How is the Bun rewrite in Rust going? • Hacker News Board

Re: How is the Bun rewrite in Rust going?

#241

Post by card_zero » Mon, Jul 27, 2026, 4:47 PM UTC

wesselbindt wrote: post #227

achenet wrote: post #223

Earlier quoted context omitted.

Frenchman here, I Google Translated that and it says "We at WC Duck recommend WC Duck"... I'm left scratching my head, if you'd care to spell out what the saying means for non-Dutch I'd appreciate it :)

It was a commercial slogan for a toilet cleaning agent. An English equivalent would be "mr clean recommends you use mr clean". Today, it is used to point out when someone tells you they themselves delivered good work. Anytime you'd use the meme of Obama giving himself a medal, you could use this phrase.

The Toilet Duck brand exists in English. Canard-WC in French, even.

Re: How is the Bun rewrite in Rust going?

#242

Post by nozzlegear » Mon, Jul 27, 2026, 4:48 PM UTC

reliabilityguy wrote: post #6

Many repeat the point of “$165k is cheaper than team of multiple engineers working on the rewrite for a year”, which I think is flawed — the team of engineers would have produced idiomatic rust, and it would take probably 100k+ of tokens more to make the bun in rust idiomatic rust.

IMO a team of engineers (presuming this is pre-AI) would have improved the existing Zig codebase, rather than spent time and money on a Rust port in the first place. In fact, I still think most teams of engineers would choose to improve what they have even now, circa AI.

Re: How is the Bun rewrite in Rust going?

#243

Post by [deleted] » Mon, Jul 27, 2026, 4:49 PM UTC

Jarred wrote: post #148

Bun’s Rust rewrite shipped in Claude Code over a month ago and barely anyone noticed. Claude Code is widely used. The Rust rewrite is going well overall. In the Bun v1.4 video, I promised a certain number of newly passing Node.js tests were added to force us to improve compatibility, and that number is not true yet. The release is delayed until it is true. The PRs to make it true are up but not merged yet. Most likel…

[deleted]

Re: How is the Bun rewrite in Rust going?

#244

Post by greenlimetea » Mon, Jul 27, 2026, 4:51 PM UTC

Rust devs are so obsessed with writing things in Rust that Rust was re-written in Rust.

Re: How is the Bun rewrite in Rust going?

#245

Post by jeremyjh » Mon, Jul 27, 2026, 4:53 PM UTC

bendmorris wrote: post #238

As a comparison point, someone decided to try to fix the issues in the Zig original and is now claiming sub-second build times, plus fixed bugs, by modernizing the codebase and sticking with best practices - indicating that all of the issues that justified the rewrite were self-inflicted and addressable. https://ziggit.dev/t/buz-a-drop-in-replacement-for-bun-using... I have no skin in this game, and the Zig version i…

> indicating that all of the issues that justified the rewrite were self-inflicted and addressable

The main issue that justified the rewrite were memory bugs, especially related to interaction with GC managed Javascript objects. There is no fully general way to prevent those bugs in Zig, and I don't see any claims that they did so in Buz.

Re: How is the Bun rewrite in Rust going?

#246

Post by throwaway613746 » Mon, Jul 27, 2026, 4:55 PM UTC

irishcoffee wrote: post #38

reliabilityguy wrote: post #6

Many repeat the point of “$165k is cheaper than team of multiple engineers working on the rewrite for a year”, which I think is flawed — the team of engineers would have produced idiomatic rust, and it would take probably 100k+ of tokens more to make the bun in rust idiomatic rust.

> produced idiomatic rust I keep seeing this. What is "un-idiomatic" rust?

[dead]

Re: How is the Bun rewrite in Rust going?

#247

Post by jraph » Mon, Jul 27, 2026, 4:56 PM UTC

Xenoamorphous wrote: post #104

_pdp_ wrote: post #98

Earlier quoted context omitted.

How does that help 99.9% of all other companies though?

Some thoughts: - just because it doesn’t help 99.9% of the companies today it doesn’t mean it won’t help them tomorrow - 0.01% of the companies employ a much bigger percentage of people - 99.9% of companies won’t need to do a project of this magnitude

This rewrite is showcased by Anthropic to sell AI rewrites to other companies.

If it turns out the rewrite cost stupid amounts of money and leads to a bad outcome, it's just a misleading ad.

We developers now need to explain that to illuminated management and colleagues.

Re: How is the Bun rewrite in Rust going?

#248

Post by throwaway613746 » Mon, Jul 27, 2026, 4:56 PM UTC

leobuskin wrote: post #93

nickcw wrote: post #86

Maybe it would have made more sense for Anthropic to rewrite Claude Code in rust, and cut out the middle man (bun)?

Nope, they want shared artifact(s) between web and desktop (not sure what do they have in mobile apps) clients (Chat/Cowork/Code/CC-cli), so TS is the way to go. It’s a reasonable choice made by engineers.

[dead]

Re: How is the Bun rewrite in Rust going?

#249

Post by inigyou » Mon, Jul 27, 2026, 4:57 PM UTC

inglor wrote: post #179

Jarred wrote: post #148

Bun’s Rust rewrite shipped in Claude Code over a month ago and barely anyone noticed. Claude Code is widely used. The Rust rewrite is going well overall. In the Bun v1.4 video, I promised a certain number of newly passing Node.js tests were added to force us to improve compatibility, and that number is not true yet. The release is delayed until it is true. The PRs to make it true are up but not merged yet. Most likel…

Take as long as you need to ensure software quality. A month without a release isn't a big deal and whomever needs a specific feature can offer to contribute or build themselves. Node has 4-6 weeks without a meaningful release (other than security stuff) pretty much every December. I think the criticism in the article is unfounded and whomever needed/wanted a release should have asked first instead of writing an "ang…

What is Node getting every 4-6 weeks that makes it noteworthy when it doesn't?

Re: How is the Bun rewrite in Rust going?

#250

Post by klausa » Mon, Jul 27, 2026, 4:58 PM UTC

wallstop wrote: post #213

chuckadams wrote: post #191

Earlier quoted context omitted.

If you could successfully write Tetris in Malbolge, I would call that impressive indeed. Just writing Hello World was a major effort IIRC. The nature of the malbolge interpreter makes it more of a cryptography exercise than a coding one.

I'm gonna jump in here with some self promo - back in college I TA'd a class that, for a few weeks, taught Malbolge, and the only assignment was for students to write a program that printed their name. After spending a lot of time thinking about the language, I came up with a relatively simple algorithm based on the language design - there are a few operators that mutate state, so basically just try combinations of t…

Pretty funny that I off-handedly used Malbolge as a random pull from my brain for “an extremely weird and not-really-but-kinda programming language” without even really remembering any details about it; and then I got to learn about your project!

Thanks for sharing!