[vm/ffi] Pointer<T extends Struct> should expose an Iterable

[safasofuoglu]

Having a struct definition, a pointer and an item count, it felt convenient to work with an iterator instead of elementAt and ref calls. I started with:

class NativeArray<T extends Struct> implements UnmodifiableListView<T> {
  Pointer<T> pointer;

  NativeArray(this.pointer, this.length);

  @override
  T get first {
    return pointer.elementAt(0);
  }
  ...
}

However, for the elementAt call, the compiler says T must be a compile-time constant.

Can this be made possible on userland? If not, would you consider implementing it on the sdk?

@dcharkes

[dcharkes]

Can this be made possible on userland? If not, would you consider implementing it on the sdk?

No, we disallow unbound type arguments (see the documentation of .ref) for performance reasons.

On Pointers to integers one can use asTypedList to get an iterator. But on Pointer<T extends Struct> we have nothing yet.

(Cross reference other missing iterator in the API: #45508)

[safasofuoglu]

Thanks @dcharkes , #45508 looks good.

[dcharkes]

Well, we still need to implement this.