; overlap_flag <- getOverlapFlag
; let (infer_specs, given_specs) = splitEithers early_specs
- ; insts1 <- mapM (genInst overlap_flag) given_specs
+ ; insts1 <- mapM (genInst True overlap_flag) given_specs
; final_specs <- extendLocalInstEnv (map (iSpec . fst) insts1) $
inferInstanceContexts overlap_flag infer_specs
- ; insts2 <- mapM (genInst overlap_flag) final_specs
+ ; insts2 <- mapM (genInst False overlap_flag) final_specs
-- Generate the generic to/from functions from each type declaration
- ; gen_binds <- mkGenericBinds is_boot
+ ; gen_binds <- mkGenericBinds is_boot tycl_decls
; (inst_info, rn_binds, rn_dus) <- renameDeriv is_boot gen_binds (insts1 ++ insts2)
; dflags <- getDOpts
rn_inst_info (InstInfo { iSpec = inst, iBinds = NewTypeDerived co })
= return (InstInfo { iSpec = inst, iBinds = NewTypeDerived co }, emptyFVs)
- rn_inst_info (InstInfo { iSpec = inst, iBinds = VanillaInst binds sigs })
+ rn_inst_info (InstInfo { iSpec = inst, iBinds = VanillaInst binds sigs standalone_deriv })
= -- Bring the right type variables into
-- scope (yuk), and rename the method binds
ASSERT( null sigs )
bindLocalNames (map Var.varName tyvars) $
do { (rn_binds, fvs) <- rnMethodBinds clas_nm (\_ -> []) [] binds
- ; return (InstInfo { iSpec = inst, iBinds = VanillaInst rn_binds [] }, fvs) }
+ ; let binds' = VanillaInst rn_binds [] standalone_deriv
+ ; return (InstInfo { iSpec = inst, iBinds = binds' }, fvs) }
where
(tyvars,_,clas,_) = instanceHead inst
clas_nm = className clas
-----------------------------------------
-mkGenericBinds :: Bool -> TcM (LHsBinds RdrName)
-mkGenericBinds is_boot
+mkGenericBinds :: Bool -> [LTyClDecl Name] -> TcM (LHsBinds RdrName)
+mkGenericBinds is_boot tycl_decls
| is_boot
= return emptyBag
| otherwise
- = do { gbl_env <- getGblEnv
- ; let tcs = typeEnvTyCons (tcg_type_env gbl_env)
- ; return (unionManyBags [ mkTyConGenericBinds tc |
- tc <- tcs, tyConHasGenerics tc ]) }
+ = do { tcs <- mapM tcLookupTyCon [ tcdName d
+ | L _ d <- tycl_decls, isDataDecl d ]
+ ; return (unionManyBags [ mkTyConGenericBinds tc
+ | tc <- tcs, tyConHasGenerics tc ]) }
-- We are only interested in the data type declarations,
-- and then only in the ones whose 'has-generics' flag is on
-- The predicate tyConHasGenerics finds both of these
mkDataTypeEqn orig dflags tvs cls cls_tys
tycon tc_args rep_tc rep_tc_args mtheta
- = case checkSideConditions dflags cls cls_tys rep_tc of
- -- NB: pass the *representation* tycon to checkSideConditions
- CanDerive -> mk_data_eqn orig tvs cls tycon tc_args rep_tc rep_tc_args mtheta
- NonDerivableClass -> bale_out (nonStdErr cls)
- DerivableClassError msg -> bale_out msg
+ | isJust mtheta = go_for_it -- Do not test side conditions for standalone deriving
+ | otherwise = case checkSideConditions dflags cls cls_tys rep_tc of
+ -- NB: pass the *representation* tycon to checkSideConditions
+ CanDerive -> go_for_it
+ NonDerivableClass -> bale_out (nonStdErr cls)
+ DerivableClassError msg -> bale_out msg
where
+ go_for_it = mk_data_eqn orig tvs cls tycon tc_args rep_tc rep_tc_args mtheta
bale_out msg = failWithTc (derivingThingErr cls cls_tys (mkTyConApp tycon tc_args) msg)
mk_data_eqn, mk_typeable_eqn
; return (if isJust mtheta then Right spec
else Left spec) }
+ | isJust mtheta = go_for_it -- Do not check side conditions for standalone deriving
| otherwise
- = case check_conditions of
- CanDerive -> mk_data_eqn orig tvs cls tycon tc_args rep_tycon rep_tc_args mtheta
- -- Use the standard H98 method
- DerivableClassError msg -> bale_out msg -- Error with standard class
+ = case checkSideConditions dflags cls cls_tys rep_tycon of
+ CanDerive -> go_for_it -- Use the standard H98 method
+ DerivableClassError msg -> bale_out msg -- Error with standard class
NonDerivableClass -- Must use newtype deriving
| newtype_deriving -> bale_out cant_derive_err -- Too hard, even with newtype deriving
| otherwise -> bale_out non_std_err -- Try newtype deriving!
where
newtype_deriving = dopt Opt_GeneralizedNewtypeDeriving dflags
- check_conditions = checkSideConditions dflags cls cls_tys rep_tycon
- bale_out msg = failWithTc (derivingThingErr cls cls_tys inst_ty msg)
+ go_for_it = mk_data_eqn orig tvs cls tycon tc_args rep_tycon rep_tc_args mtheta
+ bale_out msg = failWithTc (derivingThingErr cls cls_tys inst_ty msg)
non_std_err = nonStdErr cls $$
ptext (sLit "Try -XGeneralizedNewtypeDeriving for GHC's newtype-deriving extension")
-- Representation tycons differ from the tycon in the instance signature in
-- case of instances for indexed families.
--
-genInst :: OverlapFlag -> DerivSpec -> TcM (InstInfo RdrName, DerivAuxBinds)
-genInst oflag spec
+genInst :: Bool -- True <=> standalone deriving
+ -> OverlapFlag
+ -> DerivSpec -> TcM (InstInfo RdrName, DerivAuxBinds)
+genInst standalone_deriv oflag spec
| ds_newtype spec
= return (InstInfo { iSpec = mkInstance oflag (ds_theta spec) spec
, iBinds = NewTypeDerived co }, [])
| otherwise
- = do { let loc = getSrcSpan (ds_name spec)
- inst = mkInstance oflag (ds_theta spec) spec
- clas = ds_cls spec
+ = do { let loc = getSrcSpan (ds_name spec)
+ inst = mkInstance oflag (ds_theta spec) spec
+ clas = ds_cls spec
-- In case of a family instance, we need to use the representation
-- tycon (after all, it has the data constructors)
; fix_env <- getFixityEnv
; let (meth_binds, aux_binds) = genDerivBinds loc fix_env clas rep_tycon
-
- -- Build the InstInfo
- ; return (InstInfo { iSpec = inst,
- iBinds = VanillaInst meth_binds [] },
- aux_binds)
+ binds = VanillaInst meth_binds [] standalone_deriv
+ ; return (InstInfo { iSpec = inst, iBinds = binds }, aux_binds)
}
where
rep_tycon = ds_tc spec
-- When dealing with the deriving clause
-- co1 : N [(b,b)] ~ R1:N (b,b)
-- co2 : R1:N (b,b) ~ Tree (b,b)
+-- co : N [(b,b)] ~ Tree (b,b)
genDerivBinds :: SrcSpan -> FixityEnv -> Class -> TyCon -> (LHsBinds RdrName, DerivAuxBinds)
genDerivBinds loc fix_env clas tycon
projects / ghc-hetmet.git / blobdiff