ConcatKey.cs

Go to the documentation of this file.

using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
 
namespace System.Linq.Parallel;
 
internal struct ConcatKey<TLeftKey, TRightKey>
{
    private sealed class ConcatKeyComparer : IComparer<ConcatKey<TLeftKey, TRightKey>>
    {
        private readonly IComparer<TLeftKey> _leftComparer;
 
        private readonly IComparer<TRightKey> _rightComparer;
 
        internal ConcatKeyComparer(IComparer<TLeftKey> leftComparer, IComparer<TRightKey> rightComparer)
        {
            _leftComparer = leftComparer;
            _rightComparer = rightComparer;
        }
 
        public int Compare(ConcatKey<TLeftKey, TRightKey> x, ConcatKey<TLeftKey, TRightKey> y)
        {
            if (x._isLeft != y._isLeft)
            {
                if (!x._isLeft)
                {
                    return 1;
                }
                return -1;
            }
            if (x._isLeft)
            {
                return _leftComparer.Compare(x._leftKey, y._leftKey);
            }
            return _rightComparer.Compare(x._rightKey, y._rightKey);
        }
    }
 
    private readonly TLeftKey _leftKey;
 
    private readonly TRightKey _rightKey;
 
    private readonly bool _isLeft;
 
    private ConcatKey([AllowNull] TLeftKey leftKey, [AllowNull] TRightKey rightKey, bool isLeft)
    {
        _leftKey = leftKey;
        _rightKey = rightKey;
        _isLeft = isLeft;
    }
 
    internal static ConcatKey<TLeftKey, TRightKey> MakeLeft([AllowNull] TLeftKey leftKey)
    {
        return new ConcatKey<TLeftKey, TRightKey>(leftKey, default(TRightKey), isLeft: true);
    }
 
    internal static ConcatKey<TLeftKey, TRightKey> MakeRight([AllowNull] TRightKey rightKey)
    {
        return new ConcatKey<TLeftKey, TRightKey>(default(TLeftKey), rightKey, isLeft: false);
    }
 
    internal static IComparer<ConcatKey<TLeftKey, TRightKey>> MakeComparer(IComparer<TLeftKey> leftComparer, IComparer<TRightKey> rightComparer)
    {
        return new ConcatKeyComparer(leftComparer, rightComparer);
    }
}