Whats the big deal with Scala

Scala is as expressive as Ruby and as performant as Java and let me show you how.

Transcript

1. What’s  the  big  deal  with  Scala?   praful@thoughtworks.com  
2. Introduc=on  to  Scala   • Runs  on  JVM   • Fuses  object-­‐oriented  &   func=onal  paradigms  though   biased  towards  func=onal  style   • Sta=cally-­‐typed  
3. As  expressive  as  Ruby,     As  performant  as  Java   Why  am  I  comparing  with  Ruby  and   Java?  
4. Disclaimer   • Professionally  a  Ruby  and  Java   developer   • Haven’t  worked  with  Scala  on  a   “real”  project   • Based  on  my  experience  working   with  the  Credit  Union  Findr  
5. Why  Expressiveness?   • Not  just  preUy   • Reduces  boilerplate  code   • Less  code  to  deal  with  &  maintain   • Elegant  solu=on    
6. Ruby  class  defini=on    
7. Scala  class  defini=on  
8. Closures   • Closures  are  blocks  of  code  that   can  be  passed  around  as   parameters   • Closures  “close  over”  variables   outside  of  its  scope  
9. Closures  in  Ruby  
10. Closures  in  Scala  
11. Ruby  monkey  patching  
12. Scala  implicit  conversions  
13. Performance  and  Scalability   constructs  
14. Tail  recursion   • Special  type  of  func=on  recursion   • Final  ac=on  taken  in  a  func=on  is   the  recursive  call   • Can  avoid  penalty  of  crea=ng  a   new  stack  frame  for  each   recursive  call  
15. Lets  look  at  some  code...   Tail  recursion  
16. Parallel  collec=ons   • Just  like  regular  collec=ons     • Can  be  operated  upon  by   mul=ple  cores   • Use  Divide-­‐and-­‐conquer   algorithm   • Write-­‐your-­‐own  
17. Lets  look  at  some  code...   Parallel  collec=ons  
18. Actors   • Actors  are  high-­‐level  concurrency   construct  as  opposed  to  threads   and  shared  memory  model   • Actors  communicate  via  message   passing   • PaUern  matching  is  used  for   message  processing  
19. Lets  look  at  some  code...   Actors  
20. Cri=cism   • Slow  compiler   –   sbt  incremental  compila=on   –   Daemon  compiler   • Too  many  features  
21. Other  items  of  interest   • REPL   • TypeSafe  (Scala,  Akka,  Play!)   • Heroku  
22. Func=onal  yet  beau=ful   Rug  from  Qom,  Iran  h/p://upload.wikimedia.org/wikipedia/commons/c/ca/Farsh_Qom.JPG)  
23. Thank  you!   @todkar