Give TH the ability to get the info for a class name
In a module M, where a class G is imported from a module N, I want to get all the methods and arities of G into some Info data structure. I thought Template Haskell already offered this possibility, but sorear claimed with very high confidence that this is not the case. In general: as much information as is available to the compiler should be exposed in the Q monad upto some sane cutoff.
I think Template Haskell is not being used that much, because it has lots of arbitrary limitations and is not documented perfectly in one place. It's a vicious circle: because TH (although it costed lots of implementation effort already) is not perfect, there are little users. Because there are not many users, the implementation isn't perfect.