`unionNameSets` extractHsTyNames_s tys
get (HsFunTy ty1 ty2) = get ty1 `unionNameSets` get ty2
get (HsPredTy p) = extractHsPredTyNames p
- get (HsUsgForAllTy uv ty) = get ty
- get (HsUsgTy u ty) = get ty
get (HsOpTy ty1 tycon ty2) = get ty1 `unionNameSets` get ty2 `unionNameSets`
unitNameSet tycon
get (HsNumTy n) = emptyNameSet