X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcTyClsDecls.lhs;h=4f1fa0c5ebb168e6b22c7730fe9848ac51132fc6;hb=a202c6c4a455b7db2c5846553edf4d55145b9a3a;hp=205c881f500e3af5153936588445d4ebfdbaae77;hpb=0596517a9b4b2b32e5d375a986351102ac4540fc;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcTyClsDecls.lhs b/ghc/compiler/typecheck/TcTyClsDecls.lhs index 205c881..4f1fa0c 100644 --- a/ghc/compiler/typecheck/TcTyClsDecls.lhs +++ b/ghc/compiler/typecheck/TcTyClsDecls.lhs @@ -1,306 +1,355 @@ % -% (c) The AQUA Project, Glasgow University, 1996 +% (c) The AQUA Project, Glasgow University, 1996-1998 % \section[TcTyClsDecls]{Typecheck type and class declarations} \begin{code} -#include "HsVersions.h" - module TcTyClsDecls ( - tcTyAndClassDecls1 + tcTyAndClassDecls ) where -import Ubiq{-uitous-} +#include "HsVersions.h" -import HsSyn ( TyDecl(..), ConDecl(..), BangType(..), - ClassDecl(..), MonoType(..), PolyType(..), - Sig(..), MonoBinds, Fake, InPat ) -import RnHsSyn ( RenamedTyDecl(..), RenamedClassDecl(..) ) +import HsSyn ( HsDecl(..), TyClDecl(..), + HsType(..), HsTyVar, + ConDecl(..), ConDetails(..), BangType(..), + Sig(..), + tyClDeclName, isClassDecl, isSynDecl + ) +import RnHsSyn ( RenamedHsDecl, RenamedTyClDecl, listTyCon_name, tupleTyCon_name ) +import BasicTypes ( RecFlag(..), NewOrData(..), Arity ) import TcMonad -import Inst ( InstanceMapper(..) ) -import TcClassDcl ( tcClassDecl1 ) -import TcEnv ( tcExtendTyConEnv, tcExtendClassEnv, - tcExtendGlobalValEnv, - tcTyVarScope, tcGetEnv ) -import TcKind ( TcKind, newKindVars ) -import TcTyDecls ( tcTyDecl ) - +import Inst ( InstanceMapper ) +import TcClassDcl ( kcClassDecl, tcClassDecl1 ) +import TcEnv ( ValueEnv, TcTyThing(..), + tcExtendTypeEnv + ) +import TcTyDecls ( tcTyDecl, kcTyDecl ) +import TcMonoType ( kcHsTyVar ) +import TcType ( TcKind, newKindVar, newKindVars, kindToTcKind, zonkTcKindToKind ) + +import Type ( mkArrowKind, boxedTypeKind ) +import Class ( Class, classBigSig ) +import Var ( tyVarKind ) import Bag -import Class ( Class(..), getClassSelIds ) -import Digraph ( findSCCs, SCC(..) ) -import Name ( Name, isTyConName ) -import PprStyle -import Pretty -import UniqSet ( UniqSet(..), emptyUniqSet, - singletonUniqSet, unionUniqSets, +import Digraph ( stronglyConnComp, SCC(..) ) +import Name ( Name, NamedThing(..), getSrcLoc, isTvOcc, nameOccName ) +import Outputable +import Maybes ( mapMaybe ) +import UniqSet ( UniqSet, emptyUniqSet, + unitUniqSet, unionUniqSets, unionManyUniqSets, uniqSetToList ) +import ErrUtils ( ErrMsg ) import SrcLoc ( SrcLoc ) -import TyCon ( TyCon, getTyConDataCons ) -import Unique ( Unique ) -import Util ( panic, pprTrace ) - +import TyCon ( TyCon ) +import Unique ( Unique, Uniquable(..) ) +import UniqFM ( listToUFM, lookupUFM ) \end{code} The main function ~~~~~~~~~~~~~~~~~ \begin{code} -data Decl = TyD RenamedTyDecl | ClD RenamedClassDecl - -tcTyAndClassDecls1 :: InstanceMapper - -> Bag RenamedTyDecl -> Bag RenamedClassDecl - -> TcM s (TcEnv s) +tcTyAndClassDecls :: ValueEnv -> InstanceMapper -- Knot tying stuff + -> [RenamedHsDecl] + -> TcM s TcEnv -tcTyAndClassDecls1 inst_mapper rnty_decls rncls_decls - = sortByDependency syn_decls cls_decls decls `thenTc` \ groups -> - tcGroups inst_mapper groups - where - cls_decls = mapBag ClD rncls_decls - ty_decls = mapBag TyD rnty_decls - syn_decls = filterBag is_syn_decl ty_decls - decls = ty_decls `unionBags` cls_decls +tcTyAndClassDecls unf_env inst_mapper decls + = sortByDependency decls `thenTc` \ groups -> + tcGroups unf_env inst_mapper groups - is_syn_decl (TyD (TySynonym _ _ _ _)) = True - is_syn_decl _ = False - -tcGroups inst_mapper [] - = tcGetEnv `thenNF_Tc` \ env -> +tcGroups unf_env inst_mapper [] + = tcGetEnv `thenNF_Tc` \ env -> returnTc env -tcGroups inst_mapper (group:groups) - = tcGroup inst_mapper group `thenTc` \ new_env -> - - -- Extend the environment using the new tycons and classes - tcSetEnv new_env $ - - -- Do the remaining groups - tcGroups inst_mapper groups +tcGroups unf_env inst_mapper (group:groups) + = tcGroup unf_env inst_mapper group `thenTc` \ env -> + tcSetEnv env $ + tcGroups unf_env inst_mapper groups \end{code} Dealing with a group ~~~~~~~~~~~~~~~~~~~~ -\begin{code} -tcGroup :: InstanceMapper -> Bag Decl -> TcM s (TcEnv s) -tcGroup inst_mapper decls - = pprTrace "tcGroup: " (ppCat (map (fst.fmt_decl) (bagToList decls))) $ - - -- TIE THE KNOT - fixTc ( \ ~(tycons,classes,_) -> - - -- EXTEND TYPE AND CLASS ENVIRONMENTS - -- including their data constructors and class operations - -- NB: it's important that the tycons and classes come back in just - -- the same order from this fix as from get_binders, so that these - -- extend-env things work properly. A bit UGH-ish. - tcExtendTyConEnv tycon_names_w_arities tycons $ - tcExtendClassEnv class_names classes $ - tcExtendGlobalValEnv (concat (map getTyConDataCons tycons)) $ - tcExtendGlobalValEnv (concat (map getClassSelIds classes)) $ - - -- SNAFFLE ENV TO RETURN - tcGetEnv `thenNF_Tc` \ final_env -> - - -- DEAL WITH TYPE VARIABLES - tcTyVarScope tyvar_names ( \ tyvars -> - - -- DEAL WITH THE DEFINITIONS THEMSELVES - foldBag combine (tcDecl inst_mapper) - (returnTc (emptyBag, emptyBag)) - decls - ) `thenTc` \ (tycons,classes) -> - - returnTc (bagToList tycons, bagToList classes, final_env) - ) `thenTc` \ (_, _, final_env) -> - returnTc final_env +\begin{code} +tcGroup :: ValueEnv -> InstanceMapper -> SCC RenamedTyClDecl -> TcM s TcEnv +tcGroup unf_env inst_mapper scc + = -- Do kind checking + mapNF_Tc getTyBinding1 decls `thenNF_Tc` \ ty_env_stuff1 -> + tcExtendTypeEnv ty_env_stuff1 (mapTc kcDecl decls) `thenTc_` + + -- Tie the knot +-- traceTc (ppr (map fst ty_env_stuff1)) `thenTc_` + fixTc ( \ ~(rec_tyclss, _) -> + let + rec_env = listToUFM rec_tyclss + in + + -- Do type checking + mapNF_Tc (getTyBinding2 rec_env) ty_env_stuff1 `thenNF_Tc` \ ty_env_stuff2 -> + tcExtendTypeEnv ty_env_stuff2 $ + mapTc (tcDecl is_rec_group unf_env inst_mapper) decls `thenTc` \ tyclss -> + + tcGetEnv `thenTc` \ env -> + returnTc (tyclss, env) + ) `thenTc` \ (_, env) -> +-- traceTc (text "done" <+> ppr (map fst ty_env_stuff1)) `thenTc_` + returnTc env where - (tyvar_names, tycon_names_w_arities, class_names) = get_binders decls + is_rec_group = case scc of + AcyclicSCC _ -> NonRecursive + CyclicSCC _ -> Recursive - combine do_a do_b - = do_a `thenTc` \ (a1,a2) -> - do_b `thenTc` \ (b1,b2) -> - returnTc (a1 `unionBags` b1, a2 `unionBags` b2) + decls = case scc of + AcyclicSCC decl -> [decl] + CyclicSCC decls -> decls \end{code} Dealing with one decl ~~~~~~~~~~~~~~~~~~~~~ \begin{code} -tcDecl :: InstanceMapper - -> Decl - -> TcM s (Bag TyCon, Bag Class) +kcDecl decl + = tcAddDeclCtxt decl $ + if isClassDecl decl then + kcClassDecl decl + else + kcTyDecl decl + +tcDecl :: RecFlag -- True => recursive group + -> ValueEnv -> InstanceMapper + -> RenamedTyClDecl -> TcM s (Name, TcTyThing) + +tcDecl is_rec_group unf_env inst_mapper decl + = tcAddDeclCtxt decl $ +-- traceTc (text "Starting" <+> ppr name) `thenTc_` + if isClassDecl decl then + tcClassDecl1 unf_env inst_mapper decl `thenTc` \ clas -> +-- traceTc (text "Finished" <+> ppr name) `thenTc_` + returnTc (getName clas, AClass clas) + else + tcTyDecl is_rec_group decl `thenTc` \ tycon -> +-- traceTc (text "Finished" <+> ppr name) `thenTc_` + returnTc (getName tycon, ATyCon tycon) -tcDecl inst_mapper (TyD decl) - = tcTyDecl decl `thenTc` \ tycon -> - returnTc (unitBag tycon, emptyBag) + where + name = tyClDeclName decl + -tcDecl inst_mapper (ClD decl) - = tcClassDecl1 inst_mapper decl `thenTc` \ clas -> - returnTc (emptyBag, unitBag clas) +tcAddDeclCtxt decl thing_inside + = tcAddSrcLoc loc $ + tcAddErrCtxt ctxt $ + thing_inside + where + (name, loc, thing) + = case decl of + (ClassDecl _ name _ _ _ _ _ _ loc) -> (name, loc, "class") + (TySynonym name _ _ loc) -> (name, loc, "type synonym") + (TyData NewType _ name _ _ _ _ loc) -> (name, loc, "data type") + (TyData DataType _ name _ _ _ _ loc) -> (name, loc, "newtype") + + ctxt = hsep [ptext SLIT("In the"), text thing, + ptext SLIT("declaration for"), quotes (ppr name)] \end{code} + +getTyBinders +~~~~~~~~~~~ +Extract *binding* names from type and class decls. Type variables are +bound in type, data, newtype and class declarations, + *and* the polytypes in the class op sigs. + *and* the existentially quantified contexts in datacon decls + +Why do we need to grab all these type variables at once, including +those locally-quantified type variables in class op signatures? + + [Incidentally, this only works because the names are all unique by now.] + +Because we can only commit to the final kind of a type variable when +we've completed the mutually recursive group. For example: + +class C a where + op :: D b => a -> b -> b + +class D c where + bop :: (Monad c) => ... + +Here, the kind of the locally-polymorphic type variable "b" +depends on *all the uses of class D*. For example, the use of +Monad c in bop's type signature means that D must have kind Type->Type. + + +\begin{code} +getTyBinding1 :: RenamedTyClDecl -> NF_TcM s (Name, (TcKind, Maybe Arity, TcTyThing)) +getTyBinding1 (TySynonym name tyvars _ _) + = mapNF_Tc kcHsTyVar tyvars `thenNF_Tc` \ arg_kinds -> + newKindVar `thenNF_Tc` \ result_kind -> + returnNF_Tc (name, (foldr mkArrowKind result_kind arg_kinds, + Just (length tyvars), + ATyCon (pprPanic "ATyCon: syn" (ppr name)))) + +getTyBinding1 (TyData _ _ name tyvars _ _ _ _) + = mapNF_Tc kcHsTyVar tyvars `thenNF_Tc` \ arg_kinds -> + returnNF_Tc (name, (foldr mkArrowKind boxedTypeKind arg_kinds, + Nothing, + ATyCon (error "ATyCon: data"))) + +getTyBinding1 (ClassDecl _ name tyvars _ _ _ _ _ _) + = mapNF_Tc kcHsTyVar tyvars `thenNF_Tc` \ arg_kinds -> + returnNF_Tc (name, (foldr mkArrowKind boxedTypeKind arg_kinds, + Just (length tyvars), + AClass (error "AClass"))) + +-- Zonk the kind to its final form, and lookup the +-- recursive tycon/class +getTyBinding2 rec_env (name, (tc_kind, maybe_arity, thing)) + = zonkTcKindToKind tc_kind `thenNF_Tc` \ kind -> + returnNF_Tc (name, (kind, maybe_arity, mk_thing thing (lookupUFM rec_env name))) + where + mk_thing (ATyCon _) ~(Just (ATyCon tc)) = ATyCon tc + mk_thing (AClass _) ~(Just (AClass cls)) = AClass cls +\end{code} + + +%************************************************************************ +%* * +\subsection{Dependency analysis} +%* * +%************************************************************************ + Dependency analysis ~~~~~~~~~~~~~~~~~~~ \begin{code} -sortByDependency :: Bag Decl -> Bag Decl -> Bag Decl -> TcM s [Bag Decl] -sortByDependency syn_decls cls_decls decls - = let -- CHECK FOR SYNONYM CYCLES - syn_sccs = findSCCs mk_edges syn_decls - syn_cycles = [map fmt_decl (bagToList decls) - | CyclicSCC decls <- syn_sccs] - +sortByDependency :: [RenamedHsDecl] -> TcM s [SCC RenamedTyClDecl] +sortByDependency decls + = let -- CHECK FOR CLASS CYCLES + cls_sccs = stronglyConnComp (mapMaybe mk_cls_edges tycl_decls) + cls_cycles = [ decls | CyclicSCC decls <- cls_sccs] in - checkTc (null syn_cycles) (typeCycleErr syn_cycles) `thenTc_` + checkTc (null cls_cycles) (classCycleErr cls_cycles) `thenTc_` - let -- CHECK FOR CLASS CYCLES - cls_sccs = findSCCs mk_edges cls_decls - cls_cycles = [map fmt_decl (bagToList decls) - | CyclicSCC decls <- cls_sccs] + let -- CHECK FOR SYNONYM CYCLES + syn_sccs = stronglyConnComp (filter is_syn_decl edges) + syn_cycles = [ decls | CyclicSCC decls <- syn_sccs] in - checkTc (null cls_cycles) (classCycleErr cls_cycles) `thenTc_` + checkTc (null syn_cycles) (typeCycleErr syn_cycles) `thenTc_` - -- DO THE MAIN DEPENDENCY ANALYSIS + -- DO THE MAIN DEPENDENCY ANALYSIS let - decl_sccs = findSCCs mk_edges decls - scc_bags = map bag_acyclic decl_sccs + decl_sccs = stronglyConnComp edges in - returnTc (scc_bags) - + returnTc decl_sccs where - bag_acyclic (AcyclicSCC scc) = unitBag scc - bag_acyclic (CyclicSCC sccs) = sccs - -fmt_decl (TyD (TySynonym name _ _ _)) = (ppr PprForUser name, getSrcLoc name) -fmt_decl (ClD (ClassDecl _ name _ _ _ _ _)) = (ppr PprForUser name, getSrcLoc name) + tycl_decls = [d | TyClD d <- decls] + edges = map mk_edges tycl_decls + + is_syn_decl (d, _, _) = isSynDecl d + is_cls_decl (d, _, _) = isClassDecl d \end{code} Edges in Type/Class decls ~~~~~~~~~~~~~~~~~~~~~~~~~ + \begin{code} -mk_edges (TyD (TyData ctxt name _ condecls _ _ _)) - = (getItsUnique name, set_to_bag (get_ctxt ctxt `unionUniqSets` get_cons condecls)) -mk_edges (TyD (TyNew ctxt name _ condecl _ _ _)) - = (getItsUnique name, set_to_bag (get_ctxt ctxt `unionUniqSets` get_cons condecl)) -mk_edges (TyD (TySynonym name _ rhs _)) - = (getItsUnique name, set_to_bag (get_ty rhs)) -mk_edges (ClD (ClassDecl ctxt name _ sigs _ _ _)) - = (getItsUnique name, set_to_bag (get_ctxt ctxt `unionUniqSets` get_sigs sigs)) - -get_ctxt ctxt - = unionManyUniqSets (map (set_name.fst) ctxt) - -get_cons cons - = unionManyUniqSets (map get_con cons) - where - get_con (ConDecl _ btys _) - = unionManyUniqSets (map get_bty btys) - get_con (ConOpDecl bty1 _ bty2 _) - = unionUniqSets (get_bty bty1) (get_bty bty2) - get_con (NewConDecl _ ty _) - = get_ty ty - get_con (RecConDecl _ nbtys _) - = unionManyUniqSets (map (get_bty.snd) nbtys) - - get_bty (Banged ty) = get_ty ty - get_bty (Unbanged ty) = get_ty ty - -get_ty (MonoTyVar tv) - = emptyUniqSet -get_ty (MonoTyApp name tys) - = (if isTyConName name then set_name name else emptyUniqSet) - `unionUniqSets` get_tys tys -get_ty (MonoFunTy ty1 ty2) - = unionUniqSets (get_ty ty1) (get_ty ty2) -get_ty (MonoListTy ty) - = get_ty ty -- careful when defining [] (,,) etc as -get_ty (MonoTupleTy tys) -- [ty] (ty,ty,ty) will not give edges! - = get_tys tys -get_ty other = panic "TcTyClsDecls:get_ty" +---------------------------------------------------- +-- mk_cls_edges looks only at the context of class decls +-- Its used when we are figuring out if there's a cycle in the +-- superclass hierarchy -get_pty (HsForAllTy _ ctxt mty) - = get_ctxt ctxt `unionUniqSets` get_ty mty -get_pty other = panic "TcTyClsDecls:get_pty" +mk_cls_edges :: RenamedTyClDecl -> Maybe (RenamedTyClDecl, Unique, [Unique]) -get_tys tys - = unionManyUniqSets (map get_ty tys) +mk_cls_edges decl@(ClassDecl ctxt name _ _ _ _ _ _ _) + = Just (decl, getUnique name, map (getUnique . fst) ctxt) +mk_cls_edges other_decl + = Nothing -get_sigs sigs - = unionManyUniqSets (map get_sig sigs) - where - get_sig (ClassOpSig _ ty _ _) = get_pty ty - get_sig other = panic "TcTyClsDecls:get_sig" +---------------------------------------------------- +mk_edges :: RenamedTyClDecl -> (RenamedTyClDecl, Unique, [Unique]) -set_name name = singletonUniqSet (getItsUnique name) +mk_edges decl@(TyData _ ctxt name _ condecls derivs _ _) + = (decl, getUnique name, uniqSetToList (get_ctxt ctxt `unionUniqSets` + get_cons condecls `unionUniqSets` + get_deriv derivs)) -set_to_bag set = listToBag (uniqSetToList set) -\end{code} +mk_edges decl@(TySynonym name _ rhs _) + = (decl, getUnique name, uniqSetToList (get_ty rhs)) +mk_edges decl@(ClassDecl ctxt name _ sigs _ _ _ _ _) + = (decl, getUnique name, uniqSetToList (get_ctxt ctxt `unionUniqSets` + get_sigs sigs)) -get_binders -~~~~~~~~~~~ -Extract *binding* names from type and class decls. Type variables are -bound in type, data, newtype and class declarations and the polytypes -in the class op sigs. -Why do we need to grab all these type variables at once, including -those locally-quantified type variables in class op signatures? -Because we can only commit to the final kind of a type variable when -we've completed the mutually recursive group. For example: +---------------------------------------------------- +get_ctxt ctxt = unionManyUniqSets (map (set_name.fst) ctxt) -class C a where - op :: D b => a -> b -> b +---------------------------------------------------- +get_deriv Nothing = emptyUniqSet +get_deriv (Just clss) = unionManyUniqSets (map set_name clss) -class D c where - bop :: (Monad c) => ... +---------------------------------------------------- +get_cons cons = unionManyUniqSets (map get_con cons) -Here, the kind of the locally-polymorphic type variable "b" -depends on *all the uses of class D*. For example, the use of -Monad c in bop's type signature means that D must have kind Type->Type. +---------------------------------------------------- +get_con (ConDecl _ _ ctxt details _) + = get_ctxt ctxt `unionUniqSets` get_con_details details +---------------------------------------------------- +get_con_details (VanillaCon btys) = unionManyUniqSets (map get_bty btys) +get_con_details (InfixCon bty1 bty2) = unionUniqSets (get_bty bty1) (get_bty bty2) +get_con_details (NewCon ty) = get_ty ty +get_con_details (RecCon nbtys) = unionManyUniqSets (map (get_bty.snd) nbtys) -\begin{code} -get_binders :: Bag Decl - -> ([Name], -- TyVars; no dups - [(Name, Maybe Arity)], -- Tycons; no dups; arities for synonyms - [Name]) -- Classes; no dups +---------------------------------------------------- +get_bty (Banged ty) = get_ty ty +get_bty (Unbanged ty) = get_ty ty -get_binders decls = (bagToList tyvars, bagToList tycons, bagToList classes) - where - (tyvars, tycons, classes) = foldBag union3 get_binders1 - (emptyBag,emptyBag,emptyBag) - decls - - union3 (a1,a2,a3) (b1,b2,b3) - = (a1 `unionBags` b1, a2 `unionBags` b2, a3 `unionBags` b3) - -get_binders1 (TyD (TyData _ name tyvars _ _ _ _)) - = (listToBag tyvars, unitBag (name,Nothing), emptyBag) -get_binders1 (TyD (TyNew _ name tyvars _ _ _ _)) - = (listToBag tyvars, unitBag (name,Nothing), emptyBag) -get_binders1 (TyD (TySynonym name tyvars _ _)) - = (listToBag tyvars, unitBag (name, Just (length tyvars)), emptyBag) -get_binders1 (ClD (ClassDecl _ name tyvar sigs _ _ _)) - = (unitBag tyvar `unionBags` sigs_tvs sigs, - emptyBag, unitBag name) - -sigs_tvs sigs = unionManyBags (map sig_tvs sigs) +---------------------------------------------------- +get_ty (MonoTyVar name) + = if isTvOcc (nameOccName name) then emptyUniqSet else set_name name +get_ty (MonoTyApp ty1 ty2) + = unionUniqSets (get_ty ty1) (get_ty ty2) +get_ty (MonoFunTy ty1 ty2) + = unionUniqSets (get_ty ty1) (get_ty ty2) +get_ty (MonoListTy ty) + = set_name listTyCon_name `unionUniqSets` get_ty ty +get_ty (MonoTupleTy tys boxed) + = set_name (tupleTyCon_name boxed (length tys)) `unionUniqSets` get_tys tys +get_ty (HsForAllTy _ ctxt mty) + = get_ctxt ctxt `unionUniqSets` get_ty mty +get_ty other = panic "TcTyClsDecls:get_ty" + +---------------------------------------------------- +get_tys tys + = unionManyUniqSets (map get_ty tys) + +---------------------------------------------------- +get_sigs sigs + = unionManyUniqSets (map get_sig sigs) where - sig_tvs (ClassOpSig _ ty _ _) = pty_tvs ty - pty_tvs (HsForAllTy tvs _ _) = listToBag tvs -- tvs doesn't include the class tyvar + get_sig (ClassOpSig _ _ ty _) = get_ty ty + get_sig other = panic "TcTyClsDecls:get_sig" + +---------------------------------------------------- +set_name name = unitUniqSet (getUnique name) +set_to_bag set = listToBag (uniqSetToList set) \end{code} \begin{code} -typeCycleErr syn_cycles sty - = ppAboves (map (pp_cycle sty "Cycle in type declarations ...") syn_cycles) +typeCycleErr, classCycleErr :: [[RenamedTyClDecl]] -> ErrMsg + +typeCycleErr syn_cycles + = vcat (map (pp_cycle "Cycle in type declarations:") syn_cycles) -classCycleErr cls_cycles sty - = ppAboves (map (pp_cycle sty "Cycle in class declarations ...") cls_cycles) +classCycleErr cls_cycles + = vcat (map (pp_cycle "Cycle in class declarations:") cls_cycles) -pp_cycle sty str things - = ppHang (ppStr str) - 4 (ppAboves (map pp_thing things)) +pp_cycle str decls + = hang (text str) + 4 (vcat (map pp_decl decls)) where - pp_thing (pp_name, loc) - = ppCat [pp_name, ppr sty loc] + pp_decl decl + = hsep [quotes (ppr name), ptext SLIT("at"), ppr (getSrcLoc name)] + where + name = tyClDeclName decl \end{code}