min-sized-rust VS fancy-regex

Who knows what they did, but there are things which can be done: https://github.com/johnthagen/min-sized-rust

> By default, Rust optimizes for execution speed, compilation speed, and ease of debugging rather than binary size, since for the vast majority of applications this is ideal. But for situations where a developer wants to optimize for binary size instead, Rust provides mechanisms to accomplish this.

https://github.com/johnthagen/min-sized-rust?tab=readme-ov-f...

You can get Rust binaries pretty small: https://github.com/johnthagen/min-sized-rust

But in practice it's more like there's an overhead for "hello world" but it's a fixed overhead. So it's really only a problem where you have lots of binaries, e.g. for coreutils. The solution there is a multi-call binary like Busybox that switches on argv[0].

C programs often seem small because you don't see the size of their dependencies directly, but they obviously still take up disk space. In some cases they can be shared but actually the amount of disk space this saves is not very big except for things like libc (which Rust dynamically links) and maybe big libraries like Qt, GTK, X11.

This is a good guide on building small Rust binaries: https://github.com/johnthagen/min-sized-rust

This talks about going to extreme lengths on making the smallest Rust binary possible, 400 bytes when it was written, https://darkcoding.net/software/a-very-small-rust-binary-ind...

The thing is, you lose a lot of nice features when you do this, like panic unwinding, debug symbols, stdlib… for kernel and some embedded development it’s definitely important, but for most use cases, does it matter?

Oh it was 137, haha. I will link you to this older comment of mine: https://news.ycombinator.com/item?id=29408906

See also https://github.com/johnthagen/min-sized-rust

Are you sure? If so then this is awesome news, but I'm a bit confused; the commit in that min-sized-rust repo adding `build-std` to the README was merged in August 2021: https://github.com/johnthagen/min-sized-rust/pull/30

Are you saying that at that point the feature still hadn't "landed in Rust nightly" until recently? If so then what's the difference between a feature just being available in Rust nightly, vs having "landed"?

Rust binaries are by default nowhere close to 500MB. If they are not small enough for you, you can try https://github.com/johnthagen/min-sized-rust. By avoiding the formatting machinery and using `panic_immediate_abort` you can get about the size of C binaries.

A useful reference: https://github.com/johnthagen/min-sized-rust

https://github.com/fancy-regex/fancy-regex/issues/84 it's still open issue

Ahh, very interesting, thanks for sharing! Do you have any thoughts around why that is? I presume that's due to Oniguruma supporting a much broader feature set and something like fancy-regexp's approach with mixing a backtracking VM and NFA implementation for simple queries would be needed for better perf? (I am aware you played a role in that) [1]

I have been playing around with regex parsing through building parsers through parser combinators at runtime recently, no clue how it will perform in practice yet (structuring parser generators at runtime is challenging in general in low-level languages) but maybe that could pan out and lead to an interesting way to support broader sets of regex syntaxes like POSIX in a relatively straightforward and performant way.

[1] https://github.com/fancy-regex/fancy-regex#theory

Not an expert but fancy regex is a Rust library that uses a hybrid approach to detect whether a sub expression contains backtracking and delegates to the appropriate engine.

https://github.com/fancy-regex/fancy-regex