Family Day update

Task/Ackermann-function/JavaScript/ackermann-function-5.js

@@ -0,0 +1,38 @@
+(() => {
+    'use strict';
+
+    // ackermann :: Int -> Int -> Int
+    const ackermann = m => n => {
+        const go = (m, n) =>
+            0 === m ? (
+                succ(n)
+            ) : go(pred(m), 0 === n ? (
+                1
+            ) : go(m, pred(n)));
+        return go(m, n);
+    };
+
+    // TEST -----------------------------------------------
+    const main = () => console.log(JSON.stringify(
+        [0, 1, 2, 3].map(
+            flip(ackermann)(3)
+        )
+    ));
+
+
+    // GENERAL FUNCTIONS ----------------------------------
+
+    // flip :: (a -> b -> c) -> b -> a -> c
+    const flip = f =>
+        x => y => f(y)(x);
+
+    // pred :: Enum a => a -> a
+    const pred = x => x - 1;
+
+    // succ :: Enum a => a -> a
+    const succ = x => 1 + x;
+
+
+    // MAIN ---
+    return main();
+})();