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Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc

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Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc

#51
post #41

> 99.8% of bun’s pre-existing test suite passes on Linux x64 glibc in the rust rewrite OK, they've got a working prototype, congrats! Now it needs to be put into shape so that all the unsafe blocks are eliminated (maybe with a few tiny exceptions), and the code is turned into maintainable, readable, reasonably idiomatic Rust. I wonder how long is it going to take.

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Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc

#52
Presumably the biggest loser in all this is Zig, I only know of the language because of Bun.

But the timescale still gives me pause… just because AI lets us convert a codebase in 6 days doesn’t mean it’s wise. There are surely a lot of downstream implications! It’s always felt a little like Bun is making up a plan as it goes along (and maybe that’s unfair), this seems to underline the point.

Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc

#53

Being anthropic accuired project does he have access to mythos or it’s normal Claude we plebs have access to

As an Anthropic acquihire, not only does he have access to every model and service but he probably has infinite tokens available.

Bun powers Claude.

Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc

#54

From 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…

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Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc

#55

I 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?

> 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?

What caused you to hallucinate such a broad blanket statement? The point is the memory unsafety issues they ran into would be categorically impossible in safe Rust, which is why they're doing this in the first place.

Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc

#56

Being anthropic accuired project does he have access to mythos or it’s normal Claude we plebs have access to

This is entirely possible with Claude as it existed even last year.

The LLMs are quite good at re-writes and even better when provided an 'oracle' like a well rounded test suite or existing implementation to work against.

Its part of the reason we keep seeing "I rewrote in " posts on hackernews and when you look at the repo its more like I prompted claude to rewrite this repo in rust or whatever.

Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc

#57

I 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?

> There is a lot of quality stuff made with C/C++

There’s a lot of leaky crap written in those languages too. One of the core promises of Rust is that the compiler will catch memory issues other languages won’t experience until runtime. If Zig doesn’t offer something similar it’ll make Rust very compelling.

Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc

#58
post #37

I 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

> Bun has had an extremely high amount of crashes/memory bugs Any stats/source? Not that I think it's false > and the ugly parts look uglier (unsafe) which encourages refactoring. Looks like Bun owes that to itself to some extent, not solely because of the language

You want a better source than the actual author of Bun?

Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc

#59

Earlier quoted context omitted.

Looks like he did the maintainability performance and test suite checks and made his decision :)

Honestly, I fully support the rewrite to Rust, but he should have just owned this from the start. I'm sure he knew in the back of his mind how dedicated he was to that branch as he had already spent the equivalent of thousands of dollars in tokens by that point.

Yeah but with no guarantee that it was going to work, why should he have?

Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc

#60

Earlier quoted context omitted.

Looks like he did the maintainability performance and test suite checks and made his decision :)

Honestly, I fully support the rewrite to Rust, but he should have just owned this from the start. I'm sure he knew in the back of his mind how dedicated he was to that branch as he had already spent the equivalent of thousands of dollars in tokens by that point.

Bun was VC funded and acquired by Anthropic. He's spending company money, not his own money.
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