import createAggregator from '../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 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. If a property name or object is provided it is used to

* create a "_.property" or "_.matches" style callback respectively.

* @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, 3], [2]]

*

* var users = [

* { 'user': 'barney', 'age': 36, 'active': false },

* { 'user': 'fred', 'age': 40, 'active': true },

* { 'user': 'pebbles', 'age': 1, 'active': false }

* ];

*

* // using the "_.matches" callback shorthand

* _.map(_.partition(users, { 'age': 1 }), function(array) { return _.pluck(array, 'user'); });

* // => [['pebbles'], ['barney', 'fred']]

*

* // using the "_.property" callback shorthand

* _.map(_.partition(users, 'active'), function(array) { return _.pluck(array, 'user'); });

* // => [['fred'], ['barney', 'pebbles']]

*/

var partition = createAggregator(function(result, value, key) {

result[key ? 0 : 1].push(value);

}, function() { return [[], []]; });

export default partition;