My month off was reduced to about ten days, but there was no reason to continue this odd vacation from roguelike development so I've been working on Teemu again.
I tried to study something about functional languages, namely Haskell. I learned only that purely functional languages don't use state (aka mutable variables, or commonly known as variables). While this information didn't help me understand functional languages it actually gave me an idea for my data-driven type classes which I guess helps keep them more modular. The idea is to pass parameters to functions rather than pollute the class with external references or write the code itself elsewhere (using that classes information). Those parameters can even be reduced to flag (bool) type information, not the actual variable or object.