> "change of level" The obvious interface for such a concept would be to have matching parentheses "snap" into a kind of token field around the corresponding t

> "change of level" The obvious interface for such a concept would be to have matching parentheses "snap" into a kind of token field around the corresponding text. It would be pretty easy to then build a kind of raised relief map of code built from nested token fields that suggest elevation changes instead of nested parentheses. All in realtime as the user types, of course. In the history of Lisps is there such an interface? My gut tells me either a) no, or b) yes, there's a maximally unusable version which was abandoned immediately upon recognition that it would suffice as bait to inculcate newcomers into the cult of Lisp parentheses. Edit: clarification