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
|
//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2023 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
//
//===----------------------------------------------------------------------===//
/// The length a syntax node spans in the source code. From any AbsolutePosition
/// you reach a node's end location by adding its UTF-8 length.
public struct SourceLength: Comparable, Sendable {
/// The length in bytes when the text is represented as UTF-8.
public let utf8Length: Int
/// Construct the source length of a given text
public init(of text: String) {
self.utf8Length = text.utf8.count
}
/// Construct a source length that takes up `utf8Length` bytes when represented as UTF-8.
public init(utf8Length: Int) {
self.utf8Length = utf8Length
}
/// A zero-length source length
public static let zero: SourceLength =
SourceLength(utf8Length: 0)
/// Returns `true` if `lhs` is shorter than `rhs`.
public static func < (lhs: SourceLength, rhs: SourceLength) -> Bool {
return lhs.utf8Length < rhs.utf8Length
}
/// Combine the length of two source length.
public static func + (lhs: SourceLength, rhs: SourceLength) -> SourceLength {
let utf8Length = lhs.utf8Length + rhs.utf8Length
return SourceLength(utf8Length: utf8Length)
}
/// Extend `lhs` by `rhs` bytes.
public static func += (lhs: inout SourceLength, rhs: SourceLength) {
lhs = lhs + rhs
}
/// Return a source length that's `rhs` bytes shorter than `lhs`.
public static func - (lhs: SourceLength, rhs: SourceLength) -> SourceLength {
let utf8Length = lhs.utf8Length - rhs.utf8Length
return SourceLength(utf8Length: utf8Length)
}
/// Change `lhs` to be `rhs` bytes shorter than `lhs`.
public static func -= (lhs: inout SourceLength, rhs: SourceLength) {
lhs = lhs - rhs
}
}
extension AbsolutePosition {
/// Determine the AbsolutePosition by advancing the `lhs` by the given source
/// length.
public static func + (lhs: AbsolutePosition, rhs: SourceLength) -> AbsolutePosition {
let utf8Offset = lhs.utf8Offset + rhs.utf8Length
return AbsolutePosition(utf8Offset: utf8Offset)
}
/// Advance `lhs` by `rhs`, i.e. changing it to the position `rhs` bytes after `lhs`.
public static func += (lhs: inout AbsolutePosition, rhs: SourceLength) {
lhs = lhs + rhs
}
/// Return the position `rhs` bytes before `lhs`.
public static func - (
lhs: AbsolutePosition,
rhs: SourceLength
) -> AbsolutePosition {
let utf8Offset = lhs.utf8Offset - rhs.utf8Length
return AbsolutePosition(utf8Offset: utf8Offset)
}
/// Reverse `lhs` by `rhs`, i.e. changing it `lhs` to the position `rhs` bytes before `lhs`.
public static func -= (lhs: inout AbsolutePosition, rhs: SourceLength) {
lhs = lhs - rhs
}
}
|
