I wish I had known about this channel while was working on this year’s AoC. This is the first year I’ve completed it, and my first time writing code in Clojure. I’m sure others have much better code but if it’s of any interest, my solutions are here: https://github.com/pshapiro4broad/advent2020

I just published the source code that I was working on, which I mentioned last week. It uses Instaparse to parse class names and generate Garden data. https://github.com/green-coder/girouette Let me know if you are interested or if you have any question.

For day 12 part 1, is it safe to assume all rotations are by multiples of 90? My input suggests so, but that's not stated explicitly anywhere

My input suggested the same.

thanks @rjay

you only need to work with your (real) input. any constraints you discover there are fair game to exploit

and yeah, they're definitely 90 degree multiples