X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypes%2FTypeRep.lhs;h=48481e2bb561c771035fc95a46753a8a666d8254;hb=f098cfb236c17bcb3c46e39f9b1d7d8d8ca86003;hp=9110d68ad8309e2126dbf85d0a499c297097da8b;hpb=b00b5bc04ff36a551552470060064f0b7d84ca30;p=ghc-hetmet.git diff --git a/compiler/types/TypeRep.lhs b/compiler/types/TypeRep.lhs index 9110d68..48481e2 100644 --- a/compiler/types/TypeRep.lhs +++ b/compiler/types/TypeRep.lhs @@ -1,4 +1,5 @@ % +% (c) The University of Glasgow 2006 % (c) The GRASP/AQUA Project, Glasgow University, 1998 % \section[TypeRep]{Type - friends' interface} @@ -6,7 +7,7 @@ \begin{code} module TypeRep ( TyThing(..), - Type(..), TyNote(..), -- Representation visible + Type(..), PredType(..), -- to friends Kind, ThetaType, -- Synonyms @@ -14,14 +15,16 @@ module TypeRep ( funTyCon, -- Pretty-printing - pprType, pprParendType, pprTyThingCategory, - pprPred, pprTheta, pprThetaArrow, pprClassPred, + pprType, pprParendType, pprTypeApp, + pprTyThing, pprTyThingCategory, + pprPred, pprTheta, pprForAll, pprThetaArrow, pprClassPred, -- Kinds liftedTypeKind, unliftedTypeKind, openTypeKind, argTypeKind, ubxTupleKind, isLiftedTypeKindCon, isLiftedTypeKind, - mkArrowKind, mkArrowKinds, + mkArrowKind, mkArrowKinds, isCoercionKind, + coVarPred, -- Kind constructors... liftedTypeKindTyCon, openTypeKindTyCon, unliftedTypeKindTyCon, @@ -43,25 +46,19 @@ module TypeRep ( #include "HsVersions.h" import {-# SOURCE #-} DataCon( DataCon, dataConName ) --- friends: -import Var ( Var, Id, TyVar, tyVarKind ) -import VarSet ( TyVarSet ) -import Name ( Name, NamedThing(..), BuiltInSyntax(..), mkWiredInName ) -import OccName ( mkOccNameFS, tcName, parenSymOcc ) -import BasicTypes ( IPName, tupleParens ) -import TyCon ( TyCon, mkFunTyCon, tyConArity, tupleTyConBoxity, isTupleTyCon, - isRecursiveTyCon, isNewTyCon, mkVoidPrimTyCon, - mkSuperKindTyCon ) -import Class ( Class ) +-- friends: +import Var +import Name +import OccName +import BasicTypes +import TyCon +import Class -- others -import PrelNames ( gHC_PRIM, funTyConKey, tySuperKindTyConKey, - coSuperKindTyConKey, liftedTypeKindTyConKey, - openTypeKindTyConKey, unliftedTypeKindTyConKey, - ubxTupleKindTyConKey, argTypeKindTyConKey, listTyConKey, - parrTyConKey, hasKey ) +import PrelNames import Outputable +import FastString \end{code} %************************************************************************ @@ -171,7 +168,6 @@ data Type | AppTy Type -- Function is *not* a TyConApp Type -- It must be another AppTy, or TyVarTy - -- (or NoteTy of these) | TyConApp -- Application of a TyCon, including newtypes *and* synonyms TyCon -- *Invariant* saturated appliations of FunTyCon and @@ -197,10 +193,6 @@ data Type -- of a coercion variable; never as the argument or result -- of a FunTy (unlike ClassP, IParam) - | NoteTy -- A type with a note attached - TyNote - Type -- The expanded version - type Kind = Type -- Invariant: a kind is always -- FunTy k1 k2 -- or TyConApp PrimTyCon [...] @@ -209,8 +201,6 @@ type Kind = Type -- Invariant: a kind is always type SuperKind = Type -- Invariant: a super kind is always -- TyConApp SuperKindTyCon ... - -data TyNote = FTVNote TyVarSet -- The free type variables of the noted expression \end{code} ------------------------------------- @@ -237,7 +227,7 @@ Predicates are represented inside GHC by PredType: data PredType = ClassP Class [Type] -- Class predicate | IParam (IPName Name) Type -- Implicit parameter - | EqPred Type Type -- Equality predicate (ty1 :=: ty2) + | EqPred Type Type -- Equality predicate (ty1 ~ ty2) type ThetaType = [PredType] \end{code} @@ -256,7 +246,7 @@ represented by evidence (a dictionary, for example, of type (predRepTy p). Note [Equality predicates] ~~~~~~~~~~~~~~~~~~~~~~~~~~ - forall a b. (a :=: S b) => a -> b + forall a b. (a ~ S b) => a -> b could be represented by ForAllTy a (ForAllTy b (FunTy (PredTy (EqPred a (S b))) ...)) OR @@ -289,14 +279,17 @@ data TyThing = AnId Id | ATyCon TyCon | AClass Class -instance Outputable TyThing where - ppr thing = pprTyThingCategory thing <+> quotes (ppr (getName thing)) +instance Outputable TyThing where + ppr = pprTyThing + +pprTyThing :: TyThing -> SDoc +pprTyThing thing = pprTyThingCategory thing <+> quotes (ppr (getName thing)) pprTyThingCategory :: TyThing -> SDoc -pprTyThingCategory (ATyCon _) = ptext SLIT("Type constructor") -pprTyThingCategory (AClass _) = ptext SLIT("Class") -pprTyThingCategory (AnId _) = ptext SLIT("Identifier") -pprTyThingCategory (ADataCon _) = ptext SLIT("Data constructor") +pprTyThingCategory (ATyCon _) = ptext (sLit "Type constructor") +pprTyThingCategory (AClass _) = ptext (sLit "Class") +pprTyThingCategory (AnId _) = ptext (sLit "Identifier") +pprTyThingCategory (ADataCon _) = ptext (sLit "Data constructor") instance NamedThing TyThing where -- Can't put this with the type getName (AnId id) = getName id -- decl, because the DataCon instance @@ -318,6 +311,15 @@ We define a few wired-in type constructors here to avoid module knots -------------------------- -- First the TyCons... +funTyCon, tySuperKindTyCon, coSuperKindTyCon, liftedTypeKindTyCon, + openTypeKindTyCon, unliftedTypeKindTyCon, + ubxTupleKindTyCon, argTypeKindTyCon + :: TyCon +funTyConName, tySuperKindTyConName, coSuperKindTyConName, liftedTypeKindTyConName, + openTypeKindTyConName, unliftedTypeKindTyConName, + ubxTupleKindTyConName, argTypeKindTyConName + :: Name + funTyCon = mkFunTyCon funTyConName (mkArrowKinds [argTypeKind, openTypeKind] liftedTypeKind) -- You might think that (->) should have type (?? -> ? -> *), and you'd be right -- But if we do that we get kind errors when saying @@ -343,15 +345,16 @@ mkKindTyCon name = mkVoidPrimTyCon name tySuperKind 0 -------------------------- -- ... and now their names -tySuperKindTyConName = mkPrimTyConName FSLIT("BOX") tySuperKindTyConKey tySuperKindTyCon -coSuperKindTyConName = mkPrimTyConName FSLIT("COERCION") coSuperKindTyConKey coSuperKindTyCon -liftedTypeKindTyConName = mkPrimTyConName FSLIT("*") liftedTypeKindTyConKey liftedTypeKindTyCon -openTypeKindTyConName = mkPrimTyConName FSLIT("?") openTypeKindTyConKey openTypeKindTyCon -unliftedTypeKindTyConName = mkPrimTyConName FSLIT("#") unliftedTypeKindTyConKey unliftedTypeKindTyCon -ubxTupleKindTyConName = mkPrimTyConName FSLIT("(#)") ubxTupleKindTyConKey ubxTupleKindTyCon -argTypeKindTyConName = mkPrimTyConName FSLIT("??") argTypeKindTyConKey argTypeKindTyCon -funTyConName = mkPrimTyConName FSLIT("(->)") funTyConKey funTyCon +tySuperKindTyConName = mkPrimTyConName (fsLit "BOX") tySuperKindTyConKey tySuperKindTyCon +coSuperKindTyConName = mkPrimTyConName (fsLit "COERCION") coSuperKindTyConKey coSuperKindTyCon +liftedTypeKindTyConName = mkPrimTyConName (fsLit "*") liftedTypeKindTyConKey liftedTypeKindTyCon +openTypeKindTyConName = mkPrimTyConName (fsLit "?") openTypeKindTyConKey openTypeKindTyCon +unliftedTypeKindTyConName = mkPrimTyConName (fsLit "#") unliftedTypeKindTyConKey unliftedTypeKindTyCon +ubxTupleKindTyConName = mkPrimTyConName (fsLit "(#)") ubxTupleKindTyConKey ubxTupleKindTyCon +argTypeKindTyConName = mkPrimTyConName (fsLit "??") argTypeKindTyConKey argTypeKindTyCon +funTyConName = mkPrimTyConName (fsLit "(->)") funTyConKey funTyCon +mkPrimTyConName :: FastString -> Unique -> TyCon -> Name mkPrimTyConName occ key tycon = mkWiredInName gHC_PRIM (mkOccNameFS tcName occ) key (ATyCon tycon) @@ -365,6 +368,8 @@ mkPrimTyConName occ key tycon = mkWiredInName gHC_PRIM (mkOccNameFS tcName occ) kindTyConType :: TyCon -> Type kindTyConType kind = TyConApp kind [] +liftedTypeKind, unliftedTypeKind, openTypeKind, argTypeKind, ubxTupleKind :: Kind + liftedTypeKind = kindTyConType liftedTypeKindTyCon unliftedTypeKind = kindTyConType unliftedTypeKindTyCon openTypeKind = kindTyConType openTypeKindTyCon @@ -381,24 +386,37 @@ tySuperKind, coSuperKind :: SuperKind tySuperKind = kindTyConType tySuperKindTyCon coSuperKind = kindTyConType coSuperKindTyCon -isTySuperKind (NoteTy _ ty) = isTySuperKind ty +isTySuperKind :: SuperKind -> Bool isTySuperKind (TyConApp kc []) = kc `hasKey` tySuperKindTyConKey -isTySuperKind other = False +isTySuperKind _ = False isCoSuperKind :: SuperKind -> Bool -isCoSuperKind (NoteTy _ ty) = isCoSuperKind ty isCoSuperKind (TyConApp kc []) = kc `hasKey` coSuperKindTyConKey -isCoSuperKind other = False +isCoSuperKind _ = False ------------------- --- lastly we need a few functions on Kinds +-- Lastly we need a few functions on Kinds +isLiftedTypeKindCon :: TyCon -> Bool isLiftedTypeKindCon tc = tc `hasKey` liftedTypeKindTyConKey +isLiftedTypeKind :: Kind -> Bool isLiftedTypeKind (TyConApp tc []) = isLiftedTypeKindCon tc -isLiftedTypeKind other = False - - +isLiftedTypeKind _ = False + +isCoercionKind :: Kind -> Bool +-- All coercions are of form (ty1 ~ ty2) +-- This function is here rather than in Coercion, +-- because it's used in a knot-tied way to enforce invariants in Var +isCoercionKind (PredTy (EqPred {})) = True +isCoercionKind _ = False + +coVarPred :: CoVar -> PredType +coVarPred tv + = ASSERT( isCoVar tv ) + case tyVarKind tv of + PredTy eq -> eq + other -> pprPanic "coVarPred" (ppr tv $$ ppr other) \end{code} @@ -430,15 +448,18 @@ pprType, pprParendType :: Type -> SDoc pprType ty = ppr_type TopPrec ty pprParendType ty = ppr_type TyConPrec ty +pprTypeApp :: NamedThing a => a -> [Type] -> SDoc +-- The first arg is the tycon, or sometimes class +-- Print infix if the tycon/class looks like an operator +pprTypeApp tc tys = ppr_type_app TopPrec (getName tc) tys + ------------------ pprPred :: PredType -> SDoc pprPred (ClassP cls tys) = pprClassPred cls tys pprPred (IParam ip ty) = ppr ip <> dcolon <> pprType ty -pprPred (EqPred ty1 ty2) = sep [ppr ty1, nest 2 (ptext SLIT(":=:")), ppr ty2] - +pprPred (EqPred ty1 ty2) = sep [ppr ty1, nest 2 (ptext (sLit "~")), ppr ty2] pprClassPred :: Class -> [Type] -> SDoc -pprClassPred clas tys = parenSymOcc (getOccName clas) (ppr clas) - <+> sep (map pprParendType tys) +pprClassPred clas tys = ppr_type_app TopPrec (getName clas) tys pprTheta :: ThetaType -> SDoc pprTheta theta = parens (sep (punctuate comma (map pprPred theta))) @@ -446,7 +467,7 @@ pprTheta theta = parens (sep (punctuate comma (map pprPred theta))) pprThetaArrow :: ThetaType -> SDoc pprThetaArrow theta | null theta = empty - | otherwise = parens (sep (punctuate comma (map pprPred theta))) <+> ptext SLIT("=>") + | otherwise = parens (sep (punctuate comma (map pprPred theta))) <+> ptext (sLit "=>") ------------------ instance Outputable Type where @@ -461,13 +482,13 @@ instance Outputable name => OutputableBndr (IPName name) where ------------------ -- OK, here's the main printer +pprKind, pprParendKind :: Kind -> SDoc pprKind = pprType pprParendKind = pprParendType ppr_type :: Prec -> Type -> SDoc -ppr_type p (TyVarTy tv) = ppr tv -ppr_type p (PredTy pred) = braces (ppr pred) -ppr_type p (NoteTy other ty2) = ppr_type p ty2 +ppr_type _ (TyVarTy tv) = ppr tv +ppr_type _ (PredTy pred) = ifPprDebug (ptext (sLit "")) <> (ppr pred) ppr_type p (TyConApp tc tys) = ppr_tc_app p tc tys ppr_type p (AppTy t1 t2) = maybeParen p TyConPrec $ @@ -492,47 +513,65 @@ ppr_forall_type p ty (tvs, rho) = split1 [] ty (ctxt, tau) = split2 [] rho - split1 tvs (ForAllTy tv ty) = split1 (tv:tvs) ty - split1 tvs (NoteTy _ ty) = split1 tvs ty - split1 tvs ty = (reverse tvs, ty) + -- We need to be extra careful here as equality constraints will occur as + -- type variables with an equality kind. So, while collecting quantified + -- variables, we separate the coercion variables out and turn them into + -- equality predicates. + split1 tvs (ForAllTy tv ty) + | not (isCoVar tv) = split1 (tv:tvs) ty + split1 tvs ty = (reverse tvs, ty) - split2 ps (NoteTy _ arg -- Rather a disgusting case - `FunTy` res) = split2 ps (arg `FunTy` res) - split2 ps (PredTy p `FunTy` ty) = split2 (p:ps) ty - split2 ps (NoteTy _ ty) = split2 ps ty - split2 ps ty = (reverse ps, ty) + split2 ps (PredTy p `FunTy` ty) = split2 (p:ps) ty + split2 ps (ForAllTy tv ty) + | isCoVar tv = split2 (coVarPred tv : ps) ty + split2 ps ty = (reverse ps, ty) ppr_tc_app :: Prec -> TyCon -> [Type] -> SDoc -ppr_tc_app p tc [] +ppr_tc_app _ tc [] = ppr_tc tc -ppr_tc_app p tc [ty] +ppr_tc_app _ tc [ty] | tc `hasKey` listTyConKey = brackets (pprType ty) - | tc `hasKey` parrTyConKey = ptext SLIT("[:") <> pprType ty <> ptext SLIT(":]") - | tc `hasKey` liftedTypeKindTyConKey = ptext SLIT("*") - | tc `hasKey` unliftedTypeKindTyConKey = ptext SLIT("#") - | tc `hasKey` openTypeKindTyConKey = ptext SLIT("(?)") - | tc `hasKey` ubxTupleKindTyConKey = ptext SLIT("(#)") - | tc `hasKey` argTypeKindTyConKey = ptext SLIT("??") + | tc `hasKey` parrTyConKey = ptext (sLit "[:") <> pprType ty <> ptext (sLit ":]") + | tc `hasKey` liftedTypeKindTyConKey = ptext (sLit "*") + | tc `hasKey` unliftedTypeKindTyConKey = ptext (sLit "#") + | tc `hasKey` openTypeKindTyConKey = ptext (sLit "(?)") + | tc `hasKey` ubxTupleKindTyConKey = ptext (sLit "(#)") + | tc `hasKey` argTypeKindTyConKey = ptext (sLit "??") ppr_tc_app p tc tys | isTupleTyCon tc && tyConArity tc == length tys = tupleParens (tupleTyConBoxity tc) (sep (punctuate comma (map pprType tys))) | otherwise - = maybeParen p TyConPrec $ - ppr_tc tc <+> sep (map (ppr_type TyConPrec) tys) + = ppr_type_app p (getName tc) tys + +ppr_type_app :: Prec -> Name -> [Type] -> SDoc +-- Used for classes as well as types; that's why it's separate from ppr_tc_app +ppr_type_app p tc tys + | is_sym_occ -- Print infix if possible + , [ty1,ty2] <- tys -- We know nothing of precedence though + = maybeParen p FunPrec (sep [ppr_type FunPrec ty1, + pprInfixVar True (ppr tc) <+> ppr_type FunPrec ty2]) + | otherwise + = maybeParen p TyConPrec (hang (pprPrefixVar is_sym_occ (ppr tc)) + 2 (sep (map pprParendType tys))) + where + is_sym_occ = isSymOcc (getOccName tc) -ppr_tc :: TyCon -> SDoc -ppr_tc tc = parenSymOcc (getOccName tc) (pp_nt_debug <> ppr tc) +ppr_tc :: TyCon -> SDoc -- No brackets for SymOcc +ppr_tc tc + = pp_nt_debug <> ppr tc where pp_nt_debug | isNewTyCon tc = ifPprDebug (if isRecursiveTyCon tc - then ptext SLIT("") - else ptext SLIT("")) + then ptext (sLit "") + else ptext (sLit "")) | otherwise = empty ------------------- +pprForAll :: [TyVar] -> SDoc pprForAll [] = empty -pprForAll tvs = ptext SLIT("forall") <+> sep (map pprTvBndr tvs) <> dot +pprForAll tvs = ptext (sLit "forall") <+> sep (map pprTvBndr tvs) <> dot +pprTvBndr :: TyVar -> SDoc pprTvBndr tv | isLiftedTypeKind kind = ppr tv | otherwise = parens (ppr tv <+> dcolon <+> pprKind kind) where