JorgeCastilloPrz

@JvmStatic
fun main(args: Array<String>): Unit {
    val user1 = User(UserId("user1"))
    val user2 = User(UserId("user2"))
    val user3 = User(UserId("unknown user"))

    val maybeModule = Module(MaybeK.async())
    maybeModule.run {
      repository.allTasksByUser(user1).fix().maybe.subscribe({ println(it) }, { println(it) })
      repository.allTasksByUser(user2).fix().maybe.subscribe({ println(it) }, { println(it) })

JorgeCastilloPrz

class Module<F>(A: Async<F>) {
  private val localDataSource: LocalDataSource<F> = LocalDataSource(A)
  private val remoteDataSource: RemoteDataSource<F> = RemoteDataSource(A)
  val repository: TaskRepository<F> = 
      TaskRepository(localDataSource, remoteDataSource, A)
}

JorgeCastilloPrz

object test {

  @JvmStatic
  fun main(args: Array<String>): Unit {
    val user1 = User(UserId("user1"))
    val user2 = User(UserId("user2"))
    val user3 = User(UserId("unknown user"))

    val singleModule = Module(SingleK.async())

JorgeCastilloPrz

fun allTasksByUser(user: User): Kind<F, List<Task>> =
    localDS.allTasksByUser(user).handleErrorWith {
      when (it) {
        is UserNotInLocalStorage -> remoteDS.allTasksByUser(user)
        else -> raiseError(UnknownError(it))
      }
    }

JorgeCastilloPrz

class TaskRepository<F>(
  private val localDS: DataSource<F>,
  private val remoteDS: RemoteDataSource<F>,
  AE: ApplicativeError<F, Throwable>) : ApplicativeError<F, Throwable> by AE {

  fun allTasksByUser(user: User): Kind<F, List<Task>> =
    localDS.allTasksByUser(user).handleErrorWith {
      when (it) {
        is UserNotInLocalStorage -> remoteDS.allTasksByUser(user)
        else -> raiseError(UnknownError(it))

JorgeCastilloPrz

override fun allTasksByUser(user: User): Kind<F, List<Task>> =
    async { callback: (Either<Throwable, List<Task>>) -> Unit ->
      Option.fromNullable(internetStorage[user]).fold(
        { callback(UserNotInRemoteStorage(user).left()) },
        { callback(it.right()) }
      )
    }

JorgeCastilloPrz

class RemoteDataSource<F>(A: Async<F>) : DataSource<F>, Async<F> by A {
  private val internetStorage: Map<User, List<Task>> =
    mapOf(User(UserId("user2")) to listOf(Task("Remote Task assigned to user2")))

  override fun allTasksByUser(user: User): Kind<F, List<Task>> =
    async { callback: (Either<Throwable, List<Task>>) -> Unit ->
      Option.fromNullable(internetStorage[user]).fold(
        { callback(UserNotInRemoteStorage(user).left()) },
        { callback(it.right()) }
      )

JorgeCastilloPrz

class LocalDataSource<F>(A: ApplicativeError<F, Throwable>) : 
    DataSource<F>, ApplicativeError<F, Throwable> by A {

JorgeCastilloPrz

override fun allTasksByUser(user: User): Kind<F, List<Task>> =
    Option.fromNullable(localCache[user]).fold(
      { raiseError(UserNotInLocalStorage(user)) },
      { just(it) }
    )

JorgeCastilloPrz

class LocalDataSource<F>(A: ApplicativeError<F, Throwable>) : 
    DataSource<F>, ApplicativeError<F, Throwable> by A {
      
    private val localCache: Map<User, List<Task>> =
      mapOf(User(UserId("user1")) to listOf(Task("LocalTask assigned to user1")))

    override fun allTasksByUser(user: User): Kind<F, List<Task>> =
      Option.fromNullable(localCache[user]).fold(
        { raiseError(UserNotInLocalStorage(user)) },
        { just(it) }