1. Demo the reactive jargons
Mushtaq Ahmed
ThoughtWorks
@mushtaqA

2. getProductPage
getModule1
getModule2
getPricing
getProductSpec

3. square(a: Int): Intsquares(a: Seq[Int]): Seq[Int]

4. Demo

5. ● Async and NonBlocking mean different things
○ Async is about API
○ NonBlocking is about Implementation
● Async API can be implemented for Blocking calls!
● For NonBlocking calls, Sync API is not possible!
○ Macros and CPS transformations can be used to fake it

6. Blocking Non-blocking
Sync square(a: Int): Int XXX
Async square(a: Int): Future[Int] square(a: Int): Future[Int]
API
Implementation

7. Demo

8. ● Blocking IO is contagious
○ ExecutionContext helps to quarantine it
● Separate ExecutionContext for Blocking and
NonBlocking IO
○ Like different speed lanes

9. Demo

10. ● Error handling in Future is a bit difficult for bulk
operation
● Observable is a nicer alternative
○ Yet to explore: Retry, Timeout etc
● Observable API does not support backpressure
○ Be Careful not to introduce memory leaks

11. Single Multiple
Sync square(a: Int): Int squares(a: Seq[Int]): Seq[Int]
Async square(a: Int): Future[Int]
squares(a: Seq[Int]): Future[Seq
[Int]]
squares(a: Seq[Int]): Observable[Int]
Observable[Int] == Future[Iterable[Future[Int]]]

12. The code for demo is here:
https://github.com/mushtaq/pune-scala-symposium

13. ● We like to teach Scala
● We are planning to offer a FREE training in Pune!
○ Screening based on coding test ;)
● 4 full day sessions
○ Two consecutive Friday-Saturdays
● Sometime in May or June
○ Will announce it via @punescala/Pune Scala meetup group

14. Thank you