class/Mono.C5/UserGuideExamples/CollectionSanity.cs

   1 /*
   2  Copyright (c) 2003-2006 Niels Kokholm and Peter Sestoft
   3  Permission is hereby granted, free of charge, to any person obtaining a copy
   4  of this software and associated documentation files (the "Software"), to deal
   5  in the Software without restriction, including without limitation the rights
   6  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   7  copies of the Software, and to permit persons to whom the Software is
   8  furnished to do so, subject to the following conditions:
   9
  10  The above copyright notice and this permission notice shall be included in
  11  all copies or substantial portions of the Software.
  12
  13  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  14  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  15  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  16  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  17  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  18  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  19  SOFTWARE.
  20 */
  21
  22 // C5 example: anagrams 2004-12-08
  23
  24 // Compile with
  25 //   csc /r:C5.dll CollectionSanity.cs
  26
  27 using System;
  28 using C5;
  29 using SCG = System.Collections.Generic;
  30
  31 namespace CollectionSanity {
  32   class CollectionSanity {
  33     public static void Main(String[] args) {
  34       IList<int> col1 = new LinkedList<int>(),
  35         col2 = new LinkedList<int>(), col3 = new LinkedList<int>();
  36       col1.AddAll<int>(new int[] { 7, 9, 13 });
  37       col2.AddAll<int>(new int[] { 7, 9, 13 });
  38       col3.AddAll<int>(new int[] { 9, 7, 13 });
  39
  40       HashSet<IList<int>> hs1 = new HashSet<IList<int>>();
  41       hs1.Add(col1); hs1.Add(col2); hs1.Add(col3);
  42       Console.WriteLine("hs1 is sane: {0}", EqualityComparerSanity<int,IList<int>>(hs1));
  43     }
  44
  45     // When colls is a collection of collections, this method checks
  46     // that all `inner' collections use the exact same equalityComparer.  Note
  47     // that two equalityComparer objects may be functionally (extensionally)
  48     // identical, yet be distinct objects.  However, if the equalityComparers
  49     // were obtained from EqualityComparer<T>.Default, there will be at most one
  50     // equalityComparer for each type T.
  51
  52     public static bool EqualityComparerSanity<T,U>(ICollectionValue<U> colls)
  53       where U : IExtensible<T>
  54     {
  55       SCG.IEqualityComparer<T> equalityComparer = null;
  56       foreach (IExtensible<T> coll in colls) {
  57         if (equalityComparer == null)
  58           equalityComparer = coll.EqualityComparer;
  59         if (equalityComparer != coll.EqualityComparer)
  60           return false;
  61       }
  62       return true;
  63     }
  64   }
  65 }