Luke Boswell (Dec 05 2022 at 10:30): Luke Boswell (Dec 05 2022 at 10:30):My solution for day 5. I've only completed Part 1 so far. It will be easy to do part 2 from here; but posting anyway for anyone who would like some ideas. I'll probably continue tomorrow evening. :smiley:
Gabriel Pickl (Dec 05 2022 at 12:01):dang, i was hoping for some ideas to parse the input^^
I tried starting to implement the elm parser library, but it turns out making applicative parsers without currying is... not a thing i guess?
Gabriel Pickl (Dec 05 2022 at 12:02):i mean i can start with the mapN family of stuff. but i feel roc needs some new ideas for a nice parser. or I'm missing something and there already is one
Gabriel Pickl (Dec 05 2022 at 13:05):i completely forgot that that's what the binding syntax sugar is for^^ well i guess i'll try and build a small parser
Shritesh Bhattarai (Dec 05 2022 at 14:05):Here's my day 5. I really need to learn how to use the Parser module. Also, List.walkWithIndex might be useful in the stdlib, similar to Str.walkUtf8WithIndex and List.mapWithIndex.
Gabriel Pickl (Dec 05 2022 at 14:30):wait, there's a Parser module? I can't find it :sweat_smile:
Shritesh Bhattarai (Dec 05 2022 at 14:37):There’s one in the examples dir
Richard Feldman (Dec 05 2022 at 14:41):I'm working on adding support for packages, at which point that can become publishable as a standalone thing and you can import it from a URL alongside the platform
Gabriel Pickl (Dec 05 2022 at 14:50):i'm assuming the url resolving thing works only for platforms?
but anyway, i'm trying to write my own small parser combinator as an exercise now, kinda stuck on the types :sweat_smile: (see this topic )
Richard Feldman (Dec 05 2022 at 14:51):at the moment, yes - because we don't actually have a concept of packages yet :big_smile:
Luke Boswell (Dec 05 2022 at 19:30):I ran into some strange bugs with the digit parser on this puzzle. I played with it a while and got it working by slowly building up the parser each step at a time and running a unit test to check it works. I couldn't figure out what the issue was, it was giving me a parsing error like "??????????".
Héctor Ramón (Dec 05 2022 at 20:16):I found a weird bug in my solution where I started getting duplicated crates out of nowhere. I ended up fixing it by recreating the target stack of crates with List.walk to [] List.append. See the issue here.
Basically, I had to rewrite
newTo = List.concat to (List.reverse cratesToMove)
as
newTo = List.concat (List.walk to [] List.append) (List.reverse cratesToMove)
which should be equivalent.
Héctor Ramón (Dec 05 2022 at 20:17):I suspect there may be an issue in the internal implementation of List.
Luke Boswell (Dec 05 2022 at 21:49):@Gabriel Pickl I'll try not to cheat on future puzzles. :grinning: I took the lazy option here as I had burnt a bit of my evening time messing around with some other stuff. I've been enjoying learning about parsing with Roc.
Máté Kaszás (Dec 05 2022 at 22:00):Went with the same approach in my solution, maybe if we had transpose I would've given parsing the first part a go too :big_smile:
I'll have to try out Parser as well, maybe tomorrow!
Ayaz Hafiz (Dec 06 2022 at 23:46):My day 5: https://gist.github.com/ayazhafiz/9d315104502007f471b33ab8731be807. Im impressed by everyone that was able to parse the header of this day's input!
Gabriel Pickl (Dec 07 2022 at 00:08):My day 5
It got pretty ugly in the end because I was juggling compiler crashes by trying to rewrite code in different ways :sweat_smile: but it's a parser I guess.
It's also really slow, mainly because the parser recreates strings a lot because there's no splitAt or substring in Str
Logan Lowder (Dec 09 2022 at 04:23):Catching up!
Day5
Last updated: Jul 26 2025 at 12:14 UTC