Rust was chosen as a modeling language for two reasons:
1. Since the whole project is written in Rust, it was the most straight-forward choice. No dealing with bindings to another language or a scripting language runtime for the time being. 2. To provide an interesting alternative. I suspect that there can be a nice niche for Rust, creating infrastructure for writing models (e.g. libraries for generating screw threads, that kind of stuff).
I don't think that Rust is a great language for defining CAD models. Long-term, I suspect that the preferred choice for Fornjot will be something else. But for the time being, this decision allows me to focus on the CAD kernel.
> There also seems to be a goal overlap between Fornjot and DieselCAD
Do you have a link for DieselCAD? Searching on Google only got me car results.
Unfortunately it uses Rust for model description (compile times/learning curve).
That said, one could probably easily put a layer of scipting lang in-between. E.g. Rhai[2] or Lua or whatever.
And I guess if their tech is solid enough, someone will do that eventually and open a PR or fork the project. They do not use an existing geomtry kernel but do everything from scratch which makes this a very interesting endeavour.
There also seems to be a goal overlap between Fornjot and DieselCAD
[1] https://github.com/hannobraun/Fornjot
[2] https://rhai.rs/