blob: 3cf1e5ae5343eafbc0680f1c966e10e946d263d5 [file] [log] [blame]
'use strict';
var aFunction = require('./_a-function');
var isObject = require('./_is-object');
var invoke = require('./_invoke');
var arraySlice = [].slice;
var factories = {};
var construct = function (F, len, args) {
if (!(len in factories)) {
for (var n = [], i = 0; i < len; i++) n[i] = 'a[' + i + ']';
// eslint-disable-next-line no-new-func
factories[len] = Function('F,a', 'return new F(' + n.join(',') + ')');
} return factories[len](F, args);
};
module.exports = Function.bind || function bind(that /* , ...args */) {
var fn = aFunction(this);
var partArgs = arraySlice.call(arguments, 1);
var bound = function (/* args... */) {
var args = partArgs.concat(arraySlice.call(arguments));
return this instanceof bound ? construct(fn, args.length, args) : invoke(fn, args, that);
};
if (isObject(fn.prototype)) bound.prototype = fn.prototype;
return bound;
};