where
ppr_details (PrefixCon arg_tys) = dcolon <+> ppr (foldr mk_fun_ty res_ty arg_tys)
ppr_details (RecCon fields) = ppr fields <+> dcolon <+> ppr res_ty
- ppr_details (PrefixCon _) = pprPanic "pprConDecl" (ppr con)
mk_fun_ty a b = noLoc (HsFunTy a b)