Clj.rs – a Clojure dialect implemented in Rust | Hacker News Reader

Clj.rs – a Clojure dialect implemented in Rust

clj.rs

100 pointssimonpure35 comments

One of the killer features of Clojure is it's seamless interop with the host platform. On the JVM you do something like

(Integer/parseInt my-variable); this calls Integer.parseInt(my_variable) in Java-land

I tried to find examples for how to call Rust code and the best I could find is:

https://github.com/csm/clojurust/blob/b847a29b46e2b6b3fbe624...

It looks like you need to do a lot of leg work to introduce Rust functions into Clojure namespaces. I guess there is no way around it and this is not a criticism of clj.rs. But it doesn't seem to be as seamless as on the JVM.

Has Clojure become the new base for Lisp-like languages? What does it got going for it that people seem to want its specific flavor of lisp? Just asking since I've also seen the Clojure talk about Jank[1] recently and it has gotten me interested.

1: https://www.youtube.com/watch?v=tHgApFhevrQ

Hash table literals.

Also, living on a host language has always been part of its ethos. So if you want to be Lisp on C++ or Lisp on Rust, you’re going to be more ideologically aligned with the Clojure crowd than the Common Lisp crowd who pinch their nose and say ALGOL when you mention either.

SBCL is written in C and have FFI baked in

http://www.lichteblau.com/sbcl/doc/manual/sbcl/Foreign-Funct...

Maybe it’s too much work to write a full lisp vm in another language when it’s easier to write a loader.

Coming from Ruby, wanting to learn a Lisp, there are so many things in Clojure that make the language much easier for me to understand, compare to other Lisps. Simple things like first/rest vs car/cdr make it much more ergonomic and easy to grok, IMHO.

Yeah I alluded to this in my comment, but I think the dict literals just make for a much easier on ramp for someone familiar with Python or JS (or JSON, which is increasingly unavoidable for even C++ devs like me).

Nothing will ever be a base for lisps because theyre too malleable and the temptation ro create your own is too high

Anyway my recent favorite is Carp:

https://github.com/carp-lang/Carp

Serious projects in it? Zero

Same, I needed a Lisp that was typed for the AI era where Clojure's dynamism didn't fit the bill. Carp was a perfect fit, and I managed to create a few projects with the help of Deepseek

All Clojures are Lisps, but not all Lisps are Clojures. :)

It's immutable, has bracket syntax for data structures, and most of its standard library has very sensible naming and nil-sentinel conventions. The result is that it's astonishingly easy to read and write. The data structure sharing under the hood also keeps it performant. Finding and obtaining packages with its build systems is also easy.

Scheme gets close but has some odd naming conventions and completely wild conventions for packages (SFRI, etc). CL's entire library is full of incredibly odd names first established at the very advent of computing. Using it can be...dense. And inconsistent, since it's not purely functional and has no dedicated data structure syntax.

the data structure literals are really pleasant to work with, and oh how I miss get-in and update-in in every other language (with all the ecosystem of functions that follow that pattern and are built to work with it)

Why not name it “Cloju.rs” instead? :-)

came here to write exactly that xD

The only thing I know about Clojure is Walmart used it to rewrite their entire inventory system.

Nice, but what are the non goals?

Except maybe the compilation to native binary, this is closer to clojurescript than clojure I suppose ?

How about a comparison with Jank?

Love to see more Clojure dialects taking fruit. Jank is very promising for C++ and now we have the Rust complement

Claude sure is busy these days.

'man' of the year

Cool.

I'm already a big fan of the scheme-rs crate.

I use it any time I need a dynamic scripting language.

It allows for more flexible hot-reloading of parts of a program.

I don't personally have any Clojure interop holes that need filling.

But I can imagine a future where one moves partially away from the JVM if e.g. faster starts or leaner container images are desired.

I love scheme and rust but somehow did not know about scheme-rs! Looks like such a good project, thanks for the recommendation!

Any advantages over steel?

https://github.com/mattwparas/steel

I'm working on something similar.

My guess is, within the next 3-5 years, most ALGOL descendant languages will become obsolete, and S-exp based Lisp dialects will take over. Objectively superior.

Behold a native kernel, no inline asm or linker scripts, of any kind. The full compiler pipeline is controllable through the compiler (you can arbitrarily target, devise, or enable/disable various optimization passes, for instance you can enable LICM at will). Also has a hard 1:1 correspondence to C/C++/Rust/adding more languages soon.

   ;; GNU multiboot kernel
   (image (target x86-64) (origin 0x100000) (entry "boot32")
     (section ".multiboot" (align 4) (keep))
     (section ".bss" (align 4096) (zero))
     (stack "bootstrap" 16384) (stack "kernel" 32768)
     (assert (<= (address "kernel.end") 0x40000000) "early memory must fit the first GiB identity map"))
   
   (static header (Array u32 8)
     (declare (section ".multiboot") (used) (link-name "multiboot_header"))
     (arr (0x1badb002 0x10003 0xe4514ffb
           (link u32 (address "multiboot_header")) (link u32 (origin))
           (link u32 (+ (origin) (image-size))) (link u32 (+ (origin) (image-size)))
           (link u32 (address "boot32")))))
   (static gdt (Array u64 3) (declare (aligned 8) (link-name "boot_gdt"))
     (arr (0 0x00af9a000000ffff 0x00cf92000000ffff)))
   (static pml4 (Array u64 512) (declare (mutable) (aligned 4096) (link-name "boot_pml4")))
   (static pdpt (Array u64 512) (declare (mutable) (aligned 4096) (link-name "boot_pdpt")))
   (static pages (Array u64 512) (declare (mutable) (aligned 4096) (link-name "boot_pages")))
   
   (fn prepare-paging ()
     (declare (mode protected32) (noinline))
     (dotimes (i 512)
       (at pml4 i (->u64 0)) (at pdpt i (->u64 0))
       (at pages i (| (* (->u64 i) 0x200000) 0x83)))
     (at pml4 0 (| (link u64 (address "boot_pdpt")) 3))
     (at pdpt 0 (| (link u64 (address "boot_pages")) 3))
     (unsafe
       (x86::write-cr 'cr3 (link u64 (address "boot_pml4")))
       (x86::write-cr 'cr4 (| (x86::read-cr 'cr4) 32))
       (x86::write-msr 0xc0000080 (| (x86::read-msr 0xc0000080) 256))
       (x86::load-gdt (link VirtAddr (address "boot_gdt")) 23)))

   (fn show-greeting ()
     (unsafe
       (auto video (i->ptr (Volatile u16) 0xb8000))
       (dotimes (i 2000) (at* video i (+ 0x5725 (->u16 i))))
       (auto greeting ":d")
       (dotimes (i (size greeting))
          (auto byte (->u8 (at greeting i)))
         (at* video i (| 0x0f00 (->u16 byte)))
         (x86::out8 0xe9 byte))
       (x86::out8 0xe9 10)))

   (boot-entry boot32 (mode protected32)
     (handoff (magic eax u32) (information ebx PhysAddr))
     (with-stack "bootstrap"
       (prepare-paging)
       (unsafe
         (x86::enter-long-mode 'kernel64 8 magic information (link u64 0x123456789abcdef0)))))

   (boot-entry kernel64 (mode long64)
     (handoff (magic rdi u32) (information rsi PhysAddr) (cookie r12 u64))
     (with-stack "kernel"
       (unsafe
         (x86::write-segment 'ds 16) (x86::write-segment 'es 16) (x86::write-segment 'ss 16)
         (auto valid (and (= magic (->u32 0x2badb002)) (> (address-bits information) 0)
                          (= cookie (->u64 0x123456789abcdef0))
                          (= (& (x86::read-cr 'cr0) 0x80000001) 0x80000001)
                          (= (& (x86::read-msr 0xc0000080) 0x500) 0x500)))
         (if valid (show-greeting)
           (progn (x86::out8 0xe9 70) (x86::out8 0xe9 10))))))

Curious why you’re so bullish on S-Expressions now of all times.

It seems like the idea of the macro, and more generally of expressing code succinctly, is the closest to obsolete in my memory?

The other half of the Lisp sales pitch (image based development, constantly inspect state, hot swap code, REPL, etc) seems like what has retained currency in the LLM age.

> It seems like the idea of the macro, and more generally of expressing code succinctly, is the closest to obsolete in my memory?

That seems true in a world where we completely stop looking at code. Right now my reality is giant verbose PRs written by agents in Java, and it sucks to review.

Yeah, I mean this is somewhat compelling, although the old arguments people brought out (macros are obfuscatory) seem to grow more teeth if agents are writing the macros.

So I guess the idea is tastemaker humans spend all their time coming up with sweet macros and telling agents to refactor the ever shrinking code base.

But even still I think the main argument for S-Expressions (it’s easiest for humans to create DSLs by working on serialized AST) has become weaker. If DSLs are the best way to make a code base readable, you can now have your agent create one with whatever syntax you like!

> If DSLs are the best way to make a code base readable, you can now have your agent create one with whatever syntax you like!

I think these things are going to be true:

- For a specific well-defined coding task, an LLM coding agent will be able to execute it quicker than humans, regardless of how it does it.

- Codebases which are well organised will be easier for an LLM to manipulate than codebases which are obscure and surprising.

I mean.. I think it's plausible that something like "lisp makes DSLs easy, DSLs are a great way to arrange code" is especially true with LLMs; but I'd also think you'd need to know when to use (& when to not use) DSLs to get effective results from this.

Whereas, say, you could have the LLM come up with a DSL in a way which is high friction for the LLM to do it ... but, you'd get the result a bit slower, & maybe worse.

> It seems like the idea of the macro, and more generally of expressing code succinctly, is the closest to obsolete in my memory?

Seems more important than ever? Every model degrades the more context you use, programs that can be described more succinctly will be better made, at least when using LLMs to create these, as it's much easier to fit more "meat" per token.

I'm on the same "S-Expressions taking over is inevitable" but to be fair, I've been on this train for the last decade so maybe I'm slightly biased.

That’s a plausible story, but doesn’t seem to bear out in terms of models being amazing at Lisp. Like, Sonnet 4.5 was writing me emacs Lisp with unbalanced parentheses.

I don’t really have faith that I could write macros of such incredible brilliance that it would outweigh the models’ facility with Python.

This does look interesting, although I did get a chuckle from the "no inline assembler" claim and then seeing x86 intrinsics in the source for seeing some special registers like the segment registers, GDTP, setting IO ports, and some such. Those are of course necessary, but at least in terms of portability, they're not that far off from inline assembler.

From a quick glance over your example, it looks like a hodgepodge of Scheme, Clojure, and Common Lisp with some Rust-y constructs in it. If you don't mind elaborating, why not take some existing "embedded" dialect like Pre-Scheme and compile that? Because currently this looks a lot more like Rust-with-parenthesis rather than a Lisp. Of course if that's the goal then that's fine, but I'd like to hear some elaboration on that.

It's vibecoded which makes it unlikely it has been actually tested well.

I expect this to take over within the next couple of years. Great job!

Take over what, exactly? The java ecosystem version? The javascript ecosystem version ? The c++, clojure-like dialect ?

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