Natural Sort Order in C#

Question

Anyone have a good resource or provide a sample of a natural order sort in C# for an FileInfo array? I am implementing the IComparer interface in

Answer 1

My solution:

void Main()
{
    new[] {"a4","a3","a2","a10","b5","b4","b400","1","C1d","c1d2"}.OrderBy(x => x, new NaturalStringComparer()).Dump();
}

public class NaturalStringComparer : IComparer
{
    private static readonly Regex _re = new Regex(@"(?<=\D)(?=\d)|(?<=\d)(?=\D)", RegexOptions.Compiled);

    public int Compare(string x, string y)
    {
        x = x.ToLower();
        y = y.ToLower();
        if(string.Compare(x, 0, y, 0, Math.Min(x.Length, y.Length)) == 0)
        {
            if(x.Length == y.Length) return 0;
            return x.Length < y.Length ? -1 : 1;
        }
        var a = _re.Split(x);
        var b = _re.Split(y);
        int i = 0;
        while(true)
        {
            int r = PartCompare(a[i], b[i]);
            if(r != 0) return r;
            ++i;
        }
    }

    private static int PartCompare(string x, string y)
    {
        int a, b;
        if(int.TryParse(x, out a) && int.TryParse(y, out b))
            return a.CompareTo(b);
        return x.CompareTo(y);
    }
}

Results:

1
a2
a3
a4
a10
b4
b5
b400
C1d
c1d2