12345678910111213141516171819202122232425262728 |
- 'use strict';
- var $ = require('../internals/export');
- var call = require('../internals/function-call');
- var uncurryThis = require('../internals/function-uncurry-this');
- var aCallable = require('../internals/a-callable');
- var getIterator = require('../internals/get-iterator');
- var iterate = require('../internals/iterate');
- var push = uncurryThis([].push);
- // `Map.groupBy` method
- // https://github.com/tc39/proposal-collection-methods
- $({ target: 'Map', stat: true, forced: true }, {
- groupBy: function groupBy(iterable, keyDerivative) {
- aCallable(keyDerivative);
- var iterator = getIterator(iterable);
- var newMap = new this();
- var has = aCallable(newMap.has);
- var get = aCallable(newMap.get);
- var set = aCallable(newMap.set);
- iterate(iterator, function (element) {
- var derivedKey = keyDerivative(element);
- if (!call(has, newMap, derivedKey)) call(set, newMap, derivedKey, [element]);
- else push(call(get, newMap, derivedKey), element);
- }, { IS_ITERATOR: true });
- return newMap;
- }
- });
|