1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
|
//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift Collections open source project
//
// Copyright (c) 2023 - 2024 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
//
//===----------------------------------------------------------------------===//
#if swift(>=5.8)
@available(macOS 13.3, iOS 16.4, watchOS 9.4, tvOS 16.4, *)
extension BigSubstring {
public struct UTF16View: Sendable {
internal var _base: BigString
internal var _bounds: Range<Index>
public init(_unchecked base: BigString, in bounds: Range<Index>) {
self._base = base
self._bounds = bounds
}
public init(_ base: BigString, in bounds: Range<Index>) {
self._base = base
let lower = base._utf16Index(roundingDown: bounds.lowerBound)
let upper = base._utf16Index(roundingDown: bounds.upperBound)
self._bounds = Range(uncheckedBounds: (lower, upper))
}
internal init(_substring: BigSubstring) {
self.init(_unchecked: _substring._base, in: _substring._bounds)
}
}
public var utf16: UTF16View {
UTF16View(_substring: self)
}
}
@available(macOS 13.3, iOS 16.4, watchOS 9.4, tvOS 16.4, *)
extension BigString {
public init?(_ utf16: BigSubstring.UTF16View) {
guard
!utf16.startIndex._isUTF16TrailingSurrogate,
!utf16.endIndex._isUTF16TrailingSurrogate
else {
return nil
}
self.init(_from: utf16._base, in: utf16._bounds)
}
}
@available(macOS 13.3, iOS 16.4, watchOS 9.4, tvOS 16.4, *)
extension BigSubstring.UTF16View {
public var base: BigString.UTF16View { _base.utf16 }
}
@available(macOS 13.3, iOS 16.4, watchOS 9.4, tvOS 16.4, *)
extension BigSubstring.UTF16View: Equatable {
public static func ==(left: Self, right: Self) -> Bool {
var i1 = left._bounds.lowerBound
var i2 = right._bounds.lowerBound
var j1 = left._bounds.upperBound
var j2 = right._bounds.upperBound
// Compare first code units, if they're trailing surrogates.
guard i1._isUTF16TrailingSurrogate == i2._isUTF16TrailingSurrogate else { return false }
if i1._isUTF16TrailingSurrogate {
guard left[i1] == right[i2] else { return false }
left.formIndex(after: &i1)
left.formIndex(after: &i2)
}
guard i1 < j1, i2 < j2 else { return i1 == j1 && i2 == j2 }
// Compare last code units, if they're trailing surrogates.
guard j1._isUTF16TrailingSurrogate == j2._isUTF16TrailingSurrogate else { return false }
if j1._isUTF16TrailingSurrogate {
left.formIndex(before: &j1)
right.formIndex(before: &j2)
guard left[j1] == right[j2] else { return false}
}
return BigString.utf8IsEqual(left._base, in: i1 ..< j1, to: right._base, in: i2 ..< j2)
}
public func isIdentical(to other: Self) -> Bool {
guard self._base.isIdentical(to: other._base) else { return false }
return self._bounds == other._bounds
}
}
@available(macOS 13.3, iOS 16.4, watchOS 9.4, tvOS 16.4, *)
extension BigSubstring.UTF16View: Hashable {
public func hash(into hasher: inout Hasher) {
for codeUnit in self {
hasher.combine(codeUnit)
}
hasher.combine(0xFFFF as UInt16)
}
}
@available(macOS 13.3, iOS 16.4, watchOS 9.4, tvOS 16.4, *)
extension BigSubstring.UTF16View: Sequence {
public typealias Element = UInt16
public struct Iterator: IteratorProtocol {
var _it: BigString.UTF16View.Iterator
var _end: BigString.Index
init(_substring: BigSubstring.UTF16View) {
self._it = .init(_base: _substring._base, from: _substring.startIndex)
self._end = _substring.endIndex
}
public mutating func next() -> UInt16? {
guard _it._index < _end else { return nil }
return _it.next()
}
}
public func makeIterator() -> Iterator {
Iterator(_substring: self)
}
}
@available(macOS 13.3, iOS 16.4, watchOS 9.4, tvOS 16.4, *)
extension BigSubstring.UTF16View: BidirectionalCollection {
public typealias Index = BigString.Index
public typealias SubSequence = Self
@inline(__always)
public var startIndex: Index { _bounds.lowerBound }
@inline(__always)
public var endIndex: Index { _bounds.upperBound }
public var count: Int {
distance(from: _bounds.lowerBound, to: _bounds.upperBound)
}
@inline(__always)
public func index(after i: Index) -> Index {
precondition(i < endIndex, "Can't advance above end index")
return _base._utf16Index(after: i)
}
@inline(__always)
public func index(before i: Index) -> Index {
precondition(i > startIndex, "Can't advance below start index")
return _base._utf16Index(before: i)
}
@inline(__always)
public func index(_ i: Index, offsetBy distance: Int) -> Index {
precondition(i >= startIndex && i <= endIndex, "Index out of bounds")
let j = _base._utf16Index(i, offsetBy: distance)
precondition(j >= startIndex && j <= endIndex, "Index out of bounds")
return j
}
public func index(_ i: Index, offsetBy distance: Int, limitedBy limit: Index) -> Index? {
precondition(i >= startIndex && i <= endIndex, "Index out of bounds")
guard let j = _base._utf16Index(i, offsetBy: distance, limitedBy: limit) else { return nil }
precondition(j >= startIndex && j <= endIndex, "Index out of bounds")
return j
}
public func distance(from start: Index, to end: Index) -> Int {
precondition(start >= startIndex && start <= endIndex, "Index out of bounds")
precondition(end >= startIndex && end <= endIndex, "Index out of bounds")
return _base._utf16Distance(from: start, to: end)
}
public subscript(position: Index) -> UInt16 {
precondition(position >= startIndex && position < endIndex, "Index out of bounds")
return _base[_utf16: position]
}
public subscript(bounds: Range<Index>) -> Self {
precondition(
bounds.lowerBound >= startIndex && bounds.upperBound <= endIndex,
"Range out of bounds")
return Self(_base, in: bounds)
}
}
@available(macOS 13.3, iOS 16.4, watchOS 9.4, tvOS 16.4, *)
extension BigSubstring.UTF16View {
public func index(roundingDown i: Index) -> Index {
precondition(i >= startIndex && i <= endIndex, "Index out of bounds")
return _base._utf16Index(roundingDown: i)
}
public func index(roundingUp i: Index) -> Index {
precondition(i >= startIndex && i <= endIndex, "Index out of bounds")
return _base._utf16Index(roundingUp: i)
}
}
#endif
|
