| var createAggregator = require('../internal/createAggregator'); |
| |
| /** |
| * Creates an array of elements split into two groups, the first of which |
| * contains elements `predicate` returns truthy for, while the second of which |
| * contains elements `predicate` returns falsey for. The predicate is bound |
| * to `thisArg` and invoked with three arguments: (value, index|key, collection). |
| * |
| * If a property name is provided for `predicate` the created `_.property` |
| * style callback returns the property value of the given element. |
| * |
| * If a value is also provided for `thisArg` the created `_.matchesProperty` |
| * style callback returns `true` for elements that have a matching property |
| * value, else `false`. |
| * |
| * If an object is provided for `predicate` the created `_.matches` style |
| * callback returns `true` for elements that have the properties of the given |
| * object, else `false`. |
| * |
| * @static |
| * @memberOf _ |
| * @category Collection |
| * @param {Array|Object|string} collection The collection to iterate over. |
| * @param {Function|Object|string} [predicate=_.identity] The function invoked |
| * per iteration. |
| * @param {*} [thisArg] The `this` binding of `predicate`. |
| * @returns {Array} Returns the array of grouped elements. |
| * @example |
| * |
| * _.partition([1, 2, 3], function(n) { |
| * return n % 2; |
| * }); |
| * // => [[1, 3], [2]] |
| * |
| * _.partition([1.2, 2.3, 3.4], function(n) { |
| * return this.floor(n) % 2; |
| * }, Math); |
| * // => [[1.2, 3.4], [2.3]] |
| * |
| * var users = [ |
| * { 'user': 'barney', 'age': 36, 'active': false }, |
| * { 'user': 'fred', 'age': 40, 'active': true }, |
| * { 'user': 'pebbles', 'age': 1, 'active': false } |
| * ]; |
| * |
| * var mapper = function(array) { |
| * return _.pluck(array, 'user'); |
| * }; |
| * |
| * // using the `_.matches` callback shorthand |
| * _.map(_.partition(users, { 'age': 1, 'active': false }), mapper); |
| * // => [['pebbles'], ['barney', 'fred']] |
| * |
| * // using the `_.matchesProperty` callback shorthand |
| * _.map(_.partition(users, 'active', false), mapper); |
| * // => [['barney', 'pebbles'], ['fred']] |
| * |
| * // using the `_.property` callback shorthand |
| * _.map(_.partition(users, 'active'), mapper); |
| * // => [['fred'], ['barney', 'pebbles']] |
| */ |
| var partition = createAggregator(function(result, value, key) { |
| result[key ? 0 : 1].push(value); |
| }, function() { return [[], []]; }); |
| |
| module.exports = partition; |