AmandaI have been writing #Scala professionally for three years now. My conclusion is it’s terrible for almost everything. The compiler is slow. Most of its features are half-documented and change between versions. Compilation errors are incomprehensible and sometimes spurious. The syntax is cumbersome, the language somehow bad at being OO, FP, *and* imperative. Writing deterministic code is hard. Debugging unreliable. Runtime system is…the JVM. Build system absolutely byzantine.
lachezar@amanda modern javascript code bases compile slower than some of the bigger scala projects I have worked on, so everything is relative. Haskell is a nicer language and it still compiles equally slow (or may be even slower), but it does not have the Java interoperability (unfortunately) and you have to write your own batteries or rely in obscure abandoned projects in github.
My biggest scala disappointment is that you are vulnerable to NPE due to Java/JVM interoperability.