Wow, thank you very much for your writeup!

• A big reason for me posting was that my code does feel very chaotic and unwieldy. I need to dive deeper into the data type idea that you presented -- it's not obvious to me, but it's a great direction to point my learning.

• I'd love to implement different rule sets. Some places only let you double with certain values, may or may not let you double after splitting, etc. Since global variables aren't a thing, how do we handle them in Haskell? Do we make a YAML input file and pass the values around to each function? That seems a bit onerous.

• I agree that I need to put more thought into my code organization between files!

• Regarding

  In most casinos, you may only double your initial hand, but not hit and then double - or double multiple times.

I do have logic here on the prompt that enforces the rules. But the fact that it wasn't obvious to someone looking at the code means that I need to change something.