The fastest large-scale rewrite in the history of software engineering, likely
Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc
101–110 of 754 posts
Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc
#102Deleted
@simonw explains how hilariously misguided that paper is in one of the top comments, and how it doesn't apply remotely to a real agent harness. Plus it's not even clearly relevant here, because the model isn't trying to regurgitate the original document, but generate a new one, and there are guardrails to put it back on track in the form or a compiler and tests. Also, the test suite is very thorough, and pre-existing, and the vast majority passes already. This is skepticism for the sake of it.
Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc
#1036 days of work to do this. Even if it doesn't end up becoming meaningful, it shows just how tokens and work done will be linked now and in the future. It's going to be hard to compete with someone or a company that has more compute. They will just be able to do things you can't.
I can't help but wonder what this cost in USD assuming you paid standard rates from Anthropic. Can someone even ballpark the price?
Much less than what it’d costs for a team of rust engineers.
This is both amazing and scary; has been for a while now.
Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc
#104Very impressive that they could do this so quickly because I have been on a similar project (porting TypeScript to Rust) for 5 months. But I guess I don't have access to Mythos and unlimited tokens. I'm also close to 100% pass rate. 99.6% at the time of writing. https://tsz.dev Rust is perfect for writing all of code using LLM. It's strict type system makes is less likely to make very dumb mistakes that other languag…
When Microsoft rewrote it in go, there was a comment from one of the leads that they chose it over rust because of the similarity in paradigms (garbage collection, etc), and that using rust would've been more difficult, requiring a lot of "hoop jumping". Now that you've done it... Thoughts?
Yes indeed. More than 1 million lines of code (including tests) is jumping lots of hoops but with LLMs it's not as painful so you can just ask it to do the hard things.
Example of a Claude Code session after 2 hours of "Crunching" that came out without results https://github.com/mohsen1/tsz/pull/4868 (Edit I force pushed to PR to solve the problem, you can see the initial refuse message in the initial version of PR description)
Funny thing is, the last percent of the test have been so hard to work on that Opus 4.7 routinely bails and says "it's too involved or complicated" so I had to add prompts specifically asking it not to bail.
Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc
#105From 4 days ago: https://news.ycombinator.com/item?id=48019226 > I work on Bun and this is my branch > > This whole thread is an overreaction. 302 comments about code that does not work. We haven’t committed to rewriting. There’s a very high chance all this code gets thrown out completely. > > I’m curious to see what a working version of this looks, what it feels like, how it performs and if/how hard it’d be to get i…
cargo check reported over 16,000 compiler errors when I wrote that message. It could not print a version number or run JavaScript. I didn’t expect it to work this quickly and I also didn’t expect the performance to be as competitive. There’ll be a blog post with more details.
Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc
#106I think a lot of people taking this at face value , a lot of this was possible because of the beyond standard extensive and comprehensive test suit previously built.
Look what it can do in 6 days!
Ignore the hundreds of thousands of hours put into the original architecture and test suite that made it possible in the first place.
Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc
#107Very impressive that they could do this so quickly because I have been on a similar project (porting TypeScript to Rust) for 5 months. But I guess I don't have access to Mythos and unlimited tokens. I'm also close to 100% pass rate. 99.6% at the time of writing. https://tsz.dev Rust is perfect for writing all of code using LLM. It's strict type system makes is less likely to make very dumb mistakes that other languag…
Wow, amazing work. Pretty impressive that it is faster than the Go version already.
Thank you!
It's much faster in single file benchmarks (3 to 5x)
https://tsz.dev/benchmarks/micro
I have optimizations planned for large projects that I'm still flushing out.
Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc
#108Earlier quoted context omitted.
Exactly
This is exactly how Anthropic will market this rewrite towards companies thinking about doing more layoffs. 1 person did a rust rewrite that took 6 days that would have taken hundreds of engineers more than a year to do.
The saving grace here is a rewrite of a project with a good test suite is the sweet spot: LLMs are great at translation and do great with verifiable goals.
I agree it’s still mind blowing compared to before times, though.
Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc
#109[deleted]
Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc
#110I just want to comment that I think it's a good change if we look past the AI involvement. Bun has had an extremely high amount of crashes/memory bugs due to them using Zig, unlike Deno which is Rust. Of course, if Bun's Rust port has tons of `unsafe`, it won't magically solve them all, but it'll still get better
Is your claim that using Zig ends in an "extremely high amount of crashes/memory bugs?" Wouldn't that mean that it isn't even feasible to make high-quality software with such a tool? There is a lot of quality stuff made with C/C++, so what is Zig doing wrong?
The statement “there exists a project where zig led to an extremely high amount of crashes/memory bugs” does not imply “all zig projects have an extremely high amount of crashes/memory bugs”.
This is a classic logic problem - eg “there is an orange cat” doesn’t imply “all cats are orange”.