How to get warnings about unused imports ?

[Namespace]

You have to parse the unnamed import files, list all their 
identifiers (global variables, public functions etc.) and search 
for them. ;)
That could be a bit complicated. ;) Therefore I don't want to do 
it. Even with named imports you can get false positives.

But if you like it, you could improve it. The Lexer is my own and 
not that good, that would be start. On the wiki you can find 
other Lexer / Parsers, which are really good, but I haven't the 
time to replace my own and adapt the source or to work much on 
the project.