Is it possible to define an abstract function as extension function?

sealed class Foo {
    abstract fun bar()
}

class A : Foo()
class B : Foo()

/* in another file */

fun A.bar() {
  // implementation
}

It seems it's not possible but maybe there is something similar? I just want to move the implementation of

bar()

to other files because the LOC for the implementation is huge. I want to avoid a file with thousands of LOC. Any ideas?

I don't think there is any way to do that. In Kotlin 1.5, you will be able to move class A and class B to different files. You can enable the 1.5 features currently as a preview. https://zsmb.co/sealed-goodies-coming-in-kotlin-1-5/

ok thanks for the hint 🙂

extension methods are implemented as static methods, which is why they cannot override an abstract method.

Cool idea! I will go with this solution

interesting problem