Hi, I'm playing with the effects and I found out t...

# arrow

[than_]

Hi, I'm playing with the effects and I found out that

sealed interface DomainError
object SomeDomainError: DomainError

fun foo(): Effect<DomainError, Unit> = TODO()
fun bar(): Effect<SomeDomainError, Unit> = TODO()

fun baz() = effect<DomainError, Unit> {
    foo().bind()
    bar().bind()
}

the problem is I cannot bind result of bar even though SomeDomainError is a DomainError. Is this known limitation, oversight, or weirdness on my side 🙂 ?

[Imran/Malic]

We could make Effect E and A invariant contravariant like in Either than this compiles fine

[simon.vergauwen]

We have some options here I think.

Make R contravariant/out in Effect<R, A>, or define bind as suspend fun <EE : E, A> Effect<EE, A>.bind(): A in EffectScope<E>.

[simon.vergauwen]

We can release 1.1.3 with such a fix

[Imran/Malic]

contravariant as simon said, I meant out but keep switching them out everynow and then 😅