03 July 2007

Scala to heaven, ground

Selecting one "Programming language of the year", yes but which one?

The contenders

I pre-selected several contenders:

1. An ML language, such as OCaml
2. A "purely" functional language such as Haskell
3. A language designed for concurrency such as Erlang

Those 3 languages looked very interesting to me, each of them addressing fundamental software considerations. Well that's the rational pitch. But what was anedoctically exciting?

Observation round

Erlang was the promise to venture in a domain where I feel seriously weak, concurrent programming, with a brand new paradigm, very different from what I know. OCaml was a bit unknown to me, the only references I had were a colleague telling me that he gave up with OCaml one day the type inferencer was as lost as him and a financial company actually using it.

Haskell was perhaps the most appealing, for 2 reasons: QuickCheck (I loved Tom's Moertel description of his participation to IFCP) and the promise of mind-bending ideas baked in the language.

In order to shed more light on the subject I started reading.

"A history of Haskell, being lazy with class", is a wonderful way to introduce the language and give great insights on the "why" more than the "what" and "how". I also read "The little MLer" to become more familiar to the ML kind. And I was waiting for Joe Armstrong's book on Erlang.

But then I noticed something. Yes, that little language, there, hidden behind the others, come here!

I have a winner

What's your name? Scala
What do you know about concurrent programming? I, I have a clever actors library which may help get those performances
What about functional programming? Well, I unify the object and function approaches so you can get best of both worlds
How useful are you? I can play well with your existing java infrastructure
Do you do pattern matching and gadt? Yep
Isn't static typing to tiring? No, you just have to declare the bare minimum. The rest is inferred. By the way, this should allow me to get a top-level IDE with refactoring and code completion soon.
What about some cool stuff I have in Haskell? You mean Options, Parsers/Combinators and QuickCheck? Can do that too.
Are you system-engineering friendly? Some even pretend that dependency injection is part of me
Can you ease XML processing? I have XML literals and pattern matching against xml structures
Can I write DSLs with you? I am not Ruby but I have clever tricks that can help you a lot for that.

And the list goes on. I haven't discovered the least of what can be done with Scala and it is funny to see on the mailing list that even the language designers seems to think that there will be unexpected and surprising uses of scala features in the future.

First steps

The next steps in the "Scala to heaven" series will try to demonstrate the use of day-to-day Scala features to solve my own programming issues. As a beginner, I feel this is missing. We have good examples in the documentation, but abundance of examples won't be bad.

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