2 // System.StringComparer
5 // Marek Safar (marek.safar@seznam.cz)
7 // (C) 2005 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.
32 using System.Collections;
33 using System.Globalization;
34 using System.Runtime.InteropServices;
35 using System.Collections.Generic;
39 [Serializable, ComVisible(true)]
40 public abstract class StringComparer : IComparer, IEqualityComparer, IComparer<string>, IEqualityComparer<string>
42 class StringCultureComparer: StringComparer
47 public StringCultureComparer (CultureInfo ci, bool ignore_case)
49 this.ci = ci.CompareInfo;
50 co = ignore_case ? CompareOptions.IgnoreCase : CompareOptions.None;
53 public override int Compare (string x, string y)
55 return ci.Compare (x, y, co);
58 public override bool Equals (string x, string y)
60 return Compare (x, y) == 0;
63 public override int GetHashCode (string s)
66 throw new ArgumentNullException("s");
68 return ci.GetSortKey (s, co).GetHashCode ();
72 class OrdinalComparer : StringComparer
74 public OrdinalComparer ()
78 public override int Compare (string x, string y)
80 return String.CompareOrdinal (x, y);
83 public override bool Equals (string x, string y)
88 public override int GetHashCode (string s)
90 return s.GetHashCode ();
94 class OrdinalIgnoreCaseComparer : StringComparer
96 public OrdinalIgnoreCaseComparer ()
100 public override int Compare (string x, string y)
102 // copied from String.CompareOrdinal()
109 else if (y == null) {
113 int max = x.Length > y.Length ? y.Length : x.Length;
114 for (int i = 0; i < max; i++) {
117 char xc = Char.ToUpperInvariant (x [i]);
118 char yc = Char.ToUpperInvariant (y [i]);
122 return max < x.Length ? -1 :
123 max == y.Length ? 0 : 1;
126 public override bool Equals (string x, string y)
128 return Compare (x, y) == 0;
131 public override int GetHashCode (string s)
133 return s.GetCaseInsensitiveHashCode ();
137 static StringComparer invariantCultureIgnoreCase = new StringCultureComparer (CultureInfo.InvariantCulture, true);
138 static StringComparer invariantCulture = new StringCultureComparer (CultureInfo.InvariantCulture, false);
139 static StringComparer ordinalIgnoreCase =
140 new OrdinalIgnoreCaseComparer ();
141 static StringComparer ordinal = new OrdinalComparer ();
144 protected StringComparer ()
149 public static StringComparer CurrentCulture {
151 return new StringCultureComparer (CultureInfo.CurrentCulture, false);
155 public static StringComparer CurrentCultureIgnoreCase {
157 return new StringCultureComparer (CultureInfo.CurrentCulture, true);
161 public static StringComparer InvariantCulture {
163 return invariantCulture;
167 public static StringComparer InvariantCultureIgnoreCase {
169 return invariantCultureIgnoreCase;
173 public static StringComparer Ordinal {
174 get { return ordinal; }
177 public static StringComparer OrdinalIgnoreCase {
178 get { return ordinalIgnoreCase; }
182 public static StringComparer Create (CultureInfo culture, bool ignoreCase)
184 return new StringCultureComparer (culture, ignoreCase);
187 public int Compare (object x, object y)
196 string s_x = x as string;
198 string s_y = y as string;
200 return Compare (s_x, s_y);
203 IComparable ic = x as IComparable;
205 throw new ArgumentException ();
207 return ic.CompareTo (y);
210 public new bool Equals (object x, object y)
214 if (x == null || y == null)
217 string s_x = x as string;
219 string s_y = y as string;
221 return Equals (s_x, s_y);
226 public int GetHashCode (object o)
229 throw new ArgumentNullException("o");
231 string s = o as string;
232 return s == null ? o.GetHashCode (): GetHashCode(s);
235 public abstract int Compare (string x, string y);
236 public abstract bool Equals (string x, string y);
237 public abstract int GetHashCode (string s);