kotlinlang #coroutines

Well, that’s definitely in the spirit of what I want, but doesn’t allow for the callback wrapping since timeout functions don’t pass the continuation to the block.

pardom

03/26/2018, 6:12 PM

Do you think there’s a better alternative to the guide on wrapping callbacks?

withoutclass

03/26/2018, 6:15 PM

haven't done much of it myself

withoutclass

03/26/2018, 6:15 PM

sorry

withoutclass

03/26/2018, 6:16 PM

you can wrap

withTimeout

in a try catch, catch the timeout exception, then perform the action you'd like to happen there, but I may be making this more complex than needed since I haven't done much with continuations

pardom

03/26/2018, 6:29 PM

Ahhh… I get it now.

pardom

03/26/2018, 6:30 PM

Copy code

suspend fun someLongComputation(params: Params): Result = withTimeout(15, TimeUnit.SECONDS) { 
    suspendCoroutine { cont -> someLongComputation(params) { cont.resume(it) }
}

fabian

03/27/2018, 5:11 PM

hi, is it expected that coroutines create Exceptions that are circular (via

suppressedExceptions

) in some scenarios? For example I have an uncaught runtime Exception in a coroutine and this is the Exception delivered to `invokeOnCompletion`:

fabian

03/27/2018, 5:12 PM

@fabian uploaded a file:

Screen Shot 2018-03-26 at 2.14.44 PM.png▾

user

03/27/2018, 8:08 PM

@elizarov commented on @fabian’s file

https://kotlinlang.slack.com/files/U9WTNRATE/F9W84D39N/screen_shot_2018-03-26_at_2.14.44_pm.png▾

: That’s not circular. That’s how Java Throwable encodes missing cause. Look at the

Throwable

source.

user

03/27/2018, 8:09 PM

@elizarov commented on @fabian’s file

https://kotlinlang.slack.com/files/U9WTNRATE/F9W84D39N/screen_shot_2018-03-26_at_2.14.44_pm.png▾

: Hm… actually it is. Is see. Can you post a code that reproduces this?

user

03/27/2018, 8:10 PM

@elizarov commented on @fabian’s file

https://kotlinlang.slack.com/files/U9WTNRATE/F9W84D39N/screen_shot_2018-03-26_at_2.14.44_pm.png▾

: I would be glad if you post it directly to http://github.com/kotlin/kotlinx.coroutines/issues

fabian

03/27/2018, 8:15 PM

I'll look into creating a snippet

fabian

03/28/2018, 12:46 AM

@fabian uploaded a file: circular Exception

circular_Exception.kt

fabian

03/28/2018, 12:47 AM

@elizarov this snippet delivers an Exception with a circular reference to

invokeOnCompletion

👍 1

fabian

03/28/2018, 12:52 AM

https://github.com/Kotlin/kotlinx.coroutines/issues/305

alucard

03/29/2018, 1:15 AM

Hey guys, I was wondering if the using a coroutine in the main thread context is equivalent to use runblocking

gildor

03/29/2018, 6:54 AM

No. using a coroutine in the main thread is equivalent to using callbacks in the main thread

gildor

03/29/2018, 6:54 AM

You do not lock thread until you don’t call some code that locks thread

amrelmasry

03/29/2018, 10:42 AM

Hello, I am exploring mixing RxJava with Coroutines, I saw the

SearchPresenter

implementation from SdkSearch. I am trying use RxJava to handle multi-value input, then move to coroutines to produce the results how to emit start values in select expression in the following example, is this a good pattern ?

amrelmasry

03/29/2018, 10:43 AM

@amrelmasry uploaded a file: Untitled

-.kt

amrelmasry

03/29/2018, 10:52 AM

I know one solution is to use

startWith

on the stream before calling

openSubscription()

but I will be forced to move the time consuming operation above also, to generate stream of

Result

instead of Stream of

Event

and I am trying to make coroutines handle the logic instead (I am trying to replace complex RxJava chains with coroutines)

03/29/2018, 3:29 PM

yes it's fine. see also https://github.com/Kotlin/kotlinx.coroutines/issues/171

altavir

03/29/2018, 5:44 PM

I wonder if there is a simple way to compose suspended functions. I have a function of type

suspend ()->T

and need to transform it to

suspend ()->R

having

(T)->R

transformation on hand. It should be compact before I need it in the constructor.

altavir

03/29/2018, 5:45 PM

In Java 8 there is a

andThen

method in

Function

class which does that.

rocketraman

03/29/2018, 5:48 PM

Correction, not

forEach

in there as its not fluent, but you get the idea

altavir

03/29/2018, 5:49 PM

It is too complicated. For now solved it with extension function:

Copy code

private fun (suspend () -> Any).toValue(): (suspend () -> Value){
    return {Value.of(this.invoke())}
}

altavir

03/29/2018, 5:50 PM

It could be generalized for any transformations. Extensions forever!