Lambda implementation of interface in kotlin

Question

What would be the equivalent of that code in kotlin, nothing seems to work of what I try:

public interface AnInterface {
    void doSmth(MyClass inst, int num);
}

init:

AnInterface impl = (inst, num) -> {
    //...
}

Answer 1

If AnInterface is Java, it can work with SAM conversion:

val impl = AnInterface { inst, num -> 
     //...
}

Otherwise, if the interface is Kotlin:

• Since Kotlin 1.4, it's possible to write functional interfaces :

  fun interface AnInterface {
       fun doSmth(inst: MyClass, num: Int)
  }
  val impl = AnInterface { inst, num -> ... }
  

• Otherwise, if the interface is not functional

  interface AnInterface {
       fun doSmth(inst: MyClass, num: Int)
  }
  

  you can use the object syntax for implementing it anonymously:

  val impl = object : AnInterface {
      override fun doSmth(inst:, num: Int) {
          //...
      }
  }