2 // Lookup<TKey, TElement>.cs
5 // Alejandro Serrano "Serras" (trupill@yahoo.es)
6 // Marek Safar <marek.safar@gmail.com>
7 // Jb Evain <jbevain@novell.com>
9 // Copyright (C) 2007 Novell, Inc (http://www.novell.com)
11 // Permission is hereby granted, free of charge, to any person obtaining
12 // a copy of this software and associated documentation files (the
13 // "Software"), to deal in the Software without restriction, including
14 // without limitation the rights to use, copy, modify, merge, publish,
15 // distribute, sublicense, and/or sell copies of the Software, and to
16 // permit persons to whom the Software is furnished to do so, subject to
17 // the following conditions:
19 // The above copyright notice and this permission notice shall be
20 // included in all copies or substantial portions of the Software.
22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
33 using System.Collections;
34 using System.Collections.Generic;
36 namespace System.Linq {
38 public class Lookup<TKey, TElement> : IEnumerable<IGrouping<TKey, TElement>>, ILookup<TKey, TElement> {
40 Dictionary<TKey, IGrouping<TKey, TElement>> groups;
43 get { return groups.Count; }
46 public IEnumerable<TElement> this [TKey key] {
47 get { return groups [key]; }
50 internal Lookup (Dictionary<TKey, List<TElement>> lookup)
52 groups = new Dictionary<TKey, IGrouping<TKey, TElement>> (lookup.Comparer);
53 foreach (var slot in lookup)
54 groups.Add (slot.Key, new Grouping<TKey, TElement> (slot.Key, slot.Value));
57 public IEnumerable<TResult> ApplyResultSelector<TResult> (Func<TKey, IEnumerable<TElement>, TResult> selector)
59 foreach (var group in groups.Values)
60 yield return selector (group.Key, group);
63 public bool Contains (TKey key)
65 return groups.ContainsKey (key);
68 public IEnumerator<IGrouping<TKey, TElement>> GetEnumerator ()
70 return groups.Values.GetEnumerator ();
73 IEnumerator IEnumerable.GetEnumerator ()
75 return groups.Values.GetEnumerator ();