namespace Digits; internal static class IOExtensions { internal static IEnumerable Read10Digits(this IReadWrite io, string prompt, Stream retryText) { while (true) { var numbers = new float[10]; io.ReadNumbers(prompt, numbers); if (numbers.All(n => n == 0 || n == 1 || n == 2)) { return numbers.Select(n => (int)n); } io.Write(retryText); } } }