package foo import js.* /*function g should return 0 if a parameter is undefined 1 if parameter is 1 and 3 if parameter is 3*/ native fun f(g : (Int?)-> Int) : Boolean = js.noImpl fun box() : Boolean { val b = { (a : Int?) -> if (a == null) { 0 } else if (a == 1) { 1 } else { 3 } } return f(b) }