; gen_binds <- return emptyBag -- mkGenericBinds is_boot tycl_decls
{-
- -- Generate the generic Representable0 instances
+ -- Generate the Generic instances
-- from each type declaration
- ; repInstsMeta <- genGenericRepBinds is_boot tycl_decls
+ ; repInstsMeta <- genGenericAlls is_boot tycl_decls
; let repInsts = concat (map (\(a,_,_) -> a) repInstsMeta)
repMetaTys = map (\(_,b,_) -> b) repInstsMeta
\begin{code}
{-
--- Make the EarlyDerivSpec for Representable0
+-- Make the EarlyDerivSpec for Generic
mkGenDerivSpec :: TyCon -> TcRn (EarlyDerivSpec)
mkGenDerivSpec tc = do
- { cls <- tcLookupClass rep0ClassName
+ { cls <- tcLookupClass genClassName
; let tc_tvs = tyConTyVars tc
; let tc_app = mkTyConApp tc (mkTyVarTys tc_tvs)
; let cls_tys = []
| otherwise
= do { eqns1 <- mapAndRecoverM deriveTyData all_tydata
; eqns2 <- mapAndRecoverM deriveStandalone deriv_decls
- -- Generate EarlyDerivSpec's for Representable, if asked for
+ -- Generate EarlyDerivSpec's for Generic, if asked for
-- ; (xGenerics, xDerRep) <- genericsFlags
; xDerRep <- genericsFlag
; let allTyNames = [ tcdName d | L _ d <- tycl_decls, isDataDecl d ]
-- ; allTyDecls <- mapM tcLookupTyCon allTyNames
- -- Select only those types that derive Representable
+ -- Select only those types that derive Generic
; let sel_tydata = [ tcdName t | (L _ c, L _ t) <- all_tydata
- , getClassName c == Just rep0ClassName ]
+ , getClassName c == Just genClassName ]
; let sel_deriv_decls = catMaybes [ getTypeName t
| L _ (DerivDecl (L _ t)) <- deriv_decls
- , getClassName t == Just rep0ClassName ]
+ , getClassName t == Just genClassName ]
; derTyDecls <- mapM tcLookupTyCon $
filter (needsExtras xDerRep
(sel_tydata ++ sel_deriv_decls)) allTyNames
; return ( eqns1 ++ eqns2 -- ++ generic_instances
, generic_extras_deriv {- ++ generic_extras_flag -}) }
where
- -- We need extras if the flag DeriveRepresentable is on and this type is
- -- deriving Representable
+ -- We need extras if the flag DeriveGeneric is on and this type is
+ -- deriving Generic
needsExtras xDerRep tydata tc_name = xDerRep && tc_name `elem` tydata
-- Extracts the name of the class in the deriving
genericsFlag :: TcM Bool
genericsFlag = do dOpts <- getDOpts
return ( xopt Opt_Generics dOpts
- || xopt Opt_DeriveRepresentable dOpts)
+ || xopt Opt_DeriveGeneric dOpts)
------------------------------------------------------------------
deriveStandalone :: LDerivDecl Name -> TcM EarlyDerivSpec
-- generated method definitions should succeed. This set will be simplified
-- before being used in the instance declaration
inferConstraints _ cls inst_tys rep_tc rep_tc_args
- -- Representable0 constraints are easy
- | cls `hasKey` rep0ClassKey
+ -- Generic constraints are easy
+ | cls `hasKey` genClassKey
= []
-- The others are a bit more complicated
| otherwise
cond_functorOK False) -- Functor/Fold/Trav works ok for rank-n types
| cls_key == traversableClassKey = Just (checkFlag Opt_DeriveTraversable `andCond`
cond_functorOK False)
- | cls_key == rep0ClassKey = Just (cond_RepresentableOk `andCond`
- (checkFlag Opt_DeriveRepresentable `orCond`
+ | cls_key == genClassKey = Just (cond_RepresentableOk `andCond`
+ (checkFlag Opt_DeriveGeneric `orCond`
checkFlag Opt_Generics))
| otherwise = Nothing
where
check_con con
| isVanillaDataCon con
, all isTauTy (dataConOrigArgTys con) = Nothing
- | otherwise = Just (badCon con (ptext (sLit "does not have a Haskell-98 type")))
+ | otherwise = Just (badCon con (ptext (sLit "must have a Haskell-98 type")))
no_cons_why :: TyCon -> SDoc
no_cons_why rep_tc = quotes (pprSourceTyCon rep_tc) <+>
- ptext (sLit "has no data constructors")
+ ptext (sLit "must have at least one data constructor")
-- JPM TODO: should give better error message
cond_RepresentableOk :: Condition
cond_RepresentableOk (_,t) | canDoGenerics t = Nothing
- | otherwise = Just (ptext (sLit "Cannot derive Representable for type") <+> ppr t)
+ | otherwise = Just (ptext (sLit "Cannot derive Generic for type") <+> ppr t)
cond_enumOrProduct :: Condition
cond_enumOrProduct = cond_isEnumeration `orCond`
where
bad_cons = [ con | con <- tyConDataCons tc
, any isUnLiftedType (dataConOrigArgTys con) ]
- why = badCon (head bad_cons) (ptext (sLit "has arguments of unlifted type"))
+ why = badCon (head bad_cons) (ptext (sLit "must have only arguments of lifted type"))
cond_isEnumeration :: Condition
cond_isEnumeration (_, rep_tc)
| otherwise = Just why
where
why = sep [ quotes (pprSourceTyCon rep_tc) <+>
- ptext (sLit "is not an enumeration type")
+ ptext (sLit "must be an enumeration type")
, ptext (sLit "(an enumeration consists of one or more nullary, non-GADT constructors)") ]
-- See Note [Enumeration types] in TyCon
| otherwise = Just why
where
why = quotes (pprSourceTyCon rep_tc) <+>
- ptext (sLit "does not have precisely one constructor")
+ ptext (sLit "must have precisely one constructor")
cond_typeableOK :: Condition
-- OK for Typeable class
| otherwise = Nothing
where
too_many = quotes (pprSourceTyCon tc) <+>
- ptext (sLit "has too many arguments")
+ ptext (sLit "must have 7 or fewer arguments")
bad_kind = quotes (pprSourceTyCon tc) <+>
- ptext (sLit "has arguments of kind other than `*'")
+ ptext (sLit "must only have arguments of kind `*'")
functorLikeClassKeys :: [Unique]
functorLikeClassKeys = [functorClassKey, foldableClassKey, traversableClassKey]
cond_functorOK allowFunctions (_, rep_tc)
| null tc_tvs
= Just (ptext (sLit "Data type") <+> quotes (ppr rep_tc)
- <+> ptext (sLit "has no parameters"))
+ <+> ptext (sLit "must have some type parameters"))
| not (null bad_stupid_theta)
= Just (ptext (sLit "Data type") <+> quotes (ppr rep_tc)
- <+> ptext (sLit "has a class context") <+> pprTheta bad_stupid_theta)
+ <+> ptext (sLit "must not have a class context") <+> pprTheta bad_stupid_theta)
| otherwise
= msum (map check_con data_cons) -- msum picks the first 'Just', if any
, ft_bad_app = Just (badCon con wrong_arg)
, ft_forall = \_ x -> x }
- existential = ptext (sLit "has existential arguments")
- covariant = ptext (sLit "uses the type variable in a function argument")
- functions = ptext (sLit "contains function types")
- wrong_arg = ptext (sLit "uses the type variable in an argument other than the last")
+ existential = ptext (sLit "must not have existential arguments")
+ covariant = ptext (sLit "must not use the type variable in a function argument")
+ functions = ptext (sLit "must not contain function types")
+ wrong_arg = ptext (sLit "must not use the type variable in an argument other than the last")
checkFlag :: ExtensionFlag -> Condition
checkFlag flag (dflags, _)
non_iso_class :: Class -> Bool
--- *Never* derive Read,Show,Typeable,Data,Representable0 by isomorphism,
+-- *Never* derive Read, Show, Typeable, Data, Generic by isomorphism,
-- even with -XGeneralizedNewtypeDeriving
non_iso_class cls
= classKey cls `elem` ([ readClassKey, showClassKey, dataClassKey
- , rep0ClassKey] ++ typeableClassKeys)
+ , genClassKey] ++ typeableClassKeys)
typeableClassKeys :: [Unique]
typeableClassKeys = map getUnique typeableClassNames
,(functorClassKey, gen_Functor_binds)
,(foldableClassKey, gen_Foldable_binds)
,(traversableClassKey, gen_Traversable_binds)
- ,(rep0ClassKey, gen_Rep0_binds)
+ ,(genClassKey, genGenericBinds)
]
\end{code}
For the generic representation we need to generate:
\begin{itemize}
-\item A Representable0 instance
-\item A Rep0 type instance
+\item A Generic instance
+\item A Rep type instance
\item Many auxiliary datatypes and instances for them (for the meta-information)
\end{itemize}
-@gen_Rep0_binds@ does (1)
+@genGenericBinds@ does (1)
@genGenericRepExtras@ does (2) and (3)
-@genGenericRepBind@ does all of them
+@genGenericAll@ does all of them
\begin{code}
-{-
-genGenericRepBinds :: Bool -> [LTyClDecl Name]
- -> TcM [([(InstInfo RdrName, DerivAuxBinds)]
- , MetaTyCons, TyCon)]
-genGenericRepBinds isBoot tyclDecls
- | isBoot = return []
- | otherwise = do
- allTyDecls <- mapM tcLookupTyCon [ tcdName d | L _ d <- tyclDecls
- , isDataDecl d ]
- let tyDecls = filter tyConHasGenerics allTyDecls
- inst1 <- mapM genGenericRepBind tyDecls
- let (_repInsts, metaTyCons, _repTys) = unzip3 inst1
- metaInsts <- ASSERT (length tyDecls == length metaTyCons)
- mapM genDtMeta (zip tyDecls metaTyCons)
- return (ASSERT (length inst1 == length metaInsts)
- [ (ri : mi, ms, rt)
- | ((ri, ms, rt), mi) <- zip inst1 metaInsts ])
--}
-
-gen_Rep0_binds :: SrcSpan -> TyCon -> (LHsBinds RdrName, DerivAuxBinds)
-gen_Rep0_binds _ tc = (mkBindsRep0 tc, [ {- No DerivAuxBinds -} ])
+genGenericBinds :: SrcSpan -> TyCon -> (LHsBinds RdrName, DerivAuxBinds)
+genGenericBinds _ tc = (mkBindsRep tc, [ {- No DerivAuxBinds -} ])
genGenericRepExtras :: TyCon -> TcM (MetaTyCons, TyCon)
genGenericRepExtras tc =
let metaDts = MetaTyCons metaDTyCon metaCTyCons metaSTyCons
- rep0_tycon <- tc_mkRep0TyCon tc metaDts
+ rep0_tycon <- tc_mkRepTyCon tc metaDts
return (metaDts, rep0_tycon)
{-
-genGenericRepBind :: TyCon
+genGenericAll :: TyCon
-> TcM ((InstInfo RdrName, DerivAuxBinds), MetaTyCons, TyCon)
-genGenericRepBind tc =
+genGenericAll tc =
do (metaDts, rep0_tycon) <- genGenericRepExtras tc
- clas <- tcLookupClass rep0ClassName
+ clas <- tcLookupClass genClassName
dfun_name <- new_dfun_name clas tc
let
- mkInstRep0 = (InstInfo { iSpec = inst, iBinds = binds }
+ mkInstRep = (InstInfo { iSpec = inst, iBinds = binds }
, [ {- No DerivAuxBinds -} ])
inst = mkLocalInstance dfun NoOverlap
- binds = VanillaInst (mkBindsRep0 tc) [] False
+ binds = VanillaInst (mkBindsRep tc) [] False
tvs = tyConTyVars tc
tc_ty = mkTyConApp tc (mkTyVarTys tvs)
dfun = mkDictFunId dfun_name (tyConTyVars tc) [] clas [tc_ty]
- return (mkInstRep0, metaDts, rep0_tycon)
+ return (mkInstRep, metaDts, rep0_tycon)
-}
genDtMeta :: (TyCon, MetaTyCons) -> TcM [(InstInfo RdrName, DerivAuxBinds)]
genDtMeta (tc,metaDts) =