CellKey.cs

/*
 * NanoXLSX is a small .NET library to generate and read XLSX (Microsoft Excel 2007 or newer) files in an easy and native way
 * Copyright Raphael Stoeckli © 2026
 * This library is licensed under the MIT License.
 * You find a copy of the license in project folder or on: http://opensource.org/licenses/MIT
 */
 
using System;
 
namespace NanoXLSX.Internal
{
    internal readonly struct CellKey : IEquatable<CellKey>
    {
        internal readonly int Column;
        internal readonly int Row;

        internal CellKey(int column, int row)
        {
            Column = column;
            Row = row;
        }

        public bool Equals(CellKey other)
        {
            return Column == other.Column && Row == other.Row;
        }

        public override bool Equals(object obj)
        {
            return obj is CellKey other && Equals(other);
        }
 
        // Excel max: 16 384 columns (14 bits) × 1 048 576 rows (20 bits) — fits cleanly in 34 bits,
        // so a simple multiply+XOR gives a collision-free hash across the valid address space.
        public override int GetHashCode()
        {
            return (Row * 16384) ^ Column;
        }

        public override string ToString()
        {
            return Cell.ResolveCellAddress(Column, Row);
        }
    }
}