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편집 파일: underscore-1.3.1.js

// Underscore.js 1.3.1 // (c) 2009-2012 Jeremy Ashkenas, DocumentCloud Inc. // Underscore is freely distributable under the MIT license. // Portions of Underscore are inspired or borrowed from Prototype, // Oliver Steele's Functional, and John Resig's Micro-Templating. // For all details and documentation: // http://documentcloud.github.com/underscore (function() { // Baseline setup // -------------- // Establish the root object, `window` in the browser, or `global` on the server. var root = this; // Save the previous value of the `_` variable. var previousUnderscore = root._; // Establish the object that gets returned to break out of a loop iteration. var breaker = {}; // Save bytes in the minified (but not gzipped) version: var ArrayProto = Array.prototype, ObjProto = Object.prototype, FuncProto = Function.prototype; // Create quick reference variables for speed access to core prototypes. var slice = ArrayProto.slice, unshift = ArrayProto.unshift, toString = ObjProto.toString, hasOwnProperty = ObjProto.hasOwnProperty; // All **ECMAScript 5** native function implementations that we hope to use // are declared here. var nativeForEach = ArrayProto.forEach, nativeMap = ArrayProto.map, nativeReduce = ArrayProto.reduce, nativeReduceRight = ArrayProto.reduceRight, nativeFilter = ArrayProto.filter, nativeEvery = ArrayProto.every, nativeSome = ArrayProto.some, nativeIndexOf = ArrayProto.indexOf, nativeLastIndexOf = ArrayProto.lastIndexOf, nativeIsArray = Array.isArray, nativeKeys = Object.keys, nativeBind = FuncProto.bind; // Create a safe reference to the Underscore object for use below. var _ = function(obj) { return new wrapper(obj); }; // Export the Underscore object for **Node.js**, with // backwards-compatibility for the old `require()` API. If we're in // the browser, add `_` as a global object via a string identifier, // for Closure Compiler "advanced" mode. if (typeof exports !== 'undefined') { if (typeof module !== 'undefined' && module.exports) { exports = module.exports = _; } exports._ = _; } else { root['_'] = _; } // Current version. _.VERSION = '1.3.1'; // Collection Functions // -------------------- // The cornerstone, an `each` implementation, aka `forEach`. // Handles objects with the built-in `forEach`, arrays, and raw objects. // Delegates to **ECMAScript 5**'s native `forEach` if available. var each = _.each = _.forEach = function(obj, iterator, context) { if (obj == null) return; if (nativeForEach && obj.forEach === nativeForEach) { obj.forEach(iterator, context); } else if (obj.length === +obj.length) { for (var i = 0, l = obj.length; i < l; i++) { if (i in obj && iterator.call(context, obj[i], i, obj) === breaker) return; } } else { for (var key in obj) { if (_.has(obj, key)) { if (iterator.call(context, obj[key], key, obj) === breaker) return; } } } }; // Return the results of applying the iterator to each element. // Delegates to **ECMAScript 5**'s native `map` if available. _.map = _.collect = function(obj, iterator, context) { var results = []; if (obj == null) return results; if (nativeMap && obj.map === nativeMap) return obj.map(iterator, context); each(obj, function(value, index, list) { results[results.length] = iterator.call(context, value, index, list); }); if (obj.length === +obj.length) results.length = obj.length; return results; }; // **Reduce** builds up a single result from a list of values, aka `inject`, // or `foldl`. Delegates to **ECMAScript 5**'s native `reduce` if available. _.reduce = _.foldl = _.inject = function(obj, iterator, memo, context) { var initial = arguments.length > 2; if (obj == null) obj = []; if (nativeReduce && obj.reduce === nativeReduce) { if (context) iterator = _.bind(iterator, context); return initial ? obj.reduce(iterator, memo) : obj.reduce(iterator); } each(obj, function(value, index, list) { if (!initial) { memo = value; initial = true; } else { memo = iterator.call(context, memo, value, index, list); } }); if (!initial) throw new TypeError('Reduce of empty array with no initial value'); return memo; }; // The right-associative version of reduce, also known as `foldr`. // Delegates to **ECMAScript 5**'s native `reduceRight` if available. _.reduceRight = _.foldr = function(obj, iterator, memo, context) { var initial = arguments.length > 2; if (obj == null) obj = []; if (nativeReduceRight && obj.reduceRight === nativeReduceRight) { if (context) iterator = _.bind(iterator, context); return initial ? obj.reduceRight(iterator, memo) : obj.reduceRight(iterator); } var reversed = _.toArray(obj).reverse(); if (context && !initial) iterator = _.bind(iterator, context); return initial ? _.reduce(reversed, iterator, memo, context) : _.reduce(reversed, iterator); }; // Return the first value which passes a truth test. Aliased as `detect`. _.find = _.detect = function(obj, iterator, context) { var result; any(obj, function(value, index, list) { if (iterator.call(context, value, index, list)) { result = value; return true; } }); return result; }; // Return all the elements that pass a truth test. // Delegates to **ECMAScript 5**'s native `filter` if available. // Aliased as `select`. _.filter = _.select = function(obj, iterator, context) { var results = []; if (obj == null) return results; if (nativeFilter && obj.filter === nativeFilter) return obj.filter(iterator, context); each(obj, function(value, index, list) { if (iterator.call(context, value, index, list)) results[results.length] = value; }); return results; }; // Return all the elements for which a truth test fails. _.reject = function(obj, iterator, context) { var results = []; if (obj == null) return results; each(obj, function(value, index, list) { if (!iterator.call(context, value, index, list)) results[results.length] = value; }); return results; }; // Determine whether all of the elements match a truth test. // Delegates to **ECMAScript 5**'s native `every` if available. // Aliased as `all`. _.every = _.all = function(obj, iterator, context) { var result = true; if (obj == null) return result; if (nativeEvery && obj.every === nativeEvery) return obj.every(iterator, context); each(obj, function(value, index, list) { if (!(result = result && iterator.call(context, value, index, list))) return breaker; }); return result; }; // Determine if at least one element in the object matches a truth test. // Delegates to **ECMAScript 5**'s native `some` if available. // Aliased as `any`. var any = _.some = _.any = function(obj, iterator, context) { iterator || (iterator = _.identity); var result = false; if (obj == null) return result; if (nativeSome && obj.some === nativeSome) return obj.some(iterator, context); each(obj, function(value, index, list) { if (result || (result = iterator.call(context, value, index, list))) return breaker; }); return !!result; }; // Determine if a given value is included in the array or object using `===`. // Aliased as `contains`. _.include = _.contains = function(obj, target) { var found = false; if (obj == null) return found; if (nativeIndexOf && obj.indexOf === nativeIndexOf) return obj.indexOf(target) != -1; found = any(obj, function(value) { return value === target; }); return found; }; // Invoke a method (with arguments) on every item in a collection. _.invoke = function(obj, method) { var args = slice.call(arguments, 2); return _.map(obj, function(value) { return (_.isFunction(method) ? method || value : value[method]).apply(value, args); }); }; // Convenience version of a common use case of `map`: fetching a property. _.pluck = function(obj, key) { return _.map(obj, function(value){ return value[key]; }); }; // Return the maximum element or (element-based computation). _.max = function(obj, iterator, context) { if (!iterator && _.isArray(obj)) return Math.max.apply(Math, obj); if (!iterator && _.isEmpty(obj)) return -Infinity; var result = {computed : -Infinity}; each(obj, function(value, index, list) { var computed = iterator ? iterator.call(context, value, index, list) : value; computed >= result.computed && (result = {value : value, computed : computed}); }); return result.value; }; // Return the minimum element (or element-based computation). _.min = function(obj, iterator, context) { if (!iterator && _.isArray(obj)) return Math.min.apply(Math, obj); if (!iterator && _.isEmpty(obj)) return Infinity; var result = {computed : Infinity}; each(obj, function(value, index, list) { var computed = iterator ? iterator.call(context, value, index, list) : value; computed < result.computed && (result = {value : value, computed : computed}); }); return result.value; }; // Shuffle an array. _.shuffle = function(obj) { var shuffled = [], rand; each(obj, function(value, index, list) { if (index == 0) { shuffled[0] = value; } else { rand = Math.floor(Math.random() * (index + 1)); shuffled[index] = shuffled[rand]; shuffled[rand] = value; } }); return shuffled; }; // Sort the object's values by a criterion produced by an iterator. _.sortBy = function(obj, iterator, context) { return _.pluck(_.map(obj, function(value, index, list) { return { value : value, criteria : iterator.call(context, value, index, list) }; }).sort(function(left, right) { var a = left.criteria, b = right.criteria; return a < b ? -1 : a > b ? 1 : 0; }), 'value'); }; // Groups the object's values by a criterion. Pass either a string attribute // to group by, or a function that returns the criterion. _.groupBy = function(obj, val) { var result = {}; var iterator = _.isFunction(val) ? val : function(obj) { return obj[val]; }; each(obj, function(value, index) { var key = iterator(value, index); (result[key] || (result[key] = [])).push(value); }); return result; }; // Use a comparator function to figure out at what index an object should // be inserted so as to maintain order. Uses binary search. _.sortedIndex = function(array, obj, iterator) { iterator || (iterator = _.identity); var low = 0, high = array.length; while (low < high) { var mid = (low + high) >> 1; iterator(array[mid]) < iterator(obj) ? low = mid + 1 : high = mid; } return low; }; // Safely convert anything iterable into a real, live array. _.toArray = function(iterable) { if (!iterable) return []; if (iterable.toArray) return iterable.toArray(); if (_.isArray(iterable)) return slice.call(iterable); if (_.isArguments(iterable)) return slice.call(iterable); return _.values(iterable); }; // Return the number of elements in an object. _.size = function(obj) { return _.toArray(obj).length; }; // Array Functions // --------------- // Get the first element of an array. Passing **n** will return the first N // values in the array. Aliased as `head`. The **guard** check allows it to work // with `_.map`. _.first = _.head = function(array, n, guard) { return (n != null) && !guard ? slice.call(array, 0, n) : array[0]; }; // Returns everything but the last entry of the array. Especcialy useful on // the arguments object. Passing **n** will return all the values in // the array, excluding the last N. The **guard** check allows it to work with // `_.map`. _.initial = function(array, n, guard) { return slice.call(array, 0, array.length - ((n == null) || guard ? 1 : n)); }; // Get the last element of an array. Passing **n** will return the last N // values in the array. The **guard** check allows it to work with `_.map`. _.last = function(array, n, guard) { if ((n != null) && !guard) { return slice.call(array, Math.max(array.length - n, 0)); } else { return array[array.length - 1]; } }; // Returns everything but the first entry of the array. Aliased as `tail`. // Especially useful on the arguments object. Passing an **index** will return // the rest of the values in the array from that index onward. The **guard** // check allows it to work with `_.map`. _.rest = _.tail = function(array, index, guard) { return slice.call(array, (index == null) || guard ? 1 : index); }; // Trim out all falsy values from an array. _.compact = function(array) { return _.filter(array, function(value){ return !!value; }); }; // Return a completely flattened version of an array. _.flatten = function(array, shallow) { return _.reduce(array, function(memo, value) { if (_.isArray(value)) return memo.concat(shallow ? value : _.flatten(value)); memo[memo.length] = value; return memo; }, []); }; // Return a version of the array that does not contain the specified value(s). _.without = function(array) { return _.difference(array, slice.call(arguments, 1)); }; // Produce a duplicate-free version of the array. If the array has already // been sorted, you have the option of using a faster algorithm. // Aliased as `unique`. _.uniq = _.unique = function(array, isSorted, iterator) { var initial = iterator ? _.map(array, iterator) : array; var result = []; _.reduce(initial, function(memo, el, i) { if (0 == i || (isSorted === true ? _.last(memo) != el : !_.include(memo, el))) { memo[memo.length] = el; result[result.length] = array[i]; } return memo; }, []); return result; }; // Produce an array that contains the union: each distinct element from all of // the passed-in arrays. _.union = function() { return _.uniq(_.flatten(arguments, true)); }; // Produce an array that contains every item shared between all the // passed-in arrays. (Aliased as "intersect" for back-compat.) _.intersection = _.intersect = function(array) { var rest = slice.call(arguments, 1); return _.filter(_.uniq(array), function(item) { return _.every(rest, function(other) { return _.indexOf(other, item) >= 0; }); }); }; // Take the difference between one array and a number of other arrays. // Only the elements present in just the first array will remain. _.difference = function(array) { var rest = _.flatten(slice.call(arguments, 1)); return _.filter(array, function(value){ return !_.include(rest, value); }); }; // Zip together multiple lists into a single array -- elements that share // an index go together. _.zip = function() { var args = slice.call(arguments); var length = _.max(_.pluck(args, 'length')); var results = new Array(length); for (var i = 0; i < length; i++) results[i] = _.pluck(args, "" + i); return results; }; // If the browser doesn't supply us with indexOf (I'm looking at you, **MSIE**), // we need this function. Return the position of the first occurrence of an // item in an array, or -1 if the item is not included in the array. // Delegates to **ECMAScript 5**'s native `indexOf` if available. // If the array is large and already in sort order, pass `true` // for **isSorted** to use binary search. _.indexOf = function(array, item, isSorted) { if (array == null) return -1; var i, l; if (isSorted) { i = _.sortedIndex(array, item); return array[i] === item ? i : -1; } if (nativeIndexOf && array.indexOf === nativeIndexOf) return array.indexOf(item); for (i = 0, l = array.length; i < l; i++) if (i in array && array[i] === item) return i; return -1; }; // Delegates to **ECMAScript 5**'s native `lastIndexOf` if available. _.lastIndexOf = function(array, item) { if (array == null) return -1; if (nativeLastIndexOf && array.lastIndexOf === nativeLastIndexOf) return array.lastIndexOf(item); var i = array.length; while (i--) if (i in array && array[i] === item) return i; return -1; }; // Generate an integer Array containing an arithmetic progression. A port of // the native Python `range()` function. See // [the Python documentation](http://docs.python.org/library/functions.html#range). _.range = function(start, stop, step) { if (arguments.length <= 1) { stop = start || 0; start = 0; } step = arguments[2] || 1; var len = Math.max(Math.ceil((stop - start) / step), 0); var idx = 0; var range = new Array(len); while(idx < len) { range[idx++] = start; start += step; } return range; }; // 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(func, 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; 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 { func.apply(context, args); } whenDone(); throttling = true; }; }; // 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. _.debounce = function(func, wait) { var timeout; return function() { var context = this, args = arguments; var later = function() { timeout = null; func.apply(context, args); }; clearTimeout(timeout); timeout = setTimeout(later, wait); }; }; // 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; }; // 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. 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 (_.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? _.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 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; }; // Has 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, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;').replace(/'/g, '&#x27;').replace(/\//g,'&#x2F;'); }; // 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 = /.^/; // Within an interpolation, evaluation, or escaping, remove HTML escaping // that had been previously added. var unescape = function(code) { return code.replace(/\\\\/g, '\\').replace(/\\'/g, "'"); }; // 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(str, data) { var c = _.templateSettings; var tmpl = 'var __p=[],print=function(){__p.push.apply(__p,arguments);};' + 'with(obj||{}){__p.push(\'' + str.replace(/\\/g, '\\\\') .replace(/'/g, "\\'") .replace(c.escape || noMatch, function(match, code) { return "',_.escape(" + unescape(code) + "),'"; }) .replace(c.interpolate || noMatch, function(match, code) { return "'," + unescape(code) + ",'"; }) .replace(c.evaluate || noMatch, function(match, code) { return "');" + unescape(code).replace(/[\r\n\t]/g, ' ') + ";__p.push('"; }) .replace(/\r/g, '\\r') .replace(/\n/g, '\\n') .replace(/\t/g, '\\t') + "');}return __p.join('');"; var func = new Function('obj', '_', tmpl); if (data) return func(data, _); return function(data) { return func.call(this, data, _); }; }; // 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 wrapped = this._wrapped; method.apply(wrapped, arguments); var length = wrapped.length; if ((name == 'shift' || name == 'splice') && length === 0) delete wrapped[0]; return result(wrapped, 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);