While I think this is great, Ruby implementations are notorious for being tricky to implement 100%. Rewriting Ruby in Rust is great and all but even TruffleRuby isn't at the point where the authors recommend running a Rails app on it.

I wonder if there's a way to add some Rust into MRI. Perhaps someone could write a YARV VM or a version of the JIT in Rust. It'd complicate the build pipeline, but it'd be iterative and improve the main implementation of Ruby.

Ruby has a great black box testing suite called ruby/spec [0] that is shared among multiple Ruby implementations. Artichoke has a custom runner [1] to track progress on implementation completeness.

If Artichoke passes ruby/spec and is not compatible with MRI, that's a bug in the specs.

re: adding Rust to MRI, I'm working on extracting the mruby backend from the core VM infra + core/stdlib impls [3] which would let us use MRI as the backing VM via rutie. When the Artichoke core and stdlib is complete, this would mean that the MRI runtime could be implemented entirely in Rust [2].

[0] https://github.com/ruby/spec [1] https://github.com/artichoke/artichoke/tree/master/spec-runn... [2] https://github.com/artichoke/artichoke/issues/92 [3] https://artichoke.github.io/artichoke/artichoke_core/