Good morning. I have a function that accepts a lam...

# arrow

[Davide Giuseppe Farella]

Good morning. I have a function that accepts a lambda that returns Either<NetworkError, T>
Something like

fun <T : Any> MyFun(
    ...
    fetch: suspend () -> Either<NetworkError, T>,
    ...
): Flow<Either<DataError, T>>

Now I have a new use case, as I started supporting a guest mode, so besides NetworkError and T I need something to represent a case when the user is not logged in, which I don’t want to be part of either of the 2 mentioned.

What would you suggest to use instead of Either<NetworkError, T> ? ( Skipped = call didn’t happen )
Here are some solutions that I thought of, but dunno which one would be nicer, or if there are other solutions:
• Either<Either<NetworkError, Skipped>, T> this would be the easier one to achieve/refactor; not sure how nice it would be to nest 2 Either
• Either<NetworkResult, T>

sealed interface NetworkResult {
  object Skipped : NetworkResult
  data class Error(val networkError: NetworkError)
}

• Replace Either with a sealed interface, like following

sealed interface NetworkResult<T> {
  object Skipped : NetworkResult<Nothing>
  data class Error<Nothing>(val networkError: NetworkError)
  data class Data(val data: T)
}

The last solution is probably the cleanest, but I’d lose the Either operators that I’m currently using, like tap , fold , bind , etc
The second one would be my preferred

[Davide Giuseppe Farella]

Real life usage [here](https://github.com/4face-studi0/CineScout/tree/main/cinescout/store/src/commonMain/kotlin/store) in Store.kt and PagedStore.kt

[stojan]

I'd also go with the second option...

You could also wrote your computational block (like either {}) for your own NetworkResult type... But going with the second option is simpler

[Davide Giuseppe Farella]

Already did that before Arrow was multiplatform, but don't wanna reinvent the wheel again 😃 I'm trying the second option