I had looked into the 'ast' module a little while back, and I do agree that it's pretty neat. The main use I've seen it type checking, or adding language level

I had looked into the 'ast' module a little while back, and I do agree that it's pretty neat. The main use I've seen it type checking, or adding language level features (that would typically be done by macros in LISP). I am not aware of many tools written using 'ast', that don't try to extend the language in some way. Any thoughts there?