2016 Update

Task/Factorial/JavaScript/factorial-7.js

@@ -0,0 +1,20 @@
+(function (n) {
+    'use strict';
+
+    // factorial :: Int -> Int
+    let factorial = (n) => range(1, n).reduce(product, 1);
+
+
+    // product :: Num -> Num -> Num
+    let product = (a, b) => a * b,
+
+        // range :: Int -> Int -> [Int]
+        range = (m, n) =>
+            Array.from({
+                length: (n - m) + 1
+            }, (_, i) => m + i)
+
+
+    return factorial(n);
+
+})(18);