RFR: JDK-8298528: Clean up raw type warnings in base in bindings and collections packages [v2]

[Nir Lisker]

On Sun, 1 Jan 2023 15:23:16 GMT, John Hendrikx <jhendrikx at openjdk.org> wrote:

>> modules/javafx.base/src/main/java/javafx/collections/FXCollections.java line 709:
>> 
>>> 707:     private static class EmptyObservableList<E> extends AbstractList<E> implements ObservableList<E> {
>>> 708: 
>>> 709:         private static final ListIterator<Object> iterator = new ListIterator<>() {
>> 
>> Isn't a better fix is to not make this class static and use `<E>`? Other lists create a new iterator on each invocation, but this is effectively a singleton.
>> In fact, `EmptyObservableList` doesn't need to be declared because it's called only in one place, so it can be "inlined" when declaring the `EMPTY_LIST` field. Maybe this is out of scope.
>
> I considered all that, and don't mind changing it if we're in agreement.
> 
> The reason I didn't is that it would subtly change the iterator (it would have an unnecessary reference to its containing class).

In my opinion that's fine. The iterator might not use its reference to the list, but it's using its type information.

As for creating a new iterator on every invocation (like empty set does) or returning the same instance (like empty list does), I don't mind that much and I can't imagine it mattering in terms of performance.

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PR: https://git.openjdk.org/jfx/pull/972