Show HN: Small Clojure Interpreter(github.com)
github.com
Show HN: Small Clojure Interpreter
https://github.com/borkdude/sci
4 comments
I am constantly impressed by how prolific Borkdude, feels like every couple of months a whole new conceptual library is released...
This is cool stuff, but submitting it twice 24 hours apart is not that cool: https://news.ycombinator.com/item?id=21167211
Yet not that uncool, either.
Sorry about that. Some time after I posted that I realized "Show HN" would be the better format to show this project, but couldn't rename the title. If I'm violating any HN code of conduct, feel free to delete this post.
well, I didn't see it the first time, yet saw it this time :)
Nice project!
Nice project!
This "small" Clojure interpreter can be used from Clojure on the JVM and GraalVM and JavaScript/ClojureScript. It implements a subset of Clojure. The main goal is be able to execute snippets of Clojure in environments where you normally don't get to use Clojure's "eval" or where it isn't safe to do so.
Its main use is being the interpreter for https://github.com/borkdude/babashka, a native Clojure scripting tool which can be used to alleviate your bash pains, but it could potentially be interesting for other use cases too.
Malli (https://github.com/metosin/malli), a Clojure schema library, is using it for letting users express in code what they cannot do using the normal configuration language.
Closh is investigating if sci can be used to compile closh to native code using GraalVM: https://github.com/dundalek/closh/tree/feature/sci.
Undocumented features (still figuring out the best API):
- Explicit allowing and denying of certain symbols.
- Limit evaluation of infinite sequences.
A pure Java API is certainly possible if this is useful to anyone.
Its main use is being the interpreter for https://github.com/borkdude/babashka, a native Clojure scripting tool which can be used to alleviate your bash pains, but it could potentially be interesting for other use cases too.
Malli (https://github.com/metosin/malli), a Clojure schema library, is using it for letting users express in code what they cannot do using the normal configuration language.
Closh is investigating if sci can be used to compile closh to native code using GraalVM: https://github.com/dundalek/closh/tree/feature/sci.
Undocumented features (still figuring out the best API):
- Explicit allowing and denying of certain symbols.
- Limit evaluation of infinite sequences.
A pure Java API is certainly possible if this is useful to anyone.
It would be really nice if you could expose the parser to Javascript as well. I could use this to integrate with some Javascript tooling in my CLJS frontend (e.g. purgecss extractors).
There is a parser lib which was extracted from sci: https://github.com/borkdude/edamame. I guess that could have a JS interface, but I'm not sure what it would look like to make it useful for you.
Hit me up on Clojurians Slack or Twitter so we can discuss your needs.
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While we are all talking about self crafted Clojure runtimes. Here is mine.
Me and a friend wrote a small VM to run Clojure. We designed a costum bytecode based on LuaJit [1] for it and a compiler in Clojure to compile Clojure to that Bytecode.
We had to versions of the VM originally in pre-1.0 Rust but that was always breaking. Then we wrote it in C [3].
For those interested in the GC, we use the OpenSource 'Memory Pool System' [2] originally designed for Dylan.
Its very nice incremental GC system. It fairly simply use, you basically just implement a couple functions related to parsing your objects and the MPS gives you a neat incremental GC for free. Lots of other neat features that are easy to use out of box.
Originally I wanted to write a simple JIT for it but I never actually did it.
[1] https://github.com/clojit/clojit-doc/blob/master/Bytecode%20...
[2] https://www.ravenbrook.com/project/mps/
[3] https://github.com/clojit/clojit-cvm
Me and a friend wrote a small VM to run Clojure. We designed a costum bytecode based on LuaJit [1] for it and a compiler in Clojure to compile Clojure to that Bytecode.
We had to versions of the VM originally in pre-1.0 Rust but that was always breaking. Then we wrote it in C [3].
For those interested in the GC, we use the OpenSource 'Memory Pool System' [2] originally designed for Dylan.
Its very nice incremental GC system. It fairly simply use, you basically just implement a couple functions related to parsing your objects and the MPS gives you a neat incremental GC for free. Lots of other neat features that are easy to use out of box.
Originally I wanted to write a simple JIT for it but I never actually did it.
[1] https://github.com/clojit/clojit-doc/blob/master/Bytecode%20...
[2] https://www.ravenbrook.com/project/mps/
[3] https://github.com/clojit/clojit-cvm
Nice! I hope you will consider moving back to Rust when things have stabilised. Cross-platform compilation is much easier in Rust than in C. I think it's one of the big factors driving developers to it along with memory safety.
I would but I not really working on this anymore. There are some issues with MPS and Rust that we never fully figured out. MPS relies on scanning stack points and scaning the registers, some of those default function might not totally work with Rust.
We never figured out what the right approch was.
But there are defently very nice things you can do with Rust. The Servo team has to solve some of the same issues with and they have some interesting blogposts about memory managment.
We never figured out what the right approch was.
But there are defently very nice things you can do with Rust. The Servo team has to solve some of the same issues with and they have some interesting blogposts about memory managment.