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// Underscore.js 1.3.1
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// (c) 2009-2012 Jeremy Ashkenas, DocumentCloud Inc.
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// Underscore is freely distributable under the MIT license.
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// Portions of Underscore are inspired or borrowed from Prototype,
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// Oliver Steele's Functional, and John Resig's Micro-Templating.
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// For all details and documentation:
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// http://documentcloud.github.com/underscore
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(function() {
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// Baseline setup
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// --------------
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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 slice = ArrayProto.slice,
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unshift = ArrayProto.unshift, |
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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) { return new wrapper(obj); }; |
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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 = '1.3.1';
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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 (i in obj && 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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if (obj.length === +obj.length) results.length = obj.length;
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return results;
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}; |
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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('Reduce of empty array with no initial value'); |
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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 reversed = _.toArray(obj).reverse();
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if (context && !initial) iterator = _.bind(iterator, context);
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return initial ? _.reduce(reversed, iterator, memo, context) : _.reduce(reversed, iterator);
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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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var results = [];
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if (obj == null) return results; |
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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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// 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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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 a given value is included in the array or object using `===`.
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// Aliased as `contains`.
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_.include = _.contains = function(obj, target) { |
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var found = false; |
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if (obj == null) return found; |
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if (nativeIndexOf && obj.indexOf === nativeIndexOf) return obj.indexOf(target) != -1; |
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found = any(obj, function(value) {
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return value === target;
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}); |
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return found;
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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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return _.map(obj, function(value) { |
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return (_.isFunction(method) ? method || value : 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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// Return the maximum element or (element-based computation).
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_.max = function(obj, iterator, context) { |
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if (!iterator && _.isArray(obj)) return Math.max.apply(Math, obj); |
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if (!iterator && _.isEmpty(obj)) return -Infinity; |
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var result = {computed : -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)) return Math.min.apply(Math, obj); |
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if (!iterator && _.isEmpty(obj)) return Infinity; |
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var result = {computed : 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 shuffled = [], rand;
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each(obj, function(value, index, list) {
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if (index == 0) { |
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shuffled[0] = value;
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} else {
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rand = Math.floor(Math.random() * (index + 1));
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shuffled[index] = shuffled[rand]; |
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shuffled[rand] = value; |
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} |
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}); |
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return shuffled;
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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, iterator, context) { |
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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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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, b = right.criteria;
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return a < b ? -1 : a > b ? 1 : 0; |
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}), 'value');
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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, val) { |
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var result = {};
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var iterator = _.isFunction(val) ? val : function(obj) { return obj[val]; }; |
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each(obj, function(value, index) {
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var key = iterator(value, index);
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(result[key] || (result[key] = [])).push(value); |
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}); |
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return result;
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}; |
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// Use a comparator function to figure out at what index an object should
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// be inserted so as to maintain order. Uses binary search.
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_.sortedIndex = function(array, obj, iterator) { |
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iterator || (iterator = _.identity); |
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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(array[mid]) < iterator(obj) ? 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(iterable) { |
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if (!iterable) return []; |
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if (iterable.toArray) return iterable.toArray(); |
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if (_.isArray(iterable)) return slice.call(iterable); |
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if (_.isArguments(iterable)) return slice.call(iterable); |
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return _.values(iterable);
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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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return _.toArray(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`. The **guard** check allows it to work
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// with `_.map`.
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_.first = _.head = function(array, n, guard) { |
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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. Especcialy 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 ((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`.
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// Especially useful on the arguments object. Passing an **index** will return
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// the rest of the values in the array from that index onward. The **guard**
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// check allows it to work with `_.map`.
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_.rest = _.tail = function(array, index, guard) { |
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return slice.call(array, (index == null) || guard ? 1 : index); |
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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, function(value){ return !!value; }); |
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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 _.reduce(array, function(memo, value) { |
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if (_.isArray(value)) return memo.concat(shallow ? value : _.flatten(value)); |
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memo[memo.length] = value; |
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return memo;
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}, []); |
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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) { |
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var initial = iterator ? _.map(array, iterator) : array;
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var result = [];
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_.reduce(initial, function(memo, el, i) {
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if (0 == i || (isSorted === true ? _.last(memo) != el : !_.include(memo, el))) { |
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memo[memo.length] = el; |
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result[result.length] = array[i]; |
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} |
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return memo;
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}, []); |
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return result;
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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(_.flatten(arguments, true)); |
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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. (Aliased as "intersect" for back-compat.)
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_.intersection = _.intersect = 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 = _.flatten(slice.call(arguments, 1)); |
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return _.filter(array, function(value){ return !_.include(rest, value); }); |
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}; |
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// Zip together multiple lists into a single array -- elements that share
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// an index go together.
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_.zip = function() { |
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var args = slice.call(arguments); |
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var length = _.max(_.pluck(args, 'length')); |
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var results = new Array(length); |
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for (var i = 0; i < length; i++) results[i] = _.pluck(args, "" + i); |
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return results;
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}; |
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// If the browser doesn't supply us with indexOf (I'm looking at you, **MSIE**),
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// we need this function. Return the position of the first occurrence of an
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// item in an array, or -1 if the item is not included in the array.
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// Delegates to **ECMAScript 5**'s native `indexOf` if available.
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// If the array is large and already in sort order, pass `true`
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// for **isSorted** to use binary search.
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_.indexOf = function(array, item, isSorted) { |
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if (array == null) return -1; |
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var i, l;
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if (isSorted) {
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i = _.sortedIndex(array, item); |
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return array[i] === item ? i : -1; |
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} |
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if (nativeIndexOf && array.indexOf === nativeIndexOf) return array.indexOf(item); |
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for (i = 0, l = array.length; i < l; i++) if (i in array && array[i] === item) return i; |
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return -1; |
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}; |
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// Delegates to **ECMAScript 5**'s native `lastIndexOf` if available.
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_.lastIndexOf = function(array, item) { |
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if (array == null) return -1; |
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if (nativeLastIndexOf && array.lastIndexOf === nativeLastIndexOf) return array.lastIndexOf(item); |
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var i = array.length;
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while (i--) if (i in array && array[i] === item) return i; |
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return -1; |
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}; |
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// Generate an integer Array containing an arithmetic progression. A port of
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// the native Python `range()` function. See
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// [the Python documentation](http://docs.python.org/library/functions.html#range).
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_.range = function(start, stop, step) { |
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if (arguments.length <= 1) { |
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stop = start || 0;
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start = 0;
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} |
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step = arguments[2] || 1; |
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var len = Math.max(Math.ceil((stop - start) / step), 0); |
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var idx = 0; |
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var range = new Array(len); |
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while(idx < len) {
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range[idx++] = start; |
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start += step; |
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} |
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return range;
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}; |
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// Function (ahem) Functions
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// ------------------
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|
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// Reusable constructor function for prototype setting.
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var ctor = function(){}; |
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// Create a function bound to a given object (assigning `this`, and arguments,
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// optionally). Binding with arguments is also known as `curry`.
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// Delegates to **ECMAScript 5**'s native `Function.bind` if available.
|
478 |
// We check for `func.bind` first, to fail fast when `func` is undefined.
|
479 |
_.bind = function bind(func, context) { |
480 |
var bound, args;
|
481 |
if (func.bind === nativeBind && nativeBind) return nativeBind.apply(func, slice.call(arguments, 1)); |
482 |
if (!_.isFunction(func)) throw new TypeError; |
483 |
args = slice.call(arguments, 2); |
484 |
return bound = function() { |
485 |
if (!(this instanceof bound)) return func.apply(context, args.concat(slice.call(arguments))); |
486 |
ctor.prototype = func.prototype; |
487 |
var self = new ctor; |
488 |
var result = func.apply(self, args.concat(slice.call(arguments))); |
489 |
if (Object(result) === result) return result; |
490 |
return self;
|
491 |
}; |
492 |
}; |
493 |
|
494 |
// Bind all of an object's methods to that object. Useful for ensuring that
|
495 |
// all callbacks defined on an object belong to it.
|
496 |
_.bindAll = function(obj) { |
497 |
var funcs = slice.call(arguments, 1); |
498 |
if (funcs.length == 0) funcs = _.functions(obj); |
499 |
each(funcs, function(f) { obj[f] = _.bind(obj[f], obj); });
|
500 |
return obj;
|
501 |
}; |
502 |
|
503 |
// Memoize an expensive function by storing its results.
|
504 |
_.memoize = function(func, hasher) { |
505 |
var memo = {};
|
506 |
hasher || (hasher = _.identity); |
507 |
return function() { |
508 |
var key = hasher.apply(this, arguments); |
509 |
return _.has(memo, key) ? memo[key] : (memo[key] = func.apply(this, arguments)); |
510 |
}; |
511 |
}; |
512 |
|
513 |
// Delays a function for the given number of milliseconds, and then calls
|
514 |
// it with the arguments supplied.
|
515 |
_.delay = function(func, wait) { |
516 |
var args = slice.call(arguments, 2); |
517 |
return setTimeout(function(){ return func.apply(func, args); }, wait); |
518 |
}; |
519 |
|
520 |
// Defers a function, scheduling it to run after the current call stack has
|
521 |
// cleared.
|
522 |
_.defer = function(func) { |
523 |
return _.delay.apply(_, [func, 1].concat(slice.call(arguments, 1))); |
524 |
}; |
525 |
|
526 |
// Returns a function, that, when invoked, will only be triggered at most once
|
527 |
// during a given window of time.
|
528 |
_.throttle = function(func, wait) { |
529 |
var context, args, timeout, throttling, more;
|
530 |
var whenDone = _.debounce(function(){ more = throttling = false; }, wait); |
531 |
return function() { |
532 |
context = this; args = arguments; |
533 |
var later = function() { |
534 |
timeout = null;
|
535 |
if (more) func.apply(context, args);
|
536 |
whenDone(); |
537 |
}; |
538 |
if (!timeout) timeout = setTimeout(later, wait);
|
539 |
if (throttling) {
|
540 |
more = true;
|
541 |
} else {
|
542 |
func.apply(context, args); |
543 |
} |
544 |
whenDone(); |
545 |
throttling = true;
|
546 |
}; |
547 |
}; |
548 |
|
549 |
// Returns a function, that, as long as it continues to be invoked, will not
|
550 |
// be triggered. The function will be called after it stops being called for
|
551 |
// N milliseconds.
|
552 |
_.debounce = function(func, wait) { |
553 |
var timeout;
|
554 |
return function() { |
555 |
var context = this, args = arguments; |
556 |
var later = function() { |
557 |
timeout = null;
|
558 |
func.apply(context, args); |
559 |
}; |
560 |
clearTimeout(timeout); |
561 |
timeout = setTimeout(later, wait); |
562 |
}; |
563 |
}; |
564 |
|
565 |
// Returns a function that will be executed at most one time, no matter how
|
566 |
// often you call it. Useful for lazy initialization.
|
567 |
_.once = function(func) { |
568 |
var ran = false, memo; |
569 |
return function() { |
570 |
if (ran) return memo; |
571 |
ran = true;
|
572 |
return memo = func.apply(this, arguments); |
573 |
}; |
574 |
}; |
575 |
|
576 |
// Returns the first function passed as an argument to the second,
|
577 |
// allowing you to adjust arguments, run code before and after, and
|
578 |
// conditionally execute the original function.
|
579 |
_.wrap = function(func, wrapper) { |
580 |
return function() { |
581 |
var args = [func].concat(slice.call(arguments, 0)); |
582 |
return wrapper.apply(this, args); |
583 |
}; |
584 |
}; |
585 |
|
586 |
// Returns a function that is the composition of a list of functions, each
|
587 |
// consuming the return value of the function that follows.
|
588 |
_.compose = function() { |
589 |
var funcs = arguments; |
590 |
return function() { |
591 |
var args = arguments; |
592 |
for (var i = funcs.length - 1; i >= 0; i--) { |
593 |
args = [funcs[i].apply(this, args)];
|
594 |
} |
595 |
return args[0]; |
596 |
}; |
597 |
}; |
598 |
|
599 |
// Returns a function that will only be executed after being called N times.
|
600 |
_.after = function(times, func) { |
601 |
if (times <= 0) return func(); |
602 |
return function() { |
603 |
if (--times < 1) { return func.apply(this, arguments); } |
604 |
}; |
605 |
}; |
606 |
|
607 |
// Object Functions
|
608 |
// ----------------
|
609 |
|
610 |
// Retrieve the names of an object's properties.
|
611 |
// Delegates to **ECMAScript 5**'s native `Object.keys`
|
612 |
_.keys = nativeKeys || function(obj) {
|
613 |
if (obj !== Object(obj)) throw new TypeError('Invalid object'); |
614 |
var keys = [];
|
615 |
for (var key in obj) if (_.has(obj, key)) keys[keys.length] = key; |
616 |
return keys;
|
617 |
}; |
618 |
|
619 |
// Retrieve the values of an object's properties.
|
620 |
_.values = function(obj) { |
621 |
return _.map(obj, _.identity);
|
622 |
}; |
623 |
|
624 |
// Return a sorted list of the function names available on the object.
|
625 |
// Aliased as `methods`
|
626 |
_.functions = _.methods = function(obj) { |
627 |
var names = [];
|
628 |
for (var key in obj) { |
629 |
if (_.isFunction(obj[key])) names.push(key);
|
630 |
} |
631 |
return names.sort();
|
632 |
}; |
633 |
|
634 |
// Extend a given object with all the properties in passed-in object(s).
|
635 |
_.extend = function(obj) { |
636 |
each(slice.call(arguments, 1), function(source) { |
637 |
for (var prop in source) { |
638 |
obj[prop] = source[prop]; |
639 |
} |
640 |
}); |
641 |
return obj;
|
642 |
}; |
643 |
|
644 |
// Fill in a given object with default properties.
|
645 |
_.defaults = function(obj) { |
646 |
each(slice.call(arguments, 1), function(source) { |
647 |
for (var prop in source) { |
648 |
if (obj[prop] == null) obj[prop] = source[prop]; |
649 |
} |
650 |
}); |
651 |
return obj;
|
652 |
}; |
653 |
|
654 |
// Create a (shallow-cloned) duplicate of an object.
|
655 |
_.clone = function(obj) { |
656 |
if (!_.isObject(obj)) return obj; |
657 |
return _.isArray(obj) ? obj.slice() : _.extend({}, obj);
|
658 |
}; |
659 |
|
660 |
// Invokes interceptor with the obj, and then returns obj.
|
661 |
// The primary purpose of this method is to "tap into" a method chain, in
|
662 |
// order to perform operations on intermediate results within the chain.
|
663 |
_.tap = function(obj, interceptor) { |
664 |
interceptor(obj); |
665 |
return obj;
|
666 |
}; |
667 |
|
668 |
// Internal recursive comparison function.
|
669 |
function eq(a, b, stack) { |
670 |
// Identical objects are equal. `0 === -0`, but they aren't identical.
|
671 |
// See the Harmony `egal` proposal: http://wiki.ecmascript.org/doku.php?id=harmony:egal.
|
672 |
if (a === b) return a !== 0 || 1 / a == 1 / b; |
673 |
// A strict comparison is necessary because `null == undefined`.
|
674 |
if (a == null || b == null) return a === b; |
675 |
// Unwrap any wrapped objects.
|
676 |
if (a._chain) a = a._wrapped;
|
677 |
if (b._chain) b = b._wrapped;
|
678 |
// Invoke a custom `isEqual` method if one is provided.
|
679 |
if (a.isEqual && _.isFunction(a.isEqual)) return a.isEqual(b); |
680 |
if (b.isEqual && _.isFunction(b.isEqual)) return b.isEqual(a); |
681 |
// Compare `[[Class]]` names.
|
682 |
var className = toString.call(a);
|
683 |
if (className != toString.call(b)) return false; |
684 |
switch (className) {
|
685 |
// Strings, numbers, dates, and booleans are compared by value.
|
686 |
case '[object String]': |
687 |
// Primitives and their corresponding object wrappers are equivalent; thus, `"5"` is
|
688 |
// equivalent to `new String("5")`.
|
689 |
return a == String(b);
|
690 |
case '[object Number]': |
691 |
// `NaN`s are equivalent, but non-reflexive. An `egal` comparison is performed for
|
692 |
// other numeric values.
|
693 |
return a != +a ? b != +b : (a == 0 ? 1 / a == 1 / b : a == +b); |
694 |
case '[object Date]': |
695 |
case '[object Boolean]': |
696 |
// Coerce dates and booleans to numeric primitive values. Dates are compared by their
|
697 |
// millisecond representations. Note that invalid dates with millisecond representations
|
698 |
// of `NaN` are not equivalent.
|
699 |
return +a == +b;
|
700 |
// RegExps are compared by their source patterns and flags.
|
701 |
case '[object RegExp]': |
702 |
return a.source == b.source &&
|
703 |
a.global == b.global && |
704 |
a.multiline == b.multiline && |
705 |
a.ignoreCase == b.ignoreCase; |
706 |
} |
707 |
if (typeof a != 'object' || typeof b != 'object') return false; |
708 |
// Assume equality for cyclic structures. The algorithm for detecting cyclic
|
709 |
// structures is adapted from ES 5.1 section 15.12.3, abstract operation `JO`.
|
710 |
var length = stack.length;
|
711 |
while (length--) {
|
712 |
// Linear search. Performance is inversely proportional to the number of
|
713 |
// unique nested structures.
|
714 |
if (stack[length] == a) return true; |
715 |
} |
716 |
// Add the first object to the stack of traversed objects.
|
717 |
stack.push(a); |
718 |
var size = 0, result = true; |
719 |
// Recursively compare objects and arrays.
|
720 |
if (className == '[object Array]') { |
721 |
// Compare array lengths to determine if a deep comparison is necessary.
|
722 |
size = a.length; |
723 |
result = size == b.length; |
724 |
if (result) {
|
725 |
// Deep compare the contents, ignoring non-numeric properties.
|
726 |
while (size--) {
|
727 |
// Ensure commutative equality for sparse arrays.
|
728 |
if (!(result = size in a == size in b && eq(a[size], b[size], stack))) break; |
729 |
} |
730 |
} |
731 |
} else {
|
732 |
// Objects with different constructors are not equivalent.
|
733 |
if ('constructor' in a != 'constructor' in b || a.constructor != b.constructor) return false; |
734 |
// Deep compare objects.
|
735 |
for (var key in a) { |
736 |
if (_.has(a, key)) {
|
737 |
// Count the expected number of properties.
|
738 |
size++; |
739 |
// Deep compare each member.
|
740 |
if (!(result = _.has(b, key) && eq(a[key], b[key], stack))) break; |
741 |
} |
742 |
} |
743 |
// Ensure that both objects contain the same number of properties.
|
744 |
if (result) {
|
745 |
for (key in b) { |
746 |
if (_.has(b, key) && !(size--)) break; |
747 |
} |
748 |
result = !size; |
749 |
} |
750 |
} |
751 |
// Remove the first object from the stack of traversed objects.
|
752 |
stack.pop(); |
753 |
return result;
|
754 |
} |
755 |
|
756 |
// Perform a deep comparison to check if two objects are equal.
|
757 |
_.isEqual = function(a, b) { |
758 |
return eq(a, b, []);
|
759 |
}; |
760 |
|
761 |
// Is a given array, string, or object empty?
|
762 |
// An "empty" object has no enumerable own-properties.
|
763 |
_.isEmpty = function(obj) { |
764 |
if (_.isArray(obj) || _.isString(obj)) return obj.length === 0; |
765 |
for (var key in obj) if (_.has(obj, key)) return false; |
766 |
return true; |
767 |
}; |
768 |
|
769 |
// Is a given value a DOM element?
|
770 |
_.isElement = function(obj) { |
771 |
return !!(obj && obj.nodeType == 1); |
772 |
}; |
773 |
|
774 |
// Is a given value an array?
|
775 |
// Delegates to ECMA5's native Array.isArray
|
776 |
_.isArray = nativeIsArray || function(obj) {
|
777 |
return toString.call(obj) == '[object Array]'; |
778 |
}; |
779 |
|
780 |
// Is a given variable an object?
|
781 |
_.isObject = function(obj) { |
782 |
return obj === Object(obj);
|
783 |
}; |
784 |
|
785 |
// Is a given variable an arguments object?
|
786 |
_.isArguments = function(obj) { |
787 |
return toString.call(obj) == '[object Arguments]'; |
788 |
}; |
789 |
if (!_.isArguments(arguments)) { |
790 |
_.isArguments = function(obj) { |
791 |
return !!(obj && _.has(obj, 'callee')); |
792 |
}; |
793 |
} |
794 |
|
795 |
// Is a given value a function?
|
796 |
_.isFunction = function(obj) { |
797 |
return toString.call(obj) == '[object Function]'; |
798 |
}; |
799 |
|
800 |
// Is a given value a string?
|
801 |
_.isString = function(obj) { |
802 |
return toString.call(obj) == '[object String]'; |
803 |
}; |
804 |
|
805 |
// Is a given value a number?
|
806 |
_.isNumber = function(obj) { |
807 |
return toString.call(obj) == '[object Number]'; |
808 |
}; |
809 |
|
810 |
// Is the given value `NaN`?
|
811 |
_.isNaN = function(obj) { |
812 |
// `NaN` is the only value for which `===` is not reflexive.
|
813 |
return obj !== obj;
|
814 |
}; |
815 |
|
816 |
// Is a given value a boolean?
|
817 |
_.isBoolean = function(obj) { |
818 |
return obj === true || obj === false || toString.call(obj) == '[object Boolean]'; |
819 |
}; |
820 |
|
821 |
// Is a given value a date?
|
822 |
_.isDate = function(obj) { |
823 |
return toString.call(obj) == '[object Date]'; |
824 |
}; |
825 |
|
826 |
// Is the given value a regular expression?
|
827 |
_.isRegExp = function(obj) { |
828 |
return toString.call(obj) == '[object RegExp]'; |
829 |
}; |
830 |
|
831 |
// Is a given value equal to null?
|
832 |
_.isNull = function(obj) { |
833 |
return obj === null; |
834 |
}; |
835 |
|
836 |
// Is a given variable undefined?
|
837 |
_.isUndefined = function(obj) { |
838 |
return obj === void 0; |
839 |
}; |
840 |
|
841 |
// Has own property?
|
842 |
_.has = function(obj, key) { |
843 |
return hasOwnProperty.call(obj, key);
|
844 |
}; |
845 |
|
846 |
// Utility Functions
|
847 |
// -----------------
|
848 |
|
849 |
// Run Underscore.js in *noConflict* mode, returning the `_` variable to its
|
850 |
// previous owner. Returns a reference to the Underscore object.
|
851 |
_.noConflict = function() { |
852 |
root._ = previousUnderscore; |
853 |
return this; |
854 |
}; |
855 |
|
856 |
// Keep the identity function around for default iterators.
|
857 |
_.identity = function(value) { |
858 |
return value;
|
859 |
}; |
860 |
|
861 |
// Run a function **n** times.
|
862 |
_.times = function (n, iterator, context) { |
863 |
for (var i = 0; i < n; i++) iterator.call(context, i); |
864 |
}; |
865 |
|
866 |
// Escape a string for HTML interpolation.
|
867 |
_.escape = function(string) { |
868 |
return (''+string).replace(/&/g, '&').replace(/</g, '<').replace(/>/g, '>').replace(/"/g, '"').replace(/'/g, ''').replace(/\//g,'/'); |
869 |
}; |
870 |
|
871 |
// Add your own custom functions to the Underscore object, ensuring that
|
872 |
// they're correctly added to the OOP wrapper as well.
|
873 |
_.mixin = function(obj) { |
874 |
each(_.functions(obj), function(name){
|
875 |
addToWrapper(name, _[name] = obj[name]); |
876 |
}); |
877 |
}; |
878 |
|
879 |
// Generate a unique integer id (unique within the entire client session).
|
880 |
// Useful for temporary DOM ids.
|
881 |
var idCounter = 0; |
882 |
_.uniqueId = function(prefix) { |
883 |
var id = idCounter++;
|
884 |
return prefix ? prefix + id : id;
|
885 |
}; |
886 |
|
887 |
// By default, Underscore uses ERB-style template delimiters, change the
|
888 |
// following template settings to use alternative delimiters.
|
889 |
_.templateSettings = { |
890 |
evaluate : /<%([\s\S]+?)%>/g, |
891 |
interpolate : /<%=([\s\S]+?)%>/g, |
892 |
escape : /<%-([\s\S]+?)%>/g |
893 |
}; |
894 |
|
895 |
// When customizing `templateSettings`, if you don't want to define an
|
896 |
// interpolation, evaluation or escaping regex, we need one that is
|
897 |
// guaranteed not to match.
|
898 |
var noMatch = /.^/; |
899 |
|
900 |
// Within an interpolation, evaluation, or escaping, remove HTML escaping
|
901 |
// that had been previously added.
|
902 |
var unescape = function(code) { |
903 |
return code.replace(/\\\\/g, '\\').replace(/\\'/g, "'"); |
904 |
}; |
905 |
|
906 |
// JavaScript micro-templating, similar to John Resig's implementation.
|
907 |
// Underscore templating handles arbitrary delimiters, preserves whitespace,
|
908 |
// and correctly escapes quotes within interpolated code.
|
909 |
_.template = function(str, data) { |
910 |
var c = _.templateSettings;
|
911 |
var tmpl = 'var __p=[],print=function(){__p.push.apply(__p,arguments);};' + |
912 |
'with(obj||{}){__p.push(\'' +
|
913 |
str.replace(/\\/g, '\\\\') |
914 |
.replace(/'/g, "\\'") |
915 |
.replace(c.escape || noMatch, function(match, code) {
|
916 |
return "',_.escape(" + unescape(code) + "),'"; |
917 |
}) |
918 |
.replace(c.interpolate || noMatch, function(match, code) {
|
919 |
return "'," + unescape(code) + ",'"; |
920 |
}) |
921 |
.replace(c.evaluate || noMatch, function(match, code) {
|
922 |
return "');" + unescape(code).replace(/[\r\n\t]/g, ' ') + ";__p.push('"; |
923 |
}) |
924 |
.replace(/\r/g, '\\r') |
925 |
.replace(/\n/g, '\\n') |
926 |
.replace(/\t/g, '\\t') |
927 |
+ "');}return __p.join('');";
|
928 |
var func = new Function('obj', '_', tmpl); |
929 |
if (data) return func(data, _); |
930 |
return function(data) { |
931 |
return func.call(this, data, _); |
932 |
}; |
933 |
}; |
934 |
|
935 |
// Add a "chain" function, which will delegate to the wrapper.
|
936 |
_.chain = function(obj) { |
937 |
return _(obj).chain();
|
938 |
}; |
939 |
|
940 |
// The OOP Wrapper
|
941 |
// ---------------
|
942 |
|
943 |
// If Underscore is called as a function, it returns a wrapped object that
|
944 |
// can be used OO-style. This wrapper holds altered versions of all the
|
945 |
// underscore functions. Wrapped objects may be chained.
|
946 |
var wrapper = function(obj) { this._wrapped = obj; }; |
947 |
|
948 |
// Expose `wrapper.prototype` as `_.prototype`
|
949 |
_.prototype = wrapper.prototype; |
950 |
|
951 |
// Helper function to continue chaining intermediate results.
|
952 |
var result = function(obj, chain) { |
953 |
return chain ? _(obj).chain() : obj;
|
954 |
}; |
955 |
|
956 |
// A method to easily add functions to the OOP wrapper.
|
957 |
var addToWrapper = function(name, func) { |
958 |
wrapper.prototype[name] = function() {
|
959 |
var args = slice.call(arguments); |
960 |
unshift.call(args, this._wrapped);
|
961 |
return result(func.apply(_, args), this._chain); |
962 |
}; |
963 |
}; |
964 |
|
965 |
// Add all of the Underscore functions to the wrapper object.
|
966 |
_.mixin(_); |
967 |
|
968 |
// Add all mutator Array functions to the wrapper.
|
969 |
each(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(name) { |
970 |
var method = ArrayProto[name];
|
971 |
wrapper.prototype[name] = function() {
|
972 |
var wrapped = this._wrapped; |
973 |
method.apply(wrapped, arguments);
|
974 |
var length = wrapped.length;
|
975 |
if ((name == 'shift' || name == 'splice') && length === 0) delete wrapped[0]; |
976 |
return result(wrapped, this._chain); |
977 |
}; |
978 |
}); |
979 |
|
980 |
// Add all accessor Array functions to the wrapper.
|
981 |
each(['concat', 'join', 'slice'], function(name) { |
982 |
var method = ArrayProto[name];
|
983 |
wrapper.prototype[name] = function() {
|
984 |
return result(method.apply(this._wrapped, arguments), this._chain); |
985 |
}; |
986 |
}); |
987 |
|
988 |
// Start chaining a wrapped Underscore object.
|
989 |
wrapper.prototype.chain = function() { |
990 |
this._chain = true; |
991 |
return this; |
992 |
}; |
993 |
|
994 |
// Extracts the result from a wrapped and chained object.
|
995 |
wrapper.prototype.value = function() { |
996 |
return this._wrapped; |
997 |
}; |
998 |
|
999 |
}).call(this);
|