2016 Update

Task/Sierpinski-carpet/JavaScript/sierpinski-carpet-3.js

@@ -0,0 +1,43 @@
+(() => {
+    'use strict';
+
+    // sierpinskiCarpet :: Int -> String
+    let sierpinskiCarpet = n => {
+
+        // carpet :: Int -> [[String]]
+        let carpet = n => {
+                let xs = range(0, Math.pow(3, n) - 1);
+                return xs.map(x => xs.map(y => inCarpet(x, y)));
+            },
+
+            // https://en.wikipedia.org/wiki/Sierpinski_carpet#Construction
+
+            // inCarpet :: Int -> Int -> Bool
+            inCarpet = (x, y) =>
+                (!x || !y) ? true : !(
+                    (x % 3 === 1) &&
+                    (y % 3 === 1)
+                ) && inCarpet(
+                    x / 3 | 0,
+                    y / 3 | 0
+                );
+
+        return carpet(n)
+            .map(line => line.map(bool => bool ? '\u2588' : ' ')
+                .join(''))
+            .join('\n');
+    };
+
+    // GENERIC
+
+    // range :: Int -> Int -> [Int]
+    let range = (m, n) =>
+            Array.from({
+                length: Math.floor(n - m) + 1
+            }, (_, i) => m + i);
+
+    // TEST
+
+    return [1, 2, 3]
+        .map(sierpinskiCarpet);
+})();