After finishing up the core UDL parser I found it was extremely simple to use the core language to define schema for type checking. Right now UDL can parse a config and roughly check it against a schema (it only checks that names are correct and keys have the correct number of values). It’s functional but not very robust. No error messages, etc.
While I was finishing up the schema stuff I started thinking about how I wanted to handle the actual type checking of values. I originally planned to have primitive types basically hard coded into UDL itself, so you could say a given value was an int, float or whatever. This isn’t very flexible since you have to write code if you want to add a new type. My plan now is to provide a very simple API for adding new type checkers. Once that’s in it should be a simple matter to drive it by some simple UDL definitions! Allowing new types without new code will be really great! I hope it works out.