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

What you really want to do is to partition your set. Unfortunately in Java 8 partitioning is only possible via the terminal "collect" method. You end up with something like this:

// test data set
Set set = ImmutableSet.of(1, 2, 3, 4, 5);
// predicate separating even and odd numbers
Predicate evenNumber = n -> n % 2 == 0;

// initial set partitioned by the predicate
Map> partitioned = set.stream().collect(Collectors.partitioningBy(evenNumber));

// print even numbers
partitioned.get(true).forEach(System.out::println);
// do something else with the rest of the set (odd numbers)
doSomethingElse(partitioned.get(false))

Updated:

Scala version of the code above

val set = Set(1, 2, 3, 4, 5)
val partitioned = set.partition(_ % 2 == 0)
partitioned._1.foreach(println)
doSomethingElse(partitioned._2)`