rust-gc VS starlark-rust

rust-langdev has a lot of libraries for building compilers in Rust. Perhaps you could use these to make your implementation easier, and revisit it later if you want to build things from scratch. I'd suggest logos for lexing, LALRPOP / chumsky for parsing, and rust-gc for garbage collection.

There's nothing stopping you from doing that in Rust. See rust-gc for an example of a GC implemented in Rust. Another example is mozjs, which is Rust bindings to SpiderMonkey. The GC there is implemented in C++, but it shows how you'd structure wrapper types for GC'd pointers in Rust so that you can use them safely, even with all the "ugliness" of a browser-grade GC.

One can have a GC as a library, https://github.com/Manishearth/rust-gc

The ones I am aware of are gc and broom. None will be as simple to use as the one in old Rust as userland implementations don't have the benefit of first-class integrated compiler support.

Rust has rust-gc, which is an attempt to add opt-in GC over Rust's more traditional automatic memory management. It's a neat project, but I'm not sure where it's actually being used.

Inb4 "already exists": the question is about making it convenient, not just imlementing the behavior.

There is also a library implementation of garbage collection for Rust, made by someone from the Rust core team.

Yep! And I'd actually fully agree those are garbage collection, there's also a crate by Manish which does """real""" garbage collection—https://github.com/Manishearth/rust-gc

I don't know that I'd say it "works" - it's never a technique I've needed to use myself, but it's the approach taken by e.g. https://github.com/Manishearth/rust-gc

Anyway, I found something recent that implements "rc" but in terms of tracing: https://github.com/Manishearth/rust-gc/ . Maybe useful for projects involving graphs of objects.

I haven't seen anyone mention starlark yet. It's something I want to play with as a config language.

Aside from these, if you want some inspiration for a production-grade language built in Rust, you might want to go through the source code of Starlark and Gluon.

There is also a Rust implementation of Starlark as a starting point https://github.com/facebookexperimental/starlark-rust

To add to everyone else, please don't use YAML. Starlark is great _precisely_ because it is a readable, well known (nearly Python) language that is limited at the same time (no unbounded for loops, no way to do non-deterministic things like get the current time or `random()`).

This is a follow-up to Benchmarking mlua/rlua/rhai - Rust embedded scripting languages from 4mo ago; I just added the new Starlark implementation from Meta to the benchmark posted by @aleksru.

The Rust implementation has it as an experimental extension (https://github.com/facebookexperimental/starlark-rust/blob/m...)

u/ndmitchell has been working on a Starlark interpreter. He wrote up a blog post with some thoughts about different interpreter styles. He found that in his case using fixed sized instructions was about the same as byte-encoded ones, but compiling the AST to closures was also about the same performance as well, and doesn't need an AST->bytecode compiler.

As mentioned in other comments, type system features like algebraic data types (that Rust has) are really helpful. If you want a small-but-real example of a compiler in Rust (with an optimizer etc) then the starlark-rust compiler is good.

If your Rust program needs a more complicated configuration (conditionals, access to APIs and so on), also look at Facebook's Starlark parser and tooling[1]. Starlark is a subset of Python used by Bazel, Buck and a few other projects.

[1]: https://github.com/facebookexperimental/starlark-rust

The Facebook post gives a nice overview. It also links out to the home page for the project at https://github.com/facebookexperimental/starlark-rust/, which has an introduction and links to what Starlark is, the crates.io link, the docs.rs link etc.