This document discusses how learning Scala can help programmers. Scala is a functional programming language that allows for concise and parallel code. It promotes avoiding shared state and using message passing between actors to make parallel programming easier. The document provides several video demos and recommends resources for learning Scala, including books and commercial support from Typesafe. The overall message is that learning Scala provides an enlightening experience that can make programmers better at functional and parallel programming paradigms.

1. Level up your Java
Iulian Dogariu
Ness Technologies
20 April 2013

3. Why Learn Yet Another Language?

4. Why Learn Yet Another Language?

5. Scala
• Functional style programming
• Parallelism
• Concise code

6. Psycho therapy time !
http://www.youtube.com/watch?v=GlFU0C4YV4o&hd=1
Video demo

7. A taste of Scala
http://www.youtube.com/watch?v=GWl4jGMojr8&hd=1
Video demo

8. Functional style programming
Video demos
http://www.youtube.com/watch?v=rn7BETTPwBM&hd=1
http://www.youtube.com/watch?v=35ug8iflmjE&hd=1

9. “Smaller and more general modules can be
reused more widely, easing subsequent
programming.
This explains why functional programs are so
much smaller and easier to write than
conventional ones.”
John Hughes
Why Functional Programming Matters

10. 12
Average # of lines of code per day per programmer
(Fred Brooks – „The Mythical Man Month”)
No matter what programming language !

11. Not just a tool …

12. … but a medium of expression
XXVIII
28

13. Let’s manipulate symbols
1372 ÷ 28

14. Let’s manipulate symbols
1372 ÷ 28
1372 | 28 |
112 | 4 |
25 |
|

15. Let’s manipulate symbols
1372 ÷ 28
1372 | 28 |
112 | 49 |
252 |
252 |
0

16. Notation matters.
MCCCLXXII ÷ XXVIII
?

17. Would you rather work with …

18. … or with this
Notation matters.
A lot!

19. Parallelism and concurrency

20. Parallelism and concurrency
CPUs aren’t getting any faster
We’ll just have
more of them !

21. Parallelism and concurrency
Threads will get you in a mess, fast

22. public Object fileLock = new Object();
public Object dbLock = new Object();
public void doThis() {
synchronized (fileLock) {
synchronized (dbLock) {
logToFileAndDb(db, “Doing this !”);
}
}
}
public void doThat() {
synchronized (dbLock) {
synchronized (fileLock) {
logToFileAndDb(db, “Doing that !”);
}
}
}

24. 99.9999999 % reliability
Less than 0.63 seconds downtime
Source: Joe Armstrong http://pragprog.com/articles/erlang
… in more than 20 years !

25. 99.9999999 % reliability
Source: Joe Armstrong http://pragprog.com/articles/erlang

26. Successful Parallel Programming
Message passing
No shared state

27. Actors

28. Actors
http://www.youtube.com/watch?v=UgpCfHiCtN0&hd=1
Video demo

29. Psycho therapy squared
http://www.youtube.com/watch?v=4O0Dq6Tf6k0&hd=1
Video demo

30. Source: TIOBE index February 2013
How popular?

31. Who uses Scala?
Source: http://slideshare.net/mslinn/scala-adoption-by-enterprises

32. But will this be useful to me?

33. „________ is worth learning for the
profound enlightenment experience
you will have when you finally get it;
that experience will make you a better
programmer for the rest of your days,
even if you never actually use [it]”
-- Eric S Raymond

34. One more thing

35. specs2

36. Be Ready for Tomorrow
• Functional style programming
• Parallelism
• Concise code

37. ... But Use Your Head

38. Resources
• http://www.scala-lang.org
• Book: Martin Odersky – Programming in Scala
• Book: Venkat Subramaniam – Programming Scala
• Commercial support: Typesafe, Inc.
http://www.typesafe.com
• IDE support: IntelliJ IDEA 12

39. Thank you!
And don’t forget to fill in
the evaluation form 
hello@iuliandogariu.com