I have a proposal: How about make extension functi...

# language-proposals

[sanf0rd]

I have a proposal: How about make extension function implement interfaces:

interface SomeInterface {
    fun hi()
}

class SomeClass: SomeInterface {

}

fun SomeClass.hi() {
    print("hi")
}

So, My proposal is that the compiler can infer the interface conformance with the extension function implementation and not show an error in the class declaration. What do you think guys?

[voddan]

Please clarify how you would like such code to behave on JVM. Should corresponding Java classes implement the interfaces? Should they not?

[voddan]

Also, a proposal must include use cases, e.i situations you have encountered that would benefit from this feature

[orangy]

Also please edit your post to use triple backticks for code

[tschuchort]

you mean ad-hoc polymorphism? I want it too, but it's been rejected a lot of times already