toBlocking ignore all

[davidmoten]

When I want to use toBlocking and I want to ignore results but wait for completion I will often do

observable.count().toBlocking().single();

This works but I'd like something concise for this common use case. We have a forEach method that takes an Action1. What about a forEach overload that takes no argument?

observable.toBlocking().forEach();

or perhaps .ignoreElements()?

[akarnokd]

I've been thinking about this too and could use these new blocking methods:

• run() or subscribe() run to completion or exception
• subscribe(Observer), subscribe(Action1, Action1) and subscribe(Action1, Action1, Action0) blocking callback style
• subscribe(Subscriber) allow breaking out of the iteration and have the unsubscription properly propagate up.

[davidmoten]

Sounds good, may as well duplicate all the subscribe() overloads across to BlockingObservable that make sense. That symmetry would be nice.

[pkafel]

+1 for the topic. I have many use cases where I would love to use something like that !

[tommack]

I'll throw none() out there. Would be a void method that threw an Exception if any elements were output.

observable.ignoreElements().toBlocking().none();

[akarnokd]

See for the proposed methods in #3174.