Elias Mulhall (Oct 02 2023 at 01:35): Elias Mulhall (Oct 02 2023 at 01:35):https://github.com/mulias/roctoberfest/blob/main/advent_2022/day_01/main.roc
Isaac Van Doren (Oct 02 2023 at 01:38):That was very smooth to write in roc https://github.com/isaacvando/aoc/blob/main/roctoberfest/day1.roc
Isaac Van Doren (Oct 02 2023 at 01:39):@Elias Mulhall I didn't know you could import text files directly like that, that's awesome!
Elias Mulhall (Oct 02 2023 at 01:41):Yes!
Elias Mulhall (Oct 02 2023 at 01:47):General feedback:
nix-build https://github.com/roc-lang/roc/archive/main.tar.gz before starting the puzzle. For some reason the "last edited at" timestamp on the generated binary is Dec 31st , 1969..roc-format-failed file. Should I report those, and if so where?dbg working at all. Is it broken right now, or is this a me thing? My biggest trouble getting day 1 working was realizing I needed Str.split "\n\n" because I tried "\n" and had to jump through a bunch of hoops to print the intermediary state to realize that wasn't working. Elias Mulhall (Oct 02 2023 at 01:48):@Isaac Van Doren nice use of Result.withDefault 0, I didn't think of that. I let errors propagate all the way through and it was kind of a pain.
Elias Mulhall (Oct 02 2023 at 01:54):To be a bit more specific, open tag unions feel great for error handling, but having to deal with a list of Results was unwieldy. I created a helper to do a List (Result a e) -> Result (List a) e transformation, which works well enough. My initial name for the function was allOk, but I looked up the equivalent Elm function and saw that it was called combine so I went with that. I feel like that function could be in the Roc standard library.
Agus Zubiaga (Oct 02 2023 at 02:25):I think you could do |> List.mapTry \r -> r here, but I agree that having something like Result.combine (or join?) would be nice.
Elias Mulhall (Oct 02 2023 at 02:34):nice, I didn't think to look in List
Brendan Hansknecht (Oct 02 2023 at 02:39):For the timestamp, I think that is just a nix thing
Anton (Oct 02 2023 at 08:33):Nix sets the timestamp to 1969 because it wants to build 100% the same files every time.
Anton (Oct 02 2023 at 08:41):the formatter is failing and generating a .roc-format-failed file. Should I report those, and if so where?
Yes please :) you can do so here: https://github.com/roc-lang/roc/issues
Anton (Oct 02 2023 at 09:06):what's the current story for parsing in general? Any libraries I can take a look at?
Luke made a parser package, I don't think he released it with a url yet but you can download the roc files to use it locally.
Anton (Oct 02 2023 at 09:12):I can't get dbg working at all. Is it broken right now, or is this a me thing?
There are some bugs with dbg but it should work in most cases, can you file an issue?
Anton (Oct 02 2023 at 09:17):[...] had to jump through a bunch of hoops to print the intermediary state
We've talked before about something like dbgPipeline to print all the intermediary values in a pipeline, I'll check if we have an issue for that. It could be something nice to get done before AoC 2023.
Anton (Oct 02 2023 at 09:26):I feel like that function could be in the Roc standard library.
I've made an issue for a Result combine function.
Luke Boswell (Oct 02 2023 at 10:00):I just copied that Parser from the examples, but happy to move into it's own repository and make a URL for it if that would help people?
Erik (Oct 02 2023 at 13:36):Day 1. Cheated a little bit because I had done this before but it was back on a much older roc and roc-cli. Upgraded it really quick by removing the Process module code and fixing the return type of main. Then I refactored my part 2 solution a bit.
I noticed that the formatter does not like it if you try and put the initial state on a new line when using Lisit.walk. (Line 30).
I am curious if the state record in the part 2 solution does the mutation optimization thingy as well!
Anton (Oct 02 2023 at 15:02):I noticed that the formatter does not like it if you try and put the initial state on a new line when using Lisit.walk. (Line 30).
The formatter does not allow a lot of freedom which I like in general, it makes all roc code look consistent and thus easier to read.
In this case I would also prefer the initial state on a separate line. It's important to easily identify where an argument ends and a new one begins.
Elias Mulhall (Oct 02 2023 at 23:33):Anton said:
the formatter is failing and generating a .roc-format-failed file. Should I report those, and if so where?
Yes please :) you can do so here: https://github.com/roc-lang/roc/issues
https://github.com/roc-lang/roc/issues/5880
Last updated: Jul 26 2025 at 12:14 UTC