This is so true. It's why I love ML-languages: they help me refactor, the help me logically structure my core (through its data types) even before I start, and

This is so true. It's why I love ML-languages: they help me refactor, the help me logically structure my core (through its data types) even before I start, and it helps catch illegal states (if I use the types right) so that unit tests aren't necessary!