Hi! I am trying to model the error handling in our...

# arrow

[Lukáš Kúšik]

Hi! I am trying to model the error handling in our Android client. I have been inspired by this video

(1) Building applications with Kotlin and Arrow.kt in style - YouTube▾

, although I would like to apply these principles to the client side in this case.

Let's say that there's a Repository which uses a RemoteApi and I'd like to create a new user on the backend.

The RemoteApi does the POST call using Ktor, and returns the result of the Either<ApiError, UserDTO> type, where ApiError encapsules any network exceptions, internal server errors, etc.
Now, I would like to parse expected errors (like UserAlreadyExists) as UserError of the common DomainError sealed type (similar to the video).
I'd like the Repository to get the`Either<ApiError, UserDTO>` from the RemoteApi, process the known errors and return something like the Either<UserError, UserDTO> type.

The problem with Either<UserError, UserDTO> is, that