I want to do that allows partial implementations not actually written in class, eg:

class Foo {
    api fun bar(): String
}

// write in another file
impl fun Foo.bar() = "bar"

The reason I want to implement this is that I want the actual implementation of the

bar

function to be implemented by KSP generated code, and I want it to be a member function that does not require import and does not need to wait for

KspDebug

to finish executing before calling to

What about the existing inheritance options, interface or even an open/abstract class? Alternatively you could do it with an compiler plugin, so afaik there is no need to change the language.

Maybe kotlin language advocate

final

rather than open/abstract.😂 and I don't really want it to have subclasses. Using KCP also requires synchronous development of IDE plugins to avoid IDE errors for not implemented, and many languages actually have similar api and implementations separate logic(like header) And, api separation is actually a way to explicitly declare api. it is also a easy way to optimizing compiler's tracking of abi changes for incremental compile. It also provide a simple way to compare the api changes between old and new versions. Also, if adding a new keyword doesn't good, can we consider existing

external

keyword? Not just for interacting with native, but also for this additional api/impl seperation?

Seems a lot like

expect/actual

, although might be sort of weird to use it on just a single platform

yeah!👍 it is

expect/actual

, but I want to use it in single sourceset(platform), and maybe when no

actual

impl, it will not show the ide error

This has value over an interface because you can declare a constructor that your other classes can access directly, while still generating the implementation of some methods. You can't do the same for a purely generated implementation class.