Haskell, the pure and lazy functional programming language, has now been around for more than 25 years. It had a profound influence on many other programming languages on the JVM: Java, Clojure and Scala. In this talk you will discover which Haskell constructs have made it to the JVM ecosystem and change the way you program today. You will also get a glimpse of the features which are yet to be transferred for our greatest benefit. Warning: after this talk you might be tempted to try the real thing!

1. Eric Torreborre
What Haskell
taught us
when we were
not looking

2. About Zalando

10. MICHAEL SNOYMAN

11. Lazy
Pure

12. square x = x * x

15. Command
Template method
Action
First-class functions!
Comparator
Callable
FileFilter

20. Use functions to

28. We're moving away from OO!

32. Last nail in the coffin?

33. Smart functions
Dumb data

45. Subtyping

59. List[A]
Option[A]
Future[A]
Either[B, A]
M[A]
flatMap[A, B](ma: M[A],
f: A => M[B]): M[B]

62. M[A]

78. "It is better to have 100 functions
operate on one data structure than
10 functions on 10 data structures."