logoalt Hacker News

Rars: a Rust RAR implementation, mostly written by LLMs

63 pointsby davidsongtoday at 7:59 PM42 commentsview on HN

I spent a fortnight using Claude to create specs for every version of RAR, then another using gpt-5.5 to write compressors in Rust.

It's not fast and it's not pretty, but it works.


Comments

dclavijotoday at 9:40 PM

It wonders me that a coupe of days ago I did the same with Unique and a single skill.md, repo: https://github.com/daedalus/uniq-reconstruction, on succes I tried with rar but failed. Kudos

spprashanttoday at 9:42 PM

I have never attempted something so ambitious with AI, but this feels spot on in terms of experience. As you cede more control to the model, you will find yourself losing control on things like code quality and performance.

show 1 reply
xphostoday at 8:45 PM

Would it really take 5 years to develop rare compress and decompression that seems an extreme overestimate in time. I don't know of the compressor decompression but that seems really high

show 1 reply
esafaktoday at 8:24 PM

> It’s sloppy, it’s slow, it’s almost two megabytes in size and somewhat worse than WinRAR on compression.

As mathematicians say, optimization is left as an exercise to the reader. You did the hard part.

show 1 reply
periodjettoday at 9:17 PM

Finally, a sane and enjoyable read about a coding project. Feel like it’s been months since we had one of these that wasn’t filled to the brim with bluesky/mastodon-flavored whining about AI.

Kudos to the author. A fun read, thank you for sharing.

show 1 reply
rebolektoday at 9:14 PM

> "For the last 15 months or so my hobby has been shouting at Claude"

How can you shout at Claude when it’s

1) foobaring, bamblabooing and fghrtawing all the time without telling you what’s going on

2) when it finally interacts, it’s asking for a permission you told it 30 seconds ago "yes and do not ever ask me again until heat death of the Universe"

3) and after all of that, it just spits out: "you’re out of tokens, give up your liver or wait until next Trump’s war"

slopinthebagtoday at 8:39 PM

How do we know it's actually correct?

show 1 reply
cactusplant7374today at 8:21 PM

> and it almost earned me an OpenAI ban

Were you flagged for a cybersecurity violation?

show 1 reply
themafiatoday at 8:19 PM

> But, it works, and the world now has a free software RAR implementation.

Does it? How are you legally intending to use copyright to license this machine output? How would you know it's not encumbered in any way?

show 2 replies
npntoday at 9:09 PM

Rar is proprietary. Good luck.

show 1 reply
Imustaskforhelptoday at 8:39 PM

Kudos, this is a really cool project (even if it might be AI generated), I have starred the repo, (3rd starrer here)

One thing I have been curious at is are there any ways to stop a rar compression mid way and then continue it later?

Like suppose I have a compression happening for a large file, then would there be a possibility with this project to shut down the computer mid compression and continue it after starting it again?

I would really love it if you can add this functionality!

donbventurestoday at 9:52 PM

[flagged]

unixherotoday at 9:05 PM

Rar means weird in Norwegian and adorable in Swedish. Just for an anecdote.

show 3 replies