+++ /dev/null
-'use strict';
-var $ = require('../internals/export');
-var iterate = require('../internals/iterate');
-var aFunction = require('../internals/a-function');
-
-// `Map.groupBy` method
-// https://github.com/tc39/proposal-collection-methods
-$({ target: 'Map', stat: true }, {
- groupBy: function groupBy(iterable, keyDerivative) {
- var newMap = new this();
- aFunction(keyDerivative);
- var has = aFunction(newMap.has);
- var get = aFunction(newMap.get);
- var set = aFunction(newMap.set);
- iterate(iterable, function (element) {
- var derivedKey = keyDerivative(element);
- if (!has.call(newMap, derivedKey)) set.call(newMap, derivedKey, [element]);
- else get.call(newMap, derivedKey).push(element);
- });
- return newMap;
- }
-});