i.encodedOffset + n)
return i.encoded(offsetBy: n)
}
@usableFromInline @inline(never)