Added 'Misc./strategy.cs'

Misc./strategy.cs

@@ -0,0 +1,94 @@
+// @BAKE mcs -out:$*.exe $@ && mono $*.exe
+using System;
+using System.Collections.Generic;
+
+// --- Stratigized behaviour ---
+public interface Operation {
+    string description { get; set; }
+    ConsoleColor color { get; set; }
+    void action();
+}
+
+public class ToDown : Operation {
+    public string description { get; set; }
+    public ConsoleColor color { get; set; }
+    public void action() {
+        int n = Menu.items.FindIndex(o => o.operation == this);
+        if (n != Menu.items.Count-1) {
+            Menu.swap(n, n+1);
+        } else {
+            Menu.swap(0, n);
+        }
+    }
+}
+public class ToUp : Operation {
+    public string description { get; set; }
+    public ConsoleColor color { get; set; }
+    public void action() {
+        int n = Menu.items.FindIndex(o => o.operation == this);
+        if (n != 0) {
+            Menu.swap(n-1, n);
+        } else {
+            Menu.swap(n, Menu.items.Count-1);
+        }
+    }
+}
+public class ToTop : Operation {
+    public string description { get; set; }
+    public ConsoleColor color { get; set; }
+    public void action() {
+        int n = Menu.items.FindIndex(o => o.operation == this);
+        Menu.swap(0, n);
+    }
+}
+
+// --- Root object ---
+public class Item {
+    public string name { get; set; }
+    public ConsoleColor color { get; set; }
+    public Operation operation { get; set; }
+}
+// --- Demo ---
+public class Menu {
+    public static List<Item> items = new List<Item>();
+
+    public static void swap(int a, int b) {
+        Operation swap = items[a].operation;
+        Menu.items[a].operation = Menu.items[b].operation;
+        Menu.items[b].operation = swap;
+    }
+
+    public static void print() {
+        foreach (var item in items) {
+            Console.ForegroundColor = item.color;
+            Console.WriteLine($"{item.name}:");
+            Console.ForegroundColor = item.operation.color;
+            Console.WriteLine($"  { item.operation.description}\n");
+            Console.ResetColor();
+        }
+    }
+
+    public static void Main(string[] args) {
+        items.Add(new Item { name = "Item 1", color = ConsoleColor.Yellow,
+            operation = new ToUp { description = "Move up", color = ConsoleColor.Yellow }
+        });
+        items.Add(new Item { name = "Item 2", color = ConsoleColor.Green,
+            operation = new ToDown { description = "Move down", color = ConsoleColor.Green }
+        });
+        items.Add(new Item { name = "Item 3", color = ConsoleColor.Blue,
+            operation = new ToTop { description = "Move to top", color = ConsoleColor.Blue }
+        });
+
+        while (true) {
+            print();
+            Console.Write("$ ");
+            string input = Console.ReadLine();
+            if (string.IsNullOrEmpty(input)) continue;
+            if (int.TryParse(input, out int number)) {
+                if (number > 0 && number <= items.Count) {
+                    items[number - 1].operation.action();
+                }
+            }
+        }
+    }
+}