Hi , is there any way to get all `sealed interface` implementations ? ( Maybe classes or objects )

# getting-started

[smallufo]

Hi , is there any way to get all sealed interface implementations ? ( Maybe classes or objects )

[hho]

Does https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.reflect/-k-class/sealed-subclasses.html do what you want?

[ephemient]

if you need all recursive sealed subtypes, you'll need some sort of search algorithm; I usually use something like

val queue = ArrayDeque(T::class.sealedSubclasses)
generateSequence(queue::removeFirstOrNull).filter(mutableSetOf<KClass<*>>()::add).onEach { queue += it.sealedSubclasses }.toList()

as an easy way to achieve that

[smallufo]

Thanks @ephemient

sealed interface MySealedInterface {
  fun doSomething()
}

object Obj1 : MySealedInterface {
  override fun doSomething() {
    println("obj1 ")
  }
}

object Obj2 : MySealedInterface {
  override fun doSomething() {
    println("obj2")
  }
}

fun main() {
  
  val queue = ArrayDeque(MySealedInterface::class.sealedSubclasses)
  val impls = generateSequence(queue::removeFirstOrNull)
    .filter(mutableSetOf<KClass<*>>()::add)
    .onEach { queue += it.sealedSubclasses }
    .toList()
  
  impls.forEach { impl ->
    impl.objectInstance!!.doSomething()
  }
}

It seems working , at least for object …
but it seems there is no easier way… (without reflections)
For example : MySealedInterface.objects

[ephemient]

since you only have one level of hierarchy, you don't need the search algorithm, MySealedInterface::class.sealedSubclasses would work

[ephemient]

but no, there is no way aside from reflection or compile-time code generation