I've been searching for people who are doing this for inspiration and maybe exchanging ideas in chat. What I have seems very similar to Ezno when it comes to tracking mutations and side effects and the key idea of "maximum knowledge of a source"

I struggle a bit with communication about this topic as my way of learning has been more of a self taught trial and error process. It almost feels like the people who are building typesystems is speaking another language (especially those with a Haskell background), but I'm slowly starting to understand some of it. Your blog post however was easy to understand.

Inferring from usage is something I've been thinking about every now and then, and it seems doable if the type can mutate from some unknown type to the first expected type. In practice this doesn't seem to become a big deal if you always require input types to be typed (from arguments or some other external) but it's an interesting problem.

I think the way I would approach mutating someObj.prop1.prop2 is to do a mutation of the field when calling the function signature. I'd have to know a few things about prop2 though.

So it would effectively be something like Math.sin = (val) => {let [parent, key] = parentObject(val); parent[key] = number }

Then it would make use of the way i track mutations already.

My project's status is that it's not production ready but it's in the open. There's some use to the playground to analyze what Lua scripts might possibly do.

playground: https://capsadmin.github.io/NattLua/

source and further explanation: https://github.com/capsAdmin/nattlua

Not sure if I have any big plans, I just think it's fun and interesting to work on and maybe I want to use it for my other Lua projects. I'm not very happy with the codebase as I've written it in Lua. I'm trying to bootstrap it but it's growing in complexity faster than I can bootstrap it. But one step at a time and I should be there someday, maybe I can even port it to some other language like Rust when I have a better understanding of what I'm actually doing. :)