It's not good, it doesn't understand the TF types and recommends values that are invalid for the context, there's no inline help (you have to go look it up on the website), refactoring a variable name doesn't fully work, and you can't set breakpoints or trace through the execution to determine what's going on... I mean it's practically in the mid-80s, although most of those things worked even back then.

The lesson here is that if you plan on making a language, even a DSL, you want to be sure you're really up for it since it's a lot of work.