Fast Parse VS AdventOfCodeCSharp

Perhaps use Li Haoyi's fastparse instead? https://github.com/com-lihaoyi/fastparse

You might want to adapt Li Haoyi’s XML parser for fastparse.

Mostly a mess of pattern matching. I really need to make some generic tree utilities. Haven't been able to find a decent parser combinator that works in Scala 3 (I usually use fastparse which depends heavily on Scala 2 macros, and scala-parser-combinators works in Scala 3, but I've had a lot of trouble getting it to not be too greedy), so I used the state monad from cats to parse at the bottom of the file, which I think turned out fairly nice.

Agreed! I would say that parser combinators are the sweet spot and the right choice in most cases.

Scala has them as well, e.g.: https://com-lihaoyi.github.io/fastparse/

And the good thing is, you don't have to learn a completely new language/syntax, you can use the host language's syntax and you have full IDE support as well.

Code Here: https://github.com/Bpendragon/AdventOfCodeCSharp/blob/332e303/AdventOfCode/Solutions/Year2022/Day18-Solution.cs

C#/Csharp: Code here

rewrote it as a pair of linq oneliners (sort of, if you ignore parsing, like that's the one thing I wish C# could do better: read ints from files) https://github.com/Bpendragon/AdventOfCodeCSharp/blob/0800b/AdventOfCode/Solutions/Year2022/Day04-Solution.cs