Rust but Lisp

(github.com)

52 points | by thatxliner 3 hours ago

10 comments

  • jaggederest 36 minutes ago
    Unfortunately, given the clear LLM basis of this project, s-expressions aren't a great choice. I've found coding agents struggle really hard with s-expression parentheses matching.

    Much better to give them something more M-expr styled, I think a grammar that is LL(1) is probably helpful in that regard.

    Basically the more you can piggyback on the training data depth for algol-style and pythonic languages the better.

    • dleslie 0 minutes ago
      Opus 4.6 handles elisp just fine. But I suppose YMMV.
  • vermilingua 1 hour ago
    Claims to have all the syntax covered, but not a single example of specifying lifetimes or the turbofish, some of the trickiest rust syntax
    • kibwen 42 minutes ago
      If you already have the ability to express the grammar productions in Rust that allow for optionally-specified types (e.g. variable declaration), then you have the ability to express lifetimes and the turbofish (which is just a curious way to call a generic function with a specific type parameter). The only weird thing would be that Lisp uses the apostrophe character for something very different than Rust, but you could just pick any other way to denote lifetimes.
      • vermilingua 35 minutes ago
        Could!

        > Everything Rust has … expressed as s-expressions. No semantic gap.

    • andrepd 56 minutes ago
      It's a vibecoded parser...
  • ecto 18 minutes ago
    Readers may enjoy my lisp, Loon, which takes heavy inspiration from Rust https://loonlang.com/guide/ownership
  • OhMeadhbh 12 minutes ago
    How do you change the syntax to eliminate reverse compatibility? I guess you could change the names of most key functions between releases. But to be compatible with rust you would need to make breaking changes every release.
  • hawkice 1 hour ago
    I think some comments are missing the upside of it being precisely Rust, without any new semantics. If you want lisp that compiles to machine code, Common Lisp can get reasonably efficient. The purpose of bringing Rust into it is to surface Rust-specific semantics -- which many people quite like!
  • GalaxyNova 1 hour ago
    It seems like this is more like writing Rust in an s-expression syntax instead of having a proper lisp dialect that compiles to Rust, which is cool I guess but not very interesting.

    It's quite weird-looking for someone who's done any amount of lisp programming.

    • noosphr 1 hour ago
      >Rust semantics with LISP syntax. A transparent s-expression frontend that compiles directly to Rust — no runtime, no GC

      The first paragraph says literally that.

    • monocasa 59 minutes ago
      Yeah, it sort of reminds me of the microcode assembly of a few of the lisp machines, that, while in s-expressions were also clearly not lisp themselves. But could be an interesting target for some lisp macros.
    • shawn_w 1 hour ago
      A let that defines variables that have a lifetime beyond the scope of the expression? Yeah, that's really unusual. And it's not even the oddest looking thing from the first example block of code.
  • amelius 31 minutes ago
    This is probably what Rust's internal ASTs look like. But why would you want to input programs as ASTs?
    • physPop 29 minutes ago
      so you can do the transformations (see the rlisp macro section)
      • amelius 24 minutes ago
        Yes, but you could do the same by transforming Rust's ASTs. The only downside is that your input format is different from the format you are transforming. But the upside is that readability is much improved, which matters because code is typically read far more often than it is written.
  • stuaxo 1 hour ago
    "no runtime, no GC, just" I am BEGGING every project to not have this LLMism in their docs.

    It reads as No X no Y just slop to me every time.

    • andrepd 54 minutes ago
      It's completely nonsensical too. Why would a parser for an alternative syntax introduce a GC?!
  • nxobject 7 minutes ago
    "Lust", or "Risp"?
  • FrankWilhoit 2 hours ago
    And for why?
    • macmac 2 hours ago
      To get proper macros.
      • fao_ 1 hour ago
        Scheme already has hygenic macros, I don't get why you'd vibecode a worse (less battle tested, llm-generated) replacement. I'm not sure why this hit the front-page, to be honest, because it doesn't seem noteworthy or interesting (Anyone and their mother can vibecode something like this in eight hours)
        • wk_end 1 hour ago
          Scheme doesn't have Rust semantics, though?
        • zem 1 hour ago
          this is not a replacement for scheme, it's simply an alternative syntax for rust