As a Scala user, I spend a lot of my time thinking about my types. Making good use of types is the key to compile time correctness checking, since compilers are not yet good at checking control flow. For example, consider the following:

def foo1(o: Option[String]) = {
  if(o …

The Scala programming language is unique in terms of FP languages in that it lets you choose your own balance between pure FP and filthy imperative style. This is good and bad, but one benefit is that when you have an algorithm that doesn't immediately translate well into a functional …