I have a configuration lambda

var configure: Input.() -> Unit

as a property on

Input

itself in order to execute it later on. However, to execute it externally, I have to call

input.configure(input)

... does this sound right? I'm inclined to think so, because if I scope

input

, then I can simply call configure as

input.apply { configure() }

, but I'd like to have some feedbacks on this

Signature:

Input.() -> Unit

Matching call:

input.configure()

Signature:

(Input) -> Unit

Matching call:

configure(input)

Signature:

Input.(Input) -> Unit

Matching call:

input.configure(input)

What is your case exactly? It seems like you are confusing some of these together

if

configure

isn't in scope then it's understandable,

val fn = input.configure
fn(input)
==
input.configure(input)

but it seems that you can avoid that just by bringing it into scope

input.configure()

and

configure(input)

are allowed, not

input.configure(input)

(you can't specify the same parameter twice)

no,

configure

is an Input property

This seems super weird. Why is

configure

public here? It seems it's not supposed to be called from outside of the

Input

class, otherwise you could pass other instances of

Input

to it, and that would be quite a mess. I would suggest to create a public method inside

Input

that would simply call

configure

on

this

:

class Input(
    private val configure: Input.() -> Unit
) {
    fun initialize() {
        this.configure()
    }
}

But this looks like an XY problem, I wonder what invariants you have for the input class. Is configure supposed to be called exactly once? When? It seems it should be used when creating the

Input

instance itself

just wip