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| ; | |
| /* 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; | |
| }; | |