Add imput routines

90 Tower/csharp/Tower/UI/Input.cs

@@ -0,0 +1,83 @@
+using System;
+using System.Collections.Generic;
+
+namespace Tower.UI
+{
+    // Provides input methods which emulate the BASIC interpreter's keyboard input routines
+    internal static class Input
+    {
+        private static void Prompt(string text = "") => Console.Write($"{text}? ");
+
+        internal static bool ReadYesNo(string prompt, string retryPrompt)
+        {
+            var response = ReadString(prompt);
+
+            while (true)
+            {
+                if (response.Equals("No", StringComparison.InvariantCultureIgnoreCase)) { return false; }
+                if (response.Equals("Yes", StringComparison.InvariantCultureIgnoreCase)) { return true; }
+                response = ReadString(retryPrompt);
+            }
+        }
+
+        internal static bool TryReadNumber(Prompt prompt, out int number)
+        {
+            var message = prompt.Message;
+
+            for (int retryCount = 0; retryCount <= prompt.RetriesAllowed; retryCount++)
+            {
+                if (retryCount > 0) { Console.WriteLine(prompt.RetryMessage); }
+
+                if (prompt.TryValidateResponse(ReadNumber(message), out number)) { return true; }
+
+                if (!prompt.RepeatPrompt) { message = ""; }
+            }
+
+            Console.WriteLine(prompt.QuitMessage);
+
+            number = 0;
+            return false;
+        }
+
+        private static float ReadNumber(string prompt)
+        {
+            Prompt(prompt);
+
+            while (true)
+            {
+                var inputValues = ReadStrings();
+
+                if (TryParseNumber(inputValues[0], out var number))
+                {
+                    if (inputValues.Length > 1)
+                    {
+                        Console.WriteLine("!Extra input ingored");
+                    }
+
+                    return number;
+                }
+            }
+        }
+
+        private static string ReadString(string prompt)
+        {
+            var inputValues = ReadStrings();
+            if (inputValues.Length > 1)
+            {
+                Console.WriteLine("!Extra input ingored");
+            }
+            return inputValues[0];
+        }
+
+        private static string[] ReadStrings() => Console.ReadLine().Split(',', StringSplitOptions.TrimEntries);
+
+        private static bool TryParseNumber(string text, out float number)
+        {
+            if (float.TryParse(text, out number)) { return true; }
+
+            Console.WriteLine("!Number expected - retry input line");
+            number = default;
+            return false;
+        }
+    }
+}

90 Tower/csharp/Tower/UI/Prompt.cs

@@ -0,0 +1,41 @@
+using System.Collections.Generic;
+using System.Linq;
+using static Tower.Resources.Strings;
+
+namespace Tower.UI
+{
+    internal class Prompt
+    {
+        public static Prompt DiskCount =
+            new(DiskCountPrompt, DiskCountRetry, DiskCountQuit, 1, 2, 3, 4, 5, 6, 7) { RetriesAllowed = 2 };
+
+        public static Prompt Disk =
+            new(DiskPrompt, DiskRetry, DiskQuit, 3, 5, 7, 9, 11, 13, 15) { RepeatPrompt = false };
+
+        public static Prompt Needle = new(NeedlePrompt, NeedleRetry, NeedleQuit, 1, 2, 3);
+
+        private readonly HashSet<int> _validValues;
+
+        private Prompt(string prompt, string retryMessage, string quitMessage, params int[] validValues)
+        {
+            Message = prompt;
+            RetryMessage = retryMessage;
+            QuitMessage = quitMessage;
+            _validValues = validValues.ToHashSet();
+            RetriesAllowed = 1;
+            RepeatPrompt = true;
+        }
+
+        public string Message { get; }
+        public string RetryMessage { get; }
+        public string QuitMessage { get; }
+        public int RetriesAllowed { get; private set; }
+        public bool RepeatPrompt { get; private set; }
+
+        public bool TryValidateResponse(float number, out int integer)
+        {
+            integer = (int)number;
+            return integer == number && _validValues.Contains(integer);
+        }
+    }
+}