What is the Java equivalent of this code ```interface MyInterface lt out T gt fun process T ``` I need to convert this interface to Java because of SAM conversion but I m failing a bit here

```interface MyInterface lt T gt T process ```

Right now I have ```return object MyInterface lt Any gt override fun process String = code here ```

What is the Java equivalent of this code ```interface MyInte kotlinlang #getting-started

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Title

bodiam

03/06/2020, 7:05 AM

What is the Java equivalent of this code:

interface MyInterface<out T> {
    fun process(): T
}

I need to convert this interface to Java because of SAM conversion, but I'm failing a bit here.

Eivind Nilsbakken

03/06/2020, 7:30 AM

interface MyInterface<T> {
    T process();
}

bodiam

03/06/2020, 7:31 AM

Thanks, but are you super? I don't think that's matching the

out

parameter in my interface.

bezrukov

03/06/2020, 7:31 AM

I think there is no equivalent code in java (in java there is no idiomatic and safe way to use Interface<T> as Interface<ParentT> - you need to perform explicit cast) SAM conversion for kotlin interfaces will be supported in 1.4. Before it released you can write top-level fun

fun MyInterface(lambda): MyInterface = ...

Eivind Nilsbakken

03/06/2020, 7:32 AM

Oh, yeah. ☝️

bodiam

03/06/2020, 7:32 AM

Thanks Denis, but what do you mean with the last line?

Right now I have:

return object: MyInterface<Any> {
   override fun process(): String = {
      // code here
   }
}

but I'd like to make it a bit shorter.

bezrukov

03/06/2020, 7:35 AM

inline fun <reified T> MyInterface(crossinline lambda: () -> T) = object : MyInterface<T> {
    override fun process(): T {
        return lambda()
    }
}

then just use it

val interface: MyInterface<String> = MyInterface { "Looks like it's SAM conversion" }
val anyInterface: MyInterface<Any> = interface

so you will write:

return MyInterface {
    // code here
}

Ruckus

03/06/2020, 2:43 PM

Maybe a dumb question, but is there a reason you're not just using

() -> T

bodiam

03/08/2020, 6:14 AM

I'm not sure what you mean with

() -> T

@bezrukov It worked really well btw, thanks for that!!

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