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- 'use strict';
-
- /* eslint no-invalid-this: 1 */
-
- var ERROR_MESSAGE = 'Function.prototype.bind called on incompatible ';
- var slice = Array.prototype.slice;
- var toStr = Object.prototype.toString;
- var funcType = '[object Function]';
-
- module.exports = function bind(that) {
- var target = this;
- if (typeof target !== 'function' || toStr.call(target) !== funcType) {
- throw new TypeError(ERROR_MESSAGE + target);
- }
- var args = slice.call(arguments, 1);
-
- var bound;
- var binder = function () {
- if (this instanceof bound) {
- var result = target.apply(
- this,
- args.concat(slice.call(arguments))
- );
- if (Object(result) === result) {
- return result;
- }
- return this;
- } else {
- return target.apply(
- that,
- args.concat(slice.call(arguments))
- );
- }
- };
-
- var boundLength = Math.max(0, target.length - args.length);
- var boundArgs = [];
- for (var i = 0; i < boundLength; i++) {
- boundArgs.push('$' + i);
- }
-
- bound = Function('binder', 'return function (' + boundArgs.join(',') + '){ return binder.apply(this,arguments); }')(binder);
-
- if (target.prototype) {
- var Empty = function Empty() {};
- Empty.prototype = target.prototype;
- bound.prototype = new Empty();
- Empty.prototype = null;
- }
-
- return bound;
- };
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