An example of an OpenSCAD design written this way: https://github.com/TOGoS/OpenSCADDesigns/blob/master/2023/ex...

I wrote about the approach a little bit in this Reddit post: https://www.reddit.com/r/openscad/comments/186b54r/interpret...

The interpreter itself is just a single module: https://github.com/TOGoS/OpenSCADDesigns/blob/master/2023/li...