mark-sweep VS mmtk-core

Seconding the Make-A-Lisp and Crafting Interpreters recommendations. This post is also really great, it contains a hard written parser that you may learn from.

You mentioned you want to write your lisp in javascript so you'll be getting quite a lot of functionality for free: memory allocation and garbage collection. Just in case anyone reading is going to write in C, here's an excellent introduction to the topic:

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

Don't forget to spill the registers.

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/

Great learning project, I'm glad the author is having fun.

If they're interested in bolting on a GC, it couldn't hurt to look at MMtk. (https://www.mmtk.io/) Some high quality collection algorithms, written to be pluggable to various VMs, and written in Rust.

just here to mention https://github.com/mmtk/mmtk-core crate which provides garbage collectors. The only problem is requiring threads, which makes it unsuitable for wasm.

AFAIK, no. The opposite is true with MMtk (https://www.mmtk.io), which is a toolkit with many GC algorithms implemented that has been plugged into other runtimes, including, as it happens, OpenJDK.

IME the MPS is hard to set up correctly, and I've heard in Clasp they got in performance trouble, as per-thread allocation buffers were too small and they couldn't make the buffers larger. But indeed being conservative on the stack is a fine choice; someone mentioned Boehm being easy to use, and the MMTk is a newer option which allows for bump-allocation and being precise on the heap (like MPS), but at the moment you have to provide your own stack scanning code.