On Apr 26, 2013, at 4:37 PM, Peter Levart <peter.lev...@gmail.com> wrote:
>
> Another "interesting" usage:
>
> Iterator<?> i = ...;
>
> i.forEachRemaining(e -> {
> ...
> if (...) {
> i.forEachRemaining(dummy -> {}); // drain it
> }
> ...
> });
>
> It seems that mixing external and internal iteration in the same object is
> like a box of chocolates. For internal iteration, Iterable.forEach is more
> suitable than Iterator.forEachRemaining unless the later is specified to have
> the common state for both external and internal iteration, which means that
> internal can not be more effective than external.
>
Similar observations can apply to Spliterator as well. IIRC many
spliterator.forEachRemaining implementations set up state to be fully traversed
before looping. However, it is not possible in all cases.
I think we may have to document that a consumer must not interfere with the
current traversal otherwise behaviour is undefined.
Paul.
