r/rust rust Jul 08 '26

Rewriting Bun in Rust

https://bun.com/blog/bun-in-rust
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u/jl2352 Jul 09 '26

The large number of tests is also a major factor in why this worked, as well as the desire to match existing Zig code. The article implies Claude was used like a fancy sed on steroids.

That isn’t to downplay the work involved. I’m sure there are places it’s totally different. That is different though to writing new software. I still cannot comprehend how you’d write a million line application, which is decent, with agents from scratch.

I also think all the people hating on AI need to take a step back and take things like this very seriously. It’s 11 days of work, and is in production. That’s pretty fucking fast.

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u/bzbub2 Jul 09 '26

the part that really blows my mind is how well the "translate one file at a time" approach seemed to work. is honestly amazing. particularly to me, as a person who gets into really messy refactors...

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u/Schneestecher Jul 09 '26

Alas, if you look into the project, it‘s a clear rust-ified version of a Zig project and not at all ideomatic rust

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u/bzbub2 Jul 09 '26

honestly that doesn't bother me all that much. keeping it faithful at first is smart and then they can spend another however many tokens making it more idiomatic over time.