/
SyntaxTriviaList.Reversed.cs
161 lines (132 loc) · 4.76 KB
/
SyntaxTriviaList.Reversed.cs
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
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Runtime.InteropServices;
using Roslyn.Utilities;
namespace Microsoft.CodeAnalysis
{
public partial struct SyntaxTriviaList
{
/// <summary>
/// Reversed enumerable.
/// </summary>
public readonly struct Reversed : IEnumerable<SyntaxTrivia>, IEquatable<Reversed>
{
private readonly SyntaxTriviaList _list;
public Reversed(SyntaxTriviaList list)
{
_list = list;
}
public Enumerator GetEnumerator()
{
return new Enumerator(in _list);
}
IEnumerator<SyntaxTrivia> IEnumerable<SyntaxTrivia>.GetEnumerator()
{
if (_list.Count == 0)
{
return SpecializedCollections.EmptyEnumerator<SyntaxTrivia>();
}
return new ReversedEnumeratorImpl(in _list);
}
IEnumerator
IEnumerable.GetEnumerator()
{
if (_list.Count == 0)
{
return SpecializedCollections.EmptyEnumerator<SyntaxTrivia>();
}
return new ReversedEnumeratorImpl(in _list);
}
public override int GetHashCode()
{
return _list.GetHashCode();
}
public override bool Equals(object? obj)
{
return obj is Reversed && Equals((Reversed)obj);
}
public bool Equals(Reversed other)
{
return _list.Equals(other._list);
}
[StructLayout(LayoutKind.Auto)]
public struct Enumerator
{
private readonly SyntaxToken _token;
private readonly GreenNode? _singleNodeOrList;
private readonly int _baseIndex;
private readonly int _count;
private int _index;
private GreenNode? _current;
private int _position;
internal Enumerator(in SyntaxTriviaList list)
: this()
{
if (list.Node is object)
{
_token = list.Token;
_singleNodeOrList = list.Node;
_baseIndex = list.Index;
_count = list.Count;
_index = _count;
_current = null;
var last = list.Last();
_position = last.Position + last.FullWidth;
}
}
public bool MoveNext()
{
if (_count == 0 || _index <= 0)
{
_current = null;
return false;
}
Debug.Assert(_singleNodeOrList is object);
_index--;
_current = GetGreenNodeAt(_singleNodeOrList, _index);
Debug.Assert(_current is object);
_position -= _current.FullWidth;
return true;
}
public SyntaxTrivia Current
{
get
{
if (_current == null)
{
throw new InvalidOperationException();
}
return new SyntaxTrivia(_token, _current, _position, _baseIndex + _index);
}
}
}
private class ReversedEnumeratorImpl : IEnumerator<SyntaxTrivia>
{
private Enumerator _enumerator;
// SyntaxTriviaList is a relatively big struct so is passed as ref
internal ReversedEnumeratorImpl(in SyntaxTriviaList list)
{
_enumerator = new Enumerator(in list);
}
public SyntaxTrivia Current => _enumerator.Current;
object IEnumerator.Current => _enumerator.Current;
public bool MoveNext()
{
return _enumerator.MoveNext();
}
public void Reset()
{
throw new NotSupportedException();
}
public void Dispose()
{
}
}
}
}
}