What's a Scala 'killer app'?

Question

I'm a Java dev thinking about investing time in learning Scala to develop future apps. I've read quite a bit about the advantages of Scala over Java, but they're a bit abstract to really sell it to me emotionally.

Can someone suggest an example of an application that would really suit being developed with Scala, as opposed to Java?

Answer 1

This is such a daft question. Scala is a turing complete language: ergo it is equivalent in what can be developed to any other TC language.

It has access to all JVM libraries (including those written in Java) and hence has a leg up in terms of access to databases, media APIs, networking et cetera et cetera et cetera. Being a JVM language, it has the advantage of write-once-run-anywhere (WORA).

But of course Java has these as well! So what is Scala's strength? Well, clarity, expressivity, maintainability, extensibility et cetera et cetera et cetera.

And what app does this point you to as being a killer? Well, all of them of course! Have some fibs!

def fibs = (0, 1).repeat[Stream].map { case (a, b) => b -> (a+b) } map(_._1)

or:

lazy val fibs: Stream[Int] = 0 ::# 
  ( 1 ::# 
    fib.zip(fibs.tail).map { case (a,b) => a + b)))

PS. The only thing it is not very good for, is extremely close-to-the-metal, low-latency programming. And it's making inroads into this area too!

Answer 2

Anything that's massively parallelized that uses the Actors idiom from Erlang would be a 'killer' in my view.

Answer 3

many...

Answer 4

I think, the companies listed at Scala in the Enterprise on scala-lang.org are the examples that the community can be proud of. They use Scala for building high-concurrency (and heavy-load) distributed scalabale applications with expressive type-safe lightweight APIs, great abilities for code-reuse and creating internal DSLs, development productivity and for many more reasons.

Just to give some names:

• lift-based foursquare and Novel Pulse.
• twitter
• linked.in's Signal and Norbert