[Haskell-cafe] Unused definitions across modules in a package

[Felipe Almeida Lessa]

Hey!

GHC warns me about unused definitions in a module.  However, is it
possible to warn me about unused definitions in a package?

For example, suppose that module A exports function f and that module
B uses A.f (everything on a single package).  However, after some time
B stops using A.f.  Is there a way of receiving a warning saying that
"A exports f but no other module uses it."?

(I know that this warning wouldn't be useful for libraries, since
their whole point is to export things.)

Cheers!

--
Felipe.