Kyle Raftogianis

I admit that I didn't implement it because my original use case (parsing config files) didn't use arithmetic expressions. According to [the docs](https://www.gnu.org/software/bash/manual/html_node/Arithmetic-Expansion.html), the innards of a `$((...))` undergo variable...

Hmm right now parse(prettyPrint(ast)) == ast for all possible trees (or at least that's the goal) but adding a newline would break that. Is it ever possible for a heredoc...

You're right, it won't break that assertion. The solution looks good to me, feel free to turn it into a pull request.

Hmm, unfortunately I don't know too much about haskell performance, so I can't really say off the top of my head what's causing all the allocations. The parser certainly wasn't...

I also notice you're parsing each file twice: https://github.com/haskell/ghcup-hs/blob/fafff9dadd60e7f85d1fdea00b324bae7b40164c/lib/GHCup/Platform.hs#L153