Lo-Dash ^v0.2.0

A drop-in replacement for Underscore.js, from the devs behind jsPerf.com, that delivers performance improvements, bug fixes, and additional features.

Lo-Dash’s performance is gained by avoiding slower native methods, instead opting for simplified non-ES5 compliant methods optimized for common usage, and by leveraging function compilation to reduce the number of overall function calls.

Dive in

We’ve got API docs and unit tests.

For a list of upcoming features, check out our roadmap.

Screencasts

For more information check out these screencasts over Lo-Dash:

• Introducing Lo-Dash
• Optimizations and custom builds

Features

• AMD loader support
• _.bind supports "lazy" binding
• _.debounce’ed functions match _.throttle’ed functions’ return value behavior
• _.forEach is chainable
• _.groupBy accepts a third, thisArg, argument
• _.partial for more functional fun
• _.size supports returning the length of string values

Support

Lo-Dash has been tested in at least Chrome 5-19, Firefox 1.5-12, IE 6-9, Opera 9.25-11.64, Safari 3.0.4-5.1.3, Node.js 0.4.8-0.6.18, Narwhal 0.3.2, RingoJS 0.8, and Rhino 1.7RC3.

Custom builds

Custom builds make it easy to create lightweight versions of Lo-Dash containing only the methods you need. We handle all the method dependency and alias mapping for you.

Custom builds may be created in two ways:

1. Use theinclude argument to pass the names of the methods to include in the build.

node build include=each,filter,map,noConflict
node build include="each, filter, map, noConflict"

2. Use the exclude argument to pass the names of the methods to exclude from the build.

node build exclude=isNaN,isUndefined,union,zip
node build exclude="isNaN, isUndefined, union, zip"

Custom builds are saved to lodash.custom.js and lodash.custom.min.js.

Installation and usage

In browsers:

<script src="lodash.js"></script>

Using npm:

npm install lodash

In Node.js and RingoJS v0.8.0+:

var _ = require('lodash');

In Narwhal and RingoJS v0.7.0-:

var _ = require('lodash')._;

In Rhino:

load('lodash.js');

In an AMD loader like RequireJS:

require({
  'paths': {
    'underscore': 'path/to/lodash'
  }
},
['underscore'], function(_) {
  console.log(_.VERSION);
});

Cloning this repo

To clone this repository including all submodules, using Git 1.6.5 or later:

git clone --recursive https://github.com/bestiejs/lodash.git
cd lodash.js

For older Git versions, just use:

git clone https://github.com/bestiejs/lodash.git
cd lodash
git submodule update --init

Closed Underscore.js issues

• Fix Firefox, IE, Opera, and Safari object iteration bugs #376
• Handle arrays with undefined values correctly in IE < 9 #601
• Methods should work on pages with incorrectly shimmed native methods #7
• Register as AMD module, but still export to global #431
• _.forEach should be chainable #142
• _isNaN(new Number(NaN)) should return true [test]
• _.reduceRight should pass correct callback arguments when iterating objects [test]
• _.size should return the length of string values [test]

Optimized methods ⁽⁵⁰⁺⁾

• _.bind
• _.bindAll
• _.clone
• _.compact
• _.contains, _.include
• _.defaults
• _.defer
• _.difference
• _.each
• _.escape
• _.every, _.all
• _.extend
• _.filter, _.select
• _.find, _.detect
• _.flatten
• _.forEach, _.each
• _.functions, _.methods
• _.groupBy
• _.indexOf
• _.intersection, _.intersect
• _.invoke
• _.isEmpty
• _.isEqual
• _.isFinite
• _.isObject
• _.isString
• _.keys
• _.lastIndexOf
• _.map, _.collect
• _.max
• _.memoize
• _.min
• _.mixin
• _.pick
• _.pluck
• _.reduce, _.foldl, _.inject
• _.reject
• _.result
• _.shuffle
• _.some, _.any
• _.sortBy
• _.sortedIndex
• _.template
• _.throttle
• _.toArray
• _.union
• _.uniq, _.unique
• _.values
• _.without
• _.wrap
• _.zip
• plus all _(...) method wrappers

Changelog

^v0.2.0

• Added custom build options
• Added default _.templateSettings.variable value
• Added "lazy bind" support to _.bind
• Added native method overwrite detection to avoid bad native shims
• Added support for more AMD build optimizers and aliasing as the "underscore" module
• Added thisArg argument to _.groupBy
• Added whitespace to compiled strings
• Added _.partial method
• Commented the iterationFactory options object
• Ensured _.max and _.min support extremely large arrays
• Fixed IE < 9 [DontEnum] bug and Firefox < 3.6, Opera > 9.50 - Opera < 11.60, and Safari < 5.1’s prototype property iteration bug
• Inlined _.isFunction calls.
• Made _.debounce’ed functions match _.throttle’ed functions’ return value behavior
• Made _.escape no longer translate the ">" character
• Fixed clearTimeout typo
• Simplified all methods in the "Arrays" category
• Optimized _.debounce, _.escape, _.flatten, _.forEach, _.groupBy, _.intersection, _.invoke, _.isObject, _.max, _.min, _.pick, _.shuffle, _.sortedIndex, _.template, _.throttle, _.union, _.uniq

^v0.1.0

• Initial release

BestieJS

Lo-Dash is part of the BestieJS "Best in Class" module collection. This means we promote solid browser/environment support, ES5 precedents, unit testing, and plenty of documentation.

Author

• John-David Dalton

Contributors

• Kit Cambridge
• Mathias Bynens