Javascript可以为数组做多态鸭打字吗？ （查看详细信息）

Question

让我们从一些代码开始：

function myArray() { }
myArray.prototype = Object.create(Array.prototype);
myArray.prototype.constructor = myArray;

所以：

var myInstance = new myArray();
myInstance.push(1);
>> 1

myInstance.length
>> 1

myInstance instanceof myArray
>> true

myInstance instanceof Array
>> true

到目前为止，一切都是标准的。我想做的是：

var myNewInstance = myInstance.concat([2,3,4]);
>> [1, 2, 3, 4]
(with the above example it's [{0: 1, length: 1}, 2, 3, 4]

myNewInstance instanceof myArray
>> true

我不知道是否有正确的方式来执行此操作...我只能通过钝的魔法来实现。

我尝试过使用Object.prototype.valueOf来尝试说服对象，但这种情况无处可去。

一个非常复杂的解决方案

myArray.prototype.concat = function() {
  // We start with a new instance of our own object, myArray
  var ret = new myArray();

  // utilize the in-place `splice` to keep the type as `myArray`
  ret.splice.apply(

    // contextualize it for our own object
    ret, 
    Array.prototype.concat.apply( 
      // call it with the start and end of our empty object
      [0, 0],

      // with our object as an array
      Array.prototype.slice.call(this).concat(

        // added to the arguments, as an array
        Array.prototype.slice.call(arguments) 
      )
    ) 
  );

  // since splice returns the stuff that was removed, we
  // need to have an additional line here.
  return ret;
}


var myNewInstance = myInstance.concat([2,3,4]);
>> {0: 1, 1: 2, 2: 3, 3: 4, length: 4}

myNewInstance instanceof myArray
>> true

这是连贯的，但它确实是黑客 - 几乎就像我做错了。