iasi code camp 20 april 2013 iulian dogariu - scala

Level up your Java

Iulian DogariuNess Technologies

20 April 2013

Why Learn Yet Another Language?

Why Learn Yet Another Language?

Scala

• Functional style programming

• Parallelism

• Concise code

Psycho therapy time !

http://www.youtube.com/watch?v=GlFU0C4YV4o&hd=1

Video demo

A taste of Scala

http://www.youtube.com/watch?v=GWl4jGMojr8&hd=1

Video demo

Functional style programming

Video demos

http://www.youtube.com/watch?v=rn7BETTPwBM&hd=1

http://www.youtube.com/watch?v=35ug8iflmjE&hd=1

“Smaller and more general modules can be reused more widely, easing subsequentprogramming.

This explains why functional programs are so much smaller and easier to write than conventional ones.”

John HughesWhy Functional Programming Matters

12Average # of lines of code per day per programmer

(Fred Brooks – „The Mythical Man Month”)

No matter what programming language !

Not just a tool …

… but a medium of expression

XXVIII 28

Let’s manipulate symbols1372 ÷ 28

Let’s manipulate symbols1372 ÷ 28

1372 | 28 | 112 | 4 | 25 | |

Let’s manipulate symbols1372 ÷ 28

1372 | 28 | 112 | 49 | 252 | 252 | 0

Notation matters.

MCCCLXXII ÷ XXVIII

?

Would you rather work with …

… or with this

Notation matters. A lot!

Parallelism and concurrency

Parallelism and concurrency

CPUs aren’t getting any faster

We’ll just havemore of them !

Parallelism and concurrency

Threads will get you in a mess, fast

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 !”); } } }

99.9999999 % reliabilityLess than 0.63 seconds downtime

Source: Joe Armstrong http://pragprog.com/articles/erlang

… in more than 20 years !

99.9999999 % reliability

Source: Joe Armstrong http://pragprog.com/articles/erlang

Successful Parallel Programming

Message passing

No shared state

Actors

Actors

http://www.youtube.com/watch?v=UgpCfHiCtN0&hd=1

Video demo

Psycho therapy squared

http://www.youtube.com/watch?v=4O0Dq6Tf6k0&hd=1

Video demo

Source: TIOBE index February 2013

How popular?

Who uses Scala?

Source: http://slideshare.net/mslinn/scala-adoption-by-enterprises

But will this be useful to me?

„________ 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

One more thing

specs2

Be Ready for Tomorrow

• Functional style programming

• Parallelism

• Concise code

... But Use Your Head

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

Thank you!

And don’t forget to fill inthe evaluation form

hello@iuliandogariu.com