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
|
//===--- UTF32.swift ------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2017 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
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
extension Unicode {
@frozen
public enum UTF32: Sendable {
case _swift3Codec
}
}
extension Unicode.UTF32: Unicode.Encoding {
public typealias CodeUnit = UInt32
public typealias EncodedScalar = CollectionOfOne<UInt32>
@inlinable
internal static var _replacementCodeUnit: CodeUnit {
@inline(__always) get { return 0xFFFD }
}
@inlinable
public static var encodedReplacementCharacter: EncodedScalar {
return EncodedScalar(_replacementCodeUnit)
}
@inlinable
@inline(__always)
public static func _isScalar(_ x: CodeUnit) -> Bool {
return true
}
/// Returns whether the given code unit represents an ASCII scalar
@_alwaysEmitIntoClient
public static func isASCII(_ x: CodeUnit) -> Bool {
return x <= 0x7F
}
@inlinable
@inline(__always)
public static func decode(_ source: EncodedScalar) -> Unicode.Scalar {
return Unicode.Scalar(_unchecked: source.first!)
}
@inlinable
@inline(__always)
public static func encode(
_ source: Unicode.Scalar
) -> EncodedScalar? {
return EncodedScalar(source.value)
}
@frozen
public struct Parser: Sendable {
@inlinable
public init() { }
}
public typealias ForwardParser = Parser
public typealias ReverseParser = Parser
}
extension UTF32.Parser: Unicode.Parser {
public typealias Encoding = Unicode.UTF32
/// Parses a single Unicode scalar value from `input`.
@inlinable
public mutating func parseScalar<I: IteratorProtocol>(
from input: inout I
) -> Unicode.ParseResult<Encoding.EncodedScalar>
where I.Element == Encoding.CodeUnit {
let n = input.next()
if _fastPath(n != nil), let x = n {
// Check code unit is valid: not surrogate-reserved and within range.
guard _fastPath((x &>> 11) != 0b1101_1 && x <= 0x10ffff)
else { return .error(length: 1) }
// x is a valid scalar.
return .valid(UTF32.EncodedScalar(x))
}
return .emptyInput
}
}
|
