Indexing access for Lists and Maps considered harmful?

[spamolovko]

Reinier Zwitserloot wrote:
> I agree to the theory of your post, but, so what?
>
> Java is not going to be perfect unless java is willing to sacrifice  
> backwards compatibility, which it isn't. So, perfection can't be the  
> goal - because if it is, then no language change is ever going to make  
> it in, and paradoxically, that really brings java no closer to  
> perfection.
>   
Yes, that is true. I hope that Oracle will "sacrifice backwards 
compatibility" and implement features that are standard for other good 
languages.

And being "non perfect" is not a reason to stop evolution.

> So - so what that it isn't perfect? Let's roll with where I think you  
> are trying to go, and create 2 interfaces, where the SetIndex  
> semantics are defined as requiring the implementing class to return  
> the logical value - e.g. boxing a primitive when assigning it into a  
> list, for example.
>
> But now we can't retrofit java.util.List without breaking thousands of  
> List implementations out there, so the conclusion would have to be  
> that you can not use a List itself; you must use either a specific  
> type (such as ArrayList, retrofitted to implement SetIndex), or a  
> newly created List2 interface that also implements SetIndex. In this  
> scenario, I'm assuming the name of the method isn't set(), as that  
> would conflict with java.util.List's set which has different semantics.
>   
public interface IndexedAccess<ValueType> {

    public ValueType indexGet(int key);

    public void indexSet(int key, ValueType value);

}

interface Collection<E> extends Iterable<E>, IndexedAccess<E>

and then just use:
List<String> list = new ...
list[0] = "hello";

What is the problems here?
>
>   --Reinier Zwitserloot
>