/Test/Mono.Cecil.Tests/Linq.cs

 1using System;
 2using System.Collections.Generic;
 3
 4using Mono;
 5
 6#if !NET_3_5 && !NET_4_0
 7
 8namespace System.Linq {
 9
10	static class Enumerable {
11
12		public static IEnumerable<TRet> Select<TItem, TRet> (this IEnumerable<TItem> self, Func<TItem, TRet> selector)
13		{
14			foreach (var item in self)
15				yield return selector (item);
16		}
17
18		public static IEnumerable<T> Where<T> (this IEnumerable<T> self, Func<T, bool> predicate)
19		{
20			foreach (var item in self)
21				if (predicate (item))
22					yield return item;
23		}
24
25		public static List<T> ToList<T> (this IEnumerable<T> self)
26		{
27			return new List<T> (self);
28		}
29
30		public static T [] ToArray<T> (this IEnumerable<T> self)
31		{
32			return self.ToList ().ToArray ();
33		}
34
35		public static T First<T> (this IEnumerable<T> self)
36		{
37			using (var enumerator = self.GetEnumerator ()) {
38				if (!enumerator.MoveNext ())
39					throw new InvalidOperationException ();
40
41				return enumerator.Current;
42			}
43		}
44	}
45}
46
47#endif