hexo/node_modules/core-js/modules/_set-collection-from.js

29 lines
830 B
JavaScript

'use strict';
// https://tc39.github.io/proposal-setmap-offrom/
var $export = require('./_export');
var aFunction = require('./_a-function');
var ctx = require('./_ctx');
var forOf = require('./_for-of');
module.exports = function (COLLECTION) {
$export($export.S, COLLECTION, { from: function from(source /* , mapFn, thisArg */) {
var mapFn = arguments[1];
var mapping, A, n, cb;
aFunction(this);
mapping = mapFn !== undefined;
if (mapping) aFunction(mapFn);
if (source == undefined) return new this();
A = [];
if (mapping) {
n = 0;
cb = ctx(mapFn, arguments[2], 2);
forOf(source, false, function (nextItem) {
A.push(cb(nextItem, n++));
});
} else {
forOf(source, false, A.push, A);
}
return new this(A);
} });
};