36 lines
1.1 KiB
JavaScript
36 lines
1.1 KiB
JavaScript
var baseCallback = require('./baseCallback'),
|
|
baseEach = require('./baseEach'),
|
|
isArray = require('../lang/isArray');
|
|
|
|
/**
|
|
* Creates a `_.countBy`, `_.groupBy`, `_.indexBy`, or `_.partition` function.
|
|
*
|
|
* @private
|
|
* @param {Function} setter The function to set keys and values of the accumulator object.
|
|
* @param {Function} [initializer] The function to initialize the accumulator object.
|
|
* @returns {Function} Returns the new aggregator function.
|
|
*/
|
|
function createAggregator(setter, initializer) {
|
|
return function(collection, iteratee, thisArg) {
|
|
var result = initializer ? initializer() : {};
|
|
iteratee = baseCallback(iteratee, thisArg, 3);
|
|
|
|
if (isArray(collection)) {
|
|
var index = -1,
|
|
length = collection.length;
|
|
|
|
while (++index < length) {
|
|
var value = collection[index];
|
|
setter(result, value, iteratee(value, index, collection), collection);
|
|
}
|
|
} else {
|
|
baseEach(collection, function(value, key, collection) {
|
|
setter(result, value, iteratee(value, key, collection), collection);
|
|
});
|
|
}
|
|
return result;
|
|
};
|
|
}
|
|
|
|
module.exports = createAggregator;
|