Java 8 Stream, getting head and tail

Question

Java 8 introduced a Stream class that resembles Scala\'s Stream, a powerful lazy construct using which it is possible to do something like this very concisely:

Answer 1

The solution below does not do state mutations, except for the head/tail deconstruction of the stream.

The lazyness is obtained using IntStream.iterate. The class Prime is used to keep the generator state

    import java.util.PrimitiveIterator;
    import java.util.stream.IntStream;
    import java.util.stream.Stream;

    public class Prime {
        private final IntStream candidates;
        private final int current;

        private Prime(int current, IntStream candidates)
        {
            this.current = current;
            this.candidates = candidates;
        }

        private Prime next()
        {
            PrimitiveIterator.OfInt it = candidates.filter(n -> n % current != 0).iterator();

            int head = it.next();
            IntStream tail = IntStream.generate(it::next);

            return new Prime(head, tail);
        }

        public static Stream stream() {
            IntStream possiblePrimes = IntStream.iterate(3, i -> i + 1);

            return Stream.iterate(new Prime(2, possiblePrimes), Prime::next)
                         .map(p -> p.current);
        }
    }

The usage would be this:

Stream first10Primes = Prime.stream().limit(10)