How do I await a completableFuture inside an effec...

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[Kristian Nedrevold]

How do I await a completableFuture inside an effect {} block?

[simon.vergauwen]

The same as you would regularly do with KotlinX Coroutines, https://kotlinlang.org/api/kotlinx.coroutines/kotlinx-coroutines-jdk8/

[Kristian Nedrevold]

I think I might be misunderstanding something then, using kotlinx-coroutines-jdk8 with the .await() extension gives me a type F!. How do I actually work with this? I was trying to achieve something similar as the awaitFirst() in the coroutines reactive streams API

[simon.vergauwen]

F!? 🤔

This should give you simply A, https://kotlinlang.org/api/kotlinx.coroutines/kotlinx-coroutines-jdk8/kotlinx.coroutines.future/await.html.

It might return a platform type ! which means that Kotlin didn't find @NonNull or @Nullable and it's up to you to check the Java API and deal with potential null coming from Java.

[Kristian Nedrevold]

hmmm, maybe it's intellij then

[Kristian Nedrevold]

I will try actually building it

[Kristian Nedrevold]

Was just me getting my types wrong 🤐

[CLOVIS]

Are you using a Java https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/CompletableFuture.html instead of a Kotlin Coroutines https://kotlinlang.org/api/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines/-completable-deferred/ ?

[CLOVIS]

If so I believe there is an extension function somewhere in the coroutines lib to convert between them

[Kristian Nedrevold]

Yeah, there's a function in the coroutines-jdk8 module that has transformers. I had just messed up some generic types so everything was a bit wonky. Got it working now 🙂