Begin moving to ES6 syntax via linting changes.

.eslintrc.json

@@ -50,6 +50,7 @@
     "no-empty": 2,
     "no-plusplus": 2,
     "no-undef": 2,
+    "no-var": 2,
     "linebreak-style": 0,
     "max-depth": [
       2,

package.json

@@ -17,6 +17,7 @@
   },
   "scripts": {
     "build": "gulp build",
+    "lint": "gulp lint",
     "test": "gulp test",
     "deploy": "npm run doc:build && gh-pages -d dist -b gh-pages",
     "doc": "npm run doc:build && npm run doc:view",

src/combinatorics/cartesianproduct.js

@@ -1,14 +1,14 @@
 (function (exports) {
   'use strict';
 
-  var cartesianProduct = (function () {
-    var result;
+  let cartesianProduct = (function () {
+    let result;
 
     function cartesianProduct(sets, index, current) {
       if (index === sets.length) {
         return result.push(current.slice());
       }
-      for (var i = 0; i < sets[index].length; i += 1) {
+      for (let i = 0; i < sets[index].length; i += 1) {
         current[index] = sets[index][i];
         cartesianProduct(sets, index + 1, current);
       }

src/combinatorics/combinations.js

@@ -1,15 +1,15 @@
 (function (exports) {
   'use strict';
 
-  var combinations = (function () {
-    var res = [];
+  let combinations = (function () {
+    let res = [];
 
     function combinations(arr, k, start, idx, current) {
       if (idx === k) {
         res.push(current.slice());
         return;
       }
-      for (var i = start; i < arr.length; i += 1) {
+      for (let i = start; i < arr.length; i += 1) {
         current[idx] = arr[i];
         combinations(arr, k, i + 1, idx + 1, current);
       }
@@ -42,7 +42,7 @@
     return function (arr, k) {
       res = [];
       combinations(arr, k, 0, 0, []);
-      var temp = res;
+      let temp = res;
       // Free the extra memory
       res = null;
       return temp;

src/combinatorics/permutations.js

@@ -1,11 +1,11 @@
 (function (exports) {
   'use strict';
-  var permutations = (function () {
+  let permutations = (function () {
 
-    var res;
+    let res;
 
     function swap(arr, i, j) {
-      var temp = arr[i];
+      let temp = arr[i];
       arr[i] = arr[j];
       arr[j] = temp;
     }
@@ -14,7 +14,7 @@
       if (current >= arr.length) {
         return res.push(arr.slice());
       }
-      for (var i = current; i < arr.length; i += 1) {
+      for (let i = current; i < arr.length; i += 1) {
         swap(arr, i, current);
         permutations(arr, current + 1);
         swap(arr, i, current);
@@ -51,7 +51,7 @@
     return function (arr) {
       res = [];
       permutations(arr, 0);
-      var temp = res;
+      let temp = res;
       // Free the extra memory
       res = null;
       return temp;

src/combinatorics/variations-repetition.js

@@ -1,14 +1,14 @@
 (function (exports) {
   'use strict';
 
-  var variationsWithRepetition = (function () {
-    var res;
+  let variationsWithRepetition = (function () {
+    let res;
 
     function variations(arr, k, index, current) {
       if (k === index) {
         return res.push(current.slice());
       }
-      for (var i = 0; i < arr.length; i += 1) {
+      for (let i = 0; i < arr.length; i += 1) {
         current[index] = arr[i];
         variations(arr, k, index + 1, current);
       }
@@ -44,7 +44,7 @@
     return function (arr, k) {
       res = [];
       variations(arr, k, 0, []);
-      var temp = res;
+      let temp = res;
       res = undefined;
       return temp;
     };

src/compression/LZW/LZW.js

@@ -26,12 +26,12 @@
   };
 
   exports.LZW.compress = function (data) {
-    var i;
-    var dictionary = {};
-    var character;
-    var wc;
-    var w = '';
-    var result = [];
+    let i;
+    let dictionary = {};
+    let character;
+    let wc;
+    let w = '';
+    let result = [];
 
     for (i = 0; i < this.dictionarySize; i = i + 1) {
       dictionary[String.fromCharCode(i)] = i;
@@ -58,12 +58,12 @@
   };
 
   exports.LZW.decompress = function (compressedData) {
-    var i;
-    var dictionary = [];
-    var w;
-    var result;
-    var key;
-    var entry = '';
+    let i;
+    let dictionary = [];
+    let w;
+    let result;
+    let key;
+    let entry = '';
 
     for (i = 0; i < this.dictionarySize; i = i + 1) {
       dictionary[i] = String.fromCharCode(i);

src/compression/burrows-wheeler/burrows-wheeler.js

@@ -29,12 +29,12 @@
    */
   exports.burrowsWheeler.encode = function(str) {
     str = '$' + str;
-    var combinations = [];
+    let combinations = [];
     for (let i = 0; i < str.length; i += 1) {
       combinations.push(str.substring(i) + str.substring(0, i));
     }
-    var sorted = combinations.sort();
-    var result = [];
+    let sorted = combinations.sort();
+    let result = [];
     for (let i = 0; i < sorted.length; i += 1) {
       result.push(combinations[i][str.length - 1]);
     }
@@ -45,19 +45,19 @@
     const sortedCharSequence = encodedStr.split('').sort().join('');
     const leftSide = {};
     const rightSide = {};
-    var maxEachCharLeft = {};
-    var maxEachCharRight = {};
+    let maxEachCharLeft = {};
+    let maxEachCharRight = {};
 
     for (let i = 0; i < encodedStr.length; i += 1) {
-      var idLeft = sortedCharSequence[i];
+      let idLeft = sortedCharSequence[i];
       if (idLeft in maxEachCharLeft) {
         maxEachCharLeft[idLeft] = maxEachCharLeft[idLeft] + 1;
       } else {
         maxEachCharLeft[idLeft] = 1;
       }
       idLeft += String(maxEachCharLeft[idLeft]);
 
-      var idRight = encodedStr[i];
+      let idRight = encodedStr[i];
       if (idRight in maxEachCharRight) {
         maxEachCharRight[idRight] = maxEachCharRight[idRight] + 1;
       } else {
@@ -68,10 +68,10 @@
       leftSide[idLeft] = {char: sortedCharSequence[i], right: idRight};
       rightSide[idRight] = {char: encodedStr[i], left: idRight};
     }
-    var result = '';
-    var firstChar = sortedCharSequence[0];
-    var searchChar = firstChar + '1';
-    var endChar = searchChar;
+    let result = '';
+    let firstChar = sortedCharSequence[0];
+    let searchChar = firstChar + '1';
+    let endChar = searchChar;
     while (rightSide[leftSide[searchChar].right].left !== endChar) {
       result     += leftSide[searchChar].char;
       searchChar = rightSide[leftSide[searchChar].right].left;

src/compression/runlength/runlength.js

@@ -7,16 +7,16 @@
 (function (exports) {
   'use strict';
 
-  var runLengthEncoding = (function () {
+  let runLengthEncoding = (function () {
 
     /**
      * Converts a given string to sequence of numbers
      * This takes O(n).
      */
     function convertToAscii(str) {
-      var result = [];
-      var currentChar = '';
-      var i = 0;
+      let result = [];
+      let currentChar = '';
+      let i = 0;
       for (; i < str.length; i += 1) {
         currentChar = str[i].charCodeAt(0).toString(2);
         currentChar = new Array(9 - currentChar.length).join('0') + currentChar;
@@ -30,10 +30,10 @@
      * Takes O(n^2).
      */
     function runLength(vector) {
-      var result = [];
-      var zeros = 0;
-      var zerosTemp = '';
-      var i = 0;
+      let result = [];
+      let zeros = 0;
+      let zerosTemp = '';
+      let i = 0;
       for (; i < vector.length; i += 1) {
         if (vector[i] === '0') {
           zeros += 1;
@@ -53,7 +53,7 @@
      * Takes O(n^2).
      */
     return function (str) {
-      var asciiString = convertToAscii(str);
+      let asciiString = convertToAscii(str);
       return runLength(asciiString);
     };