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1073 lines
37 KiB
1073 lines
37 KiB
// Underscore.js 1.3.3
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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 push = ArrayProto.push,
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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 = '1.3.3';
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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) && obj[0] === +obj[0]) 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) && obj[0] === +obj[0]) 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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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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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, val, context) {
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var iterator = _.isFunction(val) ? val : function(obj) { return obj[val]; };
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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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if (a === void 0) return 1;
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if (b === void 0) return -1;
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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 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) {
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iterator || (iterator = _.identity);
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var value = iterator(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(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 (_.isArguments(obj)) return slice.call(obj);
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if (obj.toArray && _.isFunction(obj.toArray)) return obj.toArray();
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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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return _.isArray(obj) ? 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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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 ((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 (function flatten(input, 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, 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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})(array, []);
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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 results = [];
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// The `isSorted` flag is irrelevant if the array only contains two elements.
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if (array.length < 3) isSorted = true;
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_.reduce(initial, function(memo, value, index) {
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if (isSorted ? _.last(memo) !== value || !memo.length : !_.include(memo, value)) {
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memo.push(value);
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results.push(array[index]);
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}
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return memo;
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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(_.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), true);
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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
|
|
// ------------------
|
|
|
|
// Reusable constructor function for prototype setting.
|
|
var ctor = function(){};
|
|
|
|
// Create a function bound to a given object (assigning `this`, and arguments,
|
|
// optionally). Binding with arguments is also known as `curry`.
|
|
// Delegates to **ECMAScript 5**'s native `Function.bind` if available.
|
|
// We check for `func.bind` first, to fail fast when `func` is undefined.
|
|
_.bind = function bind(func, context) {
|
|
var bound, args;
|
|
if (func.bind === nativeBind && nativeBind) return nativeBind.apply(func, slice.call(arguments, 1));
|
|
if (!_.isFunction(func)) throw new TypeError;
|
|
args = slice.call(arguments, 2);
|
|
return bound = function() {
|
|
if (!(this instanceof bound)) return func.apply(context, args.concat(slice.call(arguments)));
|
|
ctor.prototype = func.prototype;
|
|
var self = new ctor;
|
|
var result = func.apply(self, args.concat(slice.call(arguments)));
|
|
if (Object(result) === result) return result;
|
|
return self;
|
|
};
|
|
};
|
|
|
|
// Bind all of an object's methods to that object. Useful for ensuring that
|
|
// all callbacks defined on an object belong to it.
|
|
_.bindAll = function(obj) {
|
|
var funcs = slice.call(arguments, 1);
|
|
if (funcs.length == 0) funcs = _.functions(obj);
|
|
each(funcs, function(f) { obj[f] = _.bind(obj[f], obj); });
|
|
return obj;
|
|
};
|
|
|
|
// Memoize an expensive function by storing its results.
|
|
_.memoize = function(func, hasher) {
|
|
var memo = {};
|
|
hasher || (hasher = _.identity);
|
|
return function() {
|
|
var key = hasher.apply(this, arguments);
|
|
return _.has(memo, key) ? memo[key] : (memo[key] = func.apply(this, arguments));
|
|
};
|
|
};
|
|
|
|
// Delays a function for the given number of milliseconds, and then calls
|
|
// it with the arguments supplied.
|
|
_.delay = function(func, wait) {
|
|
var args = slice.call(arguments, 2);
|
|
return setTimeout(function(){ return func.apply(null, args); }, wait);
|
|
};
|
|
|
|
// Defers a function, scheduling it to run after the current call stack has
|
|
// cleared.
|
|
_.defer = function(func) {
|
|
return _.delay.apply(_, [func, 1].concat(slice.call(arguments, 1)));
|
|
};
|
|
|
|
// Returns a function, that, when invoked, will only be triggered at most once
|
|
// during a given window of time.
|
|
_.throttle = function(func, wait) {
|
|
var context, args, timeout, throttling, more, result;
|
|
var whenDone = _.debounce(function(){ more = throttling = false; }, wait);
|
|
return function() {
|
|
context = this; args = arguments;
|
|
var later = function() {
|
|
timeout = null;
|
|
if (more) func.apply(context, args);
|
|
whenDone();
|
|
};
|
|
if (!timeout) timeout = setTimeout(later, wait);
|
|
if (throttling) {
|
|
more = true;
|
|
} else {
|
|
throttling = true;
|
|
result = func.apply(context, args);
|
|
}
|
|
whenDone();
|
|
return result;
|
|
};
|
|
};
|
|
|
|
// Returns a function, that, as long as it continues to be invoked, will not
|
|
// be triggered. The function will be called after it stops being called for
|
|
// N milliseconds. If `immediate` is passed, trigger the function on the
|
|
// leading edge, instead of the trailing.
|
|
_.debounce = function(func, wait, immediate) {
|
|
var timeout;
|
|
return function() {
|
|
var context = this, args = arguments;
|
|
var later = function() {
|
|
timeout = null;
|
|
if (!immediate) func.apply(context, args);
|
|
};
|
|
var callNow = immediate && !timeout;
|
|
clearTimeout(timeout);
|
|
timeout = setTimeout(later, wait);
|
|
if (callNow) func.apply(context, args);
|
|
};
|
|
};
|
|
|
|
// Returns a function that will be executed at most one time, no matter how
|
|
// often you call it. Useful for lazy initialization.
|
|
_.once = function(func) {
|
|
var ran = false, memo;
|
|
return function() {
|
|
if (ran) return memo;
|
|
ran = true;
|
|
return memo = func.apply(this, arguments);
|
|
};
|
|
};
|
|
|
|
// Returns the first function passed as an argument to the second,
|
|
// allowing you to adjust arguments, run code before and after, and
|
|
// conditionally execute the original function.
|
|
_.wrap = function(func, wrapper) {
|
|
return function() {
|
|
var args = [func].concat(slice.call(arguments, 0));
|
|
return wrapper.apply(this, args);
|
|
};
|
|
};
|
|
|
|
// Returns a function that is the composition of a list of functions, each
|
|
// consuming the return value of the function that follows.
|
|
_.compose = function() {
|
|
var funcs = arguments;
|
|
return function() {
|
|
var args = arguments;
|
|
for (var i = funcs.length - 1; i >= 0; i--) {
|
|
args = [funcs[i].apply(this, args)];
|
|
}
|
|
return args[0];
|
|
};
|
|
};
|
|
|
|
// Returns a function that will only be executed after being called N times.
|
|
_.after = function(times, func) {
|
|
if (times <= 0) return func();
|
|
return function() {
|
|
if (--times < 1) { return func.apply(this, arguments); }
|
|
};
|
|
};
|
|
|
|
// Object Functions
|
|
// ----------------
|
|
|
|
// Retrieve the names of an object's properties.
|
|
// Delegates to **ECMAScript 5**'s native `Object.keys`
|
|
_.keys = nativeKeys || function(obj) {
|
|
if (obj !== Object(obj)) throw new TypeError('Invalid object');
|
|
var keys = [];
|
|
for (var key in obj) if (_.has(obj, key)) keys[keys.length] = key;
|
|
return keys;
|
|
};
|
|
|
|
// Retrieve the values of an object's properties.
|
|
_.values = function(obj) {
|
|
return _.map(obj, _.identity);
|
|
};
|
|
|
|
// Return a sorted list of the function names available on the object.
|
|
// Aliased as `methods`
|
|
_.functions = _.methods = function(obj) {
|
|
var names = [];
|
|
for (var key in obj) {
|
|
if (_.isFunction(obj[key])) names.push(key);
|
|
}
|
|
return names.sort();
|
|
};
|
|
|
|
// Extend a given object with all the properties in passed-in object(s).
|
|
_.extend = function(obj) {
|
|
each(slice.call(arguments, 1), function(source) {
|
|
for (var prop in source) {
|
|
obj[prop] = source[prop];
|
|
}
|
|
});
|
|
return obj;
|
|
};
|
|
|
|
// Return a copy of the object only containing the whitelisted properties.
|
|
_.pick = function(obj) {
|
|
var result = {};
|
|
each(_.flatten(slice.call(arguments, 1)), function(key) {
|
|
if (key in obj) result[key] = obj[key];
|
|
});
|
|
return result;
|
|
};
|
|
|
|
// Fill in a given object with default properties.
|
|
_.defaults = function(obj) {
|
|
each(slice.call(arguments, 1), function(source) {
|
|
for (var prop in source) {
|
|
if (obj[prop] == null) obj[prop] = source[prop];
|
|
}
|
|
});
|
|
return obj;
|
|
};
|
|
|
|
// Create a (shallow-cloned) duplicate of an object.
|
|
_.clone = function(obj) {
|
|
if (!_.isObject(obj)) return obj;
|
|
return _.isArray(obj) ? obj.slice() : _.extend({}, obj);
|
|
};
|
|
|
|
// Invokes interceptor with the obj, and then returns obj.
|
|
// The primary purpose of this method is to "tap into" a method chain, in
|
|
// order to perform operations on intermediate results within the chain.
|
|
_.tap = function(obj, interceptor) {
|
|
interceptor(obj);
|
|
return obj;
|
|
};
|
|
|
|
// Internal recursive comparison function for `isEqual`.
|
|
function eq(a, b, stack) {
|
|
// Identical objects are equal. `0 === -0`, but they aren't identical.
|
|
// See the Harmony `egal` proposal: http://wiki.ecmascript.org/doku.php?id=harmony:egal.
|
|
if (a === b) return a !== 0 || 1 / a == 1 / b;
|
|
// A strict comparison is necessary because `null == undefined`.
|
|
if (a == null || b == null) return a === b;
|
|
// Unwrap any wrapped objects.
|
|
if (a._chain) a = a._wrapped;
|
|
if (b._chain) b = b._wrapped;
|
|
// Invoke a custom `isEqual` method if one is provided.
|
|
if (a.isEqual && _.isFunction(a.isEqual)) return a.isEqual(b);
|
|
if (b.isEqual && _.isFunction(b.isEqual)) return b.isEqual(a);
|
|
// Compare `[[Class]]` names.
|
|
var className = toString.call(a);
|
|
if (className != toString.call(b)) return false;
|
|
switch (className) {
|
|
// Strings, numbers, dates, and booleans are compared by value.
|
|
case '[object String]':
|
|
// Primitives and their corresponding object wrappers are equivalent; thus, `"5"` is
|
|
// equivalent to `new String("5")`.
|
|
return a == String(b);
|
|
case '[object Number]':
|
|
// `NaN`s are equivalent, but non-reflexive. An `egal` comparison is performed for
|
|
// other numeric values.
|
|
return a != +a ? b != +b : (a == 0 ? 1 / a == 1 / b : a == +b);
|
|
case '[object Date]':
|
|
case '[object Boolean]':
|
|
// Coerce dates and booleans to numeric primitive values. Dates are compared by their
|
|
// millisecond representations. Note that invalid dates with millisecond representations
|
|
// of `NaN` are not equivalent.
|
|
return +a == +b;
|
|
// RegExps are compared by their source patterns and flags.
|
|
case '[object RegExp]':
|
|
return a.source == b.source &&
|
|
a.global == b.global &&
|
|
a.multiline == b.multiline &&
|
|
a.ignoreCase == b.ignoreCase;
|
|
}
|
|
if (typeof a != 'object' || typeof b != 'object') return false;
|
|
// Assume equality for cyclic structures. The algorithm for detecting cyclic
|
|
// structures is adapted from ES 5.1 section 15.12.3, abstract operation `JO`.
|
|
var length = stack.length;
|
|
while (length--) {
|
|
// Linear search. Performance is inversely proportional to the number of
|
|
// unique nested structures.
|
|
if (stack[length] == a) return true;
|
|
}
|
|
// Add the first object to the stack of traversed objects.
|
|
stack.push(a);
|
|
var size = 0, result = true;
|
|
// Recursively compare objects and arrays.
|
|
if (className == '[object Array]') {
|
|
// Compare array lengths to determine if a deep comparison is necessary.
|
|
size = a.length;
|
|
result = size == b.length;
|
|
if (result) {
|
|
// Deep compare the contents, ignoring non-numeric properties.
|
|
while (size--) {
|
|
// Ensure commutative equality for sparse arrays.
|
|
if (!(result = size in a == size in b && eq(a[size], b[size], stack))) break;
|
|
}
|
|
}
|
|
} else {
|
|
// Objects with different constructors are not equivalent.
|
|
if ('constructor' in a != 'constructor' in b || a.constructor != b.constructor) return false;
|
|
// Deep compare objects.
|
|
for (var key in a) {
|
|
if (_.has(a, key)) {
|
|
// Count the expected number of properties.
|
|
size++;
|
|
// Deep compare each member.
|
|
if (!(result = _.has(b, key) && eq(a[key], b[key], stack))) break;
|
|
}
|
|
}
|
|
// Ensure that both objects contain the same number of properties.
|
|
if (result) {
|
|
for (key in b) {
|
|
if (_.has(b, key) && !(size--)) break;
|
|
}
|
|
result = !size;
|
|
}
|
|
}
|
|
// Remove the first object from the stack of traversed objects.
|
|
stack.pop();
|
|
return result;
|
|
}
|
|
|
|
// Perform a deep comparison to check if two objects are equal.
|
|
_.isEqual = function(a, b) {
|
|
return eq(a, b, []);
|
|
};
|
|
|
|
// Is a given array, string, or object empty?
|
|
// An "empty" object has no enumerable own-properties.
|
|
_.isEmpty = function(obj) {
|
|
if (obj == null) return true;
|
|
if (_.isArray(obj) || _.isString(obj)) return obj.length === 0;
|
|
for (var key in obj) if (_.has(obj, key)) return false;
|
|
return true;
|
|
};
|
|
|
|
// Is a given value a DOM element?
|
|
_.isElement = function(obj) {
|
|
return !!(obj && obj.nodeType == 1);
|
|
};
|
|
|
|
// Is a given value an array?
|
|
// Delegates to ECMA5's native Array.isArray
|
|
_.isArray = nativeIsArray || function(obj) {
|
|
return toString.call(obj) == '[object Array]';
|
|
};
|
|
|
|
// Is a given variable an object?
|
|
_.isObject = function(obj) {
|
|
return obj === Object(obj);
|
|
};
|
|
|
|
// Is a given variable an arguments object?
|
|
// Define a fallback version of the method in browsers (ahem, IE), where
|
|
// there isn't any inspectable "Arguments" type.
|
|
_.isArguments = function(obj) {
|
|
return toString.call(obj) == '[object Arguments]';
|
|
};
|
|
if (!_.isArguments(arguments)) {
|
|
_.isArguments = function(obj) {
|
|
return !!(obj && _.has(obj, 'callee'));
|
|
};
|
|
}
|
|
|
|
// Is a given value a function?
|
|
_.isFunction = function(obj) {
|
|
return toString.call(obj) == '[object Function]';
|
|
};
|
|
|
|
// Is a given value a string?
|
|
_.isString = function(obj) {
|
|
return toString.call(obj) == '[object String]';
|
|
};
|
|
|
|
// Is a given value a number?
|
|
_.isNumber = function(obj) {
|
|
return toString.call(obj) == '[object Number]';
|
|
};
|
|
|
|
// Is a given object a finite number?
|
|
_.isFinite = function(obj) {
|
|
return _.isNumber(obj) && isFinite(obj);
|
|
};
|
|
|
|
// Is the given value `NaN`?
|
|
_.isNaN = function(obj) {
|
|
// `NaN` is the only value for which `===` is not reflexive.
|
|
return obj !== obj;
|
|
};
|
|
|
|
// Is a given value a boolean?
|
|
_.isBoolean = function(obj) {
|
|
return obj === true || obj === false || toString.call(obj) == '[object Boolean]';
|
|
};
|
|
|
|
// Is a given value a date?
|
|
_.isDate = function(obj) {
|
|
return toString.call(obj) == '[object Date]';
|
|
};
|
|
|
|
// Is the given value a regular expression?
|
|
_.isRegExp = function(obj) {
|
|
return toString.call(obj) == '[object RegExp]';
|
|
};
|
|
|
|
// Is a given value equal to null?
|
|
_.isNull = function(obj) {
|
|
return obj === null;
|
|
};
|
|
|
|
// Is a given variable undefined?
|
|
_.isUndefined = function(obj) {
|
|
return obj === void 0;
|
|
};
|
|
|
|
// Does an object have the given "own" property?
|
|
_.has = function(obj, key) {
|
|
return hasOwnProperty.call(obj, key);
|
|
};
|
|
|
|
// Utility Functions
|
|
// -----------------
|
|
|
|
// Run Underscore.js in *noConflict* mode, returning the `_` variable to its
|
|
// previous owner. Returns a reference to the Underscore object.
|
|
_.noConflict = function() {
|
|
root._ = previousUnderscore;
|
|
return this;
|
|
};
|
|
|
|
// Keep the identity function around for default iterators.
|
|
_.identity = function(value) {
|
|
return value;
|
|
};
|
|
|
|
// Run a function **n** times.
|
|
_.times = function(n, iterator, context) {
|
|
for (var i = 0; i < n; i++) iterator.call(context, i);
|
|
};
|
|
|
|
// Escape a string for HTML interpolation.
|
|
_.escape = function(string) {
|
|
return (''+string)
|
|
.replace(/&/g, '&')
|
|
.replace(/</g, '<')
|
|
.replace(/>/g, '>')
|
|
.replace(/"/g, '"')
|
|
.replace(/'/g, ''')
|
|
.replace(/\//g,'/');
|
|
};
|
|
|
|
// If the value of the named property is a function then invoke it;
|
|
// otherwise, return it.
|
|
_.result = function(object, property) {
|
|
if (object == null) return null;
|
|
var value = object[property];
|
|
return _.isFunction(value) ? value.call(object) : value;
|
|
};
|
|
|
|
// Add your own custom functions to the Underscore object, ensuring that
|
|
// they're correctly added to the OOP wrapper as well.
|
|
_.mixin = function(obj) {
|
|
each(_.functions(obj), function(name){
|
|
addToWrapper(name, _[name] = obj[name]);
|
|
});
|
|
};
|
|
|
|
// Generate a unique integer id (unique within the entire client session).
|
|
// Useful for temporary DOM ids.
|
|
var idCounter = 0;
|
|
_.uniqueId = function(prefix) {
|
|
var id = idCounter++;
|
|
return prefix ? prefix + id : id;
|
|
};
|
|
|
|
// By default, Underscore uses ERB-style template delimiters, change the
|
|
// following template settings to use alternative delimiters.
|
|
_.templateSettings = {
|
|
evaluate : /<%([\s\S]+?)%>/g,
|
|
interpolate : /<%=([\s\S]+?)%>/g,
|
|
escape : /<%-([\s\S]+?)%>/g
|
|
};
|
|
|
|
// When customizing `templateSettings`, if you don't want to define an
|
|
// interpolation, evaluation or escaping regex, we need one that is
|
|
// guaranteed not to match.
|
|
var noMatch = /.^/;
|
|
|
|
// Certain characters need to be escaped so that they can be put into a
|
|
// string literal.
|
|
var escapes = {
|
|
'\\': '\\',
|
|
"'": "'",
|
|
'r': '\r',
|
|
'n': '\n',
|
|
't': '\t',
|
|
'u2028': '\u2028',
|
|
'u2029': '\u2029'
|
|
};
|
|
|
|
for (var p in escapes) escapes[escapes[p]] = p;
|
|
var escaper = /\\|'|\r|\n|\t|\u2028|\u2029/g;
|
|
var unescaper = /\\(\\|'|r|n|t|u2028|u2029)/g;
|
|
|
|
// Within an interpolation, evaluation, or escaping, remove HTML escaping
|
|
// that had been previously added.
|
|
var unescape = function(code) {
|
|
return code.replace(unescaper, function(match, escape) {
|
|
return escapes[escape];
|
|
});
|
|
};
|
|
|
|
// JavaScript micro-templating, similar to John Resig's implementation.
|
|
// Underscore templating handles arbitrary delimiters, preserves whitespace,
|
|
// and correctly escapes quotes within interpolated code.
|
|
_.template = function(text, data, settings) {
|
|
settings = _.defaults(settings || {}, _.templateSettings);
|
|
|
|
// Compile the template source, taking care to escape characters that
|
|
// cannot be included in a string literal and then unescape them in code
|
|
// blocks.
|
|
var source = "__p+='" + text
|
|
.replace(escaper, function(match) {
|
|
return '\\' + escapes[match];
|
|
})
|
|
.replace(settings.escape || noMatch, function(match, code) {
|
|
return "'+\n((__t=(" + unescape(code) + "))==null?'':_.escape(__t))+\n'";
|
|
})
|
|
.replace(settings.interpolate || noMatch, function(match, code) {
|
|
return "'+\n((__t=(" + unescape(code) + "))==null?'':__t)+\n'";
|
|
})
|
|
.replace(settings.evaluate || noMatch, function(match, code) {
|
|
return "';\n" + unescape(code) + "\n;__p+='";
|
|
}) + "';\n";
|
|
|
|
// If a variable is not specified, place data values in local scope.
|
|
if (!settings.variable) source = 'with(obj||{}){\n' + source + '}\n';
|
|
|
|
source = "var __t,__p='',__j=Array.prototype.join," +
|
|
"print=function(){__p+=__j.call(arguments,'')};\n" +
|
|
source + "return __p;\n";
|
|
|
|
var render = new Function(settings.variable || 'obj', '_', source);
|
|
if (data) return render(data, _);
|
|
var template = function(data) {
|
|
return render.call(this, data, _);
|
|
};
|
|
|
|
// Provide the compiled function source as a convenience for precompilation.
|
|
template.source = 'function(' + (settings.variable || 'obj') + '){\n' + source + '}';
|
|
|
|
return template;
|
|
};
|
|
|
|
// Add a "chain" function, which will delegate to the wrapper.
|
|
_.chain = function(obj) {
|
|
return _(obj).chain();
|
|
};
|
|
|
|
// The OOP Wrapper
|
|
// ---------------
|
|
|
|
// If Underscore is called as a function, it returns a wrapped object that
|
|
// can be used OO-style. This wrapper holds altered versions of all the
|
|
// underscore functions. Wrapped objects may be chained.
|
|
var wrapper = function(obj) { this._wrapped = obj; };
|
|
|
|
// Expose `wrapper.prototype` as `_.prototype`
|
|
_.prototype = wrapper.prototype;
|
|
|
|
// Helper function to continue chaining intermediate results.
|
|
var result = function(obj, chain) {
|
|
return chain ? _(obj).chain() : obj;
|
|
};
|
|
|
|
// A method to easily add functions to the OOP wrapper.
|
|
var addToWrapper = function(name, func) {
|
|
wrapper.prototype[name] = function() {
|
|
var args = slice.call(arguments);
|
|
unshift.call(args, this._wrapped);
|
|
return result(func.apply(_, args), this._chain);
|
|
};
|
|
};
|
|
|
|
// Add all of the Underscore functions to the wrapper object.
|
|
_.mixin(_);
|
|
|
|
// Add all mutator Array functions to the wrapper.
|
|
each(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(name) {
|
|
var method = ArrayProto[name];
|
|
wrapper.prototype[name] = function() {
|
|
var obj = this._wrapped;
|
|
method.apply(obj, arguments);
|
|
if ((name == 'shift' || name == 'splice') && obj.length === 0) delete obj[0];
|
|
return result(obj, this._chain);
|
|
};
|
|
});
|
|
|
|
// Add all accessor Array functions to the wrapper.
|
|
each(['concat', 'join', 'slice'], function(name) {
|
|
var method = ArrayProto[name];
|
|
wrapper.prototype[name] = function() {
|
|
return result(method.apply(this._wrapped, arguments), this._chain);
|
|
};
|
|
});
|
|
|
|
// Start chaining a wrapped Underscore object.
|
|
wrapper.prototype.chain = function() {
|
|
this._chain = true;
|
|
return this;
|
|
};
|
|
|
|
// Extracts the result from a wrapped and chained object.
|
|
wrapper.prototype.value = function() {
|
|
return this._wrapped;
|
|
};
|
|
|
|
}).call(this);
|