On Fri, May 02, 2008 at 08:30:03AM +0100, Simon Peyton-Jones wrote:
| Generally, if module A exports foo, module B imports A and re-exports | foo, and module C imports both A and B, there should be no ambiguity. | Not even if it reexports all of modules A and B. Why would e.g. GHC | need to warn in that case?
Perhaps Niklas can say whether #1148 is the bug he is describing, and if not file a new one?
Niklas's example: module A where foo x = x module B(foo) where import A module C where import A import B c = foo 'a' ghc -W says C.hs:2:0: Warning: Module `A' is imported, but nothing from it is used, except perhaps instances visible in `A' To suppress this warning, use: import A() It's true that the import can be deleted, but not that "nothing from it is used".