-- the context stuff; hence the arg_prefix binding below
mkReboxingAlt uniqs data_con (arg_prefix ++ arg_ids) rhs
where
+ -- TODO: this is *not* right; Orig vs Rep tys
(arg_prefix, arg_ids)
| isVanillaDataCon data_con -- Instantiate from commmon base
= ([], mkTemplateLocalsNum arg_base (dataConInstOrigArgTys data_con res_tys))