[ryanpers]

I'm sorry but this is possibly one of the worst comments I've seen... There is a conservation of complexity that you just can't get rid of in an application. To suggest that Scala encourages small programs, you are also suggesting that Scala is only appropriate for small problems, and thus it isn't a scalable language.

See: http://c2.com/cgi/wiki?ConservationOfComplexity

Ultimately, the baseline requirements drive the minimal complexity of code. Sure a poor programmer can drive up the complexity with unnecessary constructs, but the converse is not true: a great programmer can drive to simplicity. For example, a flight control system for a 777 can never be reduced to a single file of 700 lines of code. It will likely always be 2000+ files, and have lots of inter-dependencies.

So I guess (run time safety issues of Scala aside) Scala is not an appropriate language for complex problems by your own words?

[michaelochurch]

Scala's compile speed (with incremental compiles) is generally acceptable if you have reasonable dependency patterns. If you have cyclic dependencies, it's a problem. However, cyclic dependencies are signs of things that are wrong in development practices that can't be blamed on the language.

You mentioned flight control systems: those are unlikely to be written in Scala, being real-time systems, but if one were, it would not need to be compiled and recompiled on the fly.

Scala's a great language but it's not the right language for every problem. No language is.

[ryanpers]

Good non-answer.

For many large, non-trivial systems have several requirements: - tends to have complex dependencies - needs fast builds

This was a classic: http://www.amazon.com/Large-Scale-Software-Design-John-Lakos...

Essentially how to design C++ systems so that incremental compiles don't sink you. Developer productivity is important.

Scala is badly failing on this front IMO, it reminds me of the old bad days of C++ in a major way.