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// Underscore.js 1.4.4
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// ===================
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// > http://underscorejs.org
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// > (c) 2009-2013 Jeremy Ashkenas, DocumentCloud Inc.
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// > Underscore may be freely distributed under the MIT license.
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// Baseline setup
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// --------------
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(function() {
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// Establish the root object, `window` in the browser, or `global` on the server.
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var root = this; |
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// Save the previous value of the `_` variable.
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var previousUnderscore = root._;
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// Establish the object that gets returned to break out of a loop iteration.
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var breaker = {};
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// Save bytes in the minified (but not gzipped) version:
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var ArrayProto = Array.prototype, ObjProto = Object.prototype, FuncProto = Function.prototype;
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// Create quick reference variables for speed access to core prototypes.
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var push = ArrayProto.push,
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slice = ArrayProto.slice, |
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concat = ArrayProto.concat, |
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toString = ObjProto.toString, |
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hasOwnProperty = ObjProto.hasOwnProperty; |
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// All **ECMAScript 5** native function implementations that we hope to use
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// are declared here.
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var
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nativeForEach = ArrayProto.forEach, |
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nativeMap = ArrayProto.map, |
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nativeReduce = ArrayProto.reduce, |
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nativeReduceRight = ArrayProto.reduceRight, |
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nativeFilter = ArrayProto.filter, |
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nativeEvery = ArrayProto.every, |
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nativeSome = ArrayProto.some, |
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nativeIndexOf = ArrayProto.indexOf, |
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nativeLastIndexOf = ArrayProto.lastIndexOf, |
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nativeIsArray = Array.isArray, |
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nativeKeys = Object.keys, |
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nativeBind = FuncProto.bind; |
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// Create a safe reference to the Underscore object for use below.
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var _ = function(obj) { |
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if (obj instanceof _) return obj; |
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if (!(this instanceof _)) return new _(obj); |
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this._wrapped = obj;
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}; |
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// Export the Underscore object for **Node.js**, with
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// backwards-compatibility for the old `require()` API. If we're in
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// the browser, add `_` as a global object via a string identifier,
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// for Closure Compiler "advanced" mode.
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if (typeof exports !== 'undefined') { |
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if (typeof module !== 'undefined' && module.exports) { |
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exports = module.exports = _; |
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} |
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exports._ = _; |
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} else {
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root._ = _; |
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} |
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// Current version.
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_.VERSION = '1.4.4';
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// Collection Functions
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// --------------------
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// The cornerstone, an `each` implementation, aka `forEach`.
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// Handles objects with the built-in `forEach`, arrays, and raw objects.
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// Delegates to **ECMAScript 5**'s native `forEach` if available.
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var each = _.each = _.forEach = function(obj, iterator, context) { |
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if (obj == null) return; |
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if (nativeForEach && obj.forEach === nativeForEach) {
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obj.forEach(iterator, context); |
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} else if (obj.length === +obj.length) { |
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for (var i = 0, l = obj.length; i < l; i++) { |
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if (iterator.call(context, obj[i], i, obj) === breaker) return; |
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} |
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} else {
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for (var key in obj) { |
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if (_.has(obj, key)) {
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if (iterator.call(context, obj[key], key, obj) === breaker) return; |
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} |
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} |
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} |
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}; |
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// Return the results of applying the iterator to each element.
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// Delegates to **ECMAScript 5**'s native `map` if available.
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_.map = _.collect = function(obj, iterator, context) { |
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var results = [];
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if (obj == null) return results; |
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if (nativeMap && obj.map === nativeMap) return obj.map(iterator, context); |
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each(obj, function(value, index, list) {
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results[results.length] = iterator.call(context, value, index, list); |
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}); |
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return results;
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}; |
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var reduceError = 'Reduce of empty array with no initial value'; |
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// **Reduce** builds up a single result from a list of values, aka `inject`,
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// or `foldl`. Delegates to **ECMAScript 5**'s native `reduce` if available.
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_.reduce = _.foldl = _.inject = function(obj, iterator, memo, context) { |
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var initial = arguments.length > 2; |
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if (obj == null) obj = []; |
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if (nativeReduce && obj.reduce === nativeReduce) {
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if (context) iterator = _.bind(iterator, context);
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return initial ? obj.reduce(iterator, memo) : obj.reduce(iterator);
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} |
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each(obj, function(value, index, list) {
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if (!initial) {
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memo = value; |
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initial = true;
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} else {
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memo = iterator.call(context, memo, value, index, list); |
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} |
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}); |
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if (!initial) throw new TypeError(reduceError); |
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return memo;
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}; |
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// The right-associative version of reduce, also known as `foldr`.
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// Delegates to **ECMAScript 5**'s native `reduceRight` if available.
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_.reduceRight = _.foldr = function(obj, iterator, memo, context) { |
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var initial = arguments.length > 2; |
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if (obj == null) obj = []; |
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if (nativeReduceRight && obj.reduceRight === nativeReduceRight) {
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if (context) iterator = _.bind(iterator, context);
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return initial ? obj.reduceRight(iterator, memo) : obj.reduceRight(iterator);
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} |
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var length = obj.length;
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if (length !== +length) {
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var keys = _.keys(obj);
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length = keys.length; |
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} |
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each(obj, function(value, index, list) {
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index = keys ? keys[--length] : --length; |
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if (!initial) {
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memo = obj[index]; |
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initial = true;
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} else {
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memo = iterator.call(context, memo, obj[index], index, list); |
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} |
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}); |
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if (!initial) throw new TypeError(reduceError); |
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return memo;
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}; |
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// Return the first value which passes a truth test. Aliased as `detect`.
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_.find = _.detect = function(obj, iterator, context) { |
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var result;
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any(obj, function(value, index, list) {
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if (iterator.call(context, value, index, list)) {
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result = value; |
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return true; |
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} |
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}); |
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return result;
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}; |
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// Return all the elements that pass a truth test.
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// Delegates to **ECMAScript 5**'s native `filter` if available.
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// Aliased as `select`.
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_.filter = _.select = function(obj, iterator, context) { |
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var results = [];
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if (obj == null) return results; |
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if (nativeFilter && obj.filter === nativeFilter) return obj.filter(iterator, context); |
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each(obj, function(value, index, list) {
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if (iterator.call(context, value, index, list)) results[results.length] = value;
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}); |
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return results;
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}; |
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// Return all the elements for which a truth test fails.
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_.reject = function(obj, iterator, context) { |
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return _.filter(obj, function(value, index, list) { |
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return !iterator.call(context, value, index, list);
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}, context); |
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}; |
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// Determine whether all of the elements match a truth test.
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// Delegates to **ECMAScript 5**'s native `every` if available.
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// Aliased as `all`.
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_.every = _.all = function(obj, iterator, context) { |
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iterator || (iterator = _.identity); |
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var result = true; |
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if (obj == null) return result; |
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if (nativeEvery && obj.every === nativeEvery) return obj.every(iterator, context); |
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each(obj, function(value, index, list) {
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if (!(result = result && iterator.call(context, value, index, list))) return breaker; |
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}); |
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return !!result;
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}; |
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// Determine if at least one element in the object matches a truth test.
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// Delegates to **ECMAScript 5**'s native `some` if available.
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// Aliased as `any`.
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var any = _.some = _.any = function(obj, iterator, context) { |
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iterator || (iterator = _.identity); |
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var result = false; |
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if (obj == null) return result; |
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if (nativeSome && obj.some === nativeSome) return obj.some(iterator, context); |
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each(obj, function(value, index, list) {
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if (result || (result = iterator.call(context, value, index, list))) return breaker; |
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}); |
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return !!result;
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}; |
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// Determine if the array or object contains a given value (using `===`).
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// Aliased as `include`.
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_.contains = _.include = function(obj, target) { |
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if (obj == null) return false; |
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if (nativeIndexOf && obj.indexOf === nativeIndexOf) return obj.indexOf(target) != -1; |
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return any(obj, function(value) { |
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return value === target;
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}); |
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}; |
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// Invoke a method (with arguments) on every item in a collection.
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_.invoke = function(obj, method) { |
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var args = slice.call(arguments, 2); |
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var isFunc = _.isFunction(method);
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return _.map(obj, function(value) { |
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return (isFunc ? method : value[method]).apply(value, args);
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}); |
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}; |
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// Convenience version of a common use case of `map`: fetching a property.
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_.pluck = function(obj, key) { |
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return _.map(obj, function(value){ return value[key]; }); |
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}; |
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// Convenience version of a common use case of `filter`: selecting only objects
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// containing specific `key:value` pairs.
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_.where = function(obj, attrs, first) { |
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if (_.isEmpty(attrs)) return first ? null : []; |
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return _[first ? 'find' : 'filter'](obj, function(value) { |
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for (var key in attrs) { |
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if (attrs[key] !== value[key]) return false; |
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} |
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return true; |
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}); |
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}; |
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// Convenience version of a common use case of `find`: getting the first object
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// containing specific `key:value` pairs.
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_.findWhere = function(obj, attrs) { |
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return _.where(obj, attrs, true); |
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}; |
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// Return the maximum element or (element-based computation).
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// Can't optimize arrays of integers longer than 65,535 elements.
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// See: https://bugs.webkit.org/show_bug.cgi?id=80797
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_.max = function(obj, iterator, context) { |
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if (!iterator && _.isArray(obj) && obj[0] === +obj[0] && obj.length < 65535) { |
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return Math.max.apply(Math, obj);
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} |
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if (!iterator && _.isEmpty(obj)) return -Infinity; |
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var result = {computed : -Infinity, value: -Infinity}; |
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each(obj, function(value, index, list) {
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var computed = iterator ? iterator.call(context, value, index, list) : value;
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computed >= result.computed && (result = {value : value, computed : computed}); |
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}); |
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return result.value;
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}; |
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// Return the minimum element (or element-based computation).
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_.min = function(obj, iterator, context) { |
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if (!iterator && _.isArray(obj) && obj[0] === +obj[0] && obj.length < 65535) { |
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return Math.min.apply(Math, obj);
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} |
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if (!iterator && _.isEmpty(obj)) return Infinity; |
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var result = {computed : Infinity, value: Infinity}; |
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each(obj, function(value, index, list) {
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var computed = iterator ? iterator.call(context, value, index, list) : value;
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computed < result.computed && (result = {value : value, computed : computed}); |
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}); |
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return result.value;
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}; |
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// Shuffle an array.
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_.shuffle = function(obj) { |
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var rand;
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var index = 0; |
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var shuffled = [];
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each(obj, function(value) {
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rand = _.random(index++); |
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shuffled[index - 1] = shuffled[rand];
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shuffled[rand] = value; |
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}); |
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return shuffled;
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}; |
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// An internal function to generate lookup iterators.
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var lookupIterator = function(value) { |
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return _.isFunction(value) ? value : function(obj){ return obj[value]; }; |
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}; |
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// Sort the object's values by a criterion produced by an iterator.
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_.sortBy = function(obj, value, context) { |
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var iterator = lookupIterator(value);
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return _.pluck(_.map(obj, function(value, index, list) { |
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return {
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value : value,
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index : index,
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criteria : iterator.call(context, value, index, list)
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}; |
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}).sort(function(left, right) {
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var a = left.criteria;
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var b = right.criteria;
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if (a !== b) {
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if (a > b || a === void 0) return 1; |
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if (a < b || b === void 0) return -1; |
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} |
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return left.index < right.index ? -1 : 1; |
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}), 'value');
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}; |
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// An internal function used for aggregate "group by" operations.
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var group = function(obj, value, context, behavior) { |
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var result = {};
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var iterator = lookupIterator(value || _.identity);
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each(obj, function(value, index) {
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var key = iterator.call(context, value, index, obj);
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behavior(result, key, value); |
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}); |
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return result;
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}; |
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// Groups the object's values by a criterion. Pass either a string attribute
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// to group by, or a function that returns the criterion.
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_.groupBy = function(obj, value, context) { |
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return group(obj, value, context, function(result, key, value) { |
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(_.has(result, key) ? result[key] : (result[key] = [])).push(value); |
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}); |
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}; |
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// Counts instances of an object that group by a certain criterion. Pass
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// either a string attribute to count by, or a function that returns the
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// criterion.
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_.countBy = function(obj, value, context) { |
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return group(obj, value, context, function(result, key) { |
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if (!_.has(result, key)) result[key] = 0; |
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result[key]++; |
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}); |
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}; |
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// Use a comparator function to figure out the smallest index at which
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// an object should be inserted so as to maintain order. Uses binary search.
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_.sortedIndex = function(array, obj, iterator, context) { |
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iterator = iterator == null ? _.identity : lookupIterator(iterator);
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var value = iterator.call(context, obj);
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var low = 0, high = array.length; |
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while (low < high) {
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var mid = (low + high) >>> 1; |
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iterator.call(context, array[mid]) < value ? low = mid + 1 : high = mid;
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} |
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return low;
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}; |
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// Safely convert anything iterable into a real, live array.
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_.toArray = function(obj) { |
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if (!obj) return []; |
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if (_.isArray(obj)) return slice.call(obj); |
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if (obj.length === +obj.length) return _.map(obj, _.identity); |
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return _.values(obj);
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}; |
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// Return the number of elements in an object.
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_.size = function(obj) { |
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if (obj == null) return 0; |
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return (obj.length === +obj.length) ? obj.length : _.keys(obj).length;
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}; |
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// Array Functions
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// ---------------
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// Get the first element of an array. Passing **n** will return the first N
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// values in the array. Aliased as `head` and `take`. The **guard** check
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// allows it to work with `_.map`.
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_.first = _.head = _.take = function(array, n, guard) { |
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if (array == null) return void 0; |
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return (n != null) && !guard ? slice.call(array, 0, n) : array[0]; |
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}; |
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// Returns everything but the last entry of the array. Especially useful on
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// the arguments object. Passing **n** will return all the values in
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// the array, excluding the last N. The **guard** check allows it to work with
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// `_.map`.
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_.initial = function(array, n, guard) { |
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return slice.call(array, 0, array.length - ((n == null) || guard ? 1 : n)); |
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}; |
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// Get the last element of an array. Passing **n** will return the last N
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// values in the array. The **guard** check allows it to work with `_.map`.
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_.last = function(array, n, guard) { |
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if (array == null) return void 0; |
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if ((n != null) && !guard) { |
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return slice.call(array, Math.max(array.length - n, 0)); |
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} else {
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return array[array.length - 1]; |
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} |
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}; |
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// Returns everything but the first entry of the array. Aliased as `tail` and `drop`.
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// Especially useful on the arguments object. Passing an **n** will return
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// the rest N values in the array. The **guard**
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// check allows it to work with `_.map`.
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_.rest = _.tail = _.drop = function(array, n, guard) { |
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return slice.call(array, (n == null) || guard ? 1 : n); |
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}; |
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// Trim out all falsy values from an array.
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_.compact = function(array) { |
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return _.filter(array, _.identity);
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}; |
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// Internal implementation of a recursive `flatten` function.
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var flatten = function(input, shallow, output) { |
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each(input, function(value) {
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if (_.isArray(value)) {
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shallow ? push.apply(output, value) : flatten(value, shallow, output); |
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} else {
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output.push(value); |
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} |
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}); |
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return output;
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}; |
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// Return a completely flattened version of an array.
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_.flatten = function(array, shallow) { |
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return flatten(array, shallow, []);
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}; |
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// Return a version of the array that does not contain the specified value(s).
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_.without = function(array) { |
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return _.difference(array, slice.call(arguments, 1)); |
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}; |
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// Produce a duplicate-free version of the array. If the array has already
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// been sorted, you have the option of using a faster algorithm.
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// Aliased as `unique`.
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_.uniq = _.unique = function(array, isSorted, iterator, context) { |
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if (_.isFunction(isSorted)) {
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context = iterator; |
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iterator = isSorted; |
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isSorted = false;
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} |
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var initial = iterator ? _.map(array, iterator, context) : array;
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var results = [];
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var seen = [];
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each(initial, function(value, index) {
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if (isSorted ? (!index || seen[seen.length - 1] !== value) : !_.contains(seen, value)) { |
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seen.push(value); |
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results.push(array[index]); |
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} |
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}); |
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return results;
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}; |
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// Produce an array that contains the union: each distinct element from all of
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// the passed-in arrays.
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_.union = function() { |
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return _.uniq(concat.apply(ArrayProto, arguments)); |
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}; |
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// Produce an array that contains every item shared between all the
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// passed-in arrays.
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_.intersection = function(array) { |
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var rest = slice.call(arguments, 1); |
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return _.filter(_.uniq(array), function(item) { |
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return _.every(rest, function(other) { |
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return _.indexOf(other, item) >= 0; |
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}); |
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}); |
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}; |
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// Take the difference between one array and a number of other arrays.
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// Only the elements present in just the first array will remain.
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_.difference = function(array) { |
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var rest = concat.apply(ArrayProto, slice.call(arguments, 1)); |
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return _.filter(array, function(value){ return !_.contains(rest, value); }); |
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}; |
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// Zip together multiple lists into a single array -- elements that share
|
492 |
// an index go together.
|
493 |
_.zip = function() { |
494 |
var args = slice.call(arguments); |
495 |
var length = _.max(_.pluck(args, 'length')); |
496 |
var results = new Array(length); |
497 |
for (var i = 0; i < length; i++) { |
498 |
results[i] = _.pluck(args, "" + i);
|
499 |
} |
500 |
return results;
|
501 |
}; |
502 |
|
503 |
// Converts lists into objects. Pass either a single array of `[key, value]`
|
504 |
// pairs, or two parallel arrays of the same length -- one of keys, and one of
|
505 |
// the corresponding values.
|
506 |
_.object = function(list, values) { |
507 |
if (list == null) return {}; |
508 |
var result = {};
|
509 |
for (var i = 0, l = list.length; i < l; i++) { |
510 |
if (values) {
|
511 |
result[list[i]] = values[i]; |
512 |
} else {
|
513 |
result[list[i][0]] = list[i][1]; |
514 |
} |
515 |
} |
516 |
return result;
|
517 |
}; |
518 |
|
519 |
// If the browser doesn't supply us with indexOf (I'm looking at you, **MSIE**),
|
520 |
// we need this function. Return the position of the first occurrence of an
|
521 |
// item in an array, or -1 if the item is not included in the array.
|
522 |
// Delegates to **ECMAScript 5**'s native `indexOf` if available.
|
523 |
// If the array is large and already in sort order, pass `true`
|
524 |
// for **isSorted** to use binary search.
|
525 |
_.indexOf = function(array, item, isSorted) { |
526 |
if (array == null) return -1; |
527 |
var i = 0, l = array.length; |
528 |
if (isSorted) {
|
529 |
if (typeof isSorted == 'number') { |
530 |
i = (isSorted < 0 ? Math.max(0, l + isSorted) : isSorted); |
531 |
} else {
|
532 |
i = _.sortedIndex(array, item); |
533 |
return array[i] === item ? i : -1; |
534 |
} |
535 |
} |
536 |
if (nativeIndexOf && array.indexOf === nativeIndexOf) return array.indexOf(item, isSorted); |
537 |
for (; i < l; i++) if (array[i] === item) return i; |
538 |
return -1; |
539 |
}; |
540 |
|
541 |
// Delegates to **ECMAScript 5**'s native `lastIndexOf` if available.
|
542 |
_.lastIndexOf = function(array, item, from) { |
543 |
if (array == null) return -1; |
544 |
var hasIndex = from != null; |
545 |
if (nativeLastIndexOf && array.lastIndexOf === nativeLastIndexOf) {
|
546 |
return hasIndex ? array.lastIndexOf(item, from) : array.lastIndexOf(item);
|
547 |
} |
548 |
var i = (hasIndex ? from : array.length);
|
549 |
while (i--) if (array[i] === item) return i; |
550 |
return -1; |
551 |
}; |
552 |
|
553 |
// Generate an integer Array containing an arithmetic progression. A port of
|
554 |
// the native Python `range()` function. See
|
555 |
// [the Python documentation](http://docs.python.org/library/functions.html#range).
|
556 |
_.range = function(start, stop, step) { |
557 |
if (arguments.length <= 1) { |
558 |
stop = start || 0;
|
559 |
start = 0;
|
560 |
} |
561 |
step = arguments[2] || 1; |
562 |
|
563 |
var len = Math.max(Math.ceil((stop - start) / step), 0); |
564 |
var idx = 0; |
565 |
var range = new Array(len); |
566 |
|
567 |
while(idx < len) {
|
568 |
range[idx++] = start; |
569 |
start += step; |
570 |
} |
571 |
|
572 |
return range;
|
573 |
}; |
574 |
|
575 |
// Function (ahem) Functions
|
576 |
// ------------------
|
577 |
|
578 |
// Create a function bound to a given object (assigning `this`, and arguments,
|
579 |
// optionally). Delegates to **ECMAScript 5**'s native `Function.bind` if
|
580 |
// available.
|
581 |
_.bind = function(func, context) { |
582 |
if (func.bind === nativeBind && nativeBind) return nativeBind.apply(func, slice.call(arguments, 1)); |
583 |
var args = slice.call(arguments, 2); |
584 |
return function() { |
585 |
return func.apply(context, args.concat(slice.call(arguments))); |
586 |
}; |
587 |
}; |
588 |
|
589 |
// Partially apply a function by creating a version that has had some of its
|
590 |
// arguments pre-filled, without changing its dynamic `this` context.
|
591 |
_.partial = function(func) { |
592 |
var args = slice.call(arguments, 1); |
593 |
return function() { |
594 |
return func.apply(this, args.concat(slice.call(arguments))); |
595 |
}; |
596 |
}; |
597 |
|
598 |
// Bind all of an object's methods to that object. Useful for ensuring that
|
599 |
// all callbacks defined on an object belong to it.
|
600 |
_.bindAll = function(obj) { |
601 |
var funcs = slice.call(arguments, 1); |
602 |
if (funcs.length === 0) funcs = _.functions(obj); |
603 |
each(funcs, function(f) { obj[f] = _.bind(obj[f], obj); });
|
604 |
return obj;
|
605 |
}; |
606 |
|
607 |
// Memoize an expensive function by storing its results.
|
608 |
_.memoize = function(func, hasher) { |
609 |
var memo = {};
|
610 |
hasher || (hasher = _.identity); |
611 |
return function() { |
612 |
var key = hasher.apply(this, arguments); |
613 |
return _.has(memo, key) ? memo[key] : (memo[key] = func.apply(this, arguments)); |
614 |
}; |
615 |
}; |
616 |
|
617 |
// Delays a function for the given number of milliseconds, and then calls
|
618 |
// it with the arguments supplied.
|
619 |
_.delay = function(func, wait) { |
620 |
var args = slice.call(arguments, 2); |
621 |
return setTimeout(function(){ return func.apply(null, args); }, wait); |
622 |
}; |
623 |
|
624 |
// Defers a function, scheduling it to run after the current call stack has
|
625 |
// cleared.
|
626 |
_.defer = function(func) { |
627 |
return _.delay.apply(_, [func, 1].concat(slice.call(arguments, 1))); |
628 |
}; |
629 |
|
630 |
// Returns a function, that, when invoked, will only be triggered at most once
|
631 |
// during a given window of time.
|
632 |
_.throttle = function(func, wait) { |
633 |
var context, args, timeout, result;
|
634 |
var previous = 0; |
635 |
var later = function() { |
636 |
previous = new Date;
|
637 |
timeout = null;
|
638 |
result = func.apply(context, args); |
639 |
}; |
640 |
return function() { |
641 |
var now = new Date; |
642 |
var remaining = wait - (now - previous);
|
643 |
context = this;
|
644 |
args = arguments;
|
645 |
if (remaining <= 0) { |
646 |
clearTimeout(timeout); |
647 |
timeout = null;
|
648 |
previous = now; |
649 |
result = func.apply(context, args); |
650 |
} else if (!timeout) { |
651 |
timeout = setTimeout(later, remaining); |
652 |
} |
653 |
return result;
|
654 |
}; |
655 |
}; |
656 |
|
657 |
// Returns a function, that, as long as it continues to be invoked, will not
|
658 |
// be triggered. The function will be called after it stops being called for
|
659 |
// N milliseconds. If `immediate` is passed, trigger the function on the
|
660 |
// leading edge, instead of the trailing.
|
661 |
_.debounce = function(func, wait, immediate) { |
662 |
var timeout, result;
|
663 |
return function() { |
664 |
var context = this, args = arguments; |
665 |
var later = function() { |
666 |
timeout = null;
|
667 |
if (!immediate) result = func.apply(context, args);
|
668 |
}; |
669 |
var callNow = immediate && !timeout;
|
670 |
clearTimeout(timeout); |
671 |
timeout = setTimeout(later, wait); |
672 |
if (callNow) result = func.apply(context, args);
|
673 |
return result;
|
674 |
}; |
675 |
}; |
676 |
|
677 |
// Returns a function that will be executed at most one time, no matter how
|
678 |
// often you call it. Useful for lazy initialization.
|
679 |
_.once = function(func) { |
680 |
var ran = false, memo; |
681 |
return function() { |
682 |
if (ran) return memo; |
683 |
ran = true;
|
684 |
memo = func.apply(this, arguments); |
685 |
func = null;
|
686 |
return memo;
|
687 |
}; |
688 |
}; |
689 |
|
690 |
// Returns the first function passed as an argument to the second,
|
691 |
// allowing you to adjust arguments, run code before and after, and
|
692 |
// conditionally execute the original function.
|
693 |
_.wrap = function(func, wrapper) { |
694 |
return function() { |
695 |
var args = [func];
|
696 |
push.apply(args, arguments);
|
697 |
return wrapper.apply(this, args); |
698 |
}; |
699 |
}; |
700 |
|
701 |
// Returns a function that is the composition of a list of functions, each
|
702 |
// consuming the return value of the function that follows.
|
703 |
_.compose = function() { |
704 |
var funcs = arguments; |
705 |
return function() { |
706 |
var args = arguments; |
707 |
for (var i = funcs.length - 1; i >= 0; i--) { |
708 |
args = [funcs[i].apply(this, args)];
|
709 |
} |
710 |
return args[0]; |
711 |
}; |
712 |
}; |
713 |
|
714 |
// Returns a function that will only be executed after being called N times.
|
715 |
_.after = function(times, func) { |
716 |
if (times <= 0) return func(); |
717 |
return function() { |
718 |
if (--times < 1) { |
719 |
return func.apply(this, arguments); |
720 |
} |
721 |
}; |
722 |
}; |
723 |
|
724 |
// Object Functions
|
725 |
// ----------------
|
726 |
|
727 |
// Retrieve the names of an object's properties.
|
728 |
// Delegates to **ECMAScript 5**'s native `Object.keys`
|
729 |
_.keys = nativeKeys || function(obj) {
|
730 |
if (obj !== Object(obj)) throw new TypeError('Invalid object'); |
731 |
var keys = [];
|
732 |
for (var key in obj) if (_.has(obj, key)) keys[keys.length] = key; |
733 |
return keys;
|
734 |
}; |
735 |
|
736 |
// Retrieve the values of an object's properties.
|
737 |
_.values = function(obj) { |
738 |
var values = [];
|
739 |
for (var key in obj) if (_.has(obj, key)) values.push(obj[key]); |
740 |
return values;
|
741 |
}; |
742 |
|
743 |
// Convert an object into a list of `[key, value]` pairs.
|
744 |
_.pairs = function(obj) { |
745 |
var pairs = [];
|
746 |
for (var key in obj) if (_.has(obj, key)) pairs.push([key, obj[key]]); |
747 |
return pairs;
|
748 |
}; |
749 |
|
750 |
// Invert the keys and values of an object. The values must be serializable.
|
751 |
_.invert = function(obj) { |
752 |
var result = {};
|
753 |
for (var key in obj) if (_.has(obj, key)) result[obj[key]] = key; |
754 |
return result;
|
755 |
}; |
756 |
|
757 |
// Return a sorted list of the function names available on the object.
|
758 |
// Aliased as `methods`
|
759 |
_.functions = _.methods = function(obj) { |
760 |
var names = [];
|
761 |
for (var key in obj) { |
762 |
if (_.isFunction(obj[key])) names.push(key);
|
763 |
} |
764 |
return names.sort();
|
765 |
}; |
766 |
|
767 |
// Extend a given object with all the properties in passed-in object(s).
|
768 |
_.extend = function(obj) { |
769 |
each(slice.call(arguments, 1), function(source) { |
770 |
if (source) {
|
771 |
for (var prop in source) { |
772 |
obj[prop] = source[prop]; |
773 |
} |
774 |
} |
775 |
}); |
776 |
return obj;
|
777 |
}; |
778 |
|
779 |
// Return a copy of the object only containing the whitelisted properties.
|
780 |
_.pick = function(obj) { |
781 |
var copy = {};
|
782 |
var keys = concat.apply(ArrayProto, slice.call(arguments, 1)); |
783 |
each(keys, function(key) {
|
784 |
if (key in obj) copy[key] = obj[key]; |
785 |
}); |
786 |
return copy;
|
787 |
}; |
788 |
|
789 |
// Return a copy of the object without the blacklisted properties.
|
790 |
_.omit = function(obj) { |
791 |
var copy = {};
|
792 |
var keys = concat.apply(ArrayProto, slice.call(arguments, 1)); |
793 |
for (var key in obj) { |
794 |
if (!_.contains(keys, key)) copy[key] = obj[key];
|
795 |
} |
796 |
return copy;
|
797 |
}; |
798 |
|
799 |
// Fill in a given object with default properties.
|
800 |
_.defaults = function(obj) { |
801 |
each(slice.call(arguments, 1), function(source) { |
802 |
if (source) {
|
803 |
for (var prop in source) { |
804 |
if (obj[prop] == null) obj[prop] = source[prop]; |
805 |
} |
806 |
} |
807 |
}); |
808 |
return obj;
|
809 |
}; |
810 |
|
811 |
// Create a (shallow-cloned) duplicate of an object.
|
812 |
_.clone = function(obj) { |
813 |
if (!_.isObject(obj)) return obj; |
814 |
return _.isArray(obj) ? obj.slice() : _.extend({}, obj);
|
815 |
}; |
816 |
|
817 |
// Invokes interceptor with the obj, and then returns obj.
|
818 |
// The primary purpose of this method is to "tap into" a method chain, in
|
819 |
// order to perform operations on intermediate results within the chain.
|
820 |
_.tap = function(obj, interceptor) { |
821 |
interceptor(obj); |
822 |
return obj;
|
823 |
}; |
824 |
|
825 |
// Internal recursive comparison function for `isEqual`.
|
826 |
var eq = function(a, b, aStack, bStack) { |
827 |
// Identical objects are equal. `0 === -0`, but they aren't identical.
|
828 |
// See the Harmony `egal` proposal: http://wiki.ecmascript.org/doku.php?id=harmony:egal.
|
829 |
if (a === b) return a !== 0 || 1 / a == 1 / b; |
830 |
// A strict comparison is necessary because `null == undefined`.
|
831 |
if (a == null || b == null) return a === b; |
832 |
// Unwrap any wrapped objects.
|
833 |
if (a instanceof _) a = a._wrapped; |
834 |
if (b instanceof _) b = b._wrapped; |
835 |
// Compare `[[Class]]` names.
|
836 |
var className = toString.call(a);
|
837 |
if (className != toString.call(b)) return false; |
838 |
switch (className) {
|
839 |
// Strings, numbers, dates, and booleans are compared by value.
|
840 |
case '[object String]': |
841 |
// Primitives and their corresponding object wrappers are equivalent; thus, `"5"` is
|
842 |
// equivalent to `new String("5")`.
|
843 |
return a == String(b);
|
844 |
case '[object Number]': |
845 |
// `NaN`s are equivalent, but non-reflexive. An `egal` comparison is performed for
|
846 |
// other numeric values.
|
847 |
return a != +a ? b != +b : (a == 0 ? 1 / a == 1 / b : a == +b); |
848 |
case '[object Date]': |
849 |
case '[object Boolean]': |
850 |
// Coerce dates and booleans to numeric primitive values. Dates are compared by their
|
851 |
// millisecond representations. Note that invalid dates with millisecond representations
|
852 |
// of `NaN` are not equivalent.
|
853 |
return +a == +b;
|
854 |
// RegExps are compared by their source patterns and flags.
|
855 |
case '[object RegExp]': |
856 |
return a.source == b.source &&
|
857 |
a.global == b.global && |
858 |
a.multiline == b.multiline && |
859 |
a.ignoreCase == b.ignoreCase; |
860 |
} |
861 |
if (typeof a != 'object' || typeof b != 'object') return false; |
862 |
// Assume equality for cyclic structures. The algorithm for detecting cyclic
|
863 |
// structures is adapted from ES 5.1 section 15.12.3, abstract operation `JO`.
|
864 |
var length = aStack.length;
|
865 |
while (length--) {
|
866 |
// Linear search. Performance is inversely proportional to the number of
|
867 |
// unique nested structures.
|
868 |
if (aStack[length] == a) return bStack[length] == b; |
869 |
} |
870 |
// Add the first object to the stack of traversed objects.
|
871 |
aStack.push(a); |
872 |
bStack.push(b); |
873 |
var size = 0, result = true; |
874 |
// Recursively compare objects and arrays.
|
875 |
if (className == '[object Array]') { |
876 |
// Compare array lengths to determine if a deep comparison is necessary.
|
877 |
size = a.length; |
878 |
result = size == b.length; |
879 |
if (result) {
|
880 |
// Deep compare the contents, ignoring non-numeric properties.
|
881 |
while (size--) {
|
882 |
if (!(result = eq(a[size], b[size], aStack, bStack))) break; |
883 |
} |
884 |
} |
885 |
} else {
|
886 |
// Objects with different constructors are not equivalent, but `Object`s
|
887 |
// from different frames are.
|
888 |
var aCtor = a.constructor, bCtor = b.constructor;
|
889 |
if (aCtor !== bCtor && !(_.isFunction(aCtor) && (aCtor instanceof aCtor) && |
890 |
_.isFunction(bCtor) && (bCtor instanceof bCtor))) {
|
891 |
return false; |
892 |
} |
893 |
// Deep compare objects.
|
894 |
for (var key in a) { |
895 |
if (_.has(a, key)) {
|
896 |
// Count the expected number of properties.
|
897 |
size++; |
898 |
// Deep compare each member.
|
899 |
if (!(result = _.has(b, key) && eq(a[key], b[key], aStack, bStack))) break; |
900 |
} |
901 |
} |
902 |
// Ensure that both objects contain the same number of properties.
|
903 |
if (result) {
|
904 |
for (key in b) { |
905 |
if (_.has(b, key) && !(size--)) break; |
906 |
} |
907 |
result = !size; |
908 |
} |
909 |
} |
910 |
// Remove the first object from the stack of traversed objects.
|
911 |
aStack.pop(); |
912 |
bStack.pop(); |
913 |
return result;
|
914 |
}; |
915 |
|
916 |
// Perform a deep comparison to check if two objects are equal.
|
917 |
_.isEqual = function(a, b) { |
918 |
return eq(a, b, [], []);
|
919 |
}; |
920 |
|
921 |
// Is a given array, string, or object empty?
|
922 |
// An "empty" object has no enumerable own-properties.
|
923 |
_.isEmpty = function(obj) { |
924 |
if (obj == null) return true; |
925 |
if (_.isArray(obj) || _.isString(obj)) return obj.length === 0; |
926 |
for (var key in obj) if (_.has(obj, key)) return false; |
927 |
return true; |
928 |
}; |
929 |
|
930 |
// Is a given value a DOM element?
|
931 |
_.isElement = function(obj) { |
932 |
return !!(obj && obj.nodeType === 1); |
933 |
}; |
934 |
|
935 |
// Is a given value an array?
|
936 |
// Delegates to ECMA5's native Array.isArray
|
937 |
_.isArray = nativeIsArray || function(obj) {
|
938 |
return toString.call(obj) == '[object Array]'; |
939 |
}; |
940 |
|
941 |
// Is a given variable an object?
|
942 |
_.isObject = function(obj) { |
943 |
return obj === Object(obj);
|
944 |
}; |
945 |
|
946 |
// Add some isType methods: isArguments, isFunction, isString, isNumber, isDate, isRegExp.
|
947 |
each(['Arguments', 'Function', 'String', 'Number', 'Date', 'RegExp'], function(name) { |
948 |
_['is' + name] = function(obj) { |
949 |
return toString.call(obj) == '[object ' + name + ']'; |
950 |
}; |
951 |
}); |
952 |
|
953 |
// Define a fallback version of the method in browsers (ahem, IE), where
|
954 |
// there isn't any inspectable "Arguments" type.
|
955 |
if (!_.isArguments(arguments)) { |
956 |
_.isArguments = function(obj) { |
957 |
return !!(obj && _.has(obj, 'callee')); |
958 |
}; |
959 |
} |
960 |
|
961 |
// Optimize `isFunction` if appropriate.
|
962 |
if (typeof (/./) !== 'function') { |
963 |
_.isFunction = function(obj) { |
964 |
return typeof obj === 'function'; |
965 |
}; |
966 |
} |
967 |
|
968 |
// Is a given object a finite number?
|
969 |
_.isFinite = function(obj) { |
970 |
return isFinite(obj) && !isNaN(parseFloat(obj));
|
971 |
}; |
972 |
|
973 |
// Is the given value `NaN`? (NaN is the only number which does not equal itself).
|
974 |
_.isNaN = function(obj) { |
975 |
return _.isNumber(obj) && obj != +obj;
|
976 |
}; |
977 |
|
978 |
// Is a given value a boolean?
|
979 |
_.isBoolean = function(obj) { |
980 |
return obj === true || obj === false || toString.call(obj) == '[object Boolean]'; |
981 |
}; |
982 |
|
983 |
// Is a given value equal to null?
|
984 |
_.isNull = function(obj) { |
985 |
return obj === null; |
986 |
}; |
987 |
|
988 |
// Is a given variable undefined?
|
989 |
_.isUndefined = function(obj) { |
990 |
return obj === void 0; |
991 |
}; |
992 |
|
993 |
// Shortcut function for checking if an object has a given property directly
|
994 |
// on itself (in other words, not on a prototype).
|
995 |
_.has = function(obj, key) { |
996 |
return hasOwnProperty.call(obj, key);
|
997 |
}; |
998 |
|
999 |
// Utility Functions
|
1000 |
// -----------------
|
1001 |
|
1002 |
// Run Underscore.js in *noConflict* mode, returning the `_` variable to its
|
1003 |
// previous owner. Returns a reference to the Underscore object.
|
1004 |
_.noConflict = function() { |
1005 |
root._ = previousUnderscore; |
1006 |
return this; |
1007 |
}; |
1008 |
|
1009 |
// Keep the identity function around for default iterators.
|
1010 |
_.identity = function(value) { |
1011 |
return value;
|
1012 |
}; |
1013 |
|
1014 |
// Run a function **n** times.
|
1015 |
_.times = function(n, iterator, context) { |
1016 |
var accum = Array(n);
|
1017 |
for (var i = 0; i < n; i++) accum[i] = iterator.call(context, i); |
1018 |
return accum;
|
1019 |
}; |
1020 |
|
1021 |
// Return a random integer between min and max (inclusive).
|
1022 |
_.random = function(min, max) { |
1023 |
if (max == null) { |
1024 |
max = min; |
1025 |
min = 0;
|
1026 |
} |
1027 |
return min + Math.floor(Math.random() * (max - min + 1)); |
1028 |
}; |
1029 |
|
1030 |
// List of HTML entities for escaping.
|
1031 |
var entityMap = {
|
1032 |
escape: {
|
1033 |
'&': '&', |
1034 |
'<': '<', |
1035 |
'>': '>', |
1036 |
'"': '"', |
1037 |
"'": ''', |
1038 |
'/': '/' |
1039 |
} |
1040 |
}; |
1041 |
entityMap.unescape = _.invert(entityMap.escape); |
1042 |
|
1043 |
// Regexes containing the keys and values listed immediately above.
|
1044 |
var entityRegexes = {
|
1045 |
escape: new RegExp('[' + _.keys(entityMap.escape).join('') + ']', 'g'), |
1046 |
unescape: new RegExp('(' + _.keys(entityMap.unescape).join('|') + ')', 'g') |
1047 |
}; |
1048 |
|
1049 |
// Functions for escaping and unescaping strings to/from HTML interpolation.
|
1050 |
_.each(['escape', 'unescape'], function(method) { |
1051 |
_[method] = function(string) {
|
1052 |
if (string == null) return ''; |
1053 |
return ('' + string).replace(entityRegexes[method], function(match) { |
1054 |
return entityMap[method][match];
|
1055 |
}); |
1056 |
}; |
1057 |
}); |
1058 |
|
1059 |
// If the value of the named property is a function then invoke it;
|
1060 |
// otherwise, return it.
|
1061 |
_.result = function(object, property) { |
1062 |
if (object == null) return null; |
1063 |
var value = object[property];
|
1064 |
return _.isFunction(value) ? value.call(object) : value;
|
1065 |
}; |
1066 |
|
1067 |
// Add your own custom functions to the Underscore object.
|
1068 |
_.mixin = function(obj) { |
1069 |
each(_.functions(obj), function(name){
|
1070 |
var func = _[name] = obj[name];
|
1071 |
_.prototype[name] = function() {
|
1072 |
var args = [this._wrapped]; |
1073 |
push.apply(args, arguments);
|
1074 |
return result.call(this, func.apply(_, args)); |
1075 |
}; |
1076 |
}); |
1077 |
}; |
1078 |
|
1079 |
// Generate a unique integer id (unique within the entire client session).
|
1080 |
// Useful for temporary DOM ids.
|
1081 |
var idCounter = 0; |
1082 |
_.uniqueId = function(prefix) { |
1083 |
var id = ++idCounter + ''; |
1084 |
return prefix ? prefix + id : id;
|
1085 |
}; |
1086 |
|
1087 |
// By default, Underscore uses ERB-style template delimiters, change the
|
1088 |
// following template settings to use alternative delimiters.
|
1089 |
_.templateSettings = { |
1090 |
evaluate : /<%([\s\S]+?)%>/g, |
1091 |
interpolate : /<%=([\s\S]+?)%>/g, |
1092 |
escape : /<%-([\s\S]+?)%>/g |
1093 |
}; |
1094 |
|
1095 |
// When customizing `templateSettings`, if you don't want to define an
|
1096 |
// interpolation, evaluation or escaping regex, we need one that is
|
1097 |
// guaranteed not to match.
|
1098 |
var noMatch = /(.)^/; |
1099 |
|
1100 |
// Certain characters need to be escaped so that they can be put into a
|
1101 |
// string literal.
|
1102 |
var escapes = {
|
1103 |
"'": "'", |
1104 |
'\\': '\\', |
1105 |
'\r': 'r', |
1106 |
'\n': 'n', |
1107 |
'\t': 't', |
1108 |
'\u2028': 'u2028', |
1109 |
'\u2029': 'u2029' |
1110 |
}; |
1111 |
|
1112 |
var escaper = /\\|'|\r|\n|\t|\u2028|\u2029/g; |
1113 |
|
1114 |
// JavaScript micro-templating, similar to John Resig's implementation.
|
1115 |
// Underscore templating handles arbitrary delimiters, preserves whitespace,
|
1116 |
// and correctly escapes quotes within interpolated code.
|
1117 |
_.template = function(text, data, settings) { |
1118 |
var render;
|
1119 |
settings = _.defaults({}, settings, _.templateSettings); |
1120 |
|
1121 |
// Combine delimiters into one regular expression via alternation.
|
1122 |
var matcher = new RegExp([ |
1123 |
(settings.escape || noMatch).source, |
1124 |
(settings.interpolate || noMatch).source, |
1125 |
(settings.evaluate || noMatch).source |
1126 |
].join('|') + '|$', 'g'); |
1127 |
|
1128 |
// Compile the template source, escaping string literals appropriately.
|
1129 |
var index = 0; |
1130 |
var source = "__p+='"; |
1131 |
text.replace(matcher, function(match, escape, interpolate, evaluate, offset) {
|
1132 |
source += text.slice(index, offset) |
1133 |
.replace(escaper, function(match) { return '\\' + escapes[match]; }); |
1134 |
|
1135 |
if (escape) {
|
1136 |
source += "'+\n((__t=(" + escape + "))==null?'':_.escape(__t))+\n'"; |
1137 |
} |
1138 |
if (interpolate) {
|
1139 |
source += "'+\n((__t=(" + interpolate + "))==null?'':__t)+\n'"; |
1140 |
} |
1141 |
if (evaluate) {
|
1142 |
source += "';\n" + evaluate + "\n__p+='"; |
1143 |
} |
1144 |
index = offset + match.length; |
1145 |
return match;
|
1146 |
}); |
1147 |
source += "';\n";
|
1148 |
|
1149 |
// If a variable is not specified, place data values in local scope.
|
1150 |
if (!settings.variable) source = 'with(obj||{}){\n' + source + '}\n'; |
1151 |
|
1152 |
source = "var __t,__p='',__j=Array.prototype.join," +
|
1153 |
"print=function(){__p+=__j.call(arguments,'');};\n" +
|
1154 |
source + "return __p;\n";
|
1155 |
|
1156 |
try {
|
1157 |
render = new Function(settings.variable || 'obj', '_', source); |
1158 |
} catch (e) {
|
1159 |
e.source = source; |
1160 |
throw e;
|
1161 |
} |
1162 |
|
1163 |
if (data) return render(data, _); |
1164 |
var template = function(data) { |
1165 |
return render.call(this, data, _); |
1166 |
}; |
1167 |
|
1168 |
// Provide the compiled function source as a convenience for precompilation.
|
1169 |
template.source = 'function(' + (settings.variable || 'obj') + '){\n' + source + '}'; |
1170 |
|
1171 |
return template;
|
1172 |
}; |
1173 |
|
1174 |
// Add a "chain" function, which will delegate to the wrapper.
|
1175 |
_.chain = function(obj) { |
1176 |
return _(obj).chain();
|
1177 |
}; |
1178 |
|
1179 |
// OOP
|
1180 |
// ---------------
|
1181 |
// If Underscore is called as a function, it returns a wrapped object that
|
1182 |
// can be used OO-style. This wrapper holds altered versions of all the
|
1183 |
// underscore functions. Wrapped objects may be chained.
|
1184 |
|
1185 |
// Helper function to continue chaining intermediate results.
|
1186 |
var result = function(obj) { |
1187 |
return this._chain ? _(obj).chain() : obj; |
1188 |
}; |
1189 |
|
1190 |
// Add all of the Underscore functions to the wrapper object.
|
1191 |
_.mixin(_); |
1192 |
|
1193 |
// Add all mutator Array functions to the wrapper.
|
1194 |
each(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(name) { |
1195 |
var method = ArrayProto[name];
|
1196 |
_.prototype[name] = function() {
|
1197 |
var obj = this._wrapped; |
1198 |
method.apply(obj, arguments);
|
1199 |
if ((name == 'shift' || name == 'splice') && obj.length === 0) delete obj[0]; |
1200 |
return result.call(this, obj); |
1201 |
}; |
1202 |
}); |
1203 |
|
1204 |
// Add all accessor Array functions to the wrapper.
|
1205 |
each(['concat', 'join', 'slice'], function(name) { |
1206 |
var method = ArrayProto[name];
|
1207 |
_.prototype[name] = function() {
|
1208 |
return result.call(this, method.apply(this._wrapped, arguments)); |
1209 |
}; |
1210 |
}); |
1211 |
|
1212 |
_.extend(_.prototype, { |
1213 |
|
1214 |
// Start chaining a wrapped Underscore object.
|
1215 |
chain: function() { |
1216 |
this._chain = true; |
1217 |
return this; |
1218 |
}, |
1219 |
|
1220 |
// Extracts the result from a wrapped and chained object.
|
1221 |
value: function() { |
1222 |
return this._wrapped; |
1223 |
} |
1224 |
|
1225 |
}); |
1226 |
|
1227 |
}).call(this);
|