Is there a refactoring to introduce a lambda method parameter from a code selection?

# intellij

[holgerbrandl]

Is there a refactoring to introduce a lambda method parameter from a code selection?

[christophsturm]

yes. “introduce functional parameter”

[holgerbrandl]

Is it possible that this does not work outside of a class body, that is for functions inside a kt file?

[christophsturm]

if you post an example where it is not working for you i can try it out 🙂

[holgerbrandl]

Sure, with pleasure:

Try to use the refactoring for the implementation in foo. This fails for me, but it works for other

fun foo(){
    println("huhu")
    val a = 1
}

class IntroTest {
    fun other(){
        println("huhu")
        val a = 1
    }
}

[holgerbrandl]

image.png

[christophsturm]

works for me

[christophsturm]

if i select the val a=1 too it does not work because it makes no sense to put that into a lambda

[holgerbrandl]

It may not make sense, but it is not syntactically wrong, so it's a bug in the refactoring imho

[christophsturm]

it makes no sense because there is no way that idea can do this refactoring, and still produce compilable code.

[holgerbrandl]

Sure, it's possible:

[holgerbrandl]

`

class Something
        
        fun foo(builder: () -> Unit){
            builder()
        }

        foo{
            println("huhu")
            val a = Something()
        }

[holgerbrandl]

And it is also useful because the instantation of Something may have a side effect

[holgerbrandl]

I've filed https://youtrack.jetbrains.com/issue/KT-44323