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+// Underscore.js 1.9.1
+// http://underscorejs.org
+// (c) 2009-2018 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
+// Underscore may be freely distributed under the MIT license.
+
+(function() {
+
+ // Baseline setup
+ // --------------
+
+ // Establish the root object, `window` (`self`) in the browser, `global`
+ // on the server, or `this` in some virtual machines. We use `self`
+ // instead of `window` for `WebWorker` support.
+ var root = typeof self == 'object' && self.self === self && self ||
+ typeof global == 'object' && global.global === global && global ||
+ this ||
+ {};
+
+ // Save the previous value of the `_` variable.
+ var previousUnderscore = root._;
+
+ // Save bytes in the minified (but not gzipped) version:
+ var ArrayProto = Array.prototype, ObjProto = Object.prototype;
+ var SymbolProto = typeof Symbol !== 'undefined' ? Symbol.prototype : null;
+
+ // Create quick reference variables for speed access to core prototypes.
+ var push = ArrayProto.push,
+ slice = ArrayProto.slice,
+ toString = ObjProto.toString,
+ hasOwnProperty = ObjProto.hasOwnProperty;
+
+ // All **ECMAScript 5** native function implementations that we hope to use
+ // are declared here.
+ var nativeIsArray = Array.isArray,
+ nativeKeys = Object.keys,
+ nativeCreate = Object.create;
+
+ // Naked function reference for surrogate-prototype-swapping.
+ var Ctor = function(){};
+
+ // Create a safe reference to the Underscore object for use below.
+ var _ = function(obj) {
+ if (obj instanceof _) return obj;
+ if (!(this instanceof _)) return new _(obj);
+ this._wrapped = obj;
+ };
+
+ // Export the Underscore object for **Node.js**, with
+ // backwards-compatibility for their old module API. If we're in
+ // the browser, add `_` as a global object.
+ // (`nodeType` is checked to ensure that `module`
+ // and `exports` are not HTML elements.)
+ if (typeof exports != 'undefined' && !exports.nodeType) {
+ if (typeof module != 'undefined' && !module.nodeType && module.exports) {
+ exports = module.exports = _;
+ }
+ exports._ = _;
+ } else {
+ root._ = _;
+ }
+
+ // Current version.
+ _.VERSION = '1.9.1';
+
+ // Internal function that returns an efficient (for current engines) version
+ // of the passed-in callback, to be repeatedly applied in other Underscore
+ // functions.
+ var optimizeCb = function(func, context, argCount) {
+ if (context === void 0) return func;
+ switch (argCount == null ? 3 : argCount) {
+ case 1: return function(value) {
+ return func.call(context, value);
+ };
+ // The 2-argument case is omitted because we’re not using it.
+ case 3: return function(value, index, collection) {
+ return func.call(context, value, index, collection);
+ };
+ case 4: return function(accumulator, value, index, collection) {
+ return func.call(context, accumulator, value, index, collection);
+ };
+ }
+ return function() {
+ return func.apply(context, arguments);
+ };
+ };
+
+ var builtinIteratee;
+
+ // An internal function to generate callbacks that can be applied to each
+ // element in a collection, returning the desired result — either `identity`,
+ // an arbitrary callback, a property matcher, or a property accessor.
+ var cb = function(value, context, argCount) {
+ if (_.iteratee !== builtinIteratee) return _.iteratee(value, context);
+ if (value == null) return _.identity;
+ if (_.isFunction(value)) return optimizeCb(value, context, argCount);
+ if (_.isObject(value) && !_.isArray(value)) return _.matcher(value);
+ return _.property(value);
+ };
+
+ // External wrapper for our callback generator. Users may customize
+ // `_.iteratee` if they want additional predicate/iteratee shorthand styles.
+ // This abstraction hides the internal-only argCount argument.
+ _.iteratee = builtinIteratee = function(value, context) {
+ return cb(value, context, Infinity);
+ };
+
+ // Some functions take a variable number of arguments, or a few expected
+ // arguments at the beginning and then a variable number of values to operate
+ // on. This helper accumulates all remaining arguments past the function’s
+ // argument length (or an explicit `startIndex`), into an array that becomes
+ // the last argument. Similar to ES6’s "rest parameter".
+ var restArguments = function(func, startIndex) {
+ startIndex = startIndex == null ? func.length - 1 : +startIndex;
+ return function() {
+ var length = Math.max(arguments.length - startIndex, 0),
+ rest = Array(length),
+ index = 0;
+ for (; index < length; index++) {
+ rest[index] = arguments[index + startIndex];
+ }
+ switch (startIndex) {
+ case 0: return func.call(this, rest);
+ case 1: return func.call(this, arguments[0], rest);
+ case 2: return func.call(this, arguments[0], arguments[1], rest);
+ }
+ var args = Array(startIndex + 1);
+ for (index = 0; index < startIndex; index++) {
+ args[index] = arguments[index];
+ }
+ args[startIndex] = rest;
+ return func.apply(this, args);
+ };
+ };
+
+ // An internal function for creating a new object that inherits from another.
+ var baseCreate = function(prototype) {
+ if (!_.isObject(prototype)) return {};
+ if (nativeCreate) return nativeCreate(prototype);
+ Ctor.prototype = prototype;
+ var result = new Ctor;
+ Ctor.prototype = null;
+ return result;
+ };
+
+ var shallowProperty = function(key) {
+ return function(obj) {
+ return obj == null ? void 0 : obj[key];
+ };
+ };
+
+ var has = function(obj, path) {
+ return obj != null && hasOwnProperty.call(obj, path);
+ }
+
+ var deepGet = function(obj, path) {
+ var length = path.length;
+ for (var i = 0; i < length; i++) {
+ if (obj == null) return void 0;
+ obj = obj[path[i]];
+ }
+ return length ? obj : void 0;
+ };
+
+ // Helper for collection methods to determine whether a collection
+ // should be iterated as an array or as an object.
+ // Related: http://people.mozilla.org/~jorendorff/es6-draft.html#sec-tolength
+ // Avoids a very nasty iOS 8 JIT bug on ARM-64. #2094
+ var MAX_ARRAY_INDEX = Math.pow(2, 53) - 1;
+ var getLength = shallowProperty('length');
+ var isArrayLike = function(collection) {
+ var length = getLength(collection);
+ return typeof length == 'number' && length >= 0 && length <= MAX_ARRAY_INDEX;
+ };
+
+ // Collection Functions
+ // --------------------
+
+ // The cornerstone, an `each` implementation, aka `forEach`.
+ // Handles raw objects in addition to array-likes. Treats all
+ // sparse array-likes as if they were dense.
+ _.each = _.forEach = function(obj, iteratee, context) {
+ iteratee = optimizeCb(iteratee, context);
+ var i, length;
+ if (isArrayLike(obj)) {
+ for (i = 0, length = obj.length; i < length; i++) {
+ iteratee(obj[i], i, obj);
+ }
+ } else {
+ var keys = _.keys(obj);
+ for (i = 0, length = keys.length; i < length; i++) {
+ iteratee(obj[keys[i]], keys[i], obj);
+ }
+ }
+ return obj;
+ };
+
+ // Return the results of applying the iteratee to each element.
+ _.map = _.collect = function(obj, iteratee, context) {
+ iteratee = cb(iteratee, context);
+ var keys = !isArrayLike(obj) && _.keys(obj),
+ length = (keys || obj).length,
+ results = Array(length);
+ for (var index = 0; index < length; index++) {
+ var currentKey = keys ? keys[index] : index;
+ results[index] = iteratee(obj[currentKey], currentKey, obj);
+ }
+ return results;
+ };
+
+ // Create a reducing function iterating left or right.
+ var createReduce = function(dir) {
+ // Wrap code that reassigns argument variables in a separate function than
+ // the one that accesses `arguments.length` to avoid a perf hit. (#1991)
+ var reducer = function(obj, iteratee, memo, initial) {
+ var keys = !isArrayLike(obj) && _.keys(obj),
+ length = (keys || obj).length,
+ index = dir > 0 ? 0 : length - 1;
+ if (!initial) {
+ memo = obj[keys ? keys[index] : index];
+ index += dir;
+ }
+ for (; index >= 0 && index < length; index += dir) {
+ var currentKey = keys ? keys[index] : index;
+ memo = iteratee(memo, obj[currentKey], currentKey, obj);
+ }
+ return memo;
+ };
+
+ return function(obj, iteratee, memo, context) {
+ var initial = arguments.length >= 3;
+ return reducer(obj, optimizeCb(iteratee, context, 4), memo, initial);
+ };
+ };
+
+ // **Reduce** builds up a single result from a list of values, aka `inject`,
+ // or `foldl`.
+ _.reduce = _.foldl = _.inject = createReduce(1);
+
+ // The right-associative version of reduce, also known as `foldr`.
+ _.reduceRight = _.foldr = createReduce(-1);
+
+ // Return the first value which passes a truth test. Aliased as `detect`.
+ _.find = _.detect = function(obj, predicate, context) {
+ var keyFinder = isArrayLike(obj) ? _.findIndex : _.findKey;
+ var key = keyFinder(obj, predicate, context);
+ if (key !== void 0 && key !== -1) return obj[key];
+ };
+
+ // Return all the elements that pass a truth test.
+ // Aliased as `select`.
+ _.filter = _.select = function(obj, predicate, context) {
+ var results = [];
+ predicate = cb(predicate, context);
+ _.each(obj, function(value, index, list) {
+ if (predicate(value, index, list)) results.push(value);
+ });
+ return results;
+ };
+
+ // Return all the elements for which a truth test fails.
+ _.reject = function(obj, predicate, context) {
+ return _.filter(obj, _.negate(cb(predicate)), context);
+ };
+
+ // Determine whether all of the elements match a truth test.
+ // Aliased as `all`.
+ _.every = _.all = function(obj, predicate, context) {
+ predicate = cb(predicate, context);
+ var keys = !isArrayLike(obj) && _.keys(obj),
+ length = (keys || obj).length;
+ for (var index = 0; index < length; index++) {
+ var currentKey = keys ? keys[index] : index;
+ if (!predicate(obj[currentKey], currentKey, obj)) return false;
+ }
+ return true;
+ };
+
+ // Determine if at least one element in the object matches a truth test.
+ // Aliased as `any`.
+ _.some = _.any = function(obj, predicate, context) {
+ predicate = cb(predicate, context);
+ var keys = !isArrayLike(obj) && _.keys(obj),
+ length = (keys || obj).length;
+ for (var index = 0; index < length; index++) {
+ var currentKey = keys ? keys[index] : index;
+ if (predicate(obj[currentKey], currentKey, obj)) return true;
+ }
+ return false;
+ };
+
+ // Determine if the array or object contains a given item (using `===`).
+ // Aliased as `includes` and `include`.
+ _.contains = _.includes = _.include = function(obj, item, fromIndex, guard) {
+ if (!isArrayLike(obj)) obj = _.values(obj);
+ if (typeof fromIndex != 'number' || guard) fromIndex = 0;
+ return _.indexOf(obj, item, fromIndex) >= 0;
+ };
+
+ // Invoke a method (with arguments) on every item in a collection.
+ _.invoke = restArguments(function(obj, path, args) {
+ var contextPath, func;
+ if (_.isFunction(path)) {
+ func = path;
+ } else if (_.isArray(path)) {
+ contextPath = path.slice(0, -1);
+ path = path[path.length - 1];
+ }
+ return _.map(obj, function(context) {
+ var method = func;
+ if (!method) {
+ if (contextPath && contextPath.length) {
+ context = deepGet(context, contextPath);
+ }
+ if (context == null) return void 0;
+ method = context[path];
+ }
+ return method == null ? method : method.apply(context, args);
+ });
+ });
+
+ // Convenience version of a common use case of `map`: fetching a property.
+ _.pluck = function(obj, key) {
+ return _.map(obj, _.property(key));
+ };
+
+ // Convenience version of a common use case of `filter`: selecting only objects
+ // containing specific `key:value` pairs.
+ _.where = function(obj, attrs) {
+ return _.filter(obj, _.matcher(attrs));
+ };
+
+ // Convenience version of a common use case of `find`: getting the first object
+ // containing specific `key:value` pairs.
+ _.findWhere = function(obj, attrs) {
+ return _.find(obj, _.matcher(attrs));
+ };
+
+ // Return the maximum element (or element-based computation).
+ _.max = function(obj, iteratee, context) {
+ var result = -Infinity, lastComputed = -Infinity,
+ value, computed;
+ if (iteratee == null || typeof iteratee == 'number' && typeof obj[0] != 'object' && obj != null) {
+ obj = isArrayLike(obj) ? obj : _.values(obj);
+ for (var i = 0, length = obj.length; i < length; i++) {
+ value = obj[i];
+ if (value != null && value > result) {
+ result = value;
+ }
+ }
+ } else {
+ iteratee = cb(iteratee, context);
+ _.each(obj, function(v, index, list) {
+ computed = iteratee(v, index, list);
+ if (computed > lastComputed || computed === -Infinity && result === -Infinity) {
+ result = v;
+ lastComputed = computed;
+ }
+ });
+ }
+ return result;
+ };
+
+ // Return the minimum element (or element-based computation).
+ _.min = function(obj, iteratee, context) {
+ var result = Infinity, lastComputed = Infinity,
+ value, computed;
+ if (iteratee == null || typeof iteratee == 'number' && typeof obj[0] != 'object' && obj != null) {
+ obj = isArrayLike(obj) ? obj : _.values(obj);
+ for (var i = 0, length = obj.length; i < length; i++) {
+ value = obj[i];
+ if (value != null && value < result) {
+ result = value;
+ }
+ }
+ } else {
+ iteratee = cb(iteratee, context);
+ _.each(obj, function(v, index, list) {
+ computed = iteratee(v, index, list);
+ if (computed < lastComputed || computed === Infinity && result === Infinity) {
+ result = v;
+ lastComputed = computed;
+ }
+ });
+ }
+ return result;
+ };
+
+ // Shuffle a collection.
+ _.shuffle = function(obj) {
+ return _.sample(obj, Infinity);
+ };
+
+ // Sample **n** random values from a collection using the modern version of the
+ // [Fisher-Yates shuffle](http://en.wikipedia.org/wiki/Fisher–Yates_shuffle).
+ // If **n** is not specified, returns a single random element.
+ // The internal `guard` argument allows it to work with `map`.
+ _.sample = function(obj, n, guard) {
+ if (n == null || guard) {
+ if (!isArrayLike(obj)) obj = _.values(obj);
+ return obj[_.random(obj.length - 1)];
+ }
+ var sample = isArrayLike(obj) ? _.clone(obj) : _.values(obj);
+ var length = getLength(sample);
+ n = Math.max(Math.min(n, length), 0);
+ var last = length - 1;
+ for (var index = 0; index < n; index++) {
+ var rand = _.random(index, last);
+ var temp = sample[index];
+ sample[index] = sample[rand];
+ sample[rand] = temp;
+ }
+ return sample.slice(0, n);
+ };
+
+ // Sort the object's values by a criterion produced by an iteratee.
+ _.sortBy = function(obj, iteratee, context) {
+ var index = 0;
+ iteratee = cb(iteratee, context);
+ return _.pluck(_.map(obj, function(value, key, list) {
+ return {
+ value: value,
+ index: index++,
+ criteria: iteratee(value, key, list)
+ };
+ }).sort(function(left, right) {
+ var a = left.criteria;
+ var b = right.criteria;
+ if (a !== b) {
+ if (a > b || a === void 0) return 1;
+ if (a < b || b === void 0) return -1;
+ }
+ return left.index - right.index;
+ }), 'value');
+ };
+
+ // An internal function used for aggregate "group by" operations.
+ var group = function(behavior, partition) {
+ return function(obj, iteratee, context) {
+ var result = partition ? [[], []] : {};
+ iteratee = cb(iteratee, context);
+ _.each(obj, function(value, index) {
+ var key = iteratee(value, index, obj);
+ behavior(result, value, key);
+ });
+ return result;
+ };
+ };
+
+ // Groups the object's values by a criterion. Pass either a string attribute
+ // to group by, or a function that returns the criterion.
+ _.groupBy = group(function(result, value, key) {
+ if (has(result, key)) result[key].push(value); else result[key] = [value];
+ });
+
+ // Indexes the object's values by a criterion, similar to `groupBy`, but for
+ // when you know that your index values will be unique.
+ _.indexBy = group(function(result, value, key) {
+ result[key] = value;
+ });
+
+ // Counts instances of an object that group by a certain criterion. Pass
+ // either a string attribute to count by, or a function that returns the
+ // criterion.
+ _.countBy = group(function(result, value, key) {
+ if (has(result, key)) result[key]++; else result[key] = 1;
+ });
+
+ var reStrSymbol = /[^\ud800-\udfff]|[\ud800-\udbff][\udc00-\udfff]|[\ud800-\udfff]/g;
+ // Safely create a real, live array from anything iterable.
+ _.toArray = function(obj) {
+ if (!obj) return [];
+ if (_.isArray(obj)) return slice.call(obj);
+ if (_.isString(obj)) {
+ // Keep surrogate pair characters together
+ return obj.match(reStrSymbol);
+ }
+ if (isArrayLike(obj)) return _.map(obj, _.identity);
+ return _.values(obj);
+ };
+
+ // Return the number of elements in an object.
+ _.size = function(obj) {
+ if (obj == null) return 0;
+ return isArrayLike(obj) ? obj.length : _.keys(obj).length;
+ };
+
+ // Split a collection into two arrays: one whose elements all satisfy the given
+ // predicate, and one whose elements all do not satisfy the predicate.
+ _.partition = group(function(result, value, pass) {
+ result[pass ? 0 : 1].push(value);
+ }, true);
+
+ // Array Functions
+ // ---------------
+
+ // Get the first element of an array. Passing **n** will return the first N
+ // values in the array. Aliased as `head` and `take`. The **guard** check
+ // allows it to work with `_.map`.
+ _.first = _.head = _.take = function(array, n, guard) {
+ if (array == null || array.length < 1) return n == null ? void 0 : [];
+ if (n == null || guard) return array[0];
+ return _.initial(array, array.length - n);
+ };
+
+ // Returns everything but the last entry of the array. Especially useful on
+ // the arguments object. Passing **n** will return all the values in
+ // the array, excluding the last N.
+ _.initial = function(array, n, guard) {
+ return slice.call(array, 0, Math.max(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.
+ _.last = function(array, n, guard) {
+ if (array == null || array.length < 1) return n == null ? void 0 : [];
+ if (n == null || guard) return array[array.length - 1];
+ return _.rest(array, Math.max(0, array.length - n));
+ };
+
+ // Returns everything but the first entry of the array. Aliased as `tail` and `drop`.
+ // Especially useful on the arguments object. Passing an **n** will return
+ // the rest N values in the array.
+ _.rest = _.tail = _.drop = function(array, n, guard) {
+ return slice.call(array, n == null || guard ? 1 : n);
+ };
+
+ // Trim out all falsy values from an array.
+ _.compact = function(array) {
+ return _.filter(array, Boolean);
+ };
+
+ // Internal implementation of a recursive `flatten` function.
+ var flatten = function(input, shallow, strict, output) {
+ output = output || [];
+ var idx = output.length;
+ for (var i = 0, length = getLength(input); i < length; i++) {
+ var value = input[i];
+ if (isArrayLike(value) && (_.isArray(value) || _.isArguments(value))) {
+ // Flatten current level of array or arguments object.
+ if (shallow) {
+ var j = 0, len = value.length;
+ while (j < len) output[idx++] = value[j++];
+ } else {
+ flatten(value, shallow, strict, output);
+ idx = output.length;
+ }
+ } else if (!strict) {
+ output[idx++] = value;
+ }
+ }
+ return output;
+ };
+
+ // Flatten out an array, either recursively (by default), or just one level.
+ _.flatten = function(array, shallow) {
+ return flatten(array, shallow, false);
+ };
+
+ // Return a version of the array that does not contain the specified value(s).
+ _.without = restArguments(function(array, otherArrays) {
+ return _.difference(array, otherArrays);
+ });
+
+ // Produce a duplicate-free version of the array. If the array has already
+ // been sorted, you have the option of using a faster algorithm.
+ // The faster algorithm will not work with an iteratee if the iteratee
+ // is not a one-to-one function, so providing an iteratee will disable
+ // the faster algorithm.
+ // Aliased as `unique`.
+ _.uniq = _.unique = function(array, isSorted, iteratee, context) {
+ if (!_.isBoolean(isSorted)) {
+ context = iteratee;
+ iteratee = isSorted;
+ isSorted = false;
+ }
+ if (iteratee != null) iteratee = cb(iteratee, context);
+ var result = [];
+ var seen = [];
+ for (var i = 0, length = getLength(array); i < length; i++) {
+ var value = array[i],
+ computed = iteratee ? iteratee(value, i, array) : value;
+ if (isSorted && !iteratee) {
+ if (!i || seen !== computed) result.push(value);
+ seen = computed;
+ } else if (iteratee) {
+ if (!_.contains(seen, computed)) {
+ seen.push(computed);
+ result.push(value);
+ }
+ } else if (!_.contains(result, value)) {
+ result.push(value);
+ }
+ }
+ return result;
+ };
+
+ // Produce an array that contains the union: each distinct element from all of
+ // the passed-in arrays.
+ _.union = restArguments(function(arrays) {
+ return _.uniq(flatten(arrays, true, true));
+ });
+
+ // Produce an array that contains every item shared between all the
+ // passed-in arrays.
+ _.intersection = function(array) {
+ var result = [];
+ var argsLength = arguments.length;
+ for (var i = 0, length = getLength(array); i < length; i++) {
+ var item = array[i];
+ if (_.contains(result, item)) continue;
+ var j;
+ for (j = 1; j < argsLength; j++) {
+ if (!_.contains(arguments[j], item)) break;
+ }
+ if (j === argsLength) result.push(item);
+ }
+ return result;
+ };
+
+ // Take the difference between one array and a number of other arrays.
+ // Only the elements present in just the first array will remain.
+ _.difference = restArguments(function(array, rest) {
+ rest = flatten(rest, true, true);
+ return _.filter(array, function(value){
+ return !_.contains(rest, value);
+ });
+ });
+
+ // Complement of _.zip. Unzip accepts an array of arrays and groups
+ // each array's elements on shared indices.
+ _.unzip = function(array) {
+ var length = array && _.max(array, getLength).length || 0;
+ var result = Array(length);
+
+ for (var index = 0; index < length; index++) {
+ result[index] = _.pluck(array, index);
+ }
+ return result;
+ };
+
+ // Zip together multiple lists into a single array -- elements that share
+ // an index go together.
+ _.zip = restArguments(_.unzip);
+
+ // Converts lists into objects. Pass either a single array of `[key, value]`
+ // pairs, or two parallel arrays of the same length -- one of keys, and one of
+ // the corresponding values. Passing by pairs is the reverse of _.pairs.
+ _.object = function(list, values) {
+ var result = {};
+ for (var i = 0, length = getLength(list); i < length; i++) {
+ if (values) {
+ result[list[i]] = values[i];
+ } else {
+ result[list[i][0]] = list[i][1];
+ }
+ }
+ return result;
+ };
+
+ // Generator function to create the findIndex and findLastIndex functions.
+ var createPredicateIndexFinder = function(dir) {
+ return function(array, predicate, context) {
+ predicate = cb(predicate, context);
+ var length = getLength(array);
+ var index = dir > 0 ? 0 : length - 1;
+ for (; index >= 0 && index < length; index += dir) {
+ if (predicate(array[index], index, array)) return index;
+ }
+ return -1;
+ };
+ };
+
+ // Returns the first index on an array-like that passes a predicate test.
+ _.findIndex = createPredicateIndexFinder(1);
+ _.findLastIndex = createPredicateIndexFinder(-1);
+
+ // Use a comparator function to figure out the smallest index at which
+ // an object should be inserted so as to maintain order. Uses binary search.
+ _.sortedIndex = function(array, obj, iteratee, context) {
+ iteratee = cb(iteratee, context, 1);
+ var value = iteratee(obj);
+ var low = 0, high = getLength(array);
+ while (low < high) {
+ var mid = Math.floor((low + high) / 2);
+ if (iteratee(array[mid]) < value) low = mid + 1; else high = mid;
+ }
+ return low;
+ };
+
+ // Generator function to create the indexOf and lastIndexOf functions.
+ var createIndexFinder = function(dir, predicateFind, sortedIndex) {
+ return function(array, item, idx) {
+ var i = 0, length = getLength(array);
+ if (typeof idx == 'number') {
+ if (dir > 0) {
+ i = idx >= 0 ? idx : Math.max(idx + length, i);
+ } else {
+ length = idx >= 0 ? Math.min(idx + 1, length) : idx + length + 1;
+ }
+ } else if (sortedIndex && idx && length) {
+ idx = sortedIndex(array, item);
+ return array[idx] === item ? idx : -1;
+ }
+ if (item !== item) {
+ idx = predicateFind(slice.call(array, i, length), _.isNaN);
+ return idx >= 0 ? idx + i : -1;
+ }
+ for (idx = dir > 0 ? i : length - 1; idx >= 0 && idx < length; idx += dir) {
+ if (array[idx] === item) return idx;
+ }
+ return -1;
+ };
+ };
+
+ // Return the position of the first occurrence of an item in an array,
+ // or -1 if the item is not included in the array.
+ // If the array is large and already in sort order, pass `true`
+ // for **isSorted** to use binary search.
+ _.indexOf = createIndexFinder(1, _.findIndex, _.sortedIndex);
+ _.lastIndexOf = createIndexFinder(-1, _.findLastIndex);
+
+ // 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 (stop == null) {
+ stop = start || 0;
+ start = 0;
+ }
+ if (!step) {
+ step = stop < start ? -1 : 1;
+ }
+
+ var length = Math.max(Math.ceil((stop - start) / step), 0);
+ var range = Array(length);
+
+ for (var idx = 0; idx < length; idx++, start += step) {
+ range[idx] = start;
+ }
+
+ return range;
+ };
+
+ // Chunk a single array into multiple arrays, each containing `count` or fewer
+ // items.
+ _.chunk = function(array, count) {
+ if (count == null || count < 1) return [];
+ var result = [];
+ var i = 0, length = array.length;
+ while (i < length) {
+ result.push(slice.call(array, i, i += count));
+ }
+ return result;
+ };
+
+ // Function (ahem) Functions
+ // ------------------
+
+ // Determines whether to execute a function as a constructor
+ // or a normal function with the provided arguments.
+ var executeBound = function(sourceFunc, boundFunc, context, callingContext, args) {
+ if (!(callingContext instanceof boundFunc)) return sourceFunc.apply(context, args);
+ var self = baseCreate(sourceFunc.prototype);
+ var result = sourceFunc.apply(self, args);
+ if (_.isObject(result)) return result;
+ return self;
+ };
+
+ // Create a function bound to a given object (assigning `this`, and arguments,
+ // optionally). Delegates to **ECMAScript 5**'s native `Function.bind` if
+ // available.
+ _.bind = restArguments(function(func, context, args) {
+ if (!_.isFunction(func)) throw new TypeError('Bind must be called on a function');
+ var bound = restArguments(function(callArgs) {
+ return executeBound(func, bound, context, this, args.concat(callArgs));
+ });
+ return bound;
+ });
+
+ // Partially apply a function by creating a version that has had some of its
+ // arguments pre-filled, without changing its dynamic `this` context. _ acts
+ // as a placeholder by default, allowing any combination of arguments to be
+ // pre-filled. Set `_.partial.placeholder` for a custom placeholder argument.
+ _.partial = restArguments(function(func, boundArgs) {
+ var placeholder = _.partial.placeholder;
+ var bound = function() {
+ var position = 0, length = boundArgs.length;
+ var args = Array(length);
+ for (var i = 0; i < length; i++) {
+ args[i] = boundArgs[i] === placeholder ? arguments[position++] : boundArgs[i];
+ }
+ while (position < arguments.length) args.push(arguments[position++]);
+ return executeBound(func, bound, this, this, args);
+ };
+ return bound;
+ });
+
+ _.partial.placeholder = _;
+
+ // Bind a number of an object's methods to that object. Remaining arguments
+ // are the method names to be bound. Useful for ensuring that all callbacks
+ // defined on an object belong to it.
+ _.bindAll = restArguments(function(obj, keys) {
+ keys = flatten(keys, false, false);
+ var index = keys.length;
+ if (index < 1) throw new Error('bindAll must be passed function names');
+ while (index--) {
+ var key = keys[index];
+ obj[key] = _.bind(obj[key], obj);
+ }
+ });
+
+ // Memoize an expensive function by storing its results.
+ _.memoize = function(func, hasher) {
+ var memoize = function(key) {
+ var cache = memoize.cache;
+ var address = '' + (hasher ? hasher.apply(this, arguments) : key);
+ if (!has(cache, address)) cache[address] = func.apply(this, arguments);
+ return cache[address];
+ };
+ memoize.cache = {};
+ return memoize;
+ };
+
+ // Delays a function for the given number of milliseconds, and then calls
+ // it with the arguments supplied.
+ _.delay = restArguments(function(func, wait, args) {
+ return setTimeout(function() {
+ return func.apply(null, args);
+ }, wait);
+ });
+
+ // Defers a function, scheduling it to run after the current call stack has
+ // cleared.
+ _.defer = _.partial(_.delay, _, 1);
+
+ // Returns a function, that, when invoked, will only be triggered at most once
+ // during a given window of time. Normally, the throttled function will run
+ // as much as it can, without ever going more than once per `wait` duration;
+ // but if you'd like to disable the execution on the leading edge, pass
+ // `{leading: false}`. To disable execution on the trailing edge, ditto.
+ _.throttle = function(func, wait, options) {
+ var timeout, context, args, result;
+ var previous = 0;
+ if (!options) options = {};
+
+ var later = function() {
+ previous = options.leading === false ? 0 : _.now();
+ timeout = null;
+ result = func.apply(context, args);
+ if (!timeout) context = args = null;
+ };
+
+ var throttled = function() {
+ var now = _.now();
+ if (!previous && options.leading === false) previous = now;
+ var remaining = wait - (now - previous);
+ context = this;
+ args = arguments;
+ if (remaining <= 0 || remaining > wait) {
+ if (timeout) {
+ clearTimeout(timeout);
+ timeout = null;
+ }
+ previous = now;
+ result = func.apply(context, args);
+ if (!timeout) context = args = null;
+ } else if (!timeout && options.trailing !== false) {
+ timeout = setTimeout(later, remaining);
+ }
+ return result;
+ };
+
+ throttled.cancel = function() {
+ clearTimeout(timeout);
+ previous = 0;
+ timeout = context = args = null;
+ };
+
+ return throttled;
+ };
+
+ // 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, result;
+
+ var later = function(context, args) {
+ timeout = null;
+ if (args) result = func.apply(context, args);
+ };
+
+ var debounced = restArguments(function(args) {
+ if (timeout) clearTimeout(timeout);
+ if (immediate) {
+ var callNow = !timeout;
+ timeout = setTimeout(later, wait);
+ if (callNow) result = func.apply(this, args);
+ } else {
+ timeout = _.delay(later, wait, this, args);
+ }
+
+ return result;
+ });
+
+ debounced.cancel = function() {
+ clearTimeout(timeout);
+ timeout = null;
+ };
+
+ return debounced;
+ };
+
+ // 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 _.partial(wrapper, func);
+ };
+
+ // Returns a negated version of the passed-in predicate.
+ _.negate = function(predicate) {
+ return function() {
+ return !predicate.apply(this, arguments);
+ };
+ };
+
+ // 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 args = arguments;
+ var start = args.length - 1;
+ return function() {
+ var i = start;
+ var result = args[start].apply(this, arguments);
+ while (i--) result = args[i].call(this, result);
+ return result;
+ };
+ };
+
+ // Returns a function that will only be executed on and after the Nth call.
+ _.after = function(times, func) {
+ return function() {
+ if (--times < 1) {
+ return func.apply(this, arguments);
+ }
+ };
+ };
+
+ // Returns a function that will only be executed up to (but not including) the Nth call.
+ _.before = function(times, func) {
+ var memo;
+ return function() {
+ if (--times > 0) {
+ memo = func.apply(this, arguments);
+ }
+ if (times <= 1) func = null;
+ return memo;
+ };
+ };
+
+ // Returns a function that will be executed at most one time, no matter how
+ // often you call it. Useful for lazy initialization.
+ _.once = _.partial(_.before, 2);
+
+ _.restArguments = restArguments;
+
+ // Object Functions
+ // ----------------
+
+ // Keys in IE < 9 that won't be iterated by `for key in ...` and thus missed.
+ var hasEnumBug = !{toString: null}.propertyIsEnumerable('toString');
+ var nonEnumerableProps = ['valueOf', 'isPrototypeOf', 'toString',
+ 'propertyIsEnumerable', 'hasOwnProperty', 'toLocaleString'];
+
+ var collectNonEnumProps = function(obj, keys) {
+ var nonEnumIdx = nonEnumerableProps.length;
+ var constructor = obj.constructor;
+ var proto = _.isFunction(constructor) && constructor.prototype || ObjProto;
+
+ // Constructor is a special case.
+ var prop = 'constructor';
+ if (has(obj, prop) && !_.contains(keys, prop)) keys.push(prop);
+
+ while (nonEnumIdx--) {
+ prop = nonEnumerableProps[nonEnumIdx];
+ if (prop in obj && obj[prop] !== proto[prop] && !_.contains(keys, prop)) {
+ keys.push(prop);
+ }
+ }
+ };
+
+ // Retrieve the names of an object's own properties.
+ // Delegates to **ECMAScript 5**'s native `Object.keys`.
+ _.keys = function(obj) {
+ if (!_.isObject(obj)) return [];
+ if (nativeKeys) return nativeKeys(obj);
+ var keys = [];
+ for (var key in obj) if (has(obj, key)) keys.push(key);
+ // Ahem, IE < 9.
+ if (hasEnumBug) collectNonEnumProps(obj, keys);
+ return keys;
+ };
+
+ // Retrieve all the property names of an object.
+ _.allKeys = function(obj) {
+ if (!_.isObject(obj)) return [];
+ var keys = [];
+ for (var key in obj) keys.push(key);
+ // Ahem, IE < 9.
+ if (hasEnumBug) collectNonEnumProps(obj, keys);
+ return keys;
+ };
+
+ // Retrieve the values of an object's properties.
+ _.values = function(obj) {
+ var keys = _.keys(obj);
+ var length = keys.length;
+ var values = Array(length);
+ for (var i = 0; i < length; i++) {
+ values[i] = obj[keys[i]];
+ }
+ return values;
+ };
+
+ // Returns the results of applying the iteratee to each element of the object.
+ // In contrast to _.map it returns an object.
+ _.mapObject = function(obj, iteratee, context) {
+ iteratee = cb(iteratee, context);
+ var keys = _.keys(obj),
+ length = keys.length,
+ results = {};
+ for (var index = 0; index < length; index++) {
+ var currentKey = keys[index];
+ results[currentKey] = iteratee(obj[currentKey], currentKey, obj);
+ }
+ return results;
+ };
+
+ // Convert an object into a list of `[key, value]` pairs.
+ // The opposite of _.object.
+ _.pairs = function(obj) {
+ var keys = _.keys(obj);
+ var length = keys.length;
+ var pairs = Array(length);
+ for (var i = 0; i < length; i++) {
+ pairs[i] = [keys[i], obj[keys[i]]];
+ }
+ return pairs;
+ };
+
+ // Invert the keys and values of an object. The values must be serializable.
+ _.invert = function(obj) {
+ var result = {};
+ var keys = _.keys(obj);
+ for (var i = 0, length = keys.length; i < length; i++) {
+ result[obj[keys[i]]] = keys[i];
+ }
+ return result;
+ };
+
+ // 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();
+ };
+
+ // An internal function for creating assigner functions.
+ var createAssigner = function(keysFunc, defaults) {
+ return function(obj) {
+ var length = arguments.length;
+ if (defaults) obj = Object(obj);
+ if (length < 2 || obj == null) return obj;
+ for (var index = 1; index < length; index++) {
+ var source = arguments[index],
+ keys = keysFunc(source),
+ l = keys.length;
+ for (var i = 0; i < l; i++) {
+ var key = keys[i];
+ if (!defaults || obj[key] === void 0) obj[key] = source[key];
+ }
+ }
+ return obj;
+ };
+ };
+
+ // Extend a given object with all the properties in passed-in object(s).
+ _.extend = createAssigner(_.allKeys);
+
+ // Assigns a given object with all the own properties in the passed-in object(s).
+ // (https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object/assign)
+ _.extendOwn = _.assign = createAssigner(_.keys);
+
+ // Returns the first key on an object that passes a predicate test.
+ _.findKey = function(obj, predicate, context) {
+ predicate = cb(predicate, context);
+ var keys = _.keys(obj), key;
+ for (var i = 0, length = keys.length; i < length; i++) {
+ key = keys[i];
+ if (predicate(obj[key], key, obj)) return key;
+ }
+ };
+
+ // Internal pick helper function to determine if `obj` has key `key`.
+ var keyInObj = function(value, key, obj) {
+ return key in obj;
+ };
+
+ // Return a copy of the object only containing the whitelisted properties.
+ _.pick = restArguments(function(obj, keys) {
+ var result = {}, iteratee = keys[0];
+ if (obj == null) return result;
+ if (_.isFunction(iteratee)) {
+ if (keys.length > 1) iteratee = optimizeCb(iteratee, keys[1]);
+ keys = _.allKeys(obj);
+ } else {
+ iteratee = keyInObj;
+ keys = flatten(keys, false, false);
+ obj = Object(obj);
+ }
+ for (var i = 0, length = keys.length; i < length; i++) {
+ var key = keys[i];
+ var value = obj[key];
+ if (iteratee(value, key, obj)) result[key] = value;
+ }
+ return result;
+ });
+
+ // Return a copy of the object without the blacklisted properties.
+ _.omit = restArguments(function(obj, keys) {
+ var iteratee = keys[0], context;
+ if (_.isFunction(iteratee)) {
+ iteratee = _.negate(iteratee);
+ if (keys.length > 1) context = keys[1];
+ } else {
+ keys = _.map(flatten(keys, false, false), String);
+ iteratee = function(value, key) {
+ return !_.contains(keys, key);
+ };
+ }
+ return _.pick(obj, iteratee, context);
+ });
+
+ // Fill in a given object with default properties.
+ _.defaults = createAssigner(_.allKeys, true);
+
+ // Creates an object that inherits from the given prototype object.
+ // If additional properties are provided then they will be added to the
+ // created object.
+ _.create = function(prototype, props) {
+ var result = baseCreate(prototype);
+ if (props) _.extendOwn(result, props);
+ return result;
+ };
+
+ // 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;
+ };
+
+ // Returns whether an object has a given set of `key:value` pairs.
+ _.isMatch = function(object, attrs) {
+ var keys = _.keys(attrs), length = keys.length;
+ if (object == null) return !length;
+ var obj = Object(object);
+ for (var i = 0; i < length; i++) {
+ var key = keys[i];
+ if (attrs[key] !== obj[key] || !(key in obj)) return false;
+ }
+ return true;
+ };
+
+
+ // Internal recursive comparison function for `isEqual`.
+ var eq, deepEq;
+ eq = function(a, b, aStack, bStack) {
+ // 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;
+ // `null` or `undefined` only equal to itself (strict comparison).
+ if (a == null || b == null) return false;
+ // `NaN`s are equivalent, but non-reflexive.
+ if (a !== a) return b !== b;
+ // Exhaust primitive checks
+ var type = typeof a;
+ if (type !== 'function' && type !== 'object' && typeof b != 'object') return false;
+ return deepEq(a, b, aStack, bStack);
+ };
+
+ // Internal recursive comparison function for `isEqual`.
+ deepEq = function(a, b, aStack, bStack) {
+ // Unwrap any wrapped objects.
+ if (a instanceof _) a = a._wrapped;
+ if (b instanceof _) b = b._wrapped;
+ // Compare `[[Class]]` names.
+ var className = toString.call(a);
+ if (className !== toString.call(b)) return false;
+ switch (className) {
+ // Strings, numbers, regular expressions, dates, and booleans are compared by value.
+ case '[object RegExp]':
+ // RegExps are coerced to strings for comparison (Note: '' + /a/i === '/a/i')
+ case '[object String]':
+ // Primitives and their corresponding object wrappers are equivalent; thus, `"5"` is
+ // equivalent to `new String("5")`.
+ return '' + a === '' + b;
+ case '[object Number]':
+ // `NaN`s are equivalent, but non-reflexive.
+ // Object(NaN) is equivalent to NaN.
+ if (+a !== +a) return +b !== +b;
+ // An `egal` comparison is performed for other numeric values.
+ return +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;
+ case '[object Symbol]':
+ return SymbolProto.valueOf.call(a) === SymbolProto.valueOf.call(b);
+ }
+
+ var areArrays = className === '[object Array]';
+ if (!areArrays) {
+ if (typeof a != 'object' || typeof b != 'object') return false;
+
+ // Objects with different constructors are not equivalent, but `Object`s or `Array`s
+ // from different frames are.
+ var aCtor = a.constructor, bCtor = b.constructor;
+ if (aCtor !== bCtor && !(_.isFunction(aCtor) && aCtor instanceof aCtor &&
+ _.isFunction(bCtor) && bCtor instanceof bCtor)
+ && ('constructor' in a && 'constructor' in b)) {
+ 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`.
+
+ // Initializing stack of traversed objects.
+ // It's done here since we only need them for objects and arrays comparison.
+ aStack = aStack || [];
+ bStack = bStack || [];
+ var length = aStack.length;
+ while (length--) {
+ // Linear search. Performance is inversely proportional to the number of
+ // unique nested structures.
+ if (aStack[length] === a) return bStack[length] === b;
+ }
+
+ // Add the first object to the stack of traversed objects.
+ aStack.push(a);
+ bStack.push(b);
+
+ // Recursively compare objects and arrays.
+ if (areArrays) {
+ // Compare array lengths to determine if a deep comparison is necessary.
+ length = a.length;
+ if (length !== b.length) return false;
+ // Deep compare the contents, ignoring non-numeric properties.
+ while (length--) {
+ if (!eq(a[length], b[length], aStack, bStack)) return false;
+ }
+ } else {
+ // Deep compare objects.
+ var keys = _.keys(a), key;
+ length = keys.length;
+ // Ensure that both objects contain the same number of properties before comparing deep equality.
+ if (_.keys(b).length !== length) return false;
+ while (length--) {
+ // Deep compare each member
+ key = keys[length];
+ if (!(has(b, key) && eq(a[key], b[key], aStack, bStack))) return false;
+ }
+ }
+ // Remove the first object from the stack of traversed objects.
+ aStack.pop();
+ bStack.pop();
+ return true;
+ };
+
+ // 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 (isArrayLike(obj) && (_.isArray(obj) || _.isString(obj) || _.isArguments(obj))) return obj.length === 0;
+ return _.keys(obj).length === 0;
+ };
+
+ // 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) {
+ var type = typeof obj;
+ return type === 'function' || type === 'object' && !!obj;
+ };
+
+ // Add some isType methods: isArguments, isFunction, isString, isNumber, isDate, isRegExp, isError, isMap, isWeakMap, isSet, isWeakSet.
+ _.each(['Arguments', 'Function', 'String', 'Number', 'Date', 'RegExp', 'Error', 'Symbol', 'Map', 'WeakMap', 'Set', 'WeakSet'], function(name) {
+ _['is' + name] = function(obj) {
+ return toString.call(obj) === '[object ' + name + ']';
+ };
+ });
+
+ // Define a fallback version of the method in browsers (ahem, IE < 9), where
+ // there isn't any inspectable "Arguments" type.
+ if (!_.isArguments(arguments)) {
+ _.isArguments = function(obj) {
+ return has(obj, 'callee');
+ };
+ }
+
+ // Optimize `isFunction` if appropriate. Work around some typeof bugs in old v8,
+ // IE 11 (#1621), Safari 8 (#1929), and PhantomJS (#2236).
+ var nodelist = root.document && root.document.childNodes;
+ if (typeof /./ != 'function' && typeof Int8Array != 'object' && typeof nodelist != 'function') {
+ _.isFunction = function(obj) {
+ return typeof obj == 'function' || false;
+ };
+ }
+
+ // Is a given object a finite number?
+ _.isFinite = function(obj) {
+ return !_.isSymbol(obj) && isFinite(obj) && !isNaN(parseFloat(obj));
+ };
+
+ // Is the given value `NaN`?
+ _.isNaN = function(obj) {
+ return _.isNumber(obj) && isNaN(obj);
+ };
+
+ // Is a given value a boolean?
+ _.isBoolean = function(obj) {
+ return obj === true || obj === false || toString.call(obj) === '[object Boolean]';
+ };
+
+ // 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;
+ };
+
+ // Shortcut function for checking if an object has a given property directly
+ // on itself (in other words, not on a prototype).
+ _.has = function(obj, path) {
+ if (!_.isArray(path)) {
+ return has(obj, path);
+ }
+ var length = path.length;
+ for (var i = 0; i < length; i++) {
+ var key = path[i];
+ if (obj == null || !hasOwnProperty.call(obj, key)) {
+ return false;
+ }
+ obj = obj[key];
+ }
+ return !!length;
+ };
+
+ // 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 iteratees.
+ _.identity = function(value) {
+ return value;
+ };
+
+ // Predicate-generating functions. Often useful outside of Underscore.
+ _.constant = function(value) {
+ return function() {
+ return value;
+ };
+ };
+
+ _.noop = function(){};
+
+ // Creates a function that, when passed an object, will traverse that object’s
+ // properties down the given `path`, specified as an array of keys or indexes.
+ _.property = function(path) {
+ if (!_.isArray(path)) {
+ return shallowProperty(path);
+ }
+ return function(obj) {
+ return deepGet(obj, path);
+ };
+ };
+
+ // Generates a function for a given object that returns a given property.
+ _.propertyOf = function(obj) {
+ if (obj == null) {
+ return function(){};
+ }
+ return function(path) {
+ return !_.isArray(path) ? obj[path] : deepGet(obj, path);
+ };
+ };
+
+ // Returns a predicate for checking whether an object has a given set of
+ // `key:value` pairs.
+ _.matcher = _.matches = function(attrs) {
+ attrs = _.extendOwn({}, attrs);
+ return function(obj) {
+ return _.isMatch(obj, attrs);
+ };
+ };
+
+ // Run a function **n** times.
+ _.times = function(n, iteratee, context) {
+ var accum = Array(Math.max(0, n));
+ iteratee = optimizeCb(iteratee, context, 1);
+ for (var i = 0; i < n; i++) accum[i] = iteratee(i);
+ return accum;
+ };
+
+ // Return a random integer between min and max (inclusive).
+ _.random = function(min, max) {
+ if (max == null) {
+ max = min;
+ min = 0;
+ }
+ return min + Math.floor(Math.random() * (max - min + 1));
+ };
+
+ // A (possibly faster) way to get the current timestamp as an integer.
+ _.now = Date.now || function() {
+ return new Date().getTime();
+ };
+
+ // List of HTML entities for escaping.
+ var escapeMap = {
+ '&': '&amp;',
+ '<': '&lt;',
+ '>': '&gt;',
+ '"': '&quot;',
+ "'": '&#x27;',
+ '`': '&#x60;'
+ };
+ var unescapeMap = _.invert(escapeMap);
+
+ // Functions for escaping and unescaping strings to/from HTML interpolation.
+ var createEscaper = function(map) {
+ var escaper = function(match) {
+ return map[match];
+ };
+ // Regexes for identifying a key that needs to be escaped.
+ var source = '(?:' + _.keys(map).join('|') + ')';
+ var testRegexp = RegExp(source);
+ var replaceRegexp = RegExp(source, 'g');
+ return function(string) {
+ string = string == null ? '' : '' + string;
+ return testRegexp.test(string) ? string.replace(replaceRegexp, escaper) : string;
+ };
+ };
+ _.escape = createEscaper(escapeMap);
+ _.unescape = createEscaper(unescapeMap);
+
+ // Traverses the children of `obj` along `path`. If a child is a function, it
+ // is invoked with its parent as context. Returns the value of the final
+ // child, or `fallback` if any child is undefined.
+ _.result = function(obj, path, fallback) {
+ if (!_.isArray(path)) path = [path];
+ var length = path.length;
+ if (!length) {
+ return _.isFunction(fallback) ? fallback.call(obj) : fallback;
+ }
+ for (var i = 0; i < length; i++) {
+ var prop = obj == null ? void 0 : obj[path[i]];
+ if (prop === void 0) {
+ prop = fallback;
+ i = length; // Ensure we don't continue iterating.
+ }
+ obj = _.isFunction(prop) ? prop.call(obj) : prop;
+ }
+ return obj;
+ };
+
+ // 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',
+ '\u2028': 'u2028',
+ '\u2029': 'u2029'
+ };
+
+ var escapeRegExp = /\\|'|\r|\n|\u2028|\u2029/g;
+
+ var escapeChar = function(match) {
+ return '\\' + escapes[match];
+ };
+
+ // JavaScript micro-templating, similar to John Resig's implementation.
+ // Underscore templating handles arbitrary delimiters, preserves whitespace,
+ // and correctly escapes quotes within interpolated code.
+ // NB: `oldSettings` only exists for backwards compatibility.
+ _.template = function(text, settings, oldSettings) {
+ if (!settings && oldSettings) settings = oldSettings;
+ settings = _.defaults({}, settings, _.templateSettings);
+
+ // Combine delimiters into one regular expression via alternation.
+ var matcher = RegExp([
+ (settings.escape || noMatch).source,
+ (settings.interpolate || noMatch).source,
+ (settings.evaluate || noMatch).source
+ ].join('|') + '|$', 'g');
+
+ // Compile the template source, escaping string literals appropriately.
+ var index = 0;
+ var source = "__p+='";
+ text.replace(matcher, function(match, escape, interpolate, evaluate, offset) {
+ source += text.slice(index, offset).replace(escapeRegExp, escapeChar);
+ index = offset + match.length;
+
+ if (escape) {
+ source += "'+\n((__t=(" + escape + "))==null?'':_.escape(__t))+\n'";
+ } else if (interpolate) {
+ source += "'+\n((__t=(" + interpolate + "))==null?'':__t)+\n'";
+ } else if (evaluate) {
+ source += "';\n" + evaluate + "\n__p+='";
+ }
+
+ // Adobe VMs need the match returned to produce the correct offset.
+ return match;
+ });
+ source += "';\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;
+ try {
+ render = new Function(settings.variable || 'obj', '_', source);
+ } catch (e) {
+ e.source = source;
+ throw e;
+ }
+
+ var template = function(data) {
+ return render.call(this, data, _);
+ };
+
+ // Provide the compiled source as a convenience for precompilation.
+ var argument = settings.variable || 'obj';
+ template.source = 'function(' + argument + '){\n' + source + '}';
+
+ return template;
+ };
+
+ // Add a "chain" function. Start chaining a wrapped Underscore object.
+ _.chain = function(obj) {
+ var instance = _(obj);
+ instance._chain = true;
+ return instance;
+ };
+
+ // OOP
+ // ---------------
+ // 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.
+
+ // Helper function to continue chaining intermediate results.
+ var chainResult = function(instance, obj) {
+ return instance._chain ? _(obj).chain() : obj;
+ };
+
+ // Add your own custom functions to the Underscore object.
+ _.mixin = function(obj) {
+ _.each(_.functions(obj), function(name) {
+ var func = _[name] = obj[name];
+ _.prototype[name] = function() {
+ var args = [this._wrapped];
+ push.apply(args, arguments);
+ return chainResult(this, func.apply(_, args));
+ };
+ });
+ return _;
+ };
+
+ // 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];
+ _.prototype[name] = function() {
+ var obj = this._wrapped;
+ method.apply(obj, arguments);
+ if ((name === 'shift' || name === 'splice') && obj.length === 0) delete obj[0];
+ return chainResult(this, obj);
+ };
+ });
+
+ // Add all accessor Array functions to the wrapper.
+ _.each(['concat', 'join', 'slice'], function(name) {
+ var method = ArrayProto[name];
+ _.prototype[name] = function() {
+ return chainResult(this, method.apply(this._wrapped, arguments));
+ };
+ });
+
+ // Extracts the result from a wrapped and chained object.
+ _.prototype.value = function() {
+ return this._wrapped;
+ };
+
+ // Provide unwrapping proxy for some methods used in engine operations
+ // such as arithmetic and JSON stringification.
+ _.prototype.valueOf = _.prototype.toJSON = _.prototype.value;
+
+ _.prototype.toString = function() {
+ return String(this._wrapped);
+ };
+
+ // AMD registration happens at the end for compatibility with AMD loaders
+ // that may not enforce next-turn semantics on modules. Even though general
+ // practice for AMD registration is to be anonymous, underscore registers
+ // as a named module because, like jQuery, it is a base library that is
+ // popular enough to be bundled in a third party lib, but not be part of
+ // an AMD load request. Those cases could generate an error when an
+ // anonymous define() is called outside of a loader request.
+ if (typeof define == 'function' && define.amd) {
+ define('underscore', [], function() {
+ return _;
+ });
+ }
+}());