Hi! When I have ```class Builder { fun withSome...

# intellij

[dimsuz]

Hi! When I have

class Builder {
  fun withSomeAction(action: (P) -> Unit)
}

and autocomplete this on usage site, IDE turns this into

Builder().withSomeAction { }

which sometimes leads to programmer errors when actions are an object.
Instead I'd like to have

Builder().withSomeAction(action)

Is there a way to give IDE a hint I don't want to expand here?
I recall there was some YouTrack issue about this, but I can't find it.

[Roukanken]

I played around a bit with this, and you could use SAM interfaces:

fun interface Action {
    fun doAction(x: Int)
}

class Builder {
    fun withSomeAction(action: Action): Builder { return this }
}

then you could use em like this

val action1 = Action { TODO() }
object Action2 : Action by (Action { TODO() })
object Action3 : Action {
    override fun doAction(x: Int) = TODO()
}

Builder()
    .withSomeAction(action1)
    .withSomeAction(Action2)
    .withSomeAction(Action3)
    .withSomeAction { println(it) }

and IntelliJ will default to filling .withSomeAction(|) instead of using .withSomeAction { | }

depends on what exactly you are doing, if you want to use mostly pre-defined actions, this could be great way of doing that

[Roukanken]

actually even smth like this would work, (with changes of override fun doAction -> override fun invoke

fun interface Action : (Int) -> Unit

but it's a tiiny bit of abuse 😛

Point is, when IntelliJ sees interface there as argument, it won't autofill lambda, but since it's a functional interface, you can still use lambas normally, and bonus, you have name for the type your objects implement

[dimsuz]

Nice! Thank you for these tips!