I am waiting for someone to build a modern scripting language in Rust that has the popularity and rich tooling and capabilities of Rust as a result.

▲ ekidd 3 days ago | parent | next [-]

There are two deep capabilities that make Rust, Rust:

1. Banning shared, mutable data. You can't change data that other code might be reading. This is a huge win for threading and multiple CPUs, but it's a dramatic departure from other popular languages.

2. Knowing how data is laid out in memory. This is classic "systems programming" stuff, and it's also present in C, C++, Zed, etc. This usually goes along with making memory allocation visible (though not always in C++). This is a big win for performance.

If you wanted to build a "scripting language" version of Rust, you could probably lose (2). Languages like Haskell are even stricter than Rust, but they hide the details of memory layout. But then you need to decide whether to keep or lose (1). If you keep it, your language will have good threading, but users will need to think about ownership and borrowing. If you lose (1), then your language won't feel very much like Rust.

It would be an interesting intellectual exercise! But actually turning it into a popular scripting language would probably require the same luck and the same 10 years of work that most successful languages need to get real traction.

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coolsunglasses 3 days ago | parent [-]

>If you wanted to build a "scripting language" version of Rust, you could probably lose (2).

Not really no. I work on an interpreted language runtime in Rust professionally and it's still a huge help even if you're still eating perf pain on the interpreted language itself for the same reasons everyone else does. There's more benefit to Rust than you're really capturing here but that's to be expected, it's a short comment.

Here are some other things we get from using Rust for interpreted languages:

- The `unsafe` parts are relatively limited in scope and we have much better and more automated verification tools for `unsafe`, especially WRT undefined behavior

- Being able to make large architectural changes and work through them mechanically/quickly because of the type-checking and borrow-checking is absurdly powerful for any project, all the more so in this context.

- The library ecosystem for Rust has been fantastic for all kinds of projects but it's especially good for PL runtimes.

- LLMs are a lot better at Rust than other programming languages. I have a lot of experience using LLMs in a variety of domains and programming languages and it's far better at Rust than anything else that's expressly about programming. Arguably it's even better at Terraform and Ansible but I consider that a different category. Controversial point maybe but I get tremendous yield out of it.

- It's not just that Rust is fast. It is on par w/ C/C++ all else being equal. What's significant here is that it is a _lot_ quicker/easier to hit the 80/20 perf targets as well as the bleeding edge performance frontier in a Rust application than it is in C and C++. A lot of C and C++ projects leave performance on the table either because it's too hard to make the ownership model human-maintainable/correct or because it would be too much work to refactor for the hoped-for perf yield. Not as much an issue in Rust. You can gin up hypothetical perf improvements in Rust with gpt-5 lickety-split and the types/borrowck will catch most problems while the agent is iterating.

Shared, mutable data aren't really banned, we use it strategically in our Rust interpreter, it's just not default-permitted. Aliasing is precisely the distinction between a safe reference and an unsafe pointer in Rust. Aliasing a mutable pointer in Rust isn't UB, it's just `unsafe`. OTOH, aliasing a mutable reference _is_ UB and not allowed in Rust. Miri will catch you if you do this.

On top of all that, you have some nice kit for experimenting with JIT like Cranelift.

	▲	Cyph0n 3 days ago \| parent [-]
		> You can gin up hypothetical perf improvements in Rust with gpt-5 lickety-split and the types/borrowck will catch most problems while the agent is iterating. I am a huge Rust fan, but never really got a chance to write it in the modern LLM era. It makes absolute sense that the borrow checker would make LLM agent-driven refactors easier.

▲ jasonpeacock 3 days ago | parent | prev | next [-]

I just use Rust to do any "scripting" work. I stopped using Python and write it in Rust instead, and I'm more productive than before.

What do you need a scripting language for that's different than using Rust?

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Aeolos 3 days ago | parent [-]

How do you deal with slow compilation times?

	▲	jasonpeacock a day ago \| parent [-]
		It's not that slow? Cargo only recompiles the crates that you edit, after the first build of the dependent crates it's quick to iterate. Compilation is not the bottleneck, it's the human (me) in the loop that's doing the thinking and typing. The productivity boost comes from Rust's strong type system and ownership (much better than MyPy) which practically ensures that if it compiles, it will work. There's a lot less troubleshooting/debugging of my Rust "scripts" than when I wrote Python.

▲ librasteve 3 days ago | parent | prev | next [-]

suggest you test drive https://raku.org while you wait (spoiler alert - written in C)

▲ giancarlostoro 3 days ago | parent [-]

I have fiddled with Raku but it feels like a language thats from a parallel universe to Perl which might not get serious adoption. When I look at languages I evaluate them by libraries available for UI, database access, networking libraries and web frameworks primarily.

	▲	librasteve 3 days ago \| parent [-]
		lol Thanks for giving Raku a test drive (https://raku.org) While Raku can access all the perl CPAN modules and Python modules via Inline::Perl5 and Inline::Python, I agree native modules are also a good indication of the level of "adoptability" of a language. I would say that Raku is currently ready for "bleeding edge" and "early-adopters" but not for "early-main" (terms from Crossing the Chasm) For example, there are three pretty nice actively maintained web framework libraries: `- Cro (also HARC stack that uses Cro) - Hummingbird - Web::App` For me the strength of being an early adopter is that the community is small and friendly (with many experts who help me out) and that I can be an influential contributor to shape the ecosystem to do things that meet my needs. And this is not in an ocean of cruft (like CPAN and Python). Similar stories for each of the domains you mention: https://chatgpt.com/share/68c67f75-d654-8009-9c8d-fdb1081869...

▲ testdelacc1 3 days ago | parent | prev [-]

Like Gleam?

	▲	scotty79 3 days ago \| parent \| next [-]
		It doesn't have imperative constructs I think. So half of developers or more are out front the get go.
	▲	giancarlostoro 3 days ago \| parent \| prev [-]
		I was thinking similar but more like a Python or Lua but all in Rust.