Developers Summit 2015の発表資料

1. Scala
{Monad}

2. Who Am I
• Now: Dynalyst
• Lang: Korean(30+ years)
Japanese(8+ years)
JAVA(8.2+ years)
Scala(a year)
• AdTech: AMoAd DSP
CAA Reward

3. What Dynalyst
• Dynamic Retargeting +
Analyst
• ユーザーの趣味嗜好に適した広告配
信を行う国内初のスマートフォンに
特化したダイナミックリターゲティ
ング広告

4. Scala USAGE

5. Today’s Talk
• Monads in Scala
Standard Library
• How to use them

6. Monad?
• Effects on a value
• Structure that
represents computations
defined as sequences of
steps

7. Monad?
• Effects on a value
:unit
• Structure that represents
computations defined as
sequences of steps
:flatMap

8. Effects on a value
• VALUE
• MONAD(VALUE)
• Option(VALUE),
List(VALUE),
Try(VALUE),
Future(VALUE)

9. Sequencial
Computations
• X -> Y -> Z
• M[X] -> M[Y] -> M[Z]
f g
f’ g’

10. Behaviour
• f = X => M[Y]
g = Y => M[Z]
• X -> M[X] -> M[Y]
• M[Y] -> M[Z] -> …
unit flatMap
flatMap flatMap

11. Simple User DAO

12. Option
Effects on a
Nullable Value
(Some or None)

13. Unit

14. FlatMap

15. Effects on a
Nullable Value
Some(User) or None

16. Exception Safety?

17. Try
Effects on a
Throwable Value
(Success or Failure)

18. Unit

19. FlatMap

20. Effects on a Nullable
& Throwable Value
Success(Some(User)) or
Success(None) or
Failure(throwable)

21. Blocking Thread?

22. Future
Effects on a
Blocking Value
(Success or Failure)

23. Unit

24. FlatMap

25. Effects on a Nullable
& Throwable Value
in Asynchronously
Success(Some(User)) or
Success(None) or
Failure(throwable)

26. List
Effects on
Iterable Values
(List or Nil)

27. Monad Laws
• Left Identity
• Right Identity
• Associativity

28. Pull a value out of
Monad
• Helper Functions
:getOrElse,fold,foreach,recover…
• Pattern Match
• 3rd Party Library
:Akka,Spray…

29. Akka

30. Spray

31. Benefits
• Keep your codes CLEAN
• Easy To Guess(READABLE)
• MAINTAINABLE
• Less Code Less BUGS

32. We are Hiring!
• 一緒に働く仲間を募集しています！
Scalaに興味のある方はぜひ！
adtech_scala@cyberagent.co.jp

33. Thanks
han_sangwon@cyberagent.co.jp