Is there an equivalent to comprehension pattern fo...

# arrow

[Olivier Laforest]

Is there an equivalent to comprehension pattern for Reactor’s publisher similar to this

MonoK.fx {
  //comprehension block
}.value()

that we use to be able to do in Arrow 0.11.0 in Arrow 0.13.x?

[simon.vergauwen]

Hey @Olivier Laforest,
There is no equivalent for this, since this required some hacks on the JVM (which also prevented us from going MPP).

You should be able to do the same thing with, https://github.com/Kotlin/kotlinx.coroutines/tree/master/reactive/kotlinx-coroutines-reactor.

Instead you should be able to do:

suspend fun comprehensions(): A {
   val mono1 = one.await()
   val mono2 = two.await()
   computeA(mono1, mono2).await()
}

fun monoProgram(): Mono<A> =
  mono { comprehensions() }

This is useful because here await will check for cancellation just like flatMap does in Reactor, or bind did in fx.

If you don't care about cancellation, and/or don't want to include the whole KotlinX Coroutines dependency I could help set-up non-KotlinX Coroutines based DSL that achieves the same 🙂