実践Monix導入 / Monix in Action

2019/10/27 Scala関西サミット
2019/9/30 セプテーニ・オリジナル社内勉強会

Transcript

1. ࣮ફMONIXಋೖ
   TAISUKE OE (@OE_UIA)
   

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2. WHO AM I
   ▸ Taisuke Oe
   ▸ ϑϦʔϥϯεΤϯδχΞ
   ▸ ٕज़ΞυόΠβʔ @ Septeni Original, Inc
   ▸ ScalaMatsuri chairperson
   

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3. ຊ೔ͷ͓඼ॻ͖
   ▸ Monixͬͯͳʹʁ
   ▸ Monix Taskͷ࢖͍ํ
   ▸ Monix Taskͷಋೖͷ࢓ํ
   ▸ ෇࿥: Monix 3.0.0Ͱͷมߋ఺
   

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4. MONIXͬͯͳʹʁ
   MONIX
   ▸ ฒߦϓϩάϥϛϯάΛޮ཰Α͘ɺศརʹ͢ΔͨΊͷϥΠϒ
   ϥϦ
   ▸ ࠷৽͸v3.0.0
   ▸ cats, cats-effectʹґଘ
   ▸ ࡞ऀ͸cats-effectͷओͨΔ։ൃऀͷҰਓ(ίϛοτ਺1Ґ)
   ▸ Scala Best Practices
   

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5. MONIXͬͯͳʹʁ
   MONIXͷྺ࢙(͓·͚)
   ▸ ~v1.0 (2015/12): monifu
   ▸ Reactive Extensions (Rx)ʹΠϯεύΠΞ͞Εͨɺobservable sequenceʹΑΔඇಉظϓϩάϥϛϯά ϥΠϒϥϦ
   ▸ Zero dependency / compatible with Scalaz
   ▸ v1.0 monifu => monix΁໊લมߋ
   ▸ ‘Monifu has a lame English pronunciation’ (ӳޠͰ޷·͘͠ͳ͍ൃԻͷͨΊ)
   ▸ v2.0-M1 (2016/3): Taskͷ௥Ճ
   ▸ v2.0.0 release (2016/9)
   ▸ Optional packages: moni-cats / monix-scalaz-72
   ▸ v3.0.0-M1 (2017/8) Iterantͷ௥Ճ
   ▸ deep integration with Typelevel Cats and Cats-Effect
   ▸ v2.3.3 release (2018/1)
   ▸ v3.0.0 release (2019/9)

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6. MONIXͬͯͳʹʁ
   MONIXͷߏ੒
   ▸ monix-execution … ฒߦॲཧͰ෭࡞༻Λ͏·͘ѻ͏ͨΊͷLow Level APIɻ
   SchedulerͳͲɻ
   ▸ monix-eval … ฒߦॲཧͰ෭࡞༻Λ͏·͘ѻ͏ͨΊͷɺ७ਮؔ਺ܕσʔλߏ
   ଄ɻTask, CoevalͳͲɻ
   ▸ monix-reactive … ReactiveXͷScala࣮૷ɻObservableͳͲɻ
   ▸ monix-tail … PullܕετϦʔϜͷ७ਮؔ਺ܕσʔλߏ଄ɻIterantͳͲɻ
   ▸ monix-catnap … cats-effectͷܕΫϥεΛجʹͨ͠७ਮؔ਺ܕͷฒߦॲཧ
   ϢʔςΟϦςΟɻMVar, CircuitBreakerͳͲɻ
   

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7. MONIXͬͯͳʹʁ
   MONIXͷߏ੒
   ▸ monix-execution … ฒߦॲཧͰ෭࡞༻Λ͏·͘ѻ͏ͨΊͷLow Level
   APIɻSchedulerͳͲɻ
   ▸ monix-eval … ฒߦॲཧͰ෭࡞༻Λ͏·͘ѻ͏ͨΊͷɺ७ਮؔ਺ܕσʔλߏ
   ଄ɻTask, CoevalͳͲɻ
   ▸ monix-reactive … ReactiveXͷScala࣮૷ɻObservableͳͲɻ
   ▸ monix-tail … PullܕετϦʔϜͷ७ਮؔ਺ܕσʔλߏ଄ɻIterantͳͲɻ
   ▸ monix-catnap … cats-effectͷܕΫϥεΛجʹͨ͠७ਮؔ਺ܕͷฒߦॲཧ
   ϢʔςΟϦςΟɻMVar, CircuitBreakerͳͲɻ
   

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8. TASKͷ࢖͍ํ
   TASK IN ACTION
   

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9. MONIX TASKͷ࢖͍ํ
   BUILD.SBT
   ▸ libraryDependencies += "io.monix" %% "monix-eval" % “3.0.0"
   

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10. MONIX TASKͷ࢖͍ํ
    MONIX TASKʹΑΔฒߦϓϩάϥϛϯάୈҰา
    import Scheduler.Implicits.global
    def task(i: Int) = Task.eval {
    printCurrentThread()
    i
    }
    val cubeSum = for {
    i iCube j jCube } yield {
    printCurrentThread() //on scala-execution-context-global-57
    iCube + jCube
    }
    cubeSum.runAsync {
    case Right(value) => println(value)
    case Left(err) => println(err.getMessage)
    }
    

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11. MONIX TASKͷධՁઓུ
    MONIX TASK͸஗ԆධՁ
    ▸ ஗ԆධՁTaskΠϯελϯεΛੜ੒ͨ࣌͠఺Ͱ
    ͸ɺ࣮ߦ͞Εͳ͍ͷͰࢀরಁաɻ
    ▸ ஗ԆධՁ͔ͭಉظ
    ▸ Task.apply
    ▸ v3.0.0͔Βಉظʹͳͬͨ
    ▸ Task.eval
    ▸ Task.evalOnce
    ▸ ϝϞԽ
    ▸ ஗ԆධՁ͔ͭඇಉظ
    ▸ Task.evalAsync
    ▸ ઌߦධՁ͔ͭಉظ
    ▸ Task.now
    ▸ Task.raiseError
    ▸ ܭࢉࡁΈͷ஋Λϥοϓ͢Δ
    

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12. MONIX TASKͷධՁઓུ
    ஗ԆධՁTASKΛ࣮ߦ͢Δ
    ▸ ࣮ߦ͢Δࡍʹ͸͡ΊͯɺScheduler (ExecutionContextΛϥοϓͨ͠΋ͷʣΛ҉໧ͷҾ਺Ͱ
    ཁٻ͢Δ
    ▸ ࣮ߦ͢Δͱɺ෭࡞༻͕ൃੜ͢ΔʢՄೳੑ͕͋Δʣ
    ▸ Task#runAsync
    ▸ Task#runAsync(cb: (Either[Throwable, A]) => Unit)(implicit s: Scheduler): Cancelable
    ▸ Task#runAsyncUncancelable
    ▸ Task#runAsyncUncancelable(cb: (Either[Throwable, A]) => Unit)(implicit s: Scheduler): Unit
    ▸ Task#runAsyncAndForget
    ▸ Task#runAsyncAndForget(implicit s: Scheduler): Unit
    ▸ Task#runToFuture
    ▸ Task#runToFuture(implicit s: Scheduler): CancelableFuture[A]
    

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13. MONIX TASKͷ࢖͍ํ
    MONIX TASKʹ͓͚ΔඇಉظڥքΛཧղ͠Α͏
    import Scheduler.Implicits.global
    def task(i: Int) = Task.eval {
    printCurrentThread()
    i
    }
    val cubeSum = for {
    i iCube j jCube } yield {
    printCurrentThread() //on scala-execution-context-global-57
    iCube + jCube
    }
    cubeSum.runAsync{
    case Right(value) => println(value)
    case Left(err) => println(err.getMessage)
    }
    

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14. MONIX TASKͷ࢖͍ํ
    MONIX TASKʹ͓͚ΔඇಉظڥքΛཧղ͠Α͏
    import Scheduler.Implicits.global
    def task(i: Int) = Task.eval {
    printCurrentThread()
    i
    }
    val cubeSum = for {
    i iCube j jCube } yield {
    printCurrentThread() //on scala-execution-context-global-57
    iCube + jCube
    }
    cubeSum.runAsync{
    case Right(value) => println(value)
    case Left(err) => println(err.getMessage)
    }
    ඇಉظڥքʁ
    

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15. ඇಉظڥք
    ඇಉظڥքͱ͸ʁ
    ▸ ʮReactive Manifest GlossaryʯΑΓ
    ▸ Isolation can be defined in terms of decoupling ……
    Decoupling in time means that the sender and receiver
    …… do not need to be present at the same time for
    communication to be possible. It is enabled by adding
    asynchronous boundaries between the components ……
    

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16. ඇಉظڥք
    ඇಉظڥքͱ͸ʁ
    ▸ ʮReactive Manifest GlossaryʯΑΓ
    ▸ ִ཭ ͸ɺ੾Γ཭͢͜ͱʹΑͬͯୡ੒͞ΕΔ……࣌ؒʹ
    ͓͚Δ੾Γ཭͠ͱ͸ɺૹΓखͱड͚ख͕…….ಉ࣌ʹίϛϡχέʔ
    γϣϯ͢Δඞཁ͕ͳ͍ͱ͍͏͜ͱΛҙຯ͢Δɻ͜ͷ੾Γ཭͠͸ɺ
    ίϯϙʔωϯτؒʹඇಉظڥքΛૠೖ͢Δ͜ͱͰՄೳʹͳΔ……
    ▸ ͢ͳΘͪඇಉظڥք͸ɺૹΓखͱड͚ख͕ʮಉظ௨৴͢Δඞཁ͕ͳ
    ͍ʯͱ͍͏ؔ܎Λ໌ࣔ͢ΔͨΊͷ΋ͷ
    

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17. MONIX TASKͷඇಉظڥք
    TASK ʹ͓͚Δඇಉظڥք
    ▸ (task: Task).executeAsync
    ▸ taskͷલʹඇಉظڥքΛૠೖ
    ▸ Task.evalAsync(…) 㱻 Task.eval(…).executeAsync
    ▸ (task: Task).asyncBoundary
    ▸ taskͷޙʹඇಉظڥքΛૠೖ
    

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18. MONIX TASKͷඇಉظڥք
    ඇಉظڥք͸Ͳ͜ʁ
    import Scheduler.Implicits.global
    def task(i: Int) = Task.eval {
    printCurrentThread()
    i
    }
    val cubeSum = for {
    i iCube j jCube } yield {
    printCurrentThread() //on scala-execution-context-global-57
    iCube + jCube
    }
    cubeSum.runAsync{
    case Right(value) => println(value)
    case Left(err) => println(err.getMessage)
    }
    

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19. MONIX TASKͷඇಉظڥք
    ඇಉظڥք͸͜͜
    import Scheduler.Implicits.global
    def task(i: Int) = Task.eval {
    printCurrentThread()
    i
    }
    val cubeSum = for {
    i iCube j jCube } yield {
    printCurrentThread() //on scala-execution-context-global-57
    iCube + jCube
    }
    cubeSum.runAsync{
    case Right(value) => println(value)
    case Left(err) => println(err.getMessage)
    }
    ඇಉظڥք
    ඇಉظڥք
    

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20. MONIX TASKͷඇಉظڥք
    εϨου͕੾ΓସΘͬͯΔͷ͸͜͜
    import Scheduler.Implicits.global
    def task(i: Int) = Task.eval {
    printCurrentThread()
    i
    }
    val cubeSum = for {
    i iCube j jCube } yield {
    printCurrentThread() //on scala-execution-context-global-57
    iCube + jCube
    }
    cubeSum.runAsync{
    case Right(value) => println(value)
    case Left(err) => println(err.getMessage)
    }
    ඇಉظڥք
    ඇಉظڥք
    ݺͼग़͠εϨουʢϝΠϯʣ
    ExecutionContext಺ͷεϨουϓʔϧ
    ExecutionContext಺ͷεϨουϓʔϧ
    

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21. εϨου͕੾ΓସΘͬͯΔͷ͸͜͜
    import Scheduler.Implicits.global
    def task(i: Int) = Task.eval {
    printCurrentThread()
    i
    }
    val cubeSum = for {
    i iCube j jCube } yield {
    printCurrentThread() //on scala-execution-context-global-57
    iCube + jCube
    }
    cubeSum.runAsync{
    case Right(value) => println(value)
    case Left(err) => println(err.getMessage)
    }
    ඇಉظڥք
    ඇಉظڥքʁ
    ݺͼग़͠εϨουʢϝΠϯʣ
    ExecutionContext಺ͷεϨουϓʔϧ
    MONIX TASKͷඇಉظڥք
    

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22. MONIX TASKͷඇಉظڥք
    MONIX TASKͷඇಉظڥքͷऔΓѻ͍
    ▸ ඇಉظڥքΛૠೖͨ͠ͱ͜ΖͰ
    ▸ ಉ࣌ʹSchedulerΛ౉͍ͯ͠Δ৔߹͸ɺͦͷSchedulerͷ΋ͭεϨουϓʔϧͰ࣮ߦ͞Ε
    Δɻ
    ▸ Scheduler͕ࢦఆ͞Εͳ͍৔߹͸ɺrunAsync౳Ͱ҉໧తʹ౉ͨ͠SchedulerʢσϑΥϧτ
    ͷSchedulerʣ಺ͷεϨουϓʔϧ΁੾ΓସΘΔ
    ▸ طʹσϑΥϧτͷScheduler಺ͷεϨουϓʔϧͰ࣮ߦதͷ৔߹͸ɺ࣮ߦεϨου͸
    ੾ΓସΘΒͳ͍͜ͱ͕͋Δ
    ▸ Scalaඪ४Future͸ɺmap / flatMap͝ͱʹڧ੍తʹεϨουϓʔϧʹ౉͞ΕΔ
    ▸ Φʔόʔϔου͕େ͖͍
    

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23. TASK ʹ͓͚ΔඇಉظڥքʴSCHEDULERΛࢦఆ
    ▸ (task: Task).asyncBoundary(s: Scheduler)
    ▸ taskͷޙʹඇಉظڥքΛૠೖ͠ɺ͔࣮ͭߦ͢ΔSchedulerΛࢦఆ͢Δɻ
    ▸ (task: Task).executeOn(s: Scheduler)
    ▸ taskͷલʹඇಉظڥքΛૠೖ͠ɺ͔࣮ͭߦ͢ΔSchedulerΛࢦఆ͢Δɻ
    ▸ taskͷޙʹ΋ඇಉظڥքΛૠೖ͠ɺ͔࣮ͭߦ͢ΔSchedulerΛσϑΥϧ
    τ΁੾Γସ͑Δ
    ▸ v3.0.0͔ΒɺSwitch Back͢ΔΑ͏ʹͳͬͨ
    MONIX TASKͷඇಉظڥք
    

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24. ࣮ߦ͢ΔSCHEDULERΛࢦఆ͢Δ
    import monix.eval.Task
    def task(i: Int) = Task.eval {
    printCurrentThread()
    i
    }
    def heavyCalculation(i: Int): Task[BigDecimal] = Task.eval {
    printCurrentThread()
    Seq.fill(100)(i).foldLeft(BigDecimal(i))(_ * _)
    }
    import Scheduler.Implicits.global
    val io = Scheduler.io("blocking")
    val result = for {
    value another calculated calcu } yield calculated + calcu
    result.runAsync {
    case Right(value) =>
    printCurrentThread()
    // on scala-execution-context-global-809
    println(value)
    case Left(err) => println(err)
    }
    MONIX TASKͷඇಉظڥք
    

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25. MONIX TASKͷ࢖͍ํ
    SCALAඪ४FUTUREͱͷINTEROP
    ▸ Scalaඪ४ Futureͱͷ૬ޓม׵͕ޮ཰Α͘؆୯ʹͰ͖Δ
    ▸ Task.fromFuture[A](f: Future[A]): Task[A]
    ▸ Task.deferFuture[A](fa: => Future[A]): Task[A]
    ▸ Task.deferFutureAction[A](f: (Scheduler) => Future[A]):
    Task[A]
    ▸ Task#runToFuture(implicit s: Scheduler): CancelableFuture[A]
    

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26. SCALAඪ४FUTUREͱͷINTEROP
    TASK . FROM FUTURE
    ▸ Task.fromFuture[A](f: Future[A]): Task[A]
    ▸ ઌߦධՁ(eager)͞ΕΔTaskΛ࡞Δ
    ▸ Future.successful΍Future.faildͰఆٛ͞ΕͨFutureͳ
    ͲɺܭࢉࡁΈͷFutureΛแΉɻ
    

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27. SCALAඪ४FUTUREͱͷINTEROP
    TASK . DEFER FUTURE
    ▸ Task.deferFuture[A](fa: => Future[A]): Task[A]
    ▸ ஗ԆධՁ(lazy)͞ΕΔTaskΛ࡞Δ
    ▸ (ExecutionContextΛཁٻ͠ͳ͍) FutureΛฦ͢ܭࢉΛแ
    Ήɻ
    

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28. SCALAඪ४FUTUREͱͷINTEROP
    TASK . DEFER FUTURE ACTION
    ▸ Task.deferFutureAction[A](f: (Scheduler) => Future[A]):
    Task[A]
    ▸ ஗ԆධՁ(lazy)͞ΕΔTaskΛ࡞Δɻ
    ▸ Scheduler (ExecutionContext)ΛҾ਺ʹͱΔɺFutureΛฦ
    ͢ܭࢉΛแΉɻ͜ͷFutureʹ౉͞ΕΔExecutionContext
    ͸ɺ࠷ޙʹTask#runAsyncͰ౉ͨ͠SchedulerͷΠϯελ
    ϯεͰ͋Δɻ
    

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29. SCALAඪ४FUTUREͱͷINTEROP
    TASK . RUN TO FUTURE
    ▸ Task#runToFuture(implicit s: Scheduler):
    CancelableFuture[A]
    ▸ TaskͷධՁΛ։࢝͠ɺFuture΁ม׵͢Δ
    

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30. MONIX TASKͷ࢖͍ํ
    ਖ਼ৗύεҎ֎ͷϋϯυϦϯά
    ▸ ΤϥʔϋϯυϦϯά & ϦτϥΠ
    ▸ Ωϟϯηϧ
    ▸ Ϧιʔεղ์
    

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31. MONIX TASKͷ࢖͍ํ
    ΤϥʔϋϯυϦϯά
    import monix.eval.Task
    //ࣦഊ͢Δ͔΋
    def loadHeavyJson(id: Long): Task[JSON] = ???
    import scala.concurrent.duration._
    // Exponential BackoffͰ࠶ࢼߦ
    // 100 millis, 200 millis, 400 millis, 800 millis, 1600 millis, 3200 millis
    val heavyJson: Task[JSON] =
    ɹloadHeavyJson(123L).onErrorRestartLoop(100.millis) {
    (e, delay, retry) =>
    if(delay < 4.seconds)
    retry(delay * 2).delayExecution(delay)
    else
    Task.raiseError(e)
    ɹ}.memoizeOnSuccess //੒ޭͨ͠ΒϝϞԽ
    

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32. MONIX TASKͷ࢖͍ํ
    Ωϟϯηϧ
    import monix.eval.Task
    import monix.execution.Scheduler.Implicits.global
    val cancelable = heavyJson.runAsync {
    case Left(e) => println(e)
    case Right(json) => println(json)
    }
    //΋͠ඞཁͳΒ
    cancelable.cancel()
    

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33. MONIX TASKͷ࢖͍ํ
    Ϧιʔεղ์
    import monix.eval.Task
    class Client() {
    def get(id: Long): JSON = ???
    def release(): Unit = ???
    }
    def loadHeavyJsonByClient(id: Long): Task[JSON] =
    Task.eval(new Client())
    .bracket {
    client =>
    Task.evalAsync(client.get(id))
    } {
    client =>
    //੒൱ʹؔΘΒͣϦϦʔε
    Task.eval(client.release())
    }
    

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34. ฒྻܭࢉAPI
    ▸ tasks: Seq[Task[T]]͕͋ͬͨͱ͖
    ▸ Task.sequence(tasks) Ͱ௚ྻܭࢉ͢ΔTask[Seq[T]]
    ▸ Task.gather(tasks)Ͱฒྻܭࢉ͢ΔTask[Seq[T]]
    ▸ Task.gatherN(parallerism:Int)(tasks)Ͱɺಉ࣌ฒྻ਺ࢦఆͰ
    ฒྻܭࢉ͢ΔTask[List[A]]
    ▸ Task.parMap2(taskA, taskB)((A,B) => R)Ͱɺฒྻܭࢉ͠Task[R]
    MONIX TASKͷ࢖͍ํ
    

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35. MONIX TASKͷ࢖͍ํ
    ؔ਺ܕ༝དྷͷܕΫϥεؔ܎ͷ஌͕ࣝෆཁ
    ▸ MonadError, Applicative, Traverseͱ͍ͬͨɺ௨ৗؔ਺ܕϓ
    ϩάϥϛϯά༻ͷϥΠϒϥϦ(e.g. Cats౳)ͷܕΫϥε͕ఏڙ
    ͍ͯ͠Δsyntaxͷ͏ͪɺಛʹศརͳ΋ͷ͕MonixࣗલͰ༻ҙ
    ͞Ε͍ͯΔ
    ▸ Cats΍Scalazʹਫ਼௨͍ͯ͠ͳͯ͘΋ɺTaskΛ࢖͍͜ͳ͢͜
    ͱ͕Ͱ͖Δɻ
    

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36. ؔ਺ܕ ܕΫϥεෆཁͷTASK API
    TASK.ATTEMPT
    ▸ Task#attempt: Task[Either[Throwable, A]]
    ▸ MonadErrorܕΫϥεͷattemptͱಉ౳
    ▸ ੒ޭ஋΋͘͠͸ࣦഊ஋ΛEitherܕ΁্࣋ͪ͛Δ
    ▸ ੒ޭ͍ͯ͠Δ৔߹͸Task(Right(_: A))
    ▸ ࣦഊ͍ͯ͠Δ৔߹͸Task(Left(_: Throwable))
    

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37. ؔ਺ܕ ܕΫϥεෆཁͷTASK API
    TASK.MAP2 / TASK.PARMAP2 OR MORE
    ▸ Task.map2[A1, A2, R](fa1: Task[A1], fa2: Task[A2])(f: (A1, A2) =>
    R): Task[R] ͳͲͷmapN, parMapN
    ▸ ApplicativeܕΫϥεͷmapNͱಉ౳(࣮૷ґଘͰ௚ྻorฒྻܭࢉ
    ͞ΕΔ)
    ▸ map2͸fa1ͱfa2͸௚ྻʹܭࢉ͞ΕΔ
    ▸ fa1ͷ׬ྃޙʹfa2͕ܭࢉ͞ΕΔ
    ▸ parMap2͸fa1ͱfa2͸ฒྻʹܭࢉ͞ΕΔ
    

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38. ؔ਺ܕ ܕΫϥεෆཁͷTASK API
    TASK.SEQUENCE
    ▸ Task.sequence[A, M[X] (implicit bf: BuildFrom[M[Task[A]], A, M[A]]): Task[M[A]]
    ΍ɺTask.traverse
    ▸ TraverseܕΫϥεͷsequence , traverseͱ΄΅ಉ౳
    ▸ MͱTaskͷೖΕࢠͷॱ൪ΛೖΕସ͑Δɻ
    

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39. ؔ਺ܕ ܕΫϥεෆཁͷTASK API
    TASKͱܕΫϥε
    ▸ Task͸஗ԆධՁ͢Δࢀরಁաͳσʔλߏ଄ɻlawfulͳܕΫϥεΠϯελϯε΋༻ҙ͞Ε͍ͯΔɻ
    ▸ ७ਮؔ਺ܕͷઃܭΛͨ͠ιϑτ΢ΣΞͰ΋࢖͍΍͍͢ɻ
    ▸ cats-effect:
    ▸ Effect, ConcurrentEffect, Async, Concurrent, ContextShift
    ▸ cats:
    ▸ MonadError, Applicative, Monad, CoFlatMap
    ▸ Parallel, Monoid, Semigroup
    ▸ Future͸ઌߦධՁͰ෭࡞༻ΛҾ͖ىͨ͜͢ΊɺMonad౳ͷܕΫϥεͷlawΛຬͨ͞ͳ͍ɻ
    MonadΛཁٻ͍ͯ͠Δͱ͜ΖͰFutureΛ࢖͏ͱɺ༧ظͤ͵ΤϥʔΛҾ͖ى͜͢Մೳੑ͋Γɻ
    

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40. MONIX TASKͷ࢖͍ํ
    MONIX TASK ͷخ͍͠ͱ͜Ζʢ·ͱΊʣ
    ▸ ॊೈʹඇಉظڥքΛઃఆՄೳ
    ▸ ඞཁͳ৔ॴͰඞཁͳ͚ͩɺඇಉظॲཧʹ͢Δ͜ͱ͕Մೳ
    ▸ Scala Futureͱͷinterop͕༏ल
    ▸ Lightbend Ecosystemʹ৐ͬͨΞϓϦέʔγϣϯͰ΋ಋೖ͠΍͍͢
    ▸ ਖ਼ৗύεҎ֎ͷϋϯυϦϯά͕ॊೈ
    ▸ ΤϥʔɺϦτϥΠɺΩϟϯηϧɺϦιʔεղ์ͳͲ
    ▸ ฒྻܭࢉAPI͕๛෋
    ▸ ஗ԆධՁͷϝϦοτΛڗड
    ▸ ؔ਺ܕ༝དྷͷܕΫϥεͷ஌͕ࣝͳͯ͘΋े෼࢖͑Δ
    

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41. TASKͷಋೖͷ࢓ํ
    TASK IN ACTION
    

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42. MONIX TASKͷಋೖ
    TASKΛͲ͔͜Βಋೖͨ͠ΒΑ͍͔ʁ
    ▸ ඇಉظॲཧʹFutureΛ࢖࣮ͬͯ૷͞ΕͨγεςϜͰɺTaskΛ
    ࢖͍͍ͨ৔ॴ͕Ͱ͖ͨέʔε
    ▸ retry΍timeoutɺcancelͳͲࣦഊύεͷ؅ཧΛॊೈʹͨ͠
    ͍
    ▸ ϝϞԽΛॊೈʹߦ͍͍ͨ
    ▸ FutureͰඇಉظڥքΛ·͙ͨΦʔόʔϔου(map/
    flatMapຖ)ΛݮΒ͍ͨ͠
    

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43. TASKΛͲ͔͜Βಋೖͨ͠ΒΑ͍͔ʁ
    Domain Service
    Repository
    Repository
    Impl
    Application
    Service
    Controller
    Future
    Future
    Future
    MONIX TASKͷಋೖ
    

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44. FUTUREͰ࣮૷͞ΕͨγεςϜ
    D0MAIN
    trait UserRepository {
    type Ctx def resolveById(id: UserId)(implicit C: Ctx): Future[User]
    def update(user: User)(implicit C: Ctx): Future[Unit]
    }
    trait UserNameChangeService {
    val repository: UserRepository
    def changeName(userId: UserId, newName: String)(implicit C: repository.Ctx): Future[Unit] = {
    implicit val ec = C.ec
    for {
    user modifiedUser = user.copy(name = newName)
    _ } yield ()
    }
    }
    trait Context {
    def ec: ExecutionContext
    }
    case class UserId(value: Long) extends AnyVal
    case class User(id: UserId, name: String)
    

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45. APPLICATION
    class UserRepositoryImpl extends UserRepository {
    override type Ctx = FutureIOContext
    import UserRecord.{u, userIdBinder}
    override def resolveById(id: UserId)(implicit C: FutureIOContext): Future[User] = {
    import C._
    Future(
    Future.fromTry(
    withSQL {
    select.from(UserRecord as u).where.eq(u.id, id).limit(1)
    }.map(UserRecord(_, u.resultName)).single().apply()
    .fold[Try[User]](Failure( /* … */ )))(ur => Success(ur.toUser))
    )
    ).flatten
    }
    override def update(user: User)(implicit C: FutureIOContext): Future[Unit] = {
    import C._
    Future {
    withSQL {
    QueryDSL.update(UserRecord as u).set(u.id -> user.id.value, u.name -> user.name)
    }.update().apply()
    }
    }
    }
    class UserNameChangeServiceImpl(override val repository: UserRepositoryImpl) extends UserNameChangeService {
    def changeNameTx(userId: UserId, newName: String)(implicit ec: ExecutionContext): Future[Unit] = DB.localTx { /* … * / }
    }
    case class FutureIOContext(session: DBSession, ec: ExecutionContext) extends Context{
    implicit val dbSession: DBSession = session
    implicit val executionContext: ExecutionContext = ec
    }
    FUTUREͰ࣮૷͞ΕͨγεςϜ
    

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46. CONTROLLER
    object Runner extends App {
    val repository = new UserRepositoryImpl()
    val service = new UserNameChangeServiceImpl(repository)
    import ExecutionContext.Implicits.global
    service.changeNameTx(UserId(1L), "Martin Odersky").onComplete {
    case Success(_) => //do something
    case Failure(_) => //do something
    }
    }
    FUTUREͰ࣮૷͞ΕͨγεςϜ
    

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47. TASKΛͲ͔͜Βಋೖͨ͠ΒΑ͍͔ʁ
    Domain Service
    Repository
    Repository
    Impl
    Application
    Service
    Controller
    Future
    Future
    Task
    Future
    MONIX TASKͷಋೖ
    

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48. Domain Service
    Repository
    Repository
    Impl
    Application
    Service
    Controller
    Future
    Future
    Task
    Task.deferFutureAction
    Future
    TASKΛͲ͔͜Βಋೖͨ͠ΒΑ͍͔ʁ
    MONIX TASKͷಋೖ
    

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49. CONTROLLERͰTASKΛ࢖͏
    object Runner extends App {
    val repository = new UserRepositoryImpl()
    val service = new UserNameChangeServiceImpl(repository)
    val task =
    Task.deferFutureAction {
    implicit scheduler => service.changeNameTx(UserId(1L), "Martin Odersky")
    }.onErrorRestartLoop(0) {
    (t, current, handle) =>
    if (current < 5)
    handle(current + 1).delayExecution(300.millis)
    else
    Task.raiseError(t)
    }
    import monix.execution.Scheduler.Implicits.global
    task.runAsync {
    case Left(_) => //do something
    case Right(_) => //do something
    }
    }
    FUTUREͰ࣮૷͞ΕͨγεςϜ
    

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50. ΋͠APPLICATION SERVICEͰTASKΛ࢖͍ͨ͘ͳͬͨΒ
    Domain Service
    Repository
    Repository
    Impl
    Application
    Service
    Controller
    Future
    Future
    Task
    Task.deferFutureAction
    Future
    MONIX TASKͷಋೖ
    

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51. ΋͠APPLICATION SERVICEͰTASKΛ࢖͍ͨ͘ͳͬͨΒ
    Domain Service
    Repository
    Repository
    Impl
    Application
    Service
    Controller
    Future
    Future
    Task
    Task.deferFutureAction
    Future
    Task
    Task.deferFutureAction
    MONIX TASKͷಋೖ
    

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52. ΋͠APPLICATION SERVICEͰTASKΛ࢖͍ͨ͘ͳͬͨΒ
    Domain Service
    Repository
    Repository
    Impl
    Application
    Service
    Controller
    Task
    Future
    Future
    Task
    Task.deferFutureAction
    MONIX TASKͷಋೖ
    

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53. APPLICATION SERVICEͰTASKΛ࢖͏
    class UserNameChangeServiceImpl(override val repository:
    UserRepositoryImpl) extends UserNameChangeService {
    def changeNameTx(userId: UserId, newName: String): Task[Unit] =
    DB.localTx { session =>
    Task.deferFutureAction{ scheduler =>
    implicit val ctx = FutureIOContext(session, scheduler)
    changeName(userId, newName)
    }
    }
    }
    FUTUREͰ࣮૷͞ΕͨγεςϜ
    

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54. ΋͠REPOSITORYͷ࣮૷ͰTASKΛ࢖͍ͨ͘ͳͬͨΒ
    Domain Service
    Repository
    Repository
    Impl
    Application
    Service
    Controller
    Task
    Future
    Future
    Task
    Task.deferFutureAction
    MONIX TASKͷಋೖ
    

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55. ΋͠REPOSITORYͷ࣮૷ͰTASKΛ࢖͍ͨ͘ͳͬͨΒ
    Domain Service
    Repository
    Repository
    Impl
    Application
    Service
    Controller
    Task
    Future
    Future
    Task
    Task.deferFutureAction
    Task
    Task.deferFutureAction
    MONIX TASKͷಋೖ
    

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56. MONIX TASKͷಋೖͷ࢓ํ - ·ͱΊ
    ▸ Task͸ॊೈͳඇಉظڥքͷઃఆɺࣦഊύεͷϋϯυϦϯάͳͲɺ࣮༻
    తͳAPI͕ἧ͍ͬͯΔ
    ▸ ControllerͳͲɺෳࡶͳඇಉظॲཧ΍ɺࣦഊͷϋϯυϦϯά͕ٻΊΒ
    ΕΔͱ͜ΖͰಋೖ͠΍͍͢
    ▸ Task͸Futureͱͷinterop͕ॆ࣮͍ͯ͠ΔͨΊɺincrementalʹಋೖ͢Δ
    ͜ͱ͕Ͱ͖Δ
    ▸ ಉظॲཧͷͨΊʹFuture / Try͕ࠞࡏ͍ͯ͠Δ৔߹ɺඇಉظTaskͱಉ
    ظTaskʹͦΕͧΕஔ׵Մೳ
    MONIX TASKͷಋೖ
    

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57. MONIXΛ࢖͏ͱ͖ -༨ஊ
    ▸ Effectܕ Injection (a.k.a “tagless final”) ͢Δ΂͖͔
    ▸ Monix TaskΛ࢖͏্Ͱ͸ඞਢͰ͸ͳ͍ɻReaderTͱ߹Θͤ
    ͯ࢖͍͍ͨ࣌ͳͲɺศརͳ࣌΋͋Δɻ
    ▸ ςελϏϦςΟͳͲɺଞͷ࣠Ͱಋೖ͢΂͖͔ݕ౼͠·͠ΐ
    ͏ɻͦͷ্Ͱ͸ϝϦοτ͕͋ΔͳΒಋೖ͢Ε͹ྑ͍ɻ
    MONIX TASKͷಋೖ
    

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58. APPENDIX
    MONIX 3.0.0ͷओͳมߋ఺
    ▸ ґଘϥΠϒϥϦͷมߋ
    ▸ APIͷमਖ਼
    ▸ ڍಈͷมߋ
    ▸ ໊લͷमਖ਼
    ▸ ฒྻܭࢉAPIͷ֦ॆ
    ▸ Iterant, Fiber, Localͷ௥Ճ
    

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59. MONIX 3.0.0ͷมߋ఺
    ґଘϥΠϒϥϦͷมߋ
    ▸ Monix v2.3.3Ͱ͸ɺcore͸ґଘͤͣɺScalazͱCatsͦΕͧΕ
    ʹґଘͨ͠module͕͋ͬͨ
    ▸ Monix v3.0.0͔ΒҎԼͷϥΠϒϥϦʹґଘ͍ͯ͠Δ
    ▸ Cats 2.0.0
    ▸ Cats-effect 2.0.0
    

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60. MONIX 3.0.0ͷมߋ఺
    APIͷमਖ਼ - ڍಈͷมߋ
    ▸ Task.apply͕ඇಉظ͔Βಉظ΁
    ▸ https://github.com/monix/monix/pull/670
    ▸ https://gitter.im/monix/monix/archives/2018/05/10?
    at=5af3f835bd10f34a68ef1f1f
    

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61. MONIX 3.0.0ͷมߋ఺
    APIͷमਖ਼ - ڍಈͷมߋ
    ▸ Task#executeOn͕ɺσϑΥϧτscheduler΁ࣗಈͰswitch
    back
    ▸ https://github.com/monix/monix/pull/670
    ▸ https://gitter.im/monix/monix/archives/2018/05/10?
    at=5af3fffab84be71db9f6bfdb
    ▸ https://gitter.im/monix/monix/archives/2018/05/10?
    at=5af3fe575a1d895fae2bb6fc
    

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62. MONIX 3.0.0ͷมߋ఺
    APIͷमਖ਼ - ڍಈͷมߋ
    ▸ Task.mapBothͷҾ਺͕ಉظTaskͰ͋ͬͨͱͯ͠΋ɺࣗಈͰ
    ඇಉظʹฒྻܭࢉ͞ΕΔΑ͏मਖ਼͞Εͨ
    

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63. MONIX 3.0.0ͷมߋ఺
    APIͷमਖ਼ - ໊લͷมߋ
    ▸ Task.zipMapNܥ => Task.mapNܥ
    ▸ Task#executeWithFork => Task#executeAsync
    

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64. APIͷमਖ਼ - RUNܥAPIͷ੔ཧ
    ▸ Task#runAsync => Task#runToFuture
    ▸ Task#runOnComplete(Try[A] => Unit)
    => Task#runAsync(Either[Throwable, A] => Unit)
    MONIX 3.0.0ͷมߋ఺
    

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65. MONIX 3.0.0ͷมߋ఺
    APIͷ௥Ճ - RUNܥAPIͷ௥Ճ
    ▸ Task#runSyncStepܥ
    ▸ Task#runAsyncAndForgetܥ
    ▸ Task#runAsyncOptͳͲOptionܥ
    

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66. MONIX 3.0.0ͷมߋ఺
    APIͷ௥Ճ - ௚ྻɾฒྻܭࢉAPIͷ֦ॆ
    ▸ Task.gatherN, Task.parMapܥ, Task.wanderN͕௥Ճ͞Εͨ
    

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67. MONIX 3.0.0ͷมߋ఺
    APIͷ௥Ճ - ϦιʔεˍΤϥʔϋϯυϦϯάܥ
    ▸ Task#bracketܥ
    ▸ Task#guaranteeܥ
    ▸ Task#redeemܥ
    ▸ Task#runAsyncFܥ
    

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68. MONIX 3.0.0ͷมߋ఺
    APIͷ௥Ճ - ϧʔϓܥϝιου௥Ճ
    ▸ Task#loopForever
    ▸ Task#onErrorRestartLoop
    

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69. MONIX 3.0.0ͷมߋ఺
    APIͷ௥Ճ - CATS-EFFECT COMPATIBLEͳܕม׵
    ▸ Task#toܥ
    ▸ to[F[_]], toAsync[F[_]], toConcurrent[F[_]]
    ▸ Task.fromܥ
    ▸ fromEffect, fromConcurrentEffectͳͲ
    

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70. MONIX 3.0.0ͷมߋ఺
    MONIX 3.0.0 ͷ஫ҙࣄ߲
    ▸ 2019/10/27࣌఺Ͱ͸υΩϡϝϯτͷߋ৽͕௥͍͍͍ͭͯͳ͍
    ▸ Documentation, scaladocͷίϝϯτ
    ▸ େےͰ͸มߋ͸ͳ͍͕ɺࡉ෦ͷهड़͸৴༻͠ͳ͍ํ͕͍͍
    ▸ ඞͣ3.0.0Ͱಈ࡞֬ೝ͠Α͏
    ▸ GitHub issues / PullRequests΋ඞཁʹԠͯ͡ࢀর͠Α͏
    ▸ PullReqνϟϯε!!
    

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