Initial data commit

Task/Even-or-odd/JavaScript/even-or-odd-4.js

@@ -0,0 +1,25 @@
+(() => {
+    'use strict';
+
+    // even : Integral a => a -> Bool
+    const even = x => (x % 2) === 0;
+
+    // odd : Integral a => a -> Bool
+    const odd = x => !even(x);
+
+
+    // TEST ----------------------------------------
+    // range :: Int -> Int -> [Int]
+    const range = (m, n) =>
+        Array.from({
+            length: Math.floor(n - m) + 1
+        }, (_, i) => m + i);
+
+    // show :: a -> String
+    const show = JSON.stringify;
+
+    // xs :: [Int]
+    const xs = range(-6, 6);
+
+    return show([xs.filter(even), xs.filter(odd)]);
+})();