rlox VS boba

It's actually the other way round: part one implements an AST walking interpreter in Java while the second part builds an interpreter in C with compilation to byte code for a virtual machine that is also developed from scratch. Currently I try to build the second part solution in Rust (https://github.com/thomasbollmeier/rlox).

Great, I do the same:-). I have however only proceeded with my implementation to the Pratt expression parsing so far: https://github.com/thomasbollmeier/rlox

I have just started with a rust implementation of the VM and the interpreter from part 2 (https://github.com/ThomasBollmeier/rlox). While following the book I wonder if it wouldn't be easier to build on the interpreter from part 1 and just emit bytecode while traversing the AST.

I've done a small implementation, used in type inference, in my language Boba. And you are correct, I used the linear equation solving method.

The vast majority of October's improvements on Boba were type system and runtime bug fixes. In particular, the effect handler/delimited continuation semantics were hopelessly busted beyond a few simple examples I'd fixated on.

September was another productive month for Boba, which is starting to get more 'quality of life' improvements rather than broad new features. That doesn't make the work less important: one of the bug fixes to the type inference engine last month caught a previously unseen bug in the core Boba libraries!

Also worth checking out is Adam Gundry's work on type inference for UoM types. Or, if you want an example implementation of the Abelian unification used in standard type inference extended with UoM types, you can reference my implementation, based on solving linear equations.

August was a surprisingly productive month for the Boba compiler. A few highlights:

The next large feature for Boba (a general-purpose concatenative language) is language integrated property tests.

That's a good question! I wrote up some of my thoughts on the benefits of Go as a backend, but there's also a historical component here. The first backend I was experimenting with was compile-to-C plus a C-based runtime. Go was closer to C than C# for what I needed at the time and I thought had a nicer concurrency story as a backend.