mirror of https://github.com/dahall/Vanara.git
46 lines
1.7 KiB
C#
46 lines
1.7 KiB
C#
using System.Collections.Generic;
|
|
using System.Linq;
|
|
|
|
namespace Vanara.Collections;
|
|
|
|
/// <summary>
|
|
/// Checks the linear equality of two enumerated lists. For lists to be equal, they must have the same number of elements and each index
|
|
/// must hold the same value in each list.
|
|
/// </summary>
|
|
/// <typeparam name="T">The element type in the list.</typeparam>
|
|
public sealed class EnumerableEqualityComparer<T> : IEqualityComparer<IEnumerable<T>>
|
|
{
|
|
private static readonly EqualityComparer<T> elementComparer = EqualityComparer<T>.Default;
|
|
|
|
/// <summary>Determines whether the specified lists are equal.</summary>
|
|
/// <param name="first">The first list of type T to compare.</param>
|
|
/// <param name="second">The second list of type T to compare.</param>
|
|
/// <returns><see langword="true"/> if the two lists are equal; <see langword="false"/> otherwise.</returns>
|
|
public bool Equals(IEnumerable<T>? first, IEnumerable<T>? second)
|
|
{
|
|
if (ReferenceEquals(first, second))
|
|
return true;
|
|
if (first is null || second is null)
|
|
return false;
|
|
var e1 = first.GetEnumerator();
|
|
var e2 = second.GetEnumerator();
|
|
bool move1, move2 = false;
|
|
while ((move1 = e1.MoveNext()) && (move2 = e2.MoveNext()))
|
|
{
|
|
if (!elementComparer.Equals(e1.Current, e2.Current))
|
|
return false;
|
|
}
|
|
return move1 == move2;
|
|
}
|
|
|
|
/// <summary>Returns a hash code for the specified object.</summary>
|
|
/// <param name="list">The Object for which a hash code is to be returned.</param>
|
|
/// <returns>A hash code for the specified object.</returns>
|
|
public int GetHashCode(IEnumerable<T>? list)
|
|
{
|
|
unchecked
|
|
{
|
|
return list is null ? 0 : list.Aggregate(17, (s, e) => s * 31 + elementComparer.GetHashCode(e!));
|
|
}
|
|
}
|
|
} |