What agents mean for Rust (and vice versa)

kubb

I wonder if „hard“ languages like Haskell will make a comeback with LLMs, because the short term cost of learning the language isn’t that significant anymore contrasted with the long term benefits of the type system and better structure.

Depurator

I've been writing rust for maybe 6 years now, and Im very happy i started before the LLMs entered the scene so i had to fight the borrow checker and all that jazz. Now, I will say im extremely productive with rust and LLMs, and its also comfortable to know that I wont have to rewrite anything to a new language, rust is already the best. A famous swedish comedian talks about heroin as the "best drug". Where people usually end up and don't want to stop taking.

shevy-java

> And, naturally, I also happen to think Rust is a really good fit for agentic development To me this is a sad development. AI skynet slop is winning. Does any real human, aside from the fanboi faction, really love "agentic programming"? That is to use prompts to autogenerate text that is source code? I find that both sad and horribly uninteresting. I also stopped reading AI slop generated descriptions - they are just spam, babelfish 2.0 if you will. When I know that the human behind that text, was too lazy to write it himself or herself, why would I want to read that text? That's just a waste of my time. > But I think Rust is popular for another reason: because Rust happens to be a really good fit for agentic coding. Ok, so Rust is the perfect language for bots. Wasn't the original idea to be a great language for humans? What is the point here if AI slop auto-generates everything? Why would you need a human here? > Rust is designed to give “good performance by default”, making the idiomatic thing typically also be the fastest thing. But another key part of Rust is that you have the knobs to eke out better performance when you need it. Ok but why does this then not apply to C, C++, Java, C#, D? These can not be used rather than Rust? And you also should not run into memory issues with C like pointers - after all, AI skynet slop should generate bug-free code in C or C++ too. So I don't get why Rust would be THE ultimate slop language here. To me, if AI works, then any language can be slopped down. This reminds me of the incredibly sad presentation DHH gave on a rails-conf, aka now slop-conf, where he spoke about how AI will win and how Rust beats Ruby hands down and he only AI-slop-spams now (busy on Omarchyslop). These people don't have a "vision" that is decoupled from AI - they are businesspeople and promo-people, convincing you that AI slop is the future. To me this is very sad rather than ... "exciting".

gregwebs

Rust does have one glaring weakness: compile times. I suspect in the LLM era we will see the rise of a language or perhaps some sort of Rust redesign that achieves what Rust has with great performance and great type safety but also has better support for fast compilation. I have found that agents are good at writing Verus proofs in a Rust code base, and that these proofs have only a minimal negative effect on the normal compilation path. I have a skill for using Verus: https://github.com/gregwebs/skills-sdlc/blob/main/skills/rus...

pseudony

Another example of “I like my language and here’s why it is uniquely suitable for $thing” (here AI). I just asked chatgpt today for research on whether any feature of a programming language which has been identified in studies to make it better suited for agentic coding. Or whether popularity in the data-set has been proven to matter or even cross-language learning (knowledge from one language benefitting the LLM in writing in another). Aside from popularity, nothing I could dredge up could prove strong correlations with anything else - including types

xscott

I think we could step back and make a list of programming languages features that are helpful or harmful to LLMs writing code. I don't have a complete list, but things I've thought about: Useful error messages at compile time Fast compilation to iterate and fix those errors Efficient memory, CPU, and maybe GPU at runtime Familiar from the training data [0] One obvious/preferred way to do things Explicit types Rust hits some of those, but not all. I can't think of a language that hits all of them, but a lot of people sure love to rationalize why their own favorite language is the best choice. LLMs don't need syntax sugar and other niceties, and any errors postponed to runtime are a burden on you, not the model. We could add a few more rarely seen features to increase confidence in the results and make future modifications or switching models go better: Required pre-conditions and post-conditions Enforced limits on function or method length Mandatory test cases Enforced naming conventions Lean style proofs of correctness? (probably not) I'm on the fence about things like linear/affine types for memory management vs garbage collection. Obviously you want memory safety, but there's more than one to get that, and I don't know that you want to force contortions to build simple data structures. [0] LLMs are very capable of programming in languages they've never seen before. I've had them write programs using my own toy compilers for my own toy languages. However, you waste a lot of prompt tokens up front explaining things, and then they waste a lot of thinking tokens trying to get it right. Any new language would have a chicken and egg problem here, but LoRAs and model refinement could bridge the gap.

antoineMoPa

I've been "coding" a couple of apps with agents + rust recently and I realize how terribly huge the target/ folder can grow. Then, you run cargo clean, get a clean disk but compilation takes forever again. I routinely run out of disk space. Love the experience in general except that part.