Is there a way to limit function invocation using something like

fun doSth(action: Mode.() -> Unit)

? But

Mode

contains only functions, no properties. Although it is completely fine to create instance of

Mode

and pass it to

action(mode)

, it just doesn't quite make sense for me to create such a instance.

limit function invocation?

One example would be one can only invoke

add

,

minus

inside

fun doSth

mm, maybe do not add multiply to Mode interface?

That's what I want to do, but I just can't figure out a nice way to do it

Imo nice way: use different interface hierarchy depending on case

Cause I need to do

fun doSth(...) {
  action(mode) // Don't want to pass in mode
}

I mean something like that:

class/interface Mode {
  fun add()
  fun minus()
}

class MultipleMode: Mode {
   fun multiple()
}

I see, that lights me up