12345678910111213141516171819202122232425262728293031 |
- 'use strict';
- var bind = require('../internals/function-bind-context');
- var uncurryThis = require('../internals/function-uncurry-this');
- var IndexedObject = require('../internals/indexed-object');
- var toObject = require('../internals/to-object');
- var lengthOfArrayLike = require('../internals/length-of-array-like');
- var MapHelpers = require('../internals/map-helpers');
-
- var Map = MapHelpers.Map;
- var mapGet = MapHelpers.get;
- var mapHas = MapHelpers.has;
- var mapSet = MapHelpers.set;
- var push = uncurryThis([].push);
-
- // `Array.prototype.groupToMap` method
- // https://github.com/tc39/proposal-array-grouping
- module.exports = function groupToMap(callbackfn /* , thisArg */) {
- var O = toObject(this);
- var self = IndexedObject(O);
- var boundFunction = bind(callbackfn, arguments.length > 1 ? arguments[1] : undefined);
- var map = new Map();
- var length = lengthOfArrayLike(self);
- var index = 0;
- var key, value;
- for (;length > index; index++) {
- value = self[index];
- key = boundFunction(value, index, O);
- if (mapHas(map, key)) push(mapGet(map, key), value);
- else mapSet(map, key, [value]);
- } return map;
- };
|