Can Java 8 Streams operate on an item in a collection, and then remove it?

Question

Like just about everyone, I\'m still learning the intricacies (and loving them) of the new Java 8 Streams API. I have a question concerning usage of streams. I\'ll provide a

Answer 1

In one line no, but maybe you could make use of the partitioningBy collector:

Map> map = 
    set.stream()
       .collect(partitioningBy(Item::qualify, toSet()));

map.get(true).forEach(i -> ((Qualifier)i).operate());
set = map.get(false);

It might be more efficient as it avoids iterating the set two times, one for filtering the stream and then one for removing corresponding elements.

Otherwise I think your approach is relatively fine.