... oh, why did I mentioned Shunting Yard that's the most "unlispy"? Well it ensures the code translates to "Lisp without parenthesis"! Write with '(' and ')' if you want, it will remove it in the prettyprint intermediate code anyway. And you even write mathematical expressions in a usual way and the outcome will be prefixed! Your problems are solved..
... or you want it the other way? Then the next step is easy to put back parenthesis.. parse it and write parenthesis back around each construct. Put it then in Lisp interpreter. Will it run after such a prettyprinter juggling?
