'use strict';
-var aFunction = require('../internals/a-function');
+var global = require('../internals/global');
+var uncurryThis = require('../internals/function-uncurry-this');
+var aCallable = require('../internals/a-callable');
var isObject = require('../internals/is-object');
+var hasOwn = require('../internals/has-own-property');
+var arraySlice = require('../internals/array-slice');
-var slice = [].slice;
+var Function = global.Function;
+var concat = uncurryThis([].concat);
+var join = uncurryThis([].join);
var factories = {};
var construct = function (C, argsLength, args) {
- if (!(argsLength in factories)) {
+ if (!hasOwn(factories, argsLength)) {
for (var list = [], i = 0; i < argsLength; i++) list[i] = 'a[' + i + ']';
- // eslint-disable-next-line no-new-func -- we have no proper alternatives, IE8- only
- factories[argsLength] = Function('C,a', 'return new C(' + list.join(',') + ')');
+ factories[argsLength] = Function('C,a', 'return new C(' + join(list, ',') + ')');
} return factories[argsLength](C, args);
};
// `Function.prototype.bind` method implementation
// https://tc39.es/ecma262/#sec-function.prototype.bind
module.exports = Function.bind || function bind(that /* , ...args */) {
- var fn = aFunction(this);
- var partArgs = slice.call(arguments, 1);
+ var F = aCallable(this);
+ var Prototype = F.prototype;
+ var partArgs = arraySlice(arguments, 1);
var boundFunction = function bound(/* args... */) {
- var args = partArgs.concat(slice.call(arguments));
- return this instanceof boundFunction ? construct(fn, args.length, args) : fn.apply(that, args);
+ var args = concat(partArgs, arraySlice(arguments));
+ return this instanceof boundFunction ? construct(F, args.length, args) : F.apply(that, args);
};
- if (isObject(fn.prototype)) boundFunction.prototype = fn.prototype;
+ if (isObject(Prototype)) boundFunction.prototype = Prototype;
return boundFunction;
};