AdventOfCode23/Day1/DigitExtractor.cs

using System.Text.RegularExpressions;

namespace Day1;

public partial class DigitExtractor : IStringTransform
{
    [GeneratedRegex("[^\\d]", RegexOptions.IgnoreCase, "en-US")]
    private static partial Regex NonDigit();
    
    public string Transform(string input)
    {
        return NonDigit().Replace(input, string.Empty);
    }
}