92 lines
2.4 KiB
C#
92 lines
2.4 KiB
C#
// ==++==
|
|
//
|
|
// Copyright (c) Microsoft Corporation. All rights reserved.
|
|
//
|
|
// ==--==
|
|
// <OWNER>[....]</OWNER>
|
|
//
|
|
|
|
using System;
|
|
|
|
namespace System.Collections {
|
|
public static class StructuralComparisons {
|
|
|
|
private static volatile IComparer s_StructuralComparer;
|
|
private static volatile IEqualityComparer s_StructuralEqualityComparer;
|
|
|
|
public static IComparer StructuralComparer {
|
|
get {
|
|
IComparer comparer = s_StructuralComparer;
|
|
if (comparer == null) {
|
|
comparer = new StructuralComparer();
|
|
s_StructuralComparer = comparer;
|
|
}
|
|
return comparer;
|
|
}
|
|
}
|
|
|
|
public static IEqualityComparer StructuralEqualityComparer {
|
|
get {
|
|
IEqualityComparer comparer = s_StructuralEqualityComparer;
|
|
if (comparer == null) {
|
|
comparer = new StructuralEqualityComparer();
|
|
s_StructuralEqualityComparer = comparer;
|
|
}
|
|
return comparer;
|
|
}
|
|
}
|
|
}
|
|
|
|
[Serializable]
|
|
internal class StructuralEqualityComparer : IEqualityComparer {
|
|
public new bool Equals(Object x, Object y) {
|
|
if (x != null) {
|
|
|
|
IStructuralEquatable seObj = x as IStructuralEquatable;
|
|
|
|
if (seObj != null){
|
|
return seObj.Equals(y, this);
|
|
}
|
|
|
|
if (y != null) {
|
|
return x.Equals(y);
|
|
} else {
|
|
return false;
|
|
}
|
|
}
|
|
if (y != null) return false;
|
|
return true;
|
|
}
|
|
|
|
public int GetHashCode(Object obj) {
|
|
if (obj == null) return 0;
|
|
|
|
IStructuralEquatable seObj = obj as IStructuralEquatable;
|
|
|
|
if (seObj != null) {
|
|
return seObj.GetHashCode(this);
|
|
}
|
|
|
|
return obj.GetHashCode();
|
|
}
|
|
}
|
|
|
|
[Serializable]
|
|
internal class StructuralComparer : IComparer {
|
|
public int Compare(Object x, Object y) {
|
|
|
|
if (x == null) return y == null ? 0 : -1;
|
|
if (y == null) return 1;
|
|
|
|
IStructuralComparable scX = x as IStructuralComparable;
|
|
|
|
if (scX != null) {
|
|
return scX.CompareTo(y, this);
|
|
}
|
|
|
|
return Comparer.Default.Compare(x, y);
|
|
}
|
|
}
|
|
|
|
}
|