is it possible to create different callbacks based...

# announcements

[tipsy]

is it possible to create different callbacks based on an enum type?

on(Event.TYPE_ONE) { int ->
    // an int is available here
}

on(Event.TYPE_TWO) { string ->
    // a string is available here
}

[Shawn]

my first thought is that this might be possible with sealed classes

[Shawn]

this works:

sealed class Event {
  object TYPE_ONE : Event()
  object TYPE_TWO : Event()
}

fun on(enum: Event.TYPE_ONE, block: (Int) -> Any) {

}

fun on(enum: Event.TYPE_TWO, block: (String) -> Any) {

}

on(Event.TYPE_ONE) {
  it.inc()
}

on(Event.TYPE_TWO) {
  it.length
}

but if the enum needs to be an enum, then I don’t think you can do what you’re asking for here

[tipsy]

thanks @Shawn, i guess it doesn't need to be an enum

[tipsy]

sealed classes seem like the way to go

[Shawn]

Might I ask what the larger goal is here? Are you just working on a fancy DSL or something?

[Shawn]

It just seems unusual to use enums/sealed classes like this, at least from my experience anyhow

[tipsy]

not so fancy, just an event system

[tipsy]

events should include relevant information

[louiscad]

BTW, there's an intention in the IDE to convert an enum class to a sealed class and back to an enum class