i'm trying to convert a functional interface to kotlin: ``` @FunctionalInterface public interface E...

# getting-started

[tipsy]

i'm trying to convert a functional interface to kotlin:

@FunctionalInterface
public interface ErrorHandler {
    void handle(Request request, Response response);
}

i have typealias ErrorHandler = (request : Request, response : Response) -> Unit

which seems to work fine, except for when i try to call it in java

error(500, (req, res) -> {
    // return type expected
});

can i make this work in both languages somehow? (it used to work fine when the project was all java)

[voddan]

tipsy: looks like a common problem for kotlin void functions. Try returning kotlin.Unit or null

[tipsy]

@voddan that's a deal breaker, i'll keep it as java if that's the case

[hughg]

Does Nothing or Nothing? work as the return type?

[tipsy]

no, i tried that too