Bidirectional parsing-pretty-printing is a nice thing, with the only potentially tricky issue in an idiomatic rendering of the infix opetators with priority. Fi

Bidirectional parsing-pretty-printing is a nice thing, with the only potentially tricky issue in an idiomatic rendering of the infix opetators with priority. Firstly, parser must be aware that they are special (I am using a dedicated Pratt parser for the binaries inside a Packrat for this reason). Secondly, it is often important to print parenthesis around an expression for readability, even if it is not dictated by the priority.