Why does the lexical analyzer drop comments ?
At the moment, I am concentrating efforts deep down in the parser code, but there are other challenges: - once the expressions are parsed, we will need something that investigates to find evidence about function calls, to get an idea of where the function is defined (by the user, in a package, ...) . This is tricky, and unless you actually evaluate the code, there will be some errors made.
Are you aware of Luke Tierney's codetools package? That would seem to be the place to start. Hadley