FizzBuzz.csx

var result = Enumerable.Range(1, 100)
  .Select(i =>
  {
    switch ((Fizz: i % 3, Buzz: i % 5))
    {
      case var t when t.Fizz == 0 && t.Buzz == 0: return $"{nameof(t.Fizz)}{nameof(t.Buzz)}";
      case var t when t.Fizz == 0: return $"{nameof(t.Fizz)}";
      case var t when t.Buzz == 0: return $"{nameof(t.Buzz)}";
      default: return i.ToString(CultureInfo.InvariantCulture);
    }
  })
  .Aggregate(new StringBuilder(), (builder, s) => builder.AppendLine(s));
Console.WriteLine(result);