2 // OrderedEnumerable.cs
5 // Marek Safar <marek.safar@gmail.com>
6 // Jb Evain <jbevain@novell.com>
8 // Copyright (C) 2007 - 2008 Novell, Inc (http://www.novell.com)
10 // Permission is hereby granted, free of charge, to any person obtaining
11 // a copy of this software and associated documentation files (the
12 // "Software"), to deal in the Software without restriction, including
13 // without limitation the rights to use, copy, modify, merge, publish,
14 // distribute, sublicense, and/or sell copies of the Software, and to
15 // permit persons to whom the Software is furnished to do so, subject to
16 // the following conditions:
18 // The above copyright notice and this permission notice shall be
19 // included in all copies or substantial portions of the Software.
21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
22 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
23 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
24 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
25 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
26 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
27 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
31 using System.Collections;
32 using System.Collections.Generic;
34 namespace System.Linq {
36 abstract class OrderedEnumerable<TElement> : IOrderedEnumerable<TElement> {
38 IEnumerable<TElement> source;
40 protected OrderedEnumerable (IEnumerable<TElement> source)
45 IEnumerator IEnumerable.GetEnumerator ()
47 return GetEnumerator ();
50 public IEnumerator<TElement> GetEnumerator ()
52 return Sort (source).GetEnumerator ();
55 public abstract SortContext<TElement> CreateContext (SortContext<TElement> current);
57 protected abstract IEnumerable<TElement> Sort (IEnumerable<TElement> source);
59 public IOrderedEnumerable<TElement> CreateOrderedEnumerable<TKey> (
60 Func<TElement, TKey> selector, IComparer<TKey> comparer, bool descending)
62 return new OrderedSequence<TElement, TKey> (this, source, selector, comparer,
63 descending ? SortDirection.Descending : SortDirection.Ascending);