rust-gc VS mark-sweep

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.

Never forget:

https://journal.stuffwithstuff.com/2013/12/08/babys-first-ga...

> Let me stress here that while this collector is simple, it isn’t a toy.

> There are a ton of optimizations you can build on top of this—in GCs and programming languages, optimization is 90% of the effort—but the core code here is a legitimate real GC.

> It’s very similar to the collectors that were in Ruby and Lua until recently.

> You can ship production code that uses something exactly like this.

> Now go build something awesome!

Bob Nystrom also has a blog, and his articles are really well written (see his post on Pratt parsers / garbage collectors). I'd also recommend going through the source code for Wren, it shares a lot of code with Lox. Despite the deceptive simplicity of the implementation, it (like Lox) is incredibly fast - it's a great way to learn how to build production grade compilers in general.

Bob Nystrom (of Game Programming Patterns, Crafting Interpreters, and dartfmt fame) also wrote a tutorial[1], of a precise as opposed to a conservative garbage collector.

Regarding register scanning, Andreas Kling has made (or at least quoted) an amusing observation[2] that your C runtime already has a primitive to dump all callee-save registers onto the stack: setjmp(). So all you have to do to scan registers is to put a jmp_buf onto the stack, setjmp() to it, then scan the stack normally starting from its address.

[1] https://journal.stuffwithstuff.com/2013/12/08/babys-first-ga...

[2] https://youtu.be/IzB6iTeo8kk

- http://journal.stuffwithstuff.com/2013/12/08/babys-first-gar...

Might not be that hard: https://journal.stuffwithstuff.com/2013/12/08/babys-first-garbage-collector/

To better understand garbage collection, nothing better than implementation. This article is such a joy to read:

https://journal.stuffwithstuff.com/2013/12/08/babys-first-ga...