Basic usage question: How do I satisfy a concrete...

# arrow

[Danilo Herrera]

Basic usage question:

How do I satisfy a concrete return type to Kind<F, A>? For instance, I have a List<Animal> but want to return Kind<F, Animal>. Example:

interface AnimalMapper<F> : MonadError<F, Throwable> {

    fun Kind<F, FarmDto>.toAnimalsFromNetwork(): Kind<F, Animal> = flatMap { farmDto ->
        catch {
            farmDto.animalDtos.map {
                Animal(
                    it.id,
                    it.name
                )
            }
        }
    }
}

This yields a type inference error. Expected Kind<F, Animal>, but found Kind<F, List<Animal>>

[kioba]

the easiest would be to convert it to the arrow ListK with the .k()
ListK is the arrow List implementation and it is a arrow.Kind<ForListK, A>