dreymonde

func completion<Result>(onResult: @escaping (Result) -> Void, onError: @escaping (Error) -> Void) -> ((Result?, Error?) -> Void) {
    return { (maybeResult, maybeError) in
        if let result = maybeResult {
            onResult(result)
        } else if let error = maybeError {
            onError(error)
        } else {
            onError(SplitError.NoResultFound)
        }
    }