The "Dive!" problem is about parsing and executing commands based on twodimensional positioning data.

The command typings given in the exercise closely resemble the data type declaration syntax, so I read up about data type declarations on the Haskell wiki:

• Haskell Wiki: Type

For debugging purposes, I made my type implement the "Show" class and implemented the "show" method for my type, as shown in this post:

• StackOverflow: "Haskell: Deriving Show for custom type"

After having implemented the solutions for both parts, I realized that I could use a folding operation to apply the position changes dictated by the given commands. I learned that foldr and foldl have different results if the combinator function (applyCommandPartTwo, in this case) is not associative. The combination function's arguments are also flipped:

• StackOverflow: "Haskell - foldl and foldr?"

• ./day02.hs: My solution for part one of this puzzle
• ./input.txt: My personal puzzle input for this challenge
• ./README.md: documentation for this solution :)