I m excited for the objc interop but I m a bit puzzled about

Question

I m excited for the objc interop but I m a bit puzzled about how it s actually supposed to work How are two objc selectors `popcorn withSalt ` and `popcorn withSugar ` distinguished on the kotlin side

Peter Quade · Answer

It seems they would be callable as `popcorn foo withSalt=1 ` and `popcorn foo withSugar=2 ` on the kotlin side But what does `popcorn foo 1 ` mean then

Peter Quade · Answer

This does not compile conflicting overloads overload resolution ambiguity but works on the kotlinc REPL ``` fun foo a Int b Int Int return a + b fun foo a Int c Int Int return a c fun main args Array lt String gt println foo 1 2 println foo a=1 b=2 println foo a=1 c=2 ``` So it seems kotlin can distinguish methods functions based on the parameter names the REPL can But the compiler does not like it because it s dangerous and ambigous kotlin native is still building on my machine so I have not tried this yet with kotlin native I just looked at the interop code and the samples and was curious how this is supposed to work

svyatoslav.scherbina · Answer

gt It seems they would be callable as `popcorn foo withSalt=1 ` and `popcorn foo withSugar=2 ` on the kotlin side Yes exactly gt But what does `popcorn foo 1 ` mean then `popcorn foo 1 ` means nothing because it is ambiguous The compiler doesn t accept this gt kotlin native is still building on my machine Please note that we have ve just released Kotlin Native 0 4 mostly corresponding to current state of `master` So you probably can just download the built release

Peter Quade · Answer

Thank you for your answer That s quite interesting Does `popcorn foo 1 ` work if there is only one matching objc selector just `popcorn withSalt ` not ` withSugar ` existing I ve seen lot s of objc interop approaches to different languages and I m always curious how the fundamental question of selector gt function call is answered wink And thank you for mentioning the binaries I was not aware of them

orangy · Answer

gt But the compiler does not like it because it s dangerous and ambigous it s not the Kotlin compiler it s JVM that doesn t allow this

olonho · Answer

yes we rely upon Kotlin s ability to use overload by parameter name usually disabled but we enable it by file Suppress CONFLICTING OVERLOADS And surely if no selector conflict exists parameter name can be omitted Feel free to experiment with smth like ``` file Suppress CONFLICTING OVERLOADS fun foo a Int b Int Int return a + b fun foo a Int c Int Int return a c fun main args Array lt String gt println foo a=2 c=1 println foo a=2 b=1 Doesn t compile println foo a=2 1 ```

Peter Quade · Answer

Thank you for the additional information