SCALA PATTERNMATCHING

ANDREA ŠTEŇOVÁ

ME AND SCALAGarwan ConsultingScala experience - 2 yearsBackend and frontend applicationsPlay framework and Akka frameworkCo-organizing Slovak Scala users group

WHAT IS SCALA?Object-Oriented Meets Functional

pure functionstail recursionsfunction literalsimmutable data structures

WHO USES SCALA?

WHY YOU SHOULD TRYSCALA?

TYPE INFERENCEthat does not suck

JAVA COMPATIBILITYcall Java methods, inherit from Java classes and vice versa

POWERFUL CONCURRENCYas simple as possible

FIRST-CLASS FUNCTIONSbecause we are classy people :)

EXPRESSIONS EVERYWHERE!val c = if (b > 0) "big" else "small"

MATURE ECOSYSTEMthat keeps evolving

PATTERN MATCHINGcase statements on steroids

PATTERN MATCHINGx match { case 1 => "one" case b: Int => "two" case _ => "many"}

if(x.isInstanceOf[Int]) if( x == 1) "one" else "two"else "many"

PART 1 : BASIC EXAMPLES

YOU CAN MATCH:constants, variablessequences, tuplesany sort of datafirst-match policy

PART 2 : MORECOMPLICATED PATTERN

MATCHES

YOU CAN MATCH:case classes, option values, sequencesgreat for recursive datause of pattern guardsassign variables

PART 3 : PATTERNSEVERYWHERE

YOU CAN USE PATTERN MATCHING:in variable definitionsfor expressionserror handling

PART 4 : EXTRACTORS

WHAT ELSE?patterns can be decoupled from object's representationextracting values

THANK YOU FOR YOUR ATTENTIONandrea.stenova@garwan.sk

- CodeexamplesSlovak Scala Users Group

https://github.com/astenova/rubyslava-scala

https://www.facebook.com/groups/scalaslovensko/http://www.meetup.com/slovak-scala/