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
204
205
206
207
208
|
/* ****************************************************************************
*
* Copyright (c) Microsoft Corporation.
*
* This source code is subject to terms and conditions of the Apache License, Version 2.0. A
* copy of the license can be found in the License.html file at the root of this distribution. If
* you cannot locate the Apache License, Version 2.0, please send an email to
* dlr@microsoft.com. By using this source code in any fashion, you are agreeing to be bound
* by the terms of the Apache License, Version 2.0.
*
* You must not remove this notice, or any other, from this software.
*
*
* ***************************************************************************/
#if CLR2
using Microsoft.Scripting.Utils;
using Microsoft.Scripting.Ast;
#else
using System.Diagnostics.Contracts;
using System.Linq.Expressions;
#endif
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Diagnostics;
using System.Runtime.CompilerServices;
namespace System.Dynamic.Utils {
internal static class CollectionExtensions {
/// <summary>
/// Wraps the provided enumerable into a ReadOnlyCollection{T}
///
/// Copies all of the data into a new array, so the data can't be
/// changed after creation. The exception is if the enumerable is
/// already a ReadOnlyCollection{T}, in which case we just return it.
/// </summary>
#if !CLR2
[Pure]
#endif
internal static ReadOnlyCollection<T> ToReadOnly<T>(this IEnumerable<T> enumerable) {
if (enumerable == null) {
return EmptyReadOnlyCollection<T>.Instance;
}
#if SILVERLIGHT
if (Expression.SilverlightQuirks) {
// Allow any ReadOnlyCollection to be stored directly
// (even though this is not safe)
var r = enumerable as ReadOnlyCollection<T>;
if (r != null) {
return r;
}
}
#endif
var troc = enumerable as TrueReadOnlyCollection<T>;
if (troc != null) {
return troc;
}
var builder = enumerable as ReadOnlyCollectionBuilder<T>;
if (builder != null) {
return builder.ToReadOnlyCollection();
}
var collection = enumerable as ICollection<T>;
if (collection != null) {
int count = collection.Count;
if (count == 0) {
return EmptyReadOnlyCollection<T>.Instance;
}
T[] clone = new T[count];
collection.CopyTo(clone, 0);
return new TrueReadOnlyCollection<T>(clone);
}
// ToArray trims the excess space and speeds up access
return new TrueReadOnlyCollection<T>(new List<T>(enumerable).ToArray());
}
// We could probably improve the hashing here
internal static int ListHashCode<T>(this IEnumerable<T> list) {
var cmp = EqualityComparer<T>.Default;
int h = 6551;
foreach (T t in list) {
h ^= (h << 5) ^ cmp.GetHashCode(t);
}
return h;
}
#if !CLR2
[Pure]
#endif
internal static bool ListEquals<T>(this ICollection<T> first, ICollection<T> second) {
if (first.Count != second.Count) {
return false;
}
var cmp = EqualityComparer<T>.Default;
var f = first.GetEnumerator();
var s = second.GetEnumerator();
while (f.MoveNext()) {
s.MoveNext();
if (!cmp.Equals(f.Current, s.Current)) {
return false;
}
}
return true;
}
internal static IEnumerable<U> Select<T, U>(this IEnumerable<T> enumerable, Func<T, U> select) {
foreach (T t in enumerable) {
yield return select(t);
}
}
// Name needs to be different so it doesn't conflict with Enumerable.Select
internal static U[] Map<T, U>(this ICollection<T> collection, Func<T, U> select) {
int count = collection.Count;
U[] result = new U[count];
count = 0;
foreach (T t in collection) {
result[count++] = select(t);
}
return result;
}
internal static IEnumerable<T> Where<T>(this IEnumerable<T> enumerable, Func<T, bool> where) {
foreach (T t in enumerable) {
if (where(t)) {
yield return t;
}
}
}
internal static bool Any<T>(this IEnumerable<T> source, Func<T, bool> predicate) {
foreach (T element in source) {
if (predicate(element)) {
return true;
}
}
return false;
}
internal static bool All<T>(this IEnumerable<T> source, Func<T, bool> predicate) {
foreach (T element in source) {
if (!predicate(element)) {
return false;
}
}
return true;
}
internal static T[] RemoveFirst<T>(this T[] array) {
T[] result = new T[array.Length - 1];
Array.Copy(array, 1, result, 0, result.Length);
return result;
}
internal static T[] RemoveLast<T>(this T[] array) {
T[] result = new T[array.Length - 1];
Array.Copy(array, 0, result, 0, result.Length);
return result;
}
internal static T[] AddFirst<T>(this IList<T> list, T item) {
T[] res = new T[list.Count + 1];
res[0] = item;
list.CopyTo(res, 1);
return res;
}
internal static T[] AddLast<T>(this IList<T> list, T item) {
T[] res = new T[list.Count + 1];
list.CopyTo(res, 0);
res[list.Count] = item;
return res;
}
internal static T First<T>(this IEnumerable<T> source) {
var list = source as IList<T>;
if (list != null) {
return list[0];
}
using (var e = source.GetEnumerator()) {
if (e.MoveNext()) return e.Current;
}
throw new InvalidOperationException();
}
internal static T Last<T>(this IList<T> list) {
return list[list.Count - 1];
}
internal static T[] Copy<T>(this T[] array) {
T[] copy = new T[array.Length];
Array.Copy(array, copy, array.Length);
return copy;
}
}
internal static class EmptyReadOnlyCollection<T> {
internal static ReadOnlyCollection<T> Instance = new TrueReadOnlyCollection<T>(new T[0]);
}
}
|
