2016 Update

Task/Knuth-shuffle/JavaScript/knuth-shuffle-2.js

@@ -0,0 +1,38 @@
+(lst => {
+
+    // knuthShuffle :: [a] -> [a]
+    let knuthShuffle = lst =>
+        range(0, lst.length - 1)
+        .reduceRight((a, i) => {
+            let iRand = i ? randomInteger(0, i) : 0,
+                tmp = a[iRand];
+
+            return iRand !== i ?  (
+                a[iRand] = a[i],
+                a[i] = tmp,
+                a
+            ) : a;
+        }, lst),
+
+        // randomInteger :: Int -> Int -> Int
+        randomInteger = (low, high) =>
+        low + Math.floor(
+            (Math.random() * ((high - low) + 1))
+        ),
+
+        // range :: Int -> Int -> Maybe Int -> [Int]
+        range = (m, n, step) => {
+            let d = (step || 1) * (n >= m ? 1 : -1);
+
+            return Array.from({
+                length: Math.floor((n - m) / d) + 1
+            }, (_, i) => m + (i * d));
+        };
+
+
+    return knuthShuffle(lst);
+
+})(
+    'alpha beta gamma delta epsilon zeta eta theta iota kappa lambda mu'
+    .split(' ')
+  );

Task/Knuth-shuffle/JavaScript/knuth-shuffle-3.js

@@ -0,0 +1,2 @@
+["iota", "epsilon", "kappa", "theta", "gamma", "delta",
+"lambda", "eta", "zeta", "beta", "mu", "alpha"]

Task/Knuth-shuffle/JavaScript/knuth-shuffle-4.js

@@ -0,0 +1,56 @@
+(lst => {
+
+    // knuthShuffle :: [a] -> [a]
+    function knuthShuffle(lst) {
+        let lng = lst.length;
+
+        return lng ? range(0, lng - 1)
+            .reduceRight((a, i) => {
+                let iRand = i > 0 ? randomInteger(0, i) : 0;
+
+                return i !== iRand ? swapped(a, i, iRand) : a;
+            }, lst) : [];
+    };
+
+
+    // A non-mutating variant of swapped():
+
+    // swapped :: [a] -> Int -> Int -> [a]
+    let swapped = (lst, iFrom, iTo) => {
+            let [iLow, iHigh] = iTo > iFrom ? (
+                    [iFrom, iTo]
+            ) : [iTo, iFrom];
+
+            return iLow !== iHigh ? (
+                    [].concat(
+                        (iLow > 0 ? lst.slice(0, iLow) : []), // pre
+                        lst[iHigh],                           // DOWN
+                        lst.slice(iLow + 1, iHigh),           // mid
+                        lst[iLow],                            // UP
+                        lst.slice(iHigh + 1)                  // post
+                    )
+                ) : lst.slice(0) // (unchanged copy)
+        },
+
+        // randomInteger :: Int -> Int -> Int
+        randomInteger = (low, high) =>
+        low + Math.floor(
+            (Math.random() * ((high - low) + 1))
+        ),
+
+        // range :: Int -> Int -> Maybe Int -> [Int]
+        range = (m, n, step) => {
+            let d = (step || 1) * (n >= m ? 1 : -1);
+
+            return Array.from({
+                length: Math.floor((n - m) / d) + 1
+            }, (_, i) => m + (i * d));
+        };
+
+
+    return knuthShuffle(lst);
+
+})(
+    'alpha beta gamma delta epsilon zeta eta theta iota kappa lambda mu'
+    .split(' ')
+);

Task/Knuth-shuffle/JavaScript/knuth-shuffle-5.js

@@ -0,0 +1,2 @@
+["mu", "theta", "beta", "eta", "delta", "epsilon",
+"kappa", "alpha", "gamma", "lambda", "zeta", "iota"]