X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcDeriv.lhs;h=e4d66a612aaf89de94dcdbb75eff324dddd2ae76;hp=2edd8361058480088578edd57eba6f22d0a69acf;hb=54ef1c3c9ef6cecd968d5c1ed6ded3a1a201a870;hpb=30c122df62ec75f9ed7f392f24c2925675bf1d06 diff --git a/compiler/typecheck/TcDeriv.lhs b/compiler/typecheck/TcDeriv.lhs index 2edd836..e4d66a6 100644 --- a/compiler/typecheck/TcDeriv.lhs +++ b/compiler/typecheck/TcDeriv.lhs @@ -262,7 +262,7 @@ when the dict is constructed in TcInstDcls.tcInstDecl2 tcDeriving :: [LTyClDecl Name] -- All type constructors -> [LInstDecl Name] -- All instance declarations -> [LDerivDecl Name] -- All stand-alone deriving declarations - -> TcM ([InstInfo], -- The generated "instance decls" + -> TcM ([InstInfo Name], -- The generated "instance decls" HsValBinds Name) -- Extra generated top-level bindings tcDeriving tycl_decls inst_decls deriv_decls @@ -273,18 +273,17 @@ tcDeriving tycl_decls inst_decls deriv_decls ; overlap_flag <- getOverlapFlag ; let (infer_specs, given_specs) = splitEithers early_specs - ; (insts1, aux_binds1) <- mapAndUnzipM (genInst overlap_flag) given_specs + ; insts1 <- mapM (genInst overlap_flag) given_specs - ; final_specs <- extendLocalInstEnv (map iSpec insts1) $ + ; final_specs <- extendLocalInstEnv (map (iSpec . fst) insts1) $ inferInstanceContexts overlap_flag infer_specs - ; (insts2, aux_binds2) <- mapAndUnzipM (genInst overlap_flag) final_specs + ; insts2 <- mapM (genInst overlap_flag) final_specs ; is_boot <- tcIsHsBoot - ; rn_binds <- makeAuxBinds is_boot tycl_decls - (concat aux_binds1 ++ concat aux_binds2) - - ; let inst_info = insts1 ++ insts2 + -- Generate the generic to/from functions from each type declaration + ; gen_binds <- mkGenericBinds is_boot + ; (inst_info, rn_binds) <- renameDeriv is_boot gen_binds (insts1 ++ insts2) ; dflags <- getDOpts ; liftIO (dumpIfSet_dyn dflags Opt_D_dump_deriv "Derived instances" @@ -292,49 +291,77 @@ tcDeriving tycl_decls inst_decls deriv_decls ; return (inst_info, rn_binds) } where - ddump_deriving :: [InstInfo] -> HsValBinds Name -> SDoc + ddump_deriving :: [InstInfo Name] -> HsValBinds Name -> SDoc ddump_deriving inst_infos extra_binds = vcat (map pprInstInfoDetails inst_infos) $$ ppr extra_binds -makeAuxBinds :: Bool -> [LTyClDecl Name] -> DerivAuxBinds -> TcM (HsValBinds Name) -makeAuxBinds is_boot tycl_decls deriv_aux_binds - | is_boot -- If we are compiling a hs-boot file, - -- don't generate any derived bindings - = return emptyValBindsOut +renameDeriv :: Bool -> LHsBinds RdrName + -> [(InstInfo RdrName, DerivAuxBinds)] + -> TcM ([InstInfo Name], HsValBinds Name) +renameDeriv is_boot gen_binds insts + | is_boot -- If we are compiling a hs-boot file, don't generate any derived bindings + -- The inst-info bindings will all be empty, but it's easier to + -- just use rn_inst_info to change the type appropriately + = do { rn_inst_infos <- mapM rn_inst_info inst_infos + ; return (rn_inst_infos, emptyValBindsOut) } | otherwise - = do { let aux_binds = listToBag (map genAuxBind (rm_dups [] deriv_aux_binds)) - -- Generate any extra not-one-inst-decl-specific binds, + = discardWarnings $ -- Discard warnings about unused bindings etc + do { (rn_gen, dus_gen) <- setOptM Opt_PatternSignatures $ -- Type signatures in patterns + -- are used in the generic binds + rnTopBinds (ValBindsIn gen_binds []) + ; keepAliveSetTc (duDefs dus_gen) -- Mark these guys to be kept alive + + -- Generate and rename any extra not-one-inst-decl-specific binds, -- notably "con2tag" and/or "tag2con" functions. + -- Bring those names into scope before renaming the instances themselves + ; loc <- getSrcSpanM -- Generic loc for shared bindings + ; let aux_binds = listToBag $ map (genAuxBind loc) $ + rm_dups [] $ concat deriv_aux_binds + ; rn_aux_lhs <- rnTopBindsLHS emptyFsEnv (ValBindsIn aux_binds []) + ; let aux_names = map unLoc (collectHsValBinders rn_aux_lhs) + + ; bindLocalNames aux_names $ + do { (rn_aux, _dus) <- rnTopBindsRHS aux_names rn_aux_lhs + ; rn_inst_infos <- mapM rn_inst_info inst_infos + ; return (rn_inst_infos, rn_aux `plusHsValBinds` rn_gen) } } - -- Generate the generic to/from functions from each type declaration - ; gen_binds <- mkGenericBinds tycl_decls - - -- Rename these extra bindings, discarding warnings about unused bindings etc - -- Type signatures in patterns are used in the generic binds - ; discardWarnings $ - setOptM Opt_PatternSignatures $ - do { (rn_deriv, _dus1) <- rnTopBinds (ValBindsIn aux_binds []) - ; (rn_gen, dus_gen) <- rnTopBinds (ValBindsIn gen_binds []) - ; keepAliveSetTc (duDefs dus_gen) -- Mark these guys to - -- be kept alive - ; return (rn_deriv `plusHsValBinds` rn_gen) } } where + (inst_infos, deriv_aux_binds) = unzip insts + -- Remove duplicate requests for auxilliary bindings rm_dups acc [] = acc rm_dups acc (b:bs) | any (isDupAux b) acc = rm_dups acc bs | otherwise = rm_dups (b:acc) bs + + rn_inst_info (InstInfo { iSpec = inst, iBinds = NewTypeDerived }) + = return (InstInfo { iSpec = inst, iBinds = NewTypeDerived }) + + rn_inst_info (InstInfo { iSpec = inst, iBinds = VanillaInst binds sigs }) + = -- 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 [] }) } + where + (tyvars,_,clas,_) = instanceHead inst + clas_nm = className clas + ----------------------------------------- -mkGenericBinds :: [LTyClDecl Name] -> TcM (LHsBinds RdrName) -mkGenericBinds tycl_decls - = do { tcs <- mapM tcLookupTyCon - [ tc_name | - L _ (TyData { tcdLName = L _ tc_name }) <- tycl_decls] - -- We are only interested in the data type declarations +mkGenericBinds :: Bool -> TcM (LHsBinds RdrName) +mkGenericBinds is_boot + | 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 ]) } - -- And then only in the ones whose 'has-generics' flag is on + -- 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} @@ -393,9 +420,11 @@ deriveStandalone (L loc (DerivDecl deriv_ty)) <+> text "theta:" <+> ppr theta <+> text "tau:" <+> ppr tau) ; (cls, inst_tys) <- checkValidInstHead tau + ; checkValidInstance tvs theta cls inst_tys + -- C.f. TcInstDcls.tcLocalInstDecl1 + ; let cls_tys = take (length inst_tys - 1) inst_tys inst_ty = last inst_tys - ; traceTc (text "standalone deriving;" <+> text "class:" <+> ppr cls <+> text "class types:" <+> ppr cls_tys @@ -405,11 +434,11 @@ deriveStandalone (L loc (DerivDecl deriv_ty)) ------------------------------------------------------------------ deriveTyData :: (LHsType Name, LTyClDecl Name) -> TcM (Maybe EarlyDerivSpec) -deriveTyData (deriv_pred, L loc decl@(TyData { tcdLName = L _ tycon_name, - tcdTyVars = tv_names, - tcdTyPats = ty_pats })) - = setSrcSpan loc $ - tcAddDeclCtxt decl $ +deriveTyData (L loc deriv_pred, L _ decl@(TyData { tcdLName = L _ tycon_name, + tcdTyVars = tv_names, + tcdTyPats = ty_pats })) + = setSrcSpan loc $ -- Use the location of the 'deriving' item + tcAddDeclCtxt decl $ do { let hs_ty_args = ty_pats `orElse` map (nlHsTyVar . hsLTyVarName) tv_names hs_app = nlHsTyConApp tycon_name hs_ty_args -- We get kinding info for the tyvars by typechecking (T a b) @@ -432,24 +461,28 @@ mkEqnHelp :: InstOrigin -> [TyVar] -> Class -> [Type] -> Type -> TcRn (Maybe EarlyDerivSpec) mkEqnHelp orig tvs cls cls_tys tc_app mtheta | Just (tycon, tc_args) <- tcSplitTyConApp_maybe tc_app - = do { + , isAlgTyCon tycon -- Check for functions, primitive types etc + = do { (rep_tc, rep_tc_args) <- tcLookupFamInstExact tycon tc_args + -- Be careful to test rep_tc here: in the case of families, + -- we want to check the instance tycon, not the family tycon + -- For standalone deriving (mtheta /= Nothing), - -- check that all the data constructors are in scope + -- check that all the data constructors are in scope. + -- No need for this when deriving Typeable, becuase we don't need + -- the constructors for that. -- By this time we know that the thing is algebraic -- because we've called checkInstHead in derivingStandalone - rdr_env <- getGlobalRdrEnv - ; let hidden_data_cons = filter not_in_scope (tyConDataCons tycon) - not_in_scope dc = null (lookupGRE_Name rdr_env (dataConName dc)) - ; checkTc (isNothing mtheta || null hidden_data_cons) + ; rdr_env <- getGlobalRdrEnv + ; let hidden_data_cons = isAbstractTyCon rep_tc || any not_in_scope (tyConDataCons rep_tc) + not_in_scope dc = null (lookupGRE_Name rdr_env (dataConName dc)) + ; checkTc (isNothing mtheta || + not hidden_data_cons || + className cls `elem` typeableClassNames) (derivingHiddenErr tycon) ; mayDeriveDataTypeable <- doptM Opt_DeriveDataTypeable ; newtype_deriving <- doptM Opt_GeneralizedNewtypeDeriving - ; (rep_tc, rep_tc_args) <- tcLookupFamInstExact tycon tc_args - - -- Be careful to test rep_tc here: in the case of families, we want - -- to check the instance tycon, not the family tycon ; if isDataTyCon rep_tc then mkDataTypeEqn orig mayDeriveDataTypeable tvs cls cls_tys tycon tc_args rep_tc rep_tc_args mtheta @@ -459,15 +492,35 @@ mkEqnHelp orig tvs cls cls_tys tc_app mtheta tycon tc_args rep_tc rep_tc_args mtheta } | otherwise = baleOut (derivingThingErr cls cls_tys tc_app - (ptext SLIT("Last argument of the instance must be a type application"))) + (ptext (sLit "The last argument of the instance must be a data or newtype application"))) baleOut :: Message -> TcM (Maybe a) baleOut err = do { addErrTc err; return Nothing } \end{code} -Auxiliary lookup wrapper which requires that looked up family instances are -not type instances. If called with a vanilla tycon, the old type application -is simply returned. +Note [Looking up family instances for deriving] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +tcLookupFamInstExact is an auxiliary lookup wrapper which requires +that looked-up family instances exist. If called with a vanilla +tycon, the old type application is simply returned. + +If we have + data instance F () = ... deriving Eq + data instance F () = ... deriving Eq +then tcLookupFamInstExact will be confused by the two matches; +but that can't happen because tcInstDecls1 doesn't call tcDeriving +if there are any overlaps. + +There are two other things that might go wrong with the lookup. +First, we might see a standalone deriving clause + deriving Eq (F ()) +when there is no data instance F () in scope. + +Note that it's OK to have + data instance F [a] = ... + deriving Eq (F [(a,b)]) +where the match is not exact; the same holds for ordinary data types +with standalone deriving declrations. \begin{code} tcLookupFamInstExact :: TyCon -> [Type] -> TcM (TyCon, [Type]) @@ -477,18 +530,14 @@ tcLookupFamInstExact tycon tys | otherwise = do { maybeFamInst <- tcLookupFamInst tycon tys ; case maybeFamInst of - Nothing -> famInstNotFound tycon tys False - Just famInst@(_, rep_tys) - | not variable_only_subst -> famInstNotFound tycon tys True - | otherwise -> return famInst - where - tvs = map (Type.getTyVar - "TcDeriv.tcLookupFamInstExact") - rep_tys - variable_only_subst = all Type.isTyVarTy rep_tys && - sizeVarSet (mkVarSet tvs) == length tvs - -- renaming may have no repetitions + Nothing -> famInstNotFound tycon tys + Just famInst -> return famInst } + +famInstNotFound :: TyCon -> [Type] -> TcM a +famInstNotFound tycon tys + = failWithTc (ptext (sLit "No family instance for") + <+> quotes (pprTypeApp tycon (ppr tycon) tys)) \end{code} @@ -561,13 +610,13 @@ mk_typeable_eqn orig tvs cls tycon tc_args rep_tc _rep_tc_args mtheta -- Typeable; it depends on the arity of the type | isNothing mtheta -- deriving on a data type decl = do { checkTc (cls `hasKey` typeableClassKey) - (ptext SLIT("Use deriving( Typeable ) on a data type declaration")) + (ptext (sLit "Use deriving( Typeable ) on a data type declaration")) ; real_cls <- tcLookupClass (typeableClassNames !! tyConArity tycon) ; mk_typeable_eqn orig tvs real_cls tycon [] rep_tc [] (Just []) } | otherwise -- standaone deriving = do { checkTc (null tc_args) - (ptext SLIT("Derived typeable instance must be of form (Typeable") + (ptext (sLit "Derived typeable instance must be of form (Typeable") <> int (tyConArity tycon) <+> ppr tycon <> rparen) ; dfun_name <- new_dfun_name cls tycon ; loc <- getSrcSpanM @@ -593,8 +642,8 @@ checkSideConditions mayDeriveDataTypeable cls cls_tys rep_tc Just cond -> cond (mayDeriveDataTypeable, rep_tc) Nothing -> Just non_std_why where - ty_args_why = quotes (ppr (mkClassPred cls cls_tys)) <+> ptext SLIT("is not a class") - non_std_why = quotes (ppr cls) <+> ptext SLIT("is not a derivable class") + ty_args_why = quotes (ppr (mkClassPred cls cls_tys)) <+> ptext (sLit "is not a class") + non_std_why = quotes (ppr cls) <+> ptext (sLit "is not a derivable class") sideConditions :: Class -> Maybe Condition sideConditions cls @@ -623,7 +672,7 @@ 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 " and") $$ y) -- Both fail andCond :: Condition -> Condition -> Condition @@ -639,9 +688,9 @@ cond_std (_, rep_tc) where data_cons = tyConDataCons rep_tc no_cons_why = quotes (pprSourceTyCon rep_tc) <+> - ptext SLIT("has no data constructors") + ptext (sLit "has no data constructors") existential_why = quotes (pprSourceTyCon rep_tc) <+> - ptext SLIT("has non-Haskell-98 constructor(s)") + ptext (sLit "has non-Haskell-98 constructor(s)") cond_isEnumeration :: Condition cond_isEnumeration (_, rep_tc) @@ -649,7 +698,7 @@ cond_isEnumeration (_, rep_tc) | otherwise = Just why where why = quotes (pprSourceTyCon rep_tc) <+> - ptext SLIT("has non-nullary constructors") + ptext (sLit "has non-nullary constructors") cond_isProduct :: Condition cond_isProduct (_, rep_tc) @@ -657,7 +706,7 @@ cond_isProduct (_, rep_tc) | otherwise = Just why where why = quotes (pprSourceTyCon rep_tc) <+> - ptext SLIT("has more than one constructor") + ptext (sLit "has more than one constructor") cond_typeableOK :: Condition -- OK for Typeable class @@ -671,18 +720,18 @@ cond_typeableOK (_, rep_tc) | otherwise = Nothing where too_many = quotes (pprSourceTyCon rep_tc) <+> - ptext SLIT("has too many arguments") + ptext (sLit "has too many arguments") bad_kind = quotes (pprSourceTyCon rep_tc) <+> - ptext SLIT("has arguments of kind other than `*'") + ptext (sLit "has arguments of kind other than `*'") fam_inst = quotes (pprSourceTyCon rep_tc) <+> - ptext SLIT("is a type family") + ptext (sLit "is a type family") cond_mayDeriveDataTypeable :: Condition cond_mayDeriveDataTypeable (mayDeriveDataTypeable, _) | mayDeriveDataTypeable = Nothing | otherwise = Just why where - why = ptext SLIT("You need -XDeriveDataTypeable to derive an instance for this class") + why = ptext (sLit "You need -XDeriveDataTypeable to derive an instance for this class") std_class_via_iso :: Class -> Bool std_class_via_iso clas -- These standard classes can be derived for a newtype @@ -694,7 +743,8 @@ std_class_via_iso clas -- These standard classes can be derived for a newtype new_dfun_name :: Class -> TyCon -> TcM Name new_dfun_name clas tycon -- Just a simple wrapper - = newDFunName clas [mkTyConApp tycon []] (getSrcSpan tycon) + = do { loc <- getSrcSpanM -- The location of the instance decl, not of the tycon + ; newDFunName clas [mkTyConApp tycon []] loc } -- The type passed to newDFunName is only used to generate -- a suitable string; hence the empty type arg list \end{code} @@ -759,7 +809,7 @@ mkNewTypeEqn orig mayDeriveDataTypeable newtype_deriving tvs mb_std_err = checkSideConditions mayDeriveDataTypeable cls cls_tys rep_tycon std_err = derivingThingErr cls cls_tys tc_app $ vcat [fromJust mb_std_err, - ptext SLIT("Try -XGeneralizedNewtypeDeriving for GHC's newtype-deriving extension")] + ptext (sLit "Try -XGeneralizedNewtypeDeriving for GHC's newtype-deriving extension")] -- Here is the plan for newtype derivings. We see -- newtype T a1...an = MkT (t ak+1...an) deriving (.., C s1 .. sm, ...) @@ -850,9 +900,10 @@ mkNewTypeEqn orig mayDeriveDataTypeable newtype_deriving tvs right_arity = length cls_tys + 1 == classArity cls -- Never derive Read,Show,Typeable,Data this way - non_iso_classes = [readClassKey, showClassKey, typeableClassKey, dataClassKey] + non_iso_class cls = className cls `elem` ([readClassName, showClassName, dataClassName] ++ + typeableClassNames) can_derive_via_isomorphism - = not (getUnique cls `elem` non_iso_classes) + = not (non_iso_class cls) && right_arity -- Well kinded; -- eg not: newtype T ... deriving( ST ) -- because ST needs *2* type params @@ -893,19 +944,19 @@ mkNewTypeEqn orig mayDeriveDataTypeable newtype_deriving tvs -- arguments must be type variables (not more complex indexes) cant_derive_err = derivingThingErr cls cls_tys tc_app - (vcat [ptext SLIT("even with cunning newtype deriving:"), + (vcat [ptext (sLit "even with cunning newtype deriving:"), if isRecursiveTyCon tycon then - ptext SLIT("the newtype may be recursive") + ptext (sLit "the newtype may be recursive") else empty, if not right_arity then - quotes (ppr (mkClassPred cls cls_tys)) <+> ptext SLIT("does not have arity 1") + quotes (ppr (mkClassPred cls cls_tys)) <+> ptext (sLit "does not have arity 1") else empty, if not (n_tyargs_to_keep >= 0) then - ptext SLIT("the type constructor has wrong kind") + ptext (sLit "the type constructor has wrong kind") else if not (n_args_to_keep >= 0) then - ptext SLIT("the representation type has wrong kind") + ptext (sLit "the representation type has wrong kind") else if not eta_ok then - ptext SLIT("the eta-reduction property does not hold") + ptext (sLit "the eta-reduction property does not hold") else empty ]) \end{code} @@ -955,7 +1006,7 @@ inferInstanceContexts oflag infer_specs iterate_deriv :: Int -> [ThetaType] -> TcM [DerivSpec] iterate_deriv n current_solns | n > 20 -- Looks as if we are in an infinite loop - -- This can happen if we have -fallow-undecidable-instances + -- This can happen if we have -XUndecidableInstances -- (See TcSimplify.tcSimplifyDeriv.) = pprPanic "solveDerivEqns: probable loop" (vcat (map pprDerivSpec infer_specs) $$ ppr current_solns) @@ -1093,50 +1144,41 @@ the renamer. What a great hack! -- Representation tycons differ from the tycon in the instance signature in -- case of instances for indexed families. -- -genInst :: OverlapFlag -> DerivSpec -> TcM (InstInfo, DerivAuxBinds) +genInst :: OverlapFlag -> DerivSpec -> TcM (InstInfo RdrName, DerivAuxBinds) genInst oflag spec | ds_newtype spec = return (InstInfo { iSpec = mkInstance1 oflag spec , iBinds = NewTypeDerived }, []) | otherwise - = do { fix_env <- getFixityEnv - ; let - inst = mkInstance1 oflag spec - (tyvars,_,clas,[ty]) = instanceHead inst - clas_nm = className clas - (visible_tycon, tyArgs) = tcSplitTyConApp ty + = do { let loc = getSrcSpan (ds_name spec) + inst = mkInstance1 oflag spec + (_,_,clas,[ty]) = instanceHead inst + (visible_tycon, tyArgs) = tcSplitTyConApp ty -- In case of a family instance, we need to use the representation -- tycon (after all, it has the data constructors) ; (tycon, _) <- tcLookupFamInstExact visible_tycon tyArgs - ; let (meth_binds, aux_binds) = genDerivBinds clas fix_env tycon - - -- Bring the right type variables into - -- scope, and rename the method binds - -- It's a bit yukky that we return *renamed* InstInfo, but - -- *non-renamed* auxiliary bindings - ; (rn_meth_binds, _fvs) <- discardWarnings $ - bindLocalNames (map Var.varName tyvars) $ - rnMethodBinds clas_nm (\_ -> []) [] meth_binds + ; fix_env <- getFixityEnv + ; let (meth_binds, aux_binds) = genDerivBinds loc fix_env clas tycon -- Build the InstInfo ; return (InstInfo { iSpec = inst, - iBinds = VanillaInst rn_meth_binds [] }, + iBinds = VanillaInst meth_binds [] }, aux_binds) } -genDerivBinds :: Class -> FixityEnv -> TyCon -> (LHsBinds RdrName, DerivAuxBinds) -genDerivBinds clas fix_env tycon +genDerivBinds :: SrcSpan -> FixityEnv -> Class -> TyCon -> (LHsBinds RdrName, DerivAuxBinds) +genDerivBinds loc fix_env clas tycon | className clas `elem` typeableClassNames - = (gen_Typeable_binds tycon, []) + = (gen_Typeable_binds loc tycon, []) | otherwise = case assocMaybe gen_list (getUnique clas) of - Just gen_fn -> gen_fn tycon + Just gen_fn -> gen_fn loc tycon Nothing -> pprPanic "genDerivBinds: bad derived class" (ppr clas) where - gen_list :: [(Unique, TyCon -> (LHsBinds RdrName, DerivAuxBinds))] + gen_list :: [(Unique, SrcSpan -> TyCon -> (LHsBinds RdrName, DerivAuxBinds))] gen_list = [(eqClassKey, gen_Eq_binds) ,(ordClassKey, gen_Ord_binds) ,(enumClassKey, gen_Enum_binds) @@ -1144,7 +1186,7 @@ genDerivBinds clas fix_env tycon ,(ixClassKey, gen_Ix_binds) ,(showClassKey, gen_Show_binds fix_env) ,(readClassKey, gen_Read_binds fix_env) - ,(dataClassKey, gen_Data_binds fix_env) + ,(dataClassKey, gen_Data_binds) ] \end{code} @@ -1158,7 +1200,7 @@ genDerivBinds clas fix_env tycon \begin{code} derivingThingErr :: Class -> [Type] -> Type -> Message -> Message derivingThingErr clas tys ty why - = sep [hsep [ptext SLIT("Can't make a derived instance of"), + = sep [hsep [ptext (sLit "Can't make a derived instance of"), quotes (ppr pred)], nest 2 (parens why)] where @@ -1166,28 +1208,20 @@ derivingThingErr clas tys ty why derivingHiddenErr :: TyCon -> SDoc derivingHiddenErr tc - = hang (ptext SLIT("The data constructors of") <+> quotes (ppr tc) <+> ptext SLIT("are not all in scope")) - 2 (ptext SLIT("so you cannot derive an instance for it")) + = hang (ptext (sLit "The data constructors of") <+> quotes (ppr tc) <+> ptext (sLit "are not all in scope")) + 2 (ptext (sLit "so you cannot derive an instance for it")) standaloneCtxt :: LHsType Name -> SDoc -standaloneCtxt ty = hang (ptext SLIT("In the stand-alone deriving instance for")) +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) + = ptext (sLit "When deriving the instance for") <+> parens (pprClassPred clas inst_tys) badDerivedPred :: PredType -> Message badDerivedPred pred - = vcat [ptext SLIT("Can't derive instances where the instance context mentions"), - ptext SLIT("type variables that are not data type parameters"), - nest 2 (ptext SLIT("Offending constraint:") <+> ppr pred)] - -famInstNotFound :: TyCon -> [Type] -> Bool -> TcM a -famInstNotFound tycon tys notExact - = failWithTc (msg <+> quotes (pprTypeApp tycon (ppr tycon) tys)) - where - msg = ptext $ if notExact - then SLIT("No family instance exactly matching") - else SLIT("More than one family instance for") + = vcat [ptext (sLit "Can't derive instances where the instance context mentions"), + ptext (sLit "type variables that are not data type parameters"), + nest 2 (ptext (sLit "Offending constraint:") <+> ppr pred)] \end{code}