I’m having a hard time with

companion

and

object

usage inside my Swift code. Let say we have this Kotlin code:

class SomeClass {
    companion object {
        fun someIntFunction(): Int {
            return 1
        }
    }
}

fun SomeClass.someBoolFunction(): Boolean {
    return false
}

fun SomeClass.Companion.toSomeString(): String {
    return "to Some String"
}

object SomeOtherStatic {
    fun stringStuff(): String {
        return "String Stuff"
    }
}

And with that Swift code:

let some = SomeClass()
let someBool = some.someBoolFunction()
let someInt = SomeClass.Companion.someIntFunction()
let someString = SomeClass.Companion.toSomeString()

let otherString = SomeOtherStatic.stringStuff()

I get errors from inside Xcode:

Instance member 'someIntFunction' cannot be used on type 'SomeClass.Companion'; did you mean to use a value of this type instead?

I have this error for

someIntFunction

,

toSomeString

and

stringStuff

. The compile thinks they are instance functions 🤔 Is there something I am doing wrong? Thanks!

Yes,

companion

and

object

singletons must be accessed through a factory method when called in Swift https://kotlinlang.org/docs/reference/native/objc_interop.html#kotlin-singletons

As far as I know, those aren’t singleton members. Maybe I’m wrong. And I don’t see any singleton property in my Swift code. And the mapping table has different for ``companion` member` and

Singleton

try

SomeClass.Companion().toSomeString

Yep! That seems to work. Strange I have to instanciate my companion each time. 🤷‍♂️ Thanks!

You’ll always get the same instance of the companion

Thanks! Makes sense 🙂