I like it. I was just trying to do some simple "parsing" of a pyproject.toml file. So I wrote the standard crud of, "is it a dictionary? If so, does it have a specific key? What if it's just a string? If so, ..."

Having a dedicated syntax would mean someone could look at the patterns I'm matching and see clearly what the format of the input should be. This seems ideal for handling various user-friendly toml/yaml/json configuration formats and other semi(poorly)-structured data.

I think it also addresses a real weakness in OO: to add behavior per class you either lard up classes with not-really-relevant methods, or create a proxy class, or do the inevitable if/elif isinstance chain.