X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcDeriv.lhs;h=a6815438b33d8f22d683290535d9052eac21aa63;hp=30e57ff593fb18804df1f595d647758cb635b9ad;hb=ada48bbc7f6a43b2c042df629327902d82cea681;hpb=42400001136308c1f4a49a15c1922435518ae58d diff --git a/compiler/typecheck/TcDeriv.lhs b/compiler/typecheck/TcDeriv.lhs index 30e57ff..a681543 100644 --- a/compiler/typecheck/TcDeriv.lhs +++ b/compiler/typecheck/TcDeriv.lhs @@ -40,10 +40,13 @@ import Name import NameSet import TyCon import TcType +import BuildTyCl +import BasicTypes import Var import VarSet import PrelNames import SrcLoc +import UniqSupply import Util import ListSetOps import Outputable @@ -125,6 +128,9 @@ pprDerivSpec (DS { ds_loc = l, ds_name = n, ds_tvs = tvs, ds_cls = c, ds_tys = tys, ds_theta = rhs }) = parens (hsep [ppr l, ppr n, ppr tvs, ppr c, ppr tys] <+> equals <+> ppr rhs) + +instance Outputable DerivSpec where + ppr = pprDerivSpec \end{code} @@ -292,17 +298,21 @@ both of them. So we gather defs/uses from deriving just like anything else. tcDeriving :: [LTyClDecl Name] -- All type constructors -> [LInstDecl Name] -- All instance declarations -> [LDerivDecl Name] -- All stand-alone deriving declarations - -> TcM ([InstInfo Name], -- The generated "instance decls" - HsValBinds Name, -- Extra generated top-level bindings - DefUses) + -> TcM ([InstInfo Name] -- The generated "instance decls" + ,HsValBinds Name -- Extra generated top-level bindings + ,DefUses + ,[TyCon] -- Extra generated top-level types + ,[TyCon]) -- Extra generated type family instances tcDeriving tycl_decls inst_decls deriv_decls - = recoverM (return ([], emptyValBindsOut, emptyDUs)) $ + = recoverM (return ([], emptyValBindsOut, emptyDUs, [], [])) $ do { -- Fish the "deriving"-related information out of the TcEnv -- And make the necessary "equations". is_boot <- tcIsHsBoot ; traceTc "tcDeriving" (ppr is_boot) - ; early_specs <- makeDerivSpecs is_boot tycl_decls inst_decls deriv_decls + ; (early_specs, genericsExtras) + <- makeDerivSpecs is_boot tycl_decls inst_decls deriv_decls + ; let (repMetaTys, repTyCons, metaInsts) = unzip3 genericsExtras ; overlap_flag <- getOverlapFlag ; let (infer_specs, given_specs) = splitEithers early_specs @@ -313,19 +323,38 @@ tcDeriving tycl_decls inst_decls deriv_decls ; insts2 <- mapM (genInst False overlap_flag) final_specs - -- Generate the generic to/from functions from each type declaration - ; gen_binds <- mkGenericBinds is_boot tycl_decls - ; (inst_info, rn_binds, rn_dus) <- renameDeriv is_boot gen_binds (insts1 ++ insts2) + -- We no longer generate the old generic to/from functions + -- from each type declaration, so this is emptyBag + ; gen_binds <- return emptyBag -- mkGenericBinds is_boot tycl_decls + +{- + -- Generate the generic Representable0 instances + -- from each type declaration + ; repInstsMeta <- genGenericRepBinds is_boot tycl_decls + + ; let repInsts = concat (map (\(a,_,_) -> a) repInstsMeta) + repMetaTys = map (\(_,b,_) -> b) repInstsMeta + repTyCons = map (\(_,_,c) -> c) repInstsMeta +-} + ; (inst_info, rn_binds, rn_dus) + <- renameDeriv is_boot gen_binds (insts1 ++ insts2 ++ concat metaInsts {- ++ repInsts -}) ; dflags <- getDOpts ; liftIO (dumpIfSet_dyn dflags Opt_D_dump_deriv "Derived instances" (ddump_deriving inst_info rn_binds)) - - ; return (inst_info, rn_binds, rn_dus) } +{- + ; when (not (null inst_info)) $ + dumpDerivingInfo (ddump_deriving inst_info rn_binds) +-} + ; return ( inst_info, rn_binds, rn_dus + , concat (map metaTyCons2TyCons repMetaTys), repTyCons) } where ddump_deriving :: [InstInfo Name] -> HsValBinds Name -> SDoc ddump_deriving inst_infos extra_binds - = vcat (map pprInstInfoDetails inst_infos) $$ ppr extra_binds + = hang (ptext (sLit "Derived instances")) + 2 (vcat (map (\i -> pprInstInfoDetails i $$ text "") inst_infos) + $$ ppr extra_binds) + renameDeriv :: Bool -> LHsBinds RdrName -> [(InstInfo RdrName, DerivAuxBinds)] @@ -373,19 +402,20 @@ renameDeriv is_boot gen_binds insts , mkFVs (map dataConName (tyConDataCons tc))) -- See Note [Newtype deriving and unused constructors] - rn_inst_info (InstInfo { iSpec = inst, iBinds = VanillaInst binds sigs standalone_deriv }) + rn_inst_info 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 ; let binds' = VanillaInst rn_binds [] standalone_deriv - ; return (InstInfo { iSpec = inst, iBinds = binds' }, fvs) } + ; return (inst_info { iBinds = binds' }, fvs) } where (tyvars,_, clas,_) = instanceHead inst clas_nm = className clas ----------------------------------------- +{- Now unused mkGenericBinds :: Bool -> [LTyClDecl Name] -> TcM (LHsBinds RdrName) mkGenericBinds is_boot tycl_decls | is_boot @@ -398,6 +428,7 @@ mkGenericBinds is_boot tycl_decls -- 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 +-} \end{code} Note [Newtype deriving and unused constructors] @@ -429,21 +460,90 @@ stored in NewTypeDerived. @makeDerivSpecs@ fishes around to find the info about needed derived instances. \begin{code} +{- +-- Make the EarlyDerivSpec for Representable0 +mkGenDerivSpec :: TyCon -> TcRn (EarlyDerivSpec) +mkGenDerivSpec tc = do + { cls <- tcLookupClass rep0ClassName + ; let tc_tvs = tyConTyVars tc + ; let tc_app = mkTyConApp tc (mkTyVarTys tc_tvs) + ; let cls_tys = [] + ; let mtheta = Just [] + ; ds <- mkEqnHelp StandAloneDerivOrigin tc_tvs cls cls_tys tc_app mtheta + -- JPM TODO: StandAloneDerivOrigin?... + ; return ds } +-} +-- Make the "extras" for the generic representation +mkGenDerivExtras :: TyCon + -> TcRn (MetaTyCons, TyCon, [(InstInfo RdrName, DerivAuxBinds)]) +mkGenDerivExtras tc = do + { (metaTyCons, rep0TyInst) <- genGenericRepExtras tc + ; metaInsts <- genDtMeta (tc, metaTyCons) + ; return (metaTyCons, rep0TyInst, metaInsts) } + makeDerivSpecs :: Bool -> [LTyClDecl Name] - -> [LInstDecl Name] + -> [LInstDecl Name] -> [LDerivDecl Name] - -> TcM [EarlyDerivSpec] - + -> TcM ( [EarlyDerivSpec] + , [(MetaTyCons, TyCon, [(InstInfo RdrName, DerivAuxBinds)])]) makeDerivSpecs is_boot tycl_decls inst_decls deriv_decls | is_boot -- No 'deriving' at all in hs-boot files = do { mapM_ add_deriv_err deriv_locs - ; return [] } + ; return ([],[]) } | otherwise = do { eqns1 <- mapAndRecoverM deriveTyData all_tydata ; eqns2 <- mapAndRecoverM deriveStandalone deriv_decls - ; return (eqns1 ++ eqns2) } + -- Generate EarlyDerivSpec's for Representable, 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 + ; let sel_tydata = [ tcdName t | (L _ c, L _ t) <- all_tydata + , getClassName c == Just rep0ClassName ] + ; let sel_deriv_decls = catMaybes [ getTypeName t + | L _ (DerivDecl (L _ t)) <- deriv_decls + , getClassName t == Just rep0ClassName ] + ; derTyDecls <- mapM tcLookupTyCon $ + filter (needsExtras xDerRep + (sel_tydata ++ sel_deriv_decls)) allTyNames + -- We need to generate the extras to add to what has + -- already been derived + ; generic_extras_deriv <- mapM mkGenDerivExtras derTyDecls + -- For the remaining types, if Generics is on, we need to + -- generate both the instances and the extras, but only for the + -- types we can represent. +{- + ; let repTyDecls = filter canDoGenerics allTyDecls + ; let remTyDecls = filter (\x -> not (x `elem` derTyDecls)) repTyDecls + ; generic_instances <- if xGenerics + then mapM mkGenDerivSpec remTyDecls + else return [] + ; generic_extras_flag <- if xGenerics + then mapM mkGenDerivExtras remTyDecls + else return [] +-} + -- Merge and return everything + ; 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 + needsExtras xDerRep tydata tc_name = xDerRep && tc_name `elem` tydata + + -- Extracts the name of the class in the deriving + getClassName :: HsType Name -> Maybe Name + getClassName (HsPredTy (HsClassP n _)) = Just n + getClassName _ = Nothing + + -- Extracts the name of the type in the deriving + getTypeName :: HsType Name -> Maybe Name + getTypeName (HsTyVar n) = Just n + getTypeName (HsOpTy _ (L _ n) _) = Just n + getTypeName (HsPredTy (HsClassP _ [L _ n])) = getTypeName n + getTypeName _ = Nothing + extractTyDataPreds decls = [(p, d) | d@(L _ (TyData {tcdDerivs = Just preds})) <- decls, p <- preds] @@ -458,6 +558,11 @@ makeDerivSpecs is_boot tycl_decls inst_decls deriv_decls addErr (hang (ptext (sLit "Deriving not permitted in hs-boot file")) 2 (ptext (sLit "Use an instance declaration instead"))) +genericsFlag :: TcM Bool +genericsFlag = do dOpts <- getDOpts + return ( xopt Opt_Generics dOpts + || xopt Opt_DeriveRepresentable dOpts) + ------------------------------------------------------------------ deriveStandalone :: LDerivDecl Name -> TcM EarlyDerivSpec -- Standalone deriving declarations @@ -467,12 +572,13 @@ deriveStandalone (L loc (DerivDecl deriv_ty)) = setSrcSpan loc $ addErrCtxt (standaloneCtxt deriv_ty) $ do { traceTc "Standalone deriving decl for" (ppr deriv_ty) - ; (tvs, theta, tau) <- tcHsInstHead deriv_ty + ; (tvs, theta, cls, inst_tys) <- tcHsInstHead deriv_ty ; traceTc "Standalone deriving;" $ vcat [ text "tvs:" <+> ppr tvs , text "theta:" <+> ppr theta - , text "tau:" <+> ppr tau ] - ; (cls, inst_tys) <- checkValidInstance deriv_ty tvs theta tau + , text "cls:" <+> ppr cls + , text "tys:" <+> ppr inst_tys ] + ; checkValidInstance deriv_ty tvs theta cls inst_tys -- C.f. TcInstDcls.tcLocalInstDecl1 ; let cls_tys = take (length inst_tys - 1) inst_tys @@ -725,6 +831,11 @@ inferConstraints :: [TyVar] -> Class -> [TcType] -> TyCon -> [TcType] -> ThetaTy -- 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 + = [] + -- The others are a bit more complicated + | otherwise = ASSERT2( equalLength rep_tc_tvs all_rep_tc_args, ppr cls <+> ppr rep_tc ) stupid_constraints ++ extra_constraints ++ sc_constraints ++ con_arg_constraints @@ -748,7 +859,7 @@ inferConstraints _ cls inst_tys rep_tc rep_tc_args get_constrained_tys :: [Type] -> [Type] get_constrained_tys tys - | is_functor_like = concatMap (deepSubtypesContaining last_tv) tys + | is_functor_like = concatMap (deepSubtypesContaining last_tv) tys | otherwise = tys rep_tc_tvs = tyConTyVars rep_tc @@ -828,6 +939,9 @@ sideConditions mtheta cls 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` + checkFlag Opt_Generics)) | otherwise = Nothing where cls_key = getUnique cls @@ -846,7 +960,7 @@ orCond c1 c2 tc Nothing -> Nothing -- c1 succeeds Just x -> case c2 tc of -- c1 fails Nothing -> Nothing - Just y -> Just (x $$ ptext (sLit " and") $$ y) + Just y -> Just (x $$ ptext (sLit " or") $$ y) -- Both fail andCond :: Condition -> Condition -> Condition @@ -878,6 +992,11 @@ no_cons_why :: TyCon -> SDoc no_cons_why rep_tc = quotes (pprSourceTyCon rep_tc) <+> ptext (sLit "has no data constructors") +-- 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) + cond_enumOrProduct :: Condition cond_enumOrProduct = cond_isEnumeration `orCond` (cond_isProduct `andCond` cond_noUnliftedArgs) @@ -900,7 +1019,7 @@ cond_isEnumeration (_, rep_tc) where why = sep [ quotes (pprSourceTyCon rep_tc) <+> ptext (sLit "is not an enumeration type") - , nest 2 $ ptext (sLit "(an enumeration consists of one or more nullary constructors)") ] + , ptext (sLit "(an enumeration consists of one or more nullary, non-GADT constructors)") ] -- See Note [Enumeration types] in TyCon cond_isProduct :: Condition @@ -997,11 +1116,11 @@ std_class_via_iso clas non_iso_class :: Class -> Bool --- *Never* derive Read,Show,Typeable,Data by isomorphism, +-- *Never* derive Read,Show,Typeable,Data,Representable0 by isomorphism, -- even with -XGeneralizedNewtypeDeriving non_iso_class cls - = classKey cls `elem` ([readClassKey, showClassKey, dataClassKey] ++ - typeableClassKeys) + = classKey cls `elem` ([ readClassKey, showClassKey, dataClassKey + , rep0ClassKey] ++ typeableClassKeys) typeableClassKeys :: [Unique] typeableClassKeys = map getUnique typeableClassNames @@ -1280,7 +1399,7 @@ inferInstanceContexts oflag infer_specs gen_soln (DS { ds_loc = loc, ds_orig = orig, ds_tvs = tyvars , ds_cls = clas, ds_tys = inst_tys, ds_theta = deriv_rhs }) = setSrcSpan loc $ - addErrCtxt (derivInstCtxt clas inst_tys) $ + addErrCtxt (derivInstCtxt the_pred) $ do { -- Check for a bizarre corner case, when the derived instance decl should -- have form instance C a b => D (T a) where ... -- Note that 'b' isn't a parameter of T. This gives rise to all sorts @@ -1295,7 +1414,7 @@ inferInstanceContexts oflag infer_specs , not (tyVarsOfPred pred `subVarSet` tv_set)] ; mapM_ (addErrTc . badDerivedPred) weird_preds - ; theta <- simplifyDeriv orig tyvars deriv_rhs + ; theta <- simplifyDeriv orig the_pred tyvars deriv_rhs -- checkValidInstance tyvars theta clas inst_tys -- Not necessary; see Note [Exotic derived instance contexts] -- in TcSimplify @@ -1305,6 +1424,8 @@ inferInstanceContexts oflag infer_specs -- Hence no need to call: -- checkValidInstance tyvars theta clas inst_tys ; return (sortLe (<=) theta) } -- Canonicalise before returning the solution + where + the_pred = mkClassPred clas inst_tys ------------------------------------------------------------------ mkInstance :: OverlapFlag -> ThetaType -> DerivSpec -> Instance @@ -1400,26 +1521,26 @@ the renamer. What a great hack! 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 rep_tycon }, []) +genInst standalone_deriv oflag + spec@(DS { ds_tc = rep_tycon, ds_tc_args = rep_tc_args + , ds_theta = theta, ds_newtype = is_newtype + , ds_name = name, ds_cls = clas }) + | is_newtype + = return (InstInfo { iSpec = inst_spec + , iBinds = NewTypeDerived co rep_tycon }, []) | otherwise - = 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 - binds = VanillaInst meth_binds [] standalone_deriv - ; return (InstInfo { iSpec = inst, iBinds = binds }, aux_binds) - } + = do { fix_env <- getFixityEnv + ; let loc = getSrcSpan name + (meth_binds, aux_binds) = genDerivBinds loc fix_env clas rep_tycon + -- In case of a family instance, we need to use the representation + -- tycon (after all, it has the data constructors) + + ; return (InstInfo { iSpec = inst_spec + , iBinds = VanillaInst meth_binds [] standalone_deriv } + , aux_binds) } where - rep_tycon = ds_tc spec - rep_tc_args = ds_tc_args spec + inst_spec = mkInstance oflag theta spec co1 = case tyConFamilyCoercion_maybe rep_tycon of Just co_con -> ACo (mkTyConApp co_con rep_tc_args) Nothing -> id_co @@ -1449,20 +1570,177 @@ genDerivBinds loc fix_env clas tycon Nothing -> pprPanic "genDerivBinds: bad derived class" (ppr clas) where gen_list :: [(Unique, SrcSpan -> TyCon -> (LHsBinds RdrName, DerivAuxBinds))] - gen_list = [(eqClassKey, gen_Eq_binds) - ,(ordClassKey, gen_Ord_binds) - ,(enumClassKey, gen_Enum_binds) - ,(boundedClassKey, gen_Bounded_binds) - ,(ixClassKey, gen_Ix_binds) - ,(showClassKey, gen_Show_binds fix_env) - ,(readClassKey, gen_Read_binds fix_env) - ,(dataClassKey, gen_Data_binds) - ,(functorClassKey, gen_Functor_binds) - ,(foldableClassKey, gen_Foldable_binds) - ,(traversableClassKey, gen_Traversable_binds) + gen_list = [(eqClassKey, gen_Eq_binds) + ,(ordClassKey, gen_Ord_binds) + ,(enumClassKey, gen_Enum_binds) + ,(boundedClassKey, gen_Bounded_binds) + ,(ixClassKey, gen_Ix_binds) + ,(showClassKey, gen_Show_binds fix_env) + ,(readClassKey, gen_Read_binds fix_env) + ,(dataClassKey, gen_Data_binds) + ,(functorClassKey, gen_Functor_binds) + ,(foldableClassKey, gen_Foldable_binds) + ,(traversableClassKey, gen_Traversable_binds) + ,(rep0ClassKey, gen_Rep0_binds) ] \end{code} +%************************************************************************ +%* * +\subsection[TcDeriv-generic-binds]{Bindings for the new generic deriving mechanism} +%* * +%************************************************************************ + +For the generic representation we need to generate: +\begin{itemize} +\item A Representable0 instance +\item A Rep0 type instance +\item Many auxiliary datatypes and instances for them (for the meta-information) +\end{itemize} + +@gen_Rep0_binds@ does (1) +@genGenericRepExtras@ does (2) and (3) +@genGenericRepBind@ 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 -} ]) + +genGenericRepExtras :: TyCon -> TcM (MetaTyCons, TyCon) +genGenericRepExtras tc = + do uniqS <- newUniqueSupply + let + -- Uniques for everyone + (uniqD:uniqs) = uniqsFromSupply uniqS + (uniqsC,us) = splitAt (length tc_cons) uniqs + uniqsS :: [[Unique]] -- Unique supply for the S datatypes + uniqsS = mkUniqsS tc_arits us + mkUniqsS [] _ = [] + mkUniqsS (n:t) us = case splitAt n us of + (us1,us2) -> us1 : mkUniqsS t us2 + + tc_name = tyConName tc + tc_cons = tyConDataCons tc + tc_arits = map dataConSourceArity tc_cons + + tc_occ = nameOccName tc_name + d_occ = mkGenD tc_occ + c_occ m = mkGenC tc_occ m + s_occ m n = mkGenS tc_occ m n + mod_name = nameModule (tyConName tc) + d_name = mkExternalName uniqD mod_name d_occ wiredInSrcSpan + c_names = [ mkExternalName u mod_name (c_occ m) wiredInSrcSpan + | (u,m) <- zip uniqsC [0..] ] + s_names = [ [ mkExternalName u mod_name (s_occ m n) wiredInSrcSpan + | (u,n) <- zip us [0..] ] | (us,m) <- zip uniqsS [0..] ] + + mkTyCon name = ASSERT( isExternalName name ) + buildAlgTyCon name [] [] mkAbstractTyConRhs + NonRecursive False NoParentTyCon Nothing + + metaDTyCon <- mkTyCon d_name + metaCTyCons <- sequence [ mkTyCon c_name | c_name <- c_names ] + metaSTyCons <- mapM sequence + [ [ mkTyCon s_name + | s_name <- s_namesC ] | s_namesC <- s_names ] + + let metaDts = MetaTyCons metaDTyCon metaCTyCons metaSTyCons + + rep0_tycon <- tc_mkRep0TyCon tc metaDts + + return (metaDts, rep0_tycon) +{- +genGenericRepBind :: TyCon + -> TcM ((InstInfo RdrName, DerivAuxBinds), MetaTyCons, TyCon) +genGenericRepBind tc = + do (metaDts, rep0_tycon) <- genGenericRepExtras tc + clas <- tcLookupClass rep0ClassName + dfun_name <- new_dfun_name clas tc + let + mkInstRep0 = (InstInfo { iSpec = inst, iBinds = binds } + , [ {- No DerivAuxBinds -} ]) + inst = mkLocalInstance dfun NoOverlap + binds = VanillaInst (mkBindsRep0 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) +-} +genDtMeta :: (TyCon, MetaTyCons) -> TcM [(InstInfo RdrName, DerivAuxBinds)] +genDtMeta (tc,metaDts) = + do dClas <- tcLookupClass datatypeClassName + d_dfun_name <- new_dfun_name dClas tc + cClas <- tcLookupClass constructorClassName + c_dfun_names <- sequence [ new_dfun_name cClas tc | _ <- metaC metaDts ] + sClas <- tcLookupClass selectorClassName + s_dfun_names <- sequence (map sequence [ [ new_dfun_name sClas tc + | _ <- x ] + | x <- metaS metaDts ]) + fix_env <- getFixityEnv + + let + (dBinds,cBinds,sBinds) = mkBindsMetaD fix_env tc + + -- Datatype + d_metaTycon = metaD metaDts + d_inst = mkLocalInstance d_dfun NoOverlap + d_binds = VanillaInst dBinds [] False + d_dfun = mkDictFunId d_dfun_name (tyConTyVars tc) [] dClas + [ mkTyConTy d_metaTycon ] + d_mkInst = (InstInfo { iSpec = d_inst, iBinds = d_binds }, []) + + -- Constructor + c_metaTycons = metaC metaDts + c_insts = [ mkLocalInstance (c_dfun c ds) NoOverlap + | (c, ds) <- myZip1 c_metaTycons c_dfun_names ] + c_binds = [ VanillaInst c [] False | c <- cBinds ] + c_dfun c dfun_name = mkDictFunId dfun_name (tyConTyVars tc) [] cClas + [ mkTyConTy c ] + c_mkInst = [ (InstInfo { iSpec = is, iBinds = bs }, []) + | (is,bs) <- myZip1 c_insts c_binds ] + + -- Selector + s_metaTycons = metaS metaDts + s_insts = map (map (\(s,ds) -> mkLocalInstance (s_dfun s ds) NoOverlap)) + (myZip2 s_metaTycons s_dfun_names) + s_binds = [ [ VanillaInst s [] False | s <- ss ] | ss <- sBinds ] + s_dfun s dfun_name = mkDictFunId dfun_name (tyConTyVars tc) [] sClas + [ mkTyConTy s ] + s_mkInst = map (map (\(is,bs) -> (InstInfo {iSpec=is, iBinds=bs}, []))) + (myZip2 s_insts s_binds) + + myZip1 :: [a] -> [b] -> [(a,b)] + myZip1 l1 l2 = ASSERT (length l1 == length l2) zip l1 l2 + + myZip2 :: [[a]] -> [[b]] -> [[(a,b)]] + myZip2 l1 l2 = + ASSERT (and (zipWith (>=) (map length l1) (map length l2))) + [ zip x1 x2 | (x1,x2) <- zip l1 l2 ] + + return (d_mkInst : c_mkInst ++ concat s_mkInst) +\end{code} + %************************************************************************ %* * @@ -1509,9 +1787,9 @@ standaloneCtxt :: LHsType Name -> SDoc standaloneCtxt ty = hang (ptext (sLit "In the stand-alone deriving instance for")) 2 (quotes (ppr ty)) -derivInstCtxt :: Class -> [Type] -> Message -derivInstCtxt clas inst_tys - = ptext (sLit "When deriving the instance for") <+> parens (pprClassPred clas inst_tys) +derivInstCtxt :: PredType -> Message +derivInstCtxt pred + = ptext (sLit "When deriving the instance for") <+> parens (ppr pred) badDerivedPred :: PredType -> Message badDerivedPred pred