This is is suggested very, very often. It's been implemented a few times, but has never gained much currency. As best I can tell, it's one of those ideas that sounds good but rapidly grows either complex or kinda useless as you throw more cases at it and you just end up with lots of weird syntax thrown around instead of lots of parenthesis. It works best in a Lisp that was designed with this syntax like Dylan rather than as something you bolt onto a paren-dependent Lisp.