Live data from Hacker News

Claude Code uses Bun written in Rust now

simonwillison.net

641–650 of 920 posts

Re: Claude Code uses Bun written in Rust now

#641

Why even write Claude code in JavaScript at that point, assuming they write the application logic in node and also include the interpreter in the application?

Probably because the team lead is a web developer, and whatever he says goes. Companies are typically very hierarchical, even if they like to claim otherwise.

Re: Claude Code uses Bun written in Rust now

#642

Bah. Personally my take on the entire affair is quite negative, whatever Jarred or Simonw says about it. I think Bun owned by Anthropic and the entire rewrite with AI is not the real point (even if it's quite interesting, though). My take is that Jarred, and Bun,didn't demonstrate a serious, adult approach, from "this is my branch, you are overreacting" message to just proceeding with a 1mil+ PR merged in less than m…

Serious adults? They are in extremely short supply right now. It’s a mix of serious-wanna be, quasi religious, quasi-technical people running the show right now. I am so happy to I got to read about the 90s-2000s tech culture, and experienced the post-2008 startup culture. Just about 10 years ago people were really serious, but chill-looking. Somehow that got flipped.

The wig-vs-grok periodic cycle.

Re: Claude Code uses Bun written in Rust now

#643
post #55

Bah. Personally my take on the entire affair is quite negative, whatever Jarred or Simonw says about it. I think Bun owned by Anthropic and the entire rewrite with AI is not the real point (even if it's quite interesting, though). My take is that Jarred, and Bun,didn't demonstrate a serious, adult approach, from "this is my branch, you are overreacting" message to just proceeding with a 1mil+ PR merged in less than m…

I guess the point is none of it matters, CC users didn't notice or don't care except an exceptionally small minority.

The lowest of the bars

Re: Claude Code uses Bun written in Rust now

#644
post #223

Maybe I’m taking crazy pills, but I’m still stuck on “why the hell does a TUI need to run in terminal React by way of JavaScript” The fact that Anthropic felt the need to buy a runtime so they could make their TUI better speaks more to the quality of engineering than anything else IMO. If rewrites are so easy, why not rewrite CC in a native language? Would’ve been a hell of a lot cheaper.

I never knew that running an interactive program in my terminal would absolutely rinse my CPU and battery but that's what Claude, OpenCode and Ghostty have colluded to achieve. Even when the laptop is asleep overnight it's practically melting. I'm sure there was some logical reason for shoehorning web technology into this stack given that we have a good 40 years or so of experience with interactive terminal programs…

yep, developers from 10 or even 5 years ago would have considered it a hilarious joke

Re: Claude Code uses Bun written in Rust now

#645
post #635

Earlier quoted context omitted.

> You can just do that, and then Zig is really no less robust than Rust. If you just don't write bugs, then yes all languages are equally robust, including assembly. Zig, like C, is simply not a robust language. I don't know why this feels like something contentious? It's clearly not intended to be robust?

Zig is intended to be as robust as it can be as long as it doesn’t implicitly add code (no destructors that run code you didn’t explicitly call), or increase compiler complexity and compilation time. I don’t think it makes sense to say Zig is or isn’t intended to be robust in general. Like, we don’t say Rust isn’t robust since it doesn’t add dependent types and general purpose static verification that can do more gen…

> Like, we don’t say Rust isn’t robust since it doesn’t add dependent types and general purpose static verification that can do more general proofs.

Give it a few years! I've noticed an explosion in interest in formal verification recently, especially since nowadays the bar to entry is so low: just ask your LLM agent to give it a go.

Re: Claude Code uses Bun written in Rust now

#646

Bah. Personally my take on the entire affair is quite negative, whatever Jarred or Simonw says about it. I think Bun owned by Anthropic and the entire rewrite with AI is not the real point (even if it's quite interesting, though). My take is that Jarred, and Bun,didn't demonstrate a serious, adult approach, from "this is my branch, you are overreacting" message to just proceeding with a 1mil+ PR merged in less than m…

It really does seem like they should have been able to do an incremental rewrite with FFI. Could have easily done it with AI too.

Re: Claude Code uses Bun written in Rust now

#647
post #376

Earlier quoted context omitted.

Zig (like C) is simply not a good language to use if you're going to do many small allocations with uncorrelated lifetimes. To write robust Zig (or C) code, you must manage lifetimes yourself, for example by grouping allocations on an arena or by having fixed buffers of "things". You can just do that, and then Zig is really no less robust than Rust. But if you want to do "managed language" style allocation patterns (…

> You can just do that, and then Zig is really no less robust than Rust. If you just don't write bugs, then yes all languages are equally robust, including assembly. Zig, like C, is simply not a robust language. I don't know why this feels like something contentious? It's clearly not intended to be robust?

the buffer managemnt is just different pattern and style of code thats more low level. when you care about performance and cpu cache, you have to make sure that actual physical memory gets computed at same time as other memory near it so there is less latency.

Re: Claude Code uses Bun written in Rust now

#649
post #554

Earlier quoted context omitted.

> it happened completely in the open You don't create PRs like this when you're working "completely in the open" test ci #30412 No description provided. https://web.archive.org/web/20260509235415/https://github.co...

You don't test CI before you publish stuff?

I give the PR a proper title on creation. I don't see any reason to create a PR with a title of "test ci" and then rename it later to:

  Rewrite Bun in Rust #30412

Re: Claude Code uses Bun written in Rust now

#650

Earlier quoted context omitted.

Why? Use agent bruh. Even the bun rewrite post said that agents do writing testing everything!!! Unless AI overlords lied and we do need humans

They had a human oversee the bun rewrite, didn't they?

that's the hypocrisy I was pointing out. Lol

For their work they extensively test using humans with deep expertise

But while marketing they say just vibe code bruh

And here they can't even rewrite CC in rust? Why not! Use 1000000 agents!! Write it in platform specific binary! SAAS is dead, that's what he claimed. So what's stopping him from writing the harness in Rust or C than ReactJS?

Post reply on HN