one.util.streamex

Interface StreamEx.Emitter<T>

Type Parameters:

T - the type of the elements this emitter emits

Enclosing class:

StreamEx<T>

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public static interface StreamEx.Emitter<T>

A helper interface to build a new stream by emitting elements and creating new emitters in a chain.

Using this interface it's possible to create custom sources which cannot be easily expressed using StreamEx.iterate(Object, UnaryOperator) or StreamEx.generate(Supplier). For example, the following method generates a Collatz sequence starting from given number:

 public static Emitter<Integer> collatz(int start) {
    return action -> {
       action.accept(start);
       return start == 1 ? null : collatz(start % 2 == 0 ? start / 2 : start * 3 + 1);
    };
 }

Now you can use collatz(17).stream() to get the stream of Collatz numbers.

Since:

0.6.0

Author:

Tagir Valeev

Method Summary

Modifier and Type	Method and Description
StreamEx.Emitter<T>	next(Consumer<? super T> action) Calls the supplied consumer zero or more times to emit some elements, then returns the next emitter which will emit more, or null if nothing more to emit.
default Spliterator<T>	spliterator() Returns the spliterator which covers all the elements emitted by this emitter.
default StreamEx<T>	stream() Returns the stream which covers all the elements emitted by this emitter.

Method Detail

next

StreamEx.Emitter<T> next(Consumer<? super T> action)

Calls the supplied consumer zero or more times to emit some elements, then returns the next emitter which will emit more, or null if nothing more to emit.

Normally one element is emitted during the next() method call. However, it's not restricted: you may emit as many elements as you want, though in some cases if many elements were emitted they might be buffered consuming additional memory.

It's allowed not to emit anything (don't call the consumer). However if you do this and return new emitter which also does not emit anything, you will end up in endless loop.

Parameters:

action - consumer to be called to emit elements

Returns:

next emitter or null

spliterator

default Spliterator<T> spliterator()

Returns the spliterator which covers all the elements emitted by this emitter.

Returns:

the new spliterator

stream

default StreamEx<T> stream()

Returns the stream which covers all the elements emitted by this emitter.

Returns:

the new stream