Making the case for Scala

At first glance, Scala seems like an odd choice for developing web applications. Scala is a JVM language created by Martin Odersky of EPFL seems like an academic's testbed for a 'grand unified language' combining functional programming and strict object-oriented design. Scala is clearly gaining in popularity, but the current TIOBE Software Index places Scala at #24 with a rank of only 0.459%, far behind the #1 language, Java, which has a a rank of 17.348%. So, if you want to be on a JVM, why not stay with the undisputed champion of the TIOBE ranking since June 2001?

The key reason is money. Developer time is money. Developer time is, to a remarkably good approximation, proportional to the number of lines of codes that need to be written. This holds over a wide range of languages. Rather than regurgitate an existing piece, I urge you to read Research: Programming Style and Productivity and Scala vs Java: Conciseness equals less bugs. Scala was found to reduce lines of code by 30-35%. This should lead to a commensurate increase in productivity.

The second reason is that functional programming looks like it is the future. Erlang proves that functional programming can lead to high reliability systems with massive concurrency. Computers are becoming highly concurrent, not faster.

The third reason is more prosaic. Liftweb gives many of the advantages of Ruby on Rails and it also provides type checking. Call me old fashioned, but I get warm fuzzy feelings knowing that a compiler is preventing wide classes of errors.

The last reason is still in the future. In 2002, Phil Bagwell wrote Fast Functional Lists, Hash-Lists, Deques and Variable Length Arrays. He introduced new data structures for functional programming. Bagwell is Swiss and is at EPFL, where Martin Odersky works. So EPFL is the center of Scala. I learned about these by watching Rich Hickey's QCon London 2010 talk, Persistent Data Structures and Managed References. The slides are available on Michael Galpin's blog entry Persistent Data Strictures. This excites me, because many of the ideas of state took me back to physics, especially statistical mechanics. The talk, and Clojure's approach to state just seems right. So why is this a reason to use Scala!? Why not cut to the chase and go right to Clojure? At this point, I don't know, that may be the right answer. But Scala is a bit of a chameleon, and it seems to me that the concepts of State and Identity, as well as the persistent data structures that make this efficient, will be implemented soon in Scala. Scala 2.8 is getting Bagwell's VLists.

Suddenly, this is becoming an interesting time to be a programmer, and the JVM seems to be the epicenter of these changes. The JVM is very robust - there has been a decade of work with theorem provers that demonstrate the robustness of the design. There has also been a decade to flush out the bugs. Now, Scala, Groovy and Clojure are leveraging the JVM, and the plethora of libraries on the JVM. Full speed ahead!