Sky – an Elm-inspired language that compiles to Go

(github.com)

123 points | by whalesalad 9 hours ago

17 comments

  • melodyogonna 6 hours ago
    That's two new languages compiling to Go making HN frontpage in as many days. It seems people like everything about Go except the language itself. Me? I like everything about Go including the language, these transpiled languages are interesting though.

    But I keep wondering if they could integrate at a lower-level than the source code. Like how JVM languages integrate at the bytecode level, or LLVM languages at the LLVM level

    • MichaelNolan 5 hours ago
      > But I keep wondering if they could integrate at a lower-level than the source code.

      I’m sure they could, but targeting go source code has the benefit of giving early adopters an escape hatch. If it targeted LLVM directly, I would never consider using this at work since the risk of it being abandoned is too high. But since it targets go source, I would perhaps consider it for some low importance projects at work.

      • seabrookmx 3 hours ago
        The standard go toolchain doesn't use LLVM. Go has its own assembly format and machine code generation.
    • nu11ptr 4 hours ago
      > But I keep wondering if they could integrate at a lower-level than the source code.

      Unfortunately nothing below source code level is stable, so they would constantly be chasing changes after any Go release. I personally wish they would focus on making it accessible, as Go actually has a nice runtime and would make a good language target.

    • onlyrealcuzzo 4 hours ago
      What was the other one?

      I'm working on a language that transpiles to Zig with a custom Go-like runtime (and no garbage collector, Rust-style Affine movement instead).

      Sky seems quite cool, as it's additive to Go in interesting ways.

      I originally considered keeping the GC and just transpiling to Go so I didn't need to write a Runtime.

      Go rules! It really does. But I HATE writing/reading Go.

      So I'm glad more people are doing this!

      • osigurdson 1 hour ago
        I understand the motivation as I don't really like writing Go code. Interestingly, I don't mind reading it though (as long as the if err != nil isn't too exhausting).

        A transpilation step though? I'll accept that in Typescript (barely) but not for any other language really.

      • styluss 4 hours ago
        • onlyrealcuzzo 3 hours ago
          Awesome, this is very close to what I originally considered.
    • ksec 5 hours ago
      If we think of Go as different kind of C, then having Go as a compiled target seems to make sense as C is a compiled target.
  • taolson 3 hours ago
    Nice to see another language with Haskell / Miranda type syntax, but the vibe-coded implementation sure shows: e.g. src/Compiler/Infer.sky isUpperStart:

        isUpperStart : String -> Bool
        isUpperStart name =
            case String.slice 0 1 name of
                
                "A" ->
                    True
                
                "B" ->
                    True
                
                "C" ->
                    True
            ... for 23 more cases.
    
    And the corresponding go code in the bootstrap compiler is even worse.
    • toastal 3 hours ago
      Haskell/Miranda use `::` instead of `:` for type signatures unlike Elm & basically the rest of the family which prioritize types being less keypresses than list cons.
      • taolson 3 hours ago
        Sorry, I meant "Haskell / Miranda style syntax" -- e.g. curried functions, concise syntax with little boilerplate, etc. The word type is too overloaded ;-)
  • 1-more 4 hours ago
    I will add this to my list of Elm-inspired tools that call to mind Brian Eno's quip about the first Velvet Underground album: "I think everyone who bought one of those 30,000 copies started a band!" With Elm it feels like it's 1% of Elm users creating a language.

    https://quoteinvestigator.com/2016/03/01/velvet/

  • zem 6 hours ago
    at first glance this looks amazing! basically provides everything I have ever wanted in a full stack language. looking forward to experimenting with it.

    edit: looking through the docs/examples some more, it looks like javascript interop is fairly clunky, both because it relies on string concatenation to embed fragments of javascript, and because the string concatenation syntax is not great (and the formatter makes it even worse - see the example at https://github.com/anzellai/sky/blob/main/examples/13-skysho...)

    I would encourage you to at the least add multiline strings with interpolation support, and ideally add a small compiler for html literals.

  • skybrian 6 hours ago
    Functional languages have some good and some bad features and there's no reason to copy them all. For example, you don't need to have a Hindley-Milner type system (bidirectional is better) or currying just because it's a functional language.
    • troupo 5 hours ago
      We need more pragmatic languages. E.g. Erlang and Elixir are functional, but eschew all the things FP purists advocate for (complex type systems, purity, currying by default etc.)
      • rapind 3 hours ago
        If you like Erlang, Elixir, and Elm/Haskell, then Gleam + Lustre (which is TEA) is a pretty great fit.
        • troad 3 minutes ago
          OP suggested they like Elixir/Erlang, I'm not sure why you think they're looking for alternatives.

          I think Gleam's major appeal is types, but with all the work on Elixir's set theoretic type system, that difference will be eliminated sooner or later.

      • zem 4 hours ago
        ocaml has a complex type system but it's also very pragmatic in that it doesn't force you into any one paradigm, you can do whatever works best in a given situation. (scala arguably goes further in the "do whatever you want" direction but it also dials the complexity way up)
        • troupo 4 hours ago
          Yes! Completely forgot about OCaml because I only spent a couple of months with it
  • danpalmer 1 hour ago
    Wow, this is amazing. I always wanted to love Haskell but never really managed, Elm nailed the balance of usability and correctness, plus the architecture was beautiful.

    I've never liked Go, but its strengths are absolutely compiling to single binaries, fast compile times, and concurrency primitives (not necessarily using them) etc. Compiling to Go is a great idea.

  • librasteve 3 hours ago
    Very cool.

    I am comparing this https://github.com/anzellai/sky#tea-architecture with this https://harcstack.org (my thing) ... guess I have some work to do ;-)

  • submain 5 hours ago
    Great work :). Go doesn't have TCO. That means functional languages (no for loops) could blow up the stack. How did you solve that?
    • kubb 4 hours ago
      You can just compile any tail recursive function to a function with a loop and no recursion.
      • 1-more 4 hours ago
        This is in fact how Elm does it! Tail call recursion compiles to a while loop.
      • srean 3 hours ago
        That does not address the use case where I find tail recursion most tempting. That would be mutually recursive functions.

        If the function can be written as an idiomatic loop I probably would do so in the first place.

      • adamwk 4 hours ago
        [dead]
  • onlyrealcuzzo 4 hours ago
    First - awesome job. Congrats. Self hosting is an accomplishment!

    But I'm curious to get your thoughts on the process in hindsight.

    I understand why it's valuable: to cast a wide net in catching bugs and give a good signal that your language is generally "ready".

    I'm working on a similar language, but worried about going down the self-hosting path, as I think it'd slow me down rather than speed me up.

    How did it work for you?

    • ModernMech 3 hours ago
      What's the actual accomplishment here? It seems like the language came into existence a month ago and was written mostly by Claude. If self hosting is a matter of asking Claude to do it and it takes a couple weeks, is it really an accomplishment at all?
      • Philpax 36 minutes ago
        "I could have made that!"

        "Yes, but you didn't."

      • onlyrealcuzzo 3 hours ago
        Anything + Go's runtime is a reasonable language.

        Go's runtime is one of the greatest pieces of software ever built.

        Assuming this works - which self-hosting guarantees a minimum level of "working" - this is useful!

        I didn't want to rely on the unpredictability of a garbage collector, so I chose to build my own runtime, but it's not going to be as good as Go any time soon.

      • troosevelt 3 hours ago
        Yes, somebody has to actually do it, and they did.
  • harikb 4 hours ago
    Somewhat unrelated to the language itself:

    > The compiler bootstraps through 3+ generations of self-compilation.

    I guess it applies to any language compiler, but f you are self-hosting, you will naturally release binary packages. Please make sure you have enough support behind the project to setup secure build pipeline. As a user, we will never be able to see something even one nesting-level up.

    • troad 14 minutes ago
      I feel like there's too much of a fetish for self-hosting. There's this pernicious idea that a language isn't a 'real' language until it's self-hosted, but a self-hosted compiler imposes real costs in terms of portability, build integrity, etc.

      If I ever write a compiler - God forbid, because language design is exactly the kind of elegance bike-shedding I'll never crawl my way out of - it's going to be a straight-up C89 transpiler, with conditional asm inlines for optional modern features like SIMD. It would compile on anything and run on anything, for free, forever. Why would I ever give that up for some self-hosting social cachet?

  • __natty__ 4 hours ago
    I would love to see Java inspired language compiled to Go. I really like Go portability and standard library and Java... verbosity. I prefer explicit names, types and all the syntax around that. Graalvm is not an answer for me because as far as I'm aware it doesn't support cross-compile.
    • weavie 2 hours ago
      You could make it happen in about a week and $50 worth of tokens.
  • redoh 5 hours ago
    Elm's type system and architecture are genuinely pleasant to work with, so seeing those ideas ported to a Go compilation target is interesting. You get the safety and expressiveness of Elm but end up with a Go binary you can deploy anywhere. I wonder how the error messages compare, since that was always one of Elm's strongest features.
  • riclib 6 hours ago
    Can’t wait to play with it. Great design!
  • ch4s3 4 hours ago
    If you allow FFI are you really inspired by Elm? ;)
    • zem 43 minutes ago
      they're inspired by repeating elm's good features and fixing the bad ones!
  • tasuki 5 hours ago
    A bit too bleeding edge for me, but it does look super nice (ie exactly like Elm).
  • desireco42 1 hour ago
    Elm is a language I enjoyed the most. I love Ruby, I loved some other languages, even Haskell I enjoyed, but Elm is special. So let's make this work.

    Now that you got foundation created, let's see how to move it forward.

  • mrichman 4 hours ago
    Compiles to Go or transpiles to Go?