improve perf and update to standard style

Author: blakeembrey

README.md

@@ -1,10 +1,11 @@
 # Array Flatten
 
 [![NPM version][npm-image]][npm-url]
+[![NPM downloads][downloads-image]][downloads-url]
 [![Build status][travis-image]][travis-url]
 [![Test coverage][coveralls-image]][coveralls-url]
 
-Flatten an array of nested arrays into a single flat array. Accepts an optional depth argument.
+> Flatten an array of nested arrays into a single flat array. Accepts an optional depth.
 
 ## Installation
 
@@ -15,17 +16,17 @@ npm install array-flatten --save
 ## Usage
 
 ```javascript
-var flatten = require('array-flatten');
+var flatten = require('array-flatten')
 
-flatten([1, [2, [3, [4, [5], 6], 7], 8], 9]);
+flatten([1, [2, [3, [4, [5], 6], 7], 8], 9])
 //=> [1, 2, 3, 4, 5, 6, 7, 8, 9]
 
-flatten([1, [2, [3, [4, [5], 6], 7], 8], 9], 2);
+flatten([1, [2, [3, [4, [5], 6], 7], 8], 9], 2)
 //=> [1, 2, 3, [4, [5], 6], 7, 8, 9]
 
 (function () {
-  flatten(arguments); //=> [1, 2, 3]
-})(1, [2, 3]);
+  flatten(arguments) //=> [1, 2, 3]
+})(1, [2, 3])
 ```
 
 ## License
@@ -34,6 +35,8 @@ MIT
 
 [npm-image]: https://img.shields.io/npm/v/array-flatten.svg?style=flat
 [npm-url]: https://npmjs.org/package/array-flatten
+[downloads-image]: https://img.shields.io/npm/dm/array-flatten.svg?style=flat
+[downloads-url]: https://npmjs.org/package/array-flatten
 [travis-image]: https://img.shields.io/travis/blakeembrey/array-flatten.svg?style=flat
 [travis-url]: https://travis-ci.org/blakeembrey/array-flatten
 [coveralls-image]: https://img.shields.io/coveralls/blakeembrey/array-flatten.svg?style=flat

array-flatten.js

@@ -1,21 +1,44 @@
 /**
- * Recursive flatten function. Fastest implementation for array flattening.
+ * Recursive flatten function with depth.
  *
  * @param  {Array}  array
  * @param  {Array}  result
  * @param  {Number} depth
  * @return {Array}
  */
-function flatten (array, result, depth) {
+function flattenDepth (array, result, depth) {
   for (var i = 0; i < array.length; i++) {
-    if (depth > 0 && Array.isArray(array[i])) {
-      flatten(array[i], result, depth - 1);
+    var value = array[i]
+
+    if (depth > 0 && Array.isArray(value)) {
+      flattenDepth(value, result, depth - 1)
+    } else {
+      result.push(value)
+    }
+  }
+
+  return result
+}
+
+/**
+ * Recursive flatten function. Omitting depth is slightly faster.
+ *
+ * @param  {Array} array
+ * @param  {Array} result
+ * @return {Array}
+ */
+function flattenForever (array, result) {
+  for (var i = 0; i < array.length; i++) {
+    var value = array[i]
+
+    if (Array.isArray(value)) {
+      flattenForever(value, result)
     } else {
-      result.push(array[i]);
+      result.push(value)
     }
   }
 
-  return result;
+  return result
 }
 
 /**
@@ -26,5 +49,9 @@ function flatten (array, result, depth) {
  * @return {Array}
  */
 module.exports = function (array, depth) {
-  return flatten(array, [], depth || Infinity);
-};
+  if (depth == null) {
+    return flattenForever(array, [])
+  }
+
+  return flattenDepth(array, [], depth)
+}

package.json

@@ -1,7 +1,7 @@
 {
   "name": "array-flatten",
   "version": "1.0.2",
-  "description": "Flatten a multi-dimensional array.",
+  "description": "Flatten an array of nested arrays into a single flat array",
   "main": "array-flatten.js",
   "files": [
     "array-flatten.js",
@@ -17,7 +17,8 @@
   "keywords": [
     "array",
     "flatten",
-    "arguments"
+    "arguments",
+    "depth"
   ],
   "author": {
     "name": "Blake Embrey",
@@ -30,8 +31,9 @@
   },
   "homepage": "https://github.com/blakeembrey/array-flatten",
   "devDependencies": {
-    "istanbul": "^0.2.6",
-    "mocha": "^1.18.0",
-    "pre-commit": "0.0.9"
+    "istanbul": "^0.3.13",
+    "mocha": "^2.2.4",
+    "pre-commit": "^1.0.7",
+    "standard": "^3.7.3"
   }
 }

test.js

@@ -1,28 +1,26 @@
 /* global describe, it */
 
-var assert  = require('assert');
-var flatten = require('./');
+var assert = require('assert')
+var flatten = require('./')
 
 describe('array-flatten', function () {
   it('should flatten an array', function () {
-    assert.deepEqual(
-      flatten([1, [2, [3, [4, [5]]], 6, [[7], 8], 9], 10]),
-      [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
-    );
-  });
+    var res = flatten([1, [2, [3, [4, [5]]], 6, [[7], 8], 9], 10])
+
+    assert.deepEqual(res, [1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
+  })
 
   it('should flatten an array to a specific depth', function () {
-    assert.deepEqual(
-      flatten([1, [2, [3], 4], 5], 1),
-      [1, 2, [3], 4, 5]
-    );
-  });
+    var res = flatten([1, [2, [3], 4], 5], 1)
+
+    assert.deepEqual(res, [1, 2, [3], 4, 5])
+  })
 
   it('should clone an array when no depth is specified', function () {
-    var array = [1, 2, 3];
-    var clone = flatten(array, 0);
+    var array = [1, [2, 3]]
+    var clone = flatten(array, 0)
 
-    assert.ok(clone !== array);
-    assert.deepEqual(clone, array);
-  });
-});
+    assert.ok(clone !== array)
+    assert.deepEqual(clone, array)
+  })
+})