Sure, it's fairly easy to parse. I think probably there is a speed hit (Emacs Lisp code is very slow—though you can call out to an external C library (I've trie

Sure, it's fairly easy to parse. I think probably there is a speed hit (Emacs Lisp code is very slow—though you can call out to an external C library (I've tried it), for which ECL could be maybe used), but quite possibly it's just that, for Lisp, Paredit is mostly sufficient. I think the only case where it breaks down/has trouble is reader macros. I think it can consult SBCL somewhat upon encountering them, not entirely sure.