I've been having trouble using sealed classes on t...

# touchlab-tools

[Saad]

I've been having trouble using sealed classes on the iOS/Swift side of my app. Basically, I have a sealed class with a generic type parameter like so:

sealed class UiState<out T> {
    data object Loading : UiState<Nothing>()
    data class Success<T>(val data: T) : UiState<T>()
    data class Error(val message: String) : UiState<Nothing>()
}

and I have a viewModel I have in Swift using the observable protocol:

@MainActor
class ContentViewModel: ObservableObject {
    let profile = MyProfile()
    @Published
    private(set) var currentState: UiState<RawProfile> = ...
    
    
    func observeProfile() async {
        for await state in self.profile.profileData {
            self.currentState = state
        }
    }
}

I want to initialize currentState with UiState.Loading But I can't seem to figure out the syntax to fill in the ...
Any help would be very much appreciated!

[Tadeas Kriz]

Hi, this would be better asked in #C3PQML5NU. In any case, try UiStateLoading.shared. If your Kotlin framework is called shared, SKIE has to rename the .shared to .shared_ so it might be UiStateLoading.shared_ instead.

[Saad]

Thanks - UiStateLoading.shared_ doesn't seem to exist, and using UiStateLoading.shared gives the following error:
Cannot convert value of type 'UiState<KotlinNothing>' to expected argument type 'UiState<RawProfile>'

[Tadeas Kriz]

I see, yeah that makes sense, because Swift doesn't have a type that'd work the same way Nothing does in Kotlin, where Nothing conforms to any other type, so you can't really assign it this way