X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;ds=sidebyside;f=ghc%2Fcompiler%2Ftypes%2FType.lhs;h=643d5586285bad008c84ae18452cfd579b6139fd;hb=a5bfbd936f91d871d15857963b8a68942c12f520;hp=0a1887be16263757708830726c09286f7f7bc5ad;hpb=69e14f75a4b031e489b7774914e5a176409cea78;p=ghc-hetmet.git diff --git a/ghc/compiler/types/Type.lhs b/ghc/compiler/types/Type.lhs index 0a1887b..643d558 100644 --- a/ghc/compiler/types/Type.lhs +++ b/ghc/compiler/types/Type.lhs @@ -1,319 +1,146 @@ % % (c) The GRASP/AQUA Project, Glasgow University, 1998 % -\section[Type]{Type} +\section[Type]{Type - public interface} \begin{code} module Type ( - Type(..), TyNote(..), UsageAnn(..), -- Representation visible to friends + -- re-exports from TypeRep: + Type, Kind, TyVarSubst, - superKind, superBoxity, -- :: SuperKind + superKind, superBoxity, -- KX and BX respectively + liftedBoxity, unliftedBoxity, -- :: BX + openKindCon, -- :: KX + typeCon, -- :: BX -> KX + liftedTypeKind, unliftedTypeKind, openTypeKind, -- :: KX + mkArrowKind, mkArrowKinds, -- :: KX -> KX -> KX - boxedKind, -- :: Kind :: BX - anyBoxKind, -- :: Kind :: BX - typeCon, -- :: KindCon :: BX -> KX - anyBoxCon, -- :: KindCon :: BX - - boxedTypeKind, unboxedTypeKind, openTypeKind, -- Kind :: superKind + funTyCon, - mkArrowKind, mkArrowKinds, hasMoreBoxityInfo, + usageKindCon, -- :: KX + usageTypeKind, -- :: KX + usOnceTyCon, usManyTyCon, -- :: $ + usOnce, usMany, -- :: $ - funTyCon, + -- exports from this module: + hasMoreBoxityInfo, defaultKind, mkTyVarTy, mkTyVarTys, getTyVar, getTyVar_maybe, isTyVarTy, mkAppTy, mkAppTys, splitAppTy, splitAppTys, splitAppTy_maybe, - mkFunTy, mkFunTys, splitFunTy_maybe, splitFunTys, splitFunTysN, funResultTy, - zipFunTys, + mkFunTy, mkFunTys, splitFunTy, splitFunTy_maybe, splitFunTys, splitFunTysN, + funResultTy, funArgTy, zipFunTys, + + mkTyConApp, mkTyConTy, + tyConAppTyCon, tyConAppArgs, + splitTyConApp_maybe, splitTyConApp, + splitAlgTyConApp_maybe, splitAlgTyConApp, - mkTyConApp, mkTyConTy, splitTyConApp_maybe, - splitAlgTyConApp_maybe, splitAlgTyConApp, splitRepTyConApp_maybe, - mkDictTy, splitDictTy_maybe, isDictTy, + mkUTy, splitUTy, splitUTy_maybe, + isUTy, uaUTy, unUTy, liftUTy, mkUTyM, + isUsageKind, isUsage, isUTyVar, - mkSynTy, isSynTy, deNoteType, + mkSynTy, deNoteType, - mkUsgTy, isUsgTy{- dont use -}, isNotUsgTy, splitUsgTy, unUsgTy, tyUsg, + repType, splitRepFunTys, splitNewType_maybe, typePrimRep, mkForAllTy, mkForAllTys, splitForAllTy_maybe, splitForAllTys, - isForAllTy, applyTy, applyTys, mkPiType, + applyTy, applyTys, hoistForAllTys, isForAllTy, + -- Predicates and the like + PredType(..), getClassPredTys_maybe, getClassPredTys, + isClassPred, isTyVarClassPred, + mkDictTy, mkPredTy, mkPredTys, splitPredTy_maybe, predTyUnique, + splitDictTy, splitDictTy_maybe, isDictTy, predRepTy, splitDFunTy, + mkClassPred, predMentionsIPs, inheritablePred, isIPPred, mkPredName, + + -- Tau, Rho, Sigma TauType, RhoType, SigmaType, ThetaType, - isTauTy, - mkRhoTy, splitRhoTy, - mkSigmaTy, splitSigmaTy, + isTauTy, mkRhoTy, splitRhoTy, splitMethodTy, + mkSigmaTy, isSigmaTy, splitSigmaTy, + getDFunTyKey, -- Lifting and boxity - isUnLiftedType, isUnboxedType, isUnboxedTupleType, isAlgType, isDataType, - typePrimRep, + isUnLiftedType, isUnboxedTupleType, isAlgType, isDataType, isNewType, -- Free variables - tyVarsOfType, tyVarsOfTypes, namesOfType, typeKind, - addFreeTyVars, + tyVarsOfType, tyVarsOfTypes, tyVarsOfPred, tyVarsOfTheta, + namesOfType, usageAnnOfType, typeKind, addFreeTyVars, + namesOfDFunHead, -- Tidying up for printing tidyType, tidyTypes, tidyOpenType, tidyOpenTypes, - tidyTyVar, tidyTyVars, - tidyTopType + tidyTyVar, tidyTyVars, tidyFreeTyVars, + tidyTopType, tidyPred, + + -- Seq + seqType, seqTypes + ) where #include "HsVersions.h" -import {-# SOURCE #-} DataCon( DataCon, dataConType ) +-- We import the representation and primitive functions from TypeRep. +-- Many things are reexported, but not the representation! + +import TypeRep + +-- Other imports: + +import {-# SOURCE #-} DataCon( DataCon ) import {-# SOURCE #-} PprType( pprType ) -- Only called in debug messages import {-# SOURCE #-} Subst ( mkTyVarSubst, substTy ) -- friends: -import Var ( Id, TyVar, IdOrTyVar, UVar, - tyVarKind, tyVarName, isId, idType, setTyVarName, setVarOcc - ) +import Var ( Var, TyVar, tyVarKind, tyVarName, setTyVarName ) import VarEnv import VarSet -import Name ( NamedThing(..), Provenance(..), ExportFlag(..), - mkWiredInTyConName, mkGlobalName, mkLocalName, mkKindOccFS, tcName, - tidyOccName, TidyOccEnv - ) +import OccName ( mkDictOcc ) +import Name ( Name, NamedThing(..), OccName, mkLocalName, tidyOccName ) import NameSet import Class ( classTyCon, Class ) -import TyCon ( TyCon, KindCon, - mkFunTyCon, mkKindCon, mkSuperKindCon, - matchesTyCon, isUnboxedTupleTyCon, isUnLiftedTyCon, - isFunTyCon, isDataTyCon, isNewTyCon, +import TyCon ( TyCon, + isUnboxedTupleTyCon, isUnLiftedTyCon, + isFunTyCon, isDataTyCon, isNewTyCon, newTyConRep, isAlgTyCon, isSynTyCon, tyConArity, - tyConKind, tyConDataCons, getSynTyConDefn, - tyConPrimRep, tyConClass_maybe + tyConKind, tyConDataCons, getSynTyConDefn, + tyConPrimRep ) -- others -import BasicTypes ( Unused ) -import SrcLoc ( mkBuiltinSrcLoc, noSrcLoc ) -import PrelMods ( pREL_GHC ) import Maybes ( maybeToBool ) -import PrimRep ( PrimRep(..), isFollowableRep ) -import Unique -- quite a few *Keys -import Util ( thenCmp, mapAccumL, seqList, ($!) ) +import SrcLoc ( SrcLoc, noSrcLoc ) +import PrimRep ( PrimRep(..) ) +import Unique ( Unique, Uniquable(..) ) +import Util ( mapAccumL, seqList, thenCmp ) import Outputable - +import UniqSet ( sizeUniqSet ) -- Should come via VarSet \end{code} -%************************************************************************ -%* * -\subsection{Type Classifications} -%* * -%************************************************************************ - -A type is - - *unboxed* iff its representation is other than a pointer - Unboxed types cannot instantiate a type variable. - Unboxed types are always unlifted. - - *lifted* A type is lifted iff it has bottom as an element. - Closures always have lifted types: i.e. any - let-bound identifier in Core must have a lifted - type. Operationally, a lifted object is one that - can be entered. - (NOTE: previously "pointed"). - - *algebraic* A type with one or more constructors, whether declared - with "data" or "newtype". - An algebraic type is one that can be deconstructed - with a case expression. - *NOT* the same as lifted types, because we also - include unboxed tuples in this classification. - - *data* A type declared with "data". Also boxed tuples. - - *primitive* iff it is a built-in type that can't be expressed - in Haskell. - -Currently, all primitive types are unlifted, but that's not necessarily -the case. (E.g. Int could be primitive.) - -Some primitive types are unboxed, such as Int#, whereas some are boxed -but unlifted (such as ByteArray#). The only primitive types that we -classify as algebraic are the unboxed tuples. - -examples of type classifications: - -Type primitive boxed lifted algebraic ------------------------------------------------------------------------------ -Int#, Yes No No No -ByteArray# Yes Yes No No -(# a, b #) Yes No No Yes -( a, b ) No Yes Yes Yes -[a] No Yes Yes Yes %************************************************************************ %* * -\subsection{The data type} +\subsection{Stuff to do with kinds.} %* * %************************************************************************ - -\begin{code} -type SuperKind = Type -type Kind = Type - -type TyVarSubst = TyVarEnv Type - -data Type - = TyVarTy TyVar - - | AppTy - Type -- Function is *not* a TyConApp - Type - - | TyConApp -- Application of a TyCon - TyCon -- *Invariant* saturated appliations of FunTyCon and - -- synonyms have their own constructors, below. - [Type] -- Might not be saturated. - - | FunTy -- Special case of TyConApp: TyConApp FunTyCon [t1,t2] - Type - Type - - | NoteTy -- Saturated application of a type synonym - TyNote - Type -- The expanded version - - | ForAllTy - TyVar - Type -- TypeKind - -data TyNote - = SynNote Type -- The unexpanded version of the type synonym; always a TyConApp - | FTVNote TyVarSet -- The free type variables of the noted expression - | UsgNote UsageAnn -- The usage annotation at this node - -data UsageAnn - = UsOnce -- Used at most once - | UsMany -- Used possibly many times (no info; this annotation can be omitted) - | UsVar UVar -- Annotation is variable (should only happen inside analysis) -\end{code} - - -%************************************************************************ -%* * -\subsection{Kinds} -%* * -%************************************************************************ - -Kinds -~~~~~ -k::K = Type bx - | k -> k - | kv - -kv :: KX is a kind variable - -Type :: BX -> KX - -bx::BX = Boxed - | Unboxed - | AnyBox -- Used *only* for special built-in things - -- like error :: forall (a::*?). String -> a - -- Here, the 'a' can be instantiated to a boxed or - -- unboxed type. - | bv - -bxv :: BX is a boxity variable - -sk = KX -- A kind - | BX -- A boxity - | sk -> sk -- In ptic (BX -> KX) - -\begin{code} -mk_kind_name key str = mkGlobalName key pREL_GHC (mkKindOccFS tcName str) - (LocalDef mkBuiltinSrcLoc NotExported) - -- mk_kind_name is a bit of a hack - -- The LocalDef means that we print the name without - -- a qualifier, which is what we want for these kinds. - -- It's used for both Kinds and Boxities -\end{code} - -Define KX, BX. - -\begin{code} -superKind :: SuperKind -- KX, the type of all kinds -superKindName = mk_kind_name kindConKey SLIT("KX") -superKind = TyConApp (mkSuperKindCon superKindName) [] - -superBoxity :: SuperKind -- BX, the type of all boxities -superBoxityName = mk_kind_name boxityConKey SLIT("BX") -superBoxity = TyConApp (mkSuperKindCon superBoxityName) [] -\end{code} - -Define Boxed, Unboxed, AnyBox - -\begin{code} -boxedKind, unboxedKind, anyBoxKind :: Kind -- Of superkind superBoxity - -boxedConName = mk_kind_name boxedConKey SLIT("*") -boxedKind = TyConApp (mkKindCon boxedConName superBoxity) [] - -unboxedConName = mk_kind_name unboxedConKey SLIT("#") -unboxedKind = TyConApp (mkKindCon unboxedConName superBoxity) [] - -anyBoxConName = mk_kind_name anyBoxConKey SLIT("?") -anyBoxCon = mkKindCon anyBoxConName superBoxity -- A kind of wild card -anyBoxKind = TyConApp anyBoxCon [] -\end{code} - -Define Type - -\begin{code} -typeCon :: KindCon -typeConName = mk_kind_name typeConKey SLIT("Type") -typeCon = mkKindCon typeConName (superBoxity `FunTy` superKind) -\end{code} - -Define (Type Boxed), (Type Unboxed), (Type AnyBox) - -\begin{code} -boxedTypeKind, unboxedTypeKind, openTypeKind :: Kind -boxedTypeKind = TyConApp typeCon [boxedKind] -unboxedTypeKind = TyConApp typeCon [unboxedKind] -openTypeKind = TyConApp typeCon [anyBoxKind] - -mkArrowKind :: Kind -> Kind -> Kind -mkArrowKind k1 k2 = k1 `FunTy` k2 - -mkArrowKinds :: [Kind] -> Kind -> Kind -mkArrowKinds arg_kinds result_kind = foldr mkArrowKind result_kind arg_kinds -\end{code} - \begin{code} hasMoreBoxityInfo :: Kind -> Kind -> Bool hasMoreBoxityInfo k1 k2 - | k2 == openTypeKind = ASSERT( is_type_kind k1) True + | k2 == openTypeKind = True | otherwise = k1 == k2 - where - -- Returns true for things of form (Type x) - is_type_kind k = case splitTyConApp_maybe k of - Just (tc,[_]) -> tc == typeCon - Nothing -> False -\end{code} - - -%************************************************************************ -%* * -\subsection{Wired-in type constructors -%* * -%************************************************************************ -We define a few wired-in type constructors here to avoid module knots - -\begin{code} -funTyConName = mkWiredInTyConName funTyConKey pREL_GHC SLIT("(->)") funTyCon -funTyCon = mkFunTyCon funTyConName (mkArrowKinds [boxedTypeKind, boxedTypeKind] boxedTypeKind) +defaultKind :: Kind -> Kind +-- Used when generalising: default kind '?' to '*' +defaultKind kind | kind == openTypeKind = liftedTypeKind + | otherwise = kind \end{code} - %************************************************************************ %* * \subsection{Constructor-specific functions} @@ -333,17 +160,23 @@ mkTyVarTys = map mkTyVarTy -- a common use of mkTyVarTy getTyVar :: String -> Type -> TyVar getTyVar msg (TyVarTy tv) = tv +getTyVar msg (PredTy p) = getTyVar msg (predRepTy p) getTyVar msg (NoteTy _ t) = getTyVar msg t +getTyVar msg ty@(UsageTy _ _) = pprPanic "getTyVar: UTy:" (text msg $$ pprType ty) getTyVar msg other = panic ("getTyVar: " ++ msg) getTyVar_maybe :: Type -> Maybe TyVar getTyVar_maybe (TyVarTy tv) = Just tv getTyVar_maybe (NoteTy _ t) = getTyVar_maybe t +getTyVar_maybe (PredTy p) = getTyVar_maybe (predRepTy p) +getTyVar_maybe ty@(UsageTy _ _) = pprPanic "getTyVar_maybe: UTy:" (pprType ty) getTyVar_maybe other = Nothing isTyVarTy :: Type -> Bool isTyVarTy (TyVarTy tv) = True isTyVarTy (NoteTy _ ty) = isTyVarTy ty +isTyVarTy (PredTy p) = isTyVarTy (predRepTy p) +isTyVarTy ty@(UsageTy _ _) = pprPanic "isTyVarTy: UTy:" (pprType ty) isTyVarTy other = False \end{code} @@ -356,38 +189,47 @@ invariant that a TyConApp is always visibly so. mkAppTy maintains the invariant: use it. \begin{code} -mkAppTy orig_ty1 orig_ty2 = ASSERT2( isNotUsgTy orig_ty1 && isNotUsgTy orig_ty2, pprType orig_ty1 <+> text "to" <+> pprType orig_ty2 ) - mk_app orig_ty1 +mkAppTy orig_ty1 orig_ty2 + = ASSERT( not (isPredTy orig_ty1) ) -- Predicates are of kind * + UASSERT2( not (isUTy orig_ty2), pprType orig_ty1 <+> pprType orig_ty2 ) + -- argument must be unannotated + mk_app orig_ty1 where mk_app (NoteTy _ ty1) = mk_app ty1 mk_app (TyConApp tc tys) = mkTyConApp tc (tys ++ [orig_ty2]) + mk_app ty@(UsageTy _ _) = pprPanic "mkAppTy: UTy:" (pprType ty) mk_app ty1 = AppTy orig_ty1 orig_ty2 mkAppTys :: Type -> [Type] -> Type mkAppTys orig_ty1 [] = orig_ty1 -- This check for an empty list of type arguments - -- avoids the needless of a type synonym constructor. + -- avoids the needless loss of a type synonym constructor. -- For example: mkAppTys Rational [] -- returns to (Ratio Integer), which has needlessly lost -- the Rational part. -mkAppTys orig_ty1 orig_tys2 = ASSERT2( isNotUsgTy orig_ty1, pprType orig_ty1 ) - mk_app orig_ty1 +mkAppTys orig_ty1 orig_tys2 + = ASSERT( not (isPredTy orig_ty1) ) -- Predicates are of kind * + UASSERT2( not (any isUTy orig_tys2), pprType orig_ty1 <+> fsep (map pprType orig_tys2) ) + -- arguments must be unannotated + mk_app orig_ty1 where mk_app (NoteTy _ ty1) = mk_app ty1 mk_app (TyConApp tc tys) = mkTyConApp tc (tys ++ orig_tys2) - mk_app ty1 = ASSERT2( all isNotUsgTy orig_tys2, pprType orig_ty1 <+> text "to" <+> hsep (map pprType orig_tys2) ) - foldl AppTy orig_ty1 orig_tys2 + mk_app ty@(UsageTy _ _) = pprPanic "mkAppTys: UTy:" (pprType ty) + mk_app ty1 = foldl AppTy orig_ty1 orig_tys2 splitAppTy_maybe :: Type -> Maybe (Type, Type) -splitAppTy_maybe (FunTy ty1 ty2) = Just (TyConApp funTyCon [ty1], ty2) +splitAppTy_maybe (FunTy ty1 ty2) = Just (TyConApp funTyCon [unUTy ty1], unUTy ty2) splitAppTy_maybe (AppTy ty1 ty2) = Just (ty1, ty2) splitAppTy_maybe (NoteTy _ ty) = splitAppTy_maybe ty +splitAppTy_maybe (PredTy p) = splitAppTy_maybe (predRepTy p) splitAppTy_maybe (TyConApp tc []) = Nothing splitAppTy_maybe (TyConApp tc tys) = split tys [] where split [ty2] acc = Just (TyConApp tc (reverse acc), ty2) split (ty:tys) acc = split tys (ty:acc) +splitAppTy_maybe ty@(UsageTy _ _) = pprPanic "splitAppTy_maybe: UTy:" (pprType ty) splitAppTy_maybe other = Nothing splitAppTy :: Type -> (Type, Type) @@ -400,9 +242,11 @@ splitAppTys ty = split ty ty [] where split orig_ty (AppTy ty arg) args = split ty ty (arg:args) split orig_ty (NoteTy _ ty) args = split orig_ty ty args + split orig_ty (PredTy p) args = split orig_ty (predRepTy p) args split orig_ty (FunTy ty1 ty2) args = ASSERT( null args ) - (TyConApp funTyCon [], [ty1,ty2]) + (TyConApp funTyCon [], [unUTy ty1,unUTy ty2]) split orig_ty (TyConApp tc tc_args) args = (TyConApp tc [], tc_args ++ args) + split orig_ty (UsageTy _ _) args = pprPanic "splitAppTys: UTy:" (pprType orig_ty) split orig_ty ty args = (orig_ty, args) \end{code} @@ -413,14 +257,24 @@ splitAppTys ty = split ty ty [] \begin{code} mkFunTy :: Type -> Type -> Type -mkFunTy arg res = FunTy arg res +mkFunTy arg res = UASSERT2( isUTy arg && isUTy res, pprType arg <+> pprType res ) + FunTy arg res mkFunTys :: [Type] -> Type -> Type -mkFunTys tys ty = foldr FunTy ty tys +mkFunTys tys ty = UASSERT2( all isUTy (ty:tys), fsep (map pprType (tys++[ty])) ) + foldr FunTy ty tys + +splitFunTy :: Type -> (Type, Type) +splitFunTy (FunTy arg res) = (arg, res) +splitFunTy (NoteTy _ ty) = splitFunTy ty +splitFunTy (PredTy p) = splitFunTy (predRepTy p) +splitFunTy ty@(UsageTy _ _) = pprPanic "splitFunTy: UTy:" (pprType ty) splitFunTy_maybe :: Type -> Maybe (Type, Type) splitFunTy_maybe (FunTy arg res) = Just (arg, res) splitFunTy_maybe (NoteTy _ ty) = splitFunTy_maybe ty +splitFunTy_maybe (PredTy p) = splitFunTy_maybe (predRepTy p) +splitFunTy_maybe ty@(UsageTy _ _) = pprPanic "splitFunTy_maybe: UTy:" (pprType ty) splitFunTy_maybe other = Nothing splitFunTys :: Type -> ([Type], Type) @@ -428,6 +282,8 @@ splitFunTys ty = split [] ty ty where split args orig_ty (FunTy arg res) = split (arg:args) res res split args orig_ty (NoteTy _ ty) = split args orig_ty ty + split args orig_ty (PredTy p) = split args orig_ty (predRepTy p) + split args orig_ty (UsageTy _ _) = pprPanic "splitFunTys: UTy:" (pprType orig_ty) split args orig_ty ty = (reverse args, orig_ty) splitFunTysN :: String -> Int -> Type -> ([Type], Type) @@ -436,6 +292,8 @@ splitFunTysN msg orig_n orig_ty = split orig_n [] orig_ty orig_ty split 0 args syn_ty ty = (reverse args, syn_ty) split n args syn_ty (FunTy arg res) = split (n-1) (arg:args) res res split n args syn_ty (NoteTy _ ty) = split n args syn_ty ty + split n args syn_ty (PredTy p) = split n args syn_ty (predRepTy p) + split n args syn_ty (UsageTy _ _) = pprPanic "splitFunTysN: UTy:" (pprType orig_ty) split n args syn_ty ty = pprPanic ("splitFunTysN: " ++ msg) (int orig_n <+> pprType orig_ty) zipFunTys :: Outputable a => [a] -> Type -> ([(a,Type)], Type) @@ -444,12 +302,23 @@ zipFunTys orig_xs orig_ty = split [] orig_xs orig_ty orig_ty split acc [] nty ty = (reverse acc, nty) split acc (x:xs) nty (FunTy arg res) = split ((x,arg):acc) xs res res split acc xs nty (NoteTy _ ty) = split acc xs nty ty + split acc xs nty (PredTy p) = split acc xs nty (predRepTy p) + split acc xs nty (UsageTy _ _) = pprPanic "zipFunTys: UTy:" (ppr orig_xs <+> pprType orig_ty) split acc (x:xs) nty ty = pprPanic "zipFunTys" (ppr orig_xs <+> pprType orig_ty) funResultTy :: Type -> Type funResultTy (FunTy arg res) = res funResultTy (NoteTy _ ty) = funResultTy ty +funResultTy (PredTy p) = funResultTy (predRepTy p) +funResultTy (UsageTy _ ty) = funResultTy ty funResultTy ty = pprPanic "funResultTy" (pprType ty) + +funArgTy :: Type -> Type +funArgTy (FunTy arg res) = arg +funArgTy (NoteTy _ ty) = funArgTy ty +funArgTy (PredTy p) = funArgTy (predRepTy p) +funArgTy (UsageTy _ ty) = funArgTy ty +funArgTy ty = pprPanic "funArgTy" (pprType ty) \end{code} @@ -462,10 +331,11 @@ mkTyConApp :: TyCon -> [Type] -> Type mkTyConApp tycon tys | isFunTyCon tycon && length tys == 2 = case tys of - (ty1:ty2:_) -> FunTy ty1 ty2 + (ty1:ty2:_) -> FunTy (mkUTyM ty1) (mkUTyM ty2) | otherwise = ASSERT(not (isSynTyCon tycon)) + UASSERT2( not (any isUTy tys), ppr tycon <+> fsep (map pprType tys) ) TyConApp tycon tys mkTyConTy :: TyCon -> Type @@ -476,22 +346,41 @@ mkTyConTy tycon = ASSERT( not (isSynTyCon tycon) ) -- mean a distinct type, but all other type-constructor applications -- including functions are returned as Just .. +tyConAppTyCon :: Type -> TyCon +tyConAppTyCon ty = case splitTyConApp_maybe ty of + Just (tc,_) -> tc + Nothing -> pprPanic "tyConAppTyCon" (pprType ty) + +tyConAppArgs :: Type -> [Type] +tyConAppArgs ty = case splitTyConApp_maybe ty of + Just (_,args) -> args + Nothing -> pprPanic "tyConAppArgs" (pprType ty) + +splitTyConApp :: Type -> (TyCon, [Type]) +splitTyConApp ty = case splitTyConApp_maybe ty of + Just stuff -> stuff + Nothing -> pprPanic "splitTyConApp" (pprType ty) + splitTyConApp_maybe :: Type -> Maybe (TyCon, [Type]) splitTyConApp_maybe (TyConApp tc tys) = Just (tc, tys) -splitTyConApp_maybe (FunTy arg res) = Just (funTyCon, [arg,res]) +splitTyConApp_maybe (FunTy arg res) = Just (funTyCon, [unUTy arg,unUTy res]) splitTyConApp_maybe (NoteTy _ ty) = splitTyConApp_maybe ty +splitTyConApp_maybe (PredTy p) = splitTyConApp_maybe (predRepTy p) +splitTyConApp_maybe (UsageTy _ ty) = splitTyConApp_maybe ty splitTyConApp_maybe other = Nothing -- splitAlgTyConApp_maybe looks for -- *saturated* applications of *algebraic* data types -- "Algebraic" => newtype, data type, or dictionary (not function types) --- We return the constructors too. +-- We return the constructors too, so there had better be some. splitAlgTyConApp_maybe :: Type -> Maybe (TyCon, [Type], [DataCon]) splitAlgTyConApp_maybe (TyConApp tc tys) - | isAlgTyCon tc && + | isAlgTyCon tc && tyConArity tc == length tys = Just (tc, tys, tyConDataCons tc) splitAlgTyConApp_maybe (NoteTy _ ty) = splitAlgTyConApp_maybe ty +splitAlgTyConApp_maybe (PredTy p) = splitAlgTyConApp_maybe (predRepTy p) +splitAlgTyConApp_maybe (UsageTy _ ty)= splitAlgTyConApp_maybe ty splitAlgTyConApp_maybe other = Nothing splitAlgTyConApp :: Type -> (TyCon, [Type], [DataCon]) @@ -499,56 +388,13 @@ splitAlgTyConApp :: Type -> (TyCon, [Type], [DataCon]) splitAlgTyConApp (TyConApp tc tys) = ASSERT( isAlgTyCon tc && tyConArity tc == length tys ) (tc, tys, tyConDataCons tc) splitAlgTyConApp (NoteTy _ ty) = splitAlgTyConApp ty +splitAlgTyConApp (PredTy p) = splitAlgTyConApp (predRepTy p) +splitAlgTyConApp (UsageTy _ ty) = splitAlgTyConApp ty +#ifdef DEBUG +splitAlgTyConApp ty = pprPanic "splitAlgTyConApp" (pprType ty) +#endif \end{code} -"Dictionary" types are just ordinary data types, but you can -tell from the type constructor whether it's a dictionary or not. - -\begin{code} -mkDictTy :: Class -> [Type] -> Type -mkDictTy clas tys = TyConApp (classTyCon clas) tys - -splitDictTy_maybe :: Type -> Maybe (Class, [Type]) -splitDictTy_maybe (TyConApp tc tys) - | maybeToBool maybe_class - && tyConArity tc == length tys = Just (clas, tys) - where - maybe_class = tyConClass_maybe tc - Just clas = maybe_class - -splitDictTy_maybe (NoteTy _ ty) = splitDictTy_maybe ty -splitDictTy_maybe other = Nothing - -isDictTy :: Type -> Bool - -- This version is slightly more efficient than (maybeToBool . splitDictTy) -isDictTy (TyConApp tc tys) - | maybeToBool (tyConClass_maybe tc) - && tyConArity tc == length tys - = True -isDictTy (NoteTy _ ty) = isDictTy ty -isDictTy other = False -\end{code} - -splitRepTyConApp_maybe is like splitTyConApp_maybe except -that it looks through - (a) for-alls, and - (b) newtypes -in addition to synonyms. It's useful in the back end where we're not -interested in newtypes anymore. - -\begin{code} -splitRepTyConApp_maybe :: Type -> Maybe (TyCon, [Type]) -splitRepTyConApp_maybe (FunTy arg res) = Just (funTyCon, [arg,res]) -splitRepTyConApp_maybe (NoteTy _ ty) = splitRepTyConApp_maybe ty -splitRepTyConApp_maybe (ForAllTy _ ty) = splitRepTyConApp_maybe ty -splitRepTyConApp_maybe (TyConApp tc tys) - | isNewTyCon tc - = case splitFunTy_maybe (applyTys (dataConType (head (tyConDataCons tc))) tys) of - Just (rep_ty, _) -> splitRepTyConApp_maybe rep_ty - | otherwise - = Just (tc,tys) -splitRepTyConApp_maybe other = Nothing -\end{code} --------------------------------------------------------------------- SynTy @@ -557,23 +403,26 @@ splitRepTyConApp_maybe other = Nothing \begin{code} mkSynTy syn_tycon tys = ASSERT( isSynTyCon syn_tycon ) - ASSERT( isNotUsgTy body ) + ASSERT( length tyvars == length tys ) NoteTy (SynNote (TyConApp syn_tycon tys)) (substTy (mkTyVarSubst tyvars tys) body) where (tyvars, body) = getSynTyConDefn syn_tycon -isSynTy (NoteTy (SynNote _) _) = True -isSynTy other = False - deNoteType :: Type -> Type - -- Sorry for the cute name + -- Remove synonyms, but not Preds deNoteType ty@(TyVarTy tyvar) = ty deNoteType (TyConApp tycon tys) = TyConApp tycon (map deNoteType tys) +deNoteType (PredTy p) = PredTy (deNotePred p) deNoteType (NoteTy _ ty) = deNoteType ty deNoteType (AppTy fun arg) = AppTy (deNoteType fun) (deNoteType arg) deNoteType (FunTy fun arg) = FunTy (deNoteType fun) (deNoteType arg) deNoteType (ForAllTy tv ty) = ForAllTy tv (deNoteType ty) +deNoteType (UsageTy u ty) = UsageTy u (deNoteType ty) + +deNotePred :: PredType -> PredType +deNotePred (ClassP c tys) = ClassP c (map deNoteType tys) +deNotePred (IParam n ty) = IParam n (deNoteType ty) \end{code} Notes on type synonyms @@ -591,74 +440,55 @@ The reason is that we then get better (shorter) type signatures in interfaces. Notably this plays a role in tcTySigs in TcBinds.lhs. + Representation types + ~~~~~~~~~~~~~~~~~~~~ - ---------------------------------------------------------------------- - UsgNote - ~~~~~~~ - -NB: Invariant: if present, usage note is at the very top of the type. -This should be carefully preserved. - -In some parts of the compiler, comments use the _Once Upon a -Polymorphic Type_ (POPL'99) usage of "sigma = usage-annotated type; -tau = un-usage-annotated type"; unfortunately this conflicts with the -rho/tau/theta/sigma usage in the rest of the compiler. -(KSW 1999-04) +repType looks through + (a) for-alls, and + (b) newtypes + (c) synonyms + (d) predicates + (e) usage annotations +It's useful in the back end where we're not +interested in newtypes anymore. \begin{code} -mkUsgTy :: UsageAnn -> Type -> Type -#ifndef USMANY -mkUsgTy UsMany ty = ASSERT2( isNotUsgTy ty, pprType ty ) - ty -#endif -mkUsgTy usg ty = ASSERT2( isNotUsgTy ty, pprType ty ) - NoteTy (UsgNote usg) ty - --- The isUsgTy function is utterly useless if UsManys are omitted. --- Be warned! KSW 1999-04. -isUsgTy :: Type -> Bool -#ifndef USMANY -isUsgTy _ = True -#else -isUsgTy (NoteTy (UsgNote _) _) = True -isUsgTy other = False -#endif - --- The isNotUsgTy function may return a false True if UsManys are omitted; --- in other words, A SSERT( isNotUsgTy ty ) may be useful but --- A SSERT( not (isNotUsg ty) ) is asking for trouble. KSW 1999-04. -isNotUsgTy :: Type -> Bool -isNotUsgTy (NoteTy (UsgNote _) _) = False -isNotUsgTy other = True - --- splitUsgTy_maybe is not exported, since it is meaningless if --- UsManys are omitted. It is used in several places in this module, --- however. KSW 1999-04. -splitUsgTy_maybe :: Type -> Maybe (UsageAnn,Type) -splitUsgTy_maybe (NoteTy (UsgNote usg) ty2) = ASSERT( isNotUsgTy ty2 ) - Just (usg,ty2) -splitUsgTy_maybe ty = Nothing - -splitUsgTy :: Type -> (UsageAnn,Type) -splitUsgTy ty = case splitUsgTy_maybe ty of - Just ans -> ans - Nothing -> -#ifndef USMANY - (UsMany,ty) -#else - pprPanic "splitUsgTy: no usage annot:" $ pprType ty -#endif - -tyUsg :: Type -> UsageAnn -tyUsg = fst . splitUsgTy +repType :: Type -> Type +repType (ForAllTy _ ty) = repType ty +repType (NoteTy _ ty) = repType ty +repType (PredTy p) = repType (predRepTy p) +repType (UsageTy _ ty) = repType ty +repType ty = case splitNewType_maybe ty of + Just ty' -> repType ty' -- Still re-apply repType in case of for-all + Nothing -> ty + +splitRepFunTys :: Type -> ([Type], Type) +-- Like splitFunTys, but looks through newtypes and for-alls +splitRepFunTys ty = split [] (repType ty) + where + split args (FunTy arg res) = split (arg:args) (repType res) + split args ty = (reverse args, ty) -unUsgTy :: Type -> Type --- strip outer usage annotation if present -unUsgTy ty = case splitUsgTy_maybe ty of - Just (_,ty1) -> ASSERT2( isNotUsgTy ty1, pprType ty ) - ty1 - Nothing -> ty +typePrimRep :: Type -> PrimRep +typePrimRep ty = case repType ty of + TyConApp tc _ -> tyConPrimRep tc + FunTy _ _ -> PtrRep + AppTy _ _ -> PtrRep -- ?? + TyVarTy _ -> PtrRep + +splitNewType_maybe :: Type -> Maybe Type +-- Find the representation of a newtype, if it is one +-- Looks through multiple levels of newtype, but does not look through for-alls +splitNewType_maybe (NoteTy _ ty) = splitNewType_maybe ty +splitNewType_maybe (PredTy p) = splitNewType_maybe (predRepTy p) +splitNewType_maybe (UsageTy _ ty) = splitNewType_maybe ty +splitNewType_maybe (TyConApp tc tys) = case newTyConRep tc of + Just rep_ty -> ASSERT( length tys == tyConArity tc ) + -- The assert should hold because repType should + -- only be applied to *types* (of kind *) + Just (applyTys rep_ty tys) + Nothing -> Nothing +splitNewType_maybe other = Nothing \end{code} @@ -667,143 +497,365 @@ unUsgTy ty = case splitUsgTy_maybe ty of ForAllTy ~~~~~~~~ -We need to be clever here with usage annotations; they need to be -lifted or lowered through the forall as appropriate. - \begin{code} mkForAllTy :: TyVar -> Type -> Type -mkForAllTy tyvar ty = case splitUsgTy_maybe ty of - Just (usg,ty') -> NoteTy (UsgNote usg) - (ForAllTy tyvar ty') - Nothing -> ForAllTy tyvar ty +mkForAllTy tyvar ty + = mkForAllTys [tyvar] ty mkForAllTys :: [TyVar] -> Type -> Type -mkForAllTys tyvars ty = case splitUsgTy_maybe ty of - Just (usg,ty') -> NoteTy (UsgNote usg) - (foldr ForAllTy ty' tyvars) - Nothing -> foldr ForAllTy ty tyvars +mkForAllTys tyvars ty + = case splitUTy_maybe ty of + Just (u,ty1) -> UASSERT2( not (mkVarSet tyvars `intersectsVarSet` tyVarsOfType u), + ptext SLIT("mkForAllTys: usage scope") + <+> ppr tyvars <+> pprType ty ) + mkUTy u (foldr ForAllTy ty1 tyvars) -- we lift usage annotations over foralls + Nothing -> foldr ForAllTy ty tyvars + +isForAllTy :: Type -> Bool +isForAllTy (NoteTy _ ty) = isForAllTy ty +isForAllTy (ForAllTy _ _) = True +isForAllTy (UsageTy _ ty) = isForAllTy ty +isForAllTy other_ty = False splitForAllTy_maybe :: Type -> Maybe (TyVar, Type) -splitForAllTy_maybe ty = case splitUsgTy_maybe ty of - Just (usg,ty') -> do (tyvar,ty'') <- splitFAT_m ty' - return (tyvar, NoteTy (UsgNote usg) ty'') - Nothing -> splitFAT_m ty +splitForAllTy_maybe ty = splitFAT_m ty where - splitFAT_m (NoteTy _ ty) = splitFAT_m ty - splitFAT_m (ForAllTy tyvar ty) = Just(tyvar, ty) - splitFAT_m _ = Nothing - -isForAllTy :: Type -> Bool -isForAllTy (NoteTy _ ty) = isForAllTy ty -isForAllTy (ForAllTy tyvar ty) = True -isForAllTy _ = False + splitFAT_m (NoteTy _ ty) = splitFAT_m ty + splitFAT_m (PredTy p) = splitFAT_m (predRepTy p) + splitFAT_m (ForAllTy tyvar ty) = Just(tyvar, ty) + splitFAT_m (UsageTy _ ty) = splitFAT_m ty + splitFAT_m _ = Nothing splitForAllTys :: Type -> ([TyVar], Type) -splitForAllTys ty = case splitUsgTy_maybe ty of - Just (usg,ty') -> let (tvs,ty'') = split ty' ty' [] - in (tvs, NoteTy (UsgNote usg) ty'') - Nothing -> split ty ty [] +splitForAllTys ty = split ty ty [] where - split orig_ty (ForAllTy tv ty) tvs = split ty ty (tv:tvs) - split orig_ty (NoteTy _ ty) tvs = split orig_ty ty tvs - split orig_ty t tvs = (reverse tvs, orig_ty) + split orig_ty (ForAllTy tv ty) tvs = split ty ty (tv:tvs) + split orig_ty (NoteTy _ ty) tvs = split orig_ty ty tvs + split orig_ty (PredTy p) tvs = split orig_ty (predRepTy p) tvs + split orig_ty (UsageTy _ ty) tvs = split orig_ty ty tvs + split orig_ty t tvs = (reverse tvs, orig_ty) \end{code} -@mkPiType@ makes a (->) type or a forall type, depending on whether -it is given a type variable or a term variable. +-- (mkPiType now in CoreUtils) -\begin{code} -mkPiType :: IdOrTyVar -> Type -> Type -- The more polymorphic version doesn't work... -mkPiType v ty | isId v = mkFunTy (idType v) ty - | otherwise = mkForAllTy v ty -\end{code} - -Applying a for-all to its arguments +Applying a for-all to its arguments. Lift usage annotation as required. \begin{code} applyTy :: Type -> Type -> Type -applyTy (NoteTy note@(UsgNote _) fun) arg = NoteTy note (applyTy fun arg) -applyTy (NoteTy _ fun) arg = applyTy fun arg -applyTy (ForAllTy tv ty) arg = ASSERT( isNotUsgTy arg ) - substTy (mkTyVarSubst [tv] [arg]) ty -applyTy other arg = panic "applyTy" +applyTy (PredTy p) arg = applyTy (predRepTy p) arg +applyTy (NoteTy _ fun) arg = applyTy fun arg +applyTy (ForAllTy tv ty) arg = UASSERT2( not (isUTy arg), + ptext SLIT("applyTy") + <+> pprType ty <+> pprType arg ) + substTy (mkTyVarSubst [tv] [arg]) ty +applyTy (UsageTy u ty) arg = UsageTy u (applyTy ty arg) +applyTy other arg = panic "applyTy" applyTys :: Type -> [Type] -> Type applyTys fun_ty arg_tys - = substTy (mkTyVarSubst tvs arg_tys) ty + = UASSERT2( not (any isUTy arg_tys), ptext SLIT("applyTys") <+> pprType fun_ty ) + (case mu of + Just u -> UsageTy u + Nothing -> id) $ + substTy (mkTyVarSubst tvs arg_tys) ty where - (tvs, ty) = split fun_ty arg_tys + (mu, tvs, ty) = split fun_ty arg_tys - split fun_ty [] = ([], fun_ty) + split fun_ty [] = (Nothing, [], fun_ty) split (NoteTy _ fun_ty) args = split fun_ty args - split (ForAllTy tv fun_ty) (arg:args) = ASSERT2( isNotUsgTy arg, vcat (map pprType arg_tys) $$ - text "in application of" <+> pprType fun_ty) - case split fun_ty args of - (tvs, ty) -> (tv:tvs, ty) + split (PredTy p) args = split (predRepTy p) args + split (ForAllTy tv fun_ty) (arg:args) = case split fun_ty args of + (mu, tvs, ty) -> (mu, tv:tvs, ty) + split (UsageTy u ty) args = case split ty args of + (Nothing, tvs, ty) -> (Just u, tvs, ty) + (Just _ , _ , _ ) -> pprPanic "applyTys:" + (pprType fun_ty) split other_ty args = panic "applyTys" +\end{code} -{- OLD version with bogus usage stuff +\begin{code} +hoistForAllTys :: Type -> Type + -- Move all the foralls to the top + -- e.g. T -> forall a. a ==> forall a. T -> a + -- Careful: LOSES USAGE ANNOTATIONS! +hoistForAllTys ty + = case hoist ty of { (tvs, body) -> mkForAllTys tvs body } + where + hoist :: Type -> ([TyVar], Type) + hoist ty = case splitFunTys ty of { (args, res) -> + case splitForAllTys res of { + ([], body) -> ([], ty) ; + (tvs1, body1) -> case hoist body1 of { (tvs2,body2) -> + (tvs1 ++ tvs2, mkFunTys args body2) + }}} +\end{code} - ************* CHECK WITH KEITH ************** - go env ty [] = substTy (mkVarEnv env) ty - go env (NoteTy note@(UsgNote _) fun) - args = NoteTy note (go env fun args) - go env (NoteTy _ fun) args = go env fun args - go env (ForAllTy tv ty) (arg:args) = go ((tv,arg):env) ty args - go env other args = panic "applyTys" --} +--------------------------------------------------------------------- + UsageTy + ~~~~~~~ + +Constructing and taking apart usage types. + +\begin{code} +mkUTy :: Type -> Type -> Type +mkUTy u ty + = ASSERT2( typeKind u == usageTypeKind, ptext SLIT("mkUTy:") <+> pprType u <+> pprType ty ) + UASSERT2( not (isUTy ty), ptext SLIT("mkUTy:") <+> pprType u <+> pprType ty ) + -- if u == usMany then ty else : ToDo? KSW 2000-10 +#ifdef DO_USAGES + UsageTy u ty +#else + ty +#endif + +splitUTy :: Type -> (Type {- :: $ -}, Type) +splitUTy orig_ty + = case splitUTy_maybe orig_ty of + Just (u,ty) -> (u,ty) +#ifdef DO_USAGES + Nothing -> pprPanic "splitUTy:" (pprType orig_ty) +#else + Nothing -> (usMany,orig_ty) -- default annotation ToDo KSW 2000-10 +#endif + +splitUTy_maybe :: Type -> Maybe (Type {- :: $ -}, Type) +splitUTy_maybe (UsageTy u ty) = Just (u,ty) +splitUTy_maybe (NoteTy _ ty) = splitUTy_maybe ty +splitUTy_maybe other_ty = Nothing + +isUTy :: Type -> Bool + -- has usage annotation +isUTy = maybeToBool . splitUTy_maybe + +uaUTy :: Type -> Type + -- extract annotation +uaUTy = fst . splitUTy + +unUTy :: Type -> Type + -- extract unannotated type +unUTy = snd . splitUTy +\end{code} + +\begin{code} +liftUTy :: (Type -> Type) -> Type -> Type + -- lift outer usage annot over operation on unannotated types +liftUTy f ty + = let + (u,ty') = splitUTy ty + in + mkUTy u (f ty') +\end{code} + +\begin{code} +mkUTyM :: Type -> Type + -- put TOP (no info) annotation on unannotated type +mkUTyM ty = mkUTy usMany ty +\end{code} + +\begin{code} +isUsageKind :: Kind -> Bool +isUsageKind k + = ASSERT( typeKind k == superKind ) + k == usageTypeKind + +isUsage :: Type -> Bool +isUsage ty + = isUsageKind (typeKind ty) + +isUTyVar :: Var -> Bool +isUTyVar v + = isUsageKind (tyVarKind v) \end{code} -Note that we allow applications to be of usage-annotated- types, as an -extension: we handle them by lifting the annotation outside. The -argument, however, must still be unannotated. %************************************************************************ %* * -\subsection{Stuff to do with the source-language types} +\subsection{Predicates} %* * %************************************************************************ +"Dictionary" types are just ordinary data types, but you can +tell from the type constructor whether it's a dictionary or not. + \begin{code} -type RhoType = Type -type TauType = Type -type ThetaType = [(Class, [Type])] -type SigmaType = Type +mkClassPred clas tys = UASSERT2( not (any isUTy tys), ppr clas <+> fsep (map pprType tys) ) + ClassP clas tys + +isClassPred (ClassP clas tys) = True +isClassPred other = False + +isIPPred (IParam _ _) = True +isIPPred other = False + +isTyVarClassPred (ClassP clas tys) = all isTyVarTy tys +isTyVarClassPred other = False + +getClassPredTys_maybe :: PredType -> Maybe (Class, [Type]) +getClassPredTys_maybe (ClassP clas tys) = Just (clas, tys) +getClassPredTys_maybe _ = Nothing + +getClassPredTys :: PredType -> (Class, [Type]) +getClassPredTys (ClassP clas tys) = (clas, tys) + +inheritablePred :: PredType -> Bool +-- Can be inherited by a context. For example, consider +-- f x = let g y = (?v, y+x) +-- in (g 3 with ?v = 8, +-- g 4 with ?v = 9) +-- The point is that g's type must be quantifed over ?v: +-- g :: (?v :: a) => a -> a +-- but it doesn't need to be quantified over the Num a dictionary +-- which can be free in g's rhs, and shared by both calls to g +inheritablePred (ClassP _ _) = True +inheritablePred other = False + +predMentionsIPs :: PredType -> NameSet -> Bool +predMentionsIPs (IParam n _) ns = n `elemNameSet` ns +predMentionsIPs other ns = False + +mkDictTy :: Class -> [Type] -> Type +mkDictTy clas tys = UASSERT2( not (any isUTy tys), ppr clas <+> fsep (map pprType tys) ) + mkPredTy (ClassP clas tys) + +mkPredTy :: PredType -> Type +mkPredTy pred = PredTy pred + +mkPredTys :: ThetaType -> [Type] +mkPredTys preds = map PredTy preds + +predTyUnique :: PredType -> Unique +predTyUnique (IParam n _) = getUnique n +predTyUnique (ClassP clas tys) = getUnique clas + +predRepTy :: PredType -> Type +-- Convert a predicate to its "representation type"; +-- the type of evidence for that predicate, which is actually passed at runtime +predRepTy (ClassP clas tys) = TyConApp (classTyCon clas) tys +predRepTy (IParam n ty) = ty + +isPredTy :: Type -> Bool +isPredTy (NoteTy _ ty) = isPredTy ty +isPredTy (PredTy _) = True +isPredTy (UsageTy _ ty)= isPredTy ty +isPredTy _ = False + +isDictTy :: Type -> Bool +isDictTy (NoteTy _ ty) = isDictTy ty +isDictTy (PredTy (ClassP _ _)) = True +isDictTy (UsageTy _ ty) = isDictTy ty +isDictTy other = False + +splitPredTy_maybe :: Type -> Maybe PredType +splitPredTy_maybe (NoteTy _ ty) = splitPredTy_maybe ty +splitPredTy_maybe (PredTy p) = Just p +splitPredTy_maybe (UsageTy _ ty)= splitPredTy_maybe ty +splitPredTy_maybe other = Nothing + +splitDictTy :: Type -> (Class, [Type]) +splitDictTy (NoteTy _ ty) = splitDictTy ty +splitDictTy (PredTy (ClassP clas tys)) = (clas, tys) + +splitDictTy_maybe :: Type -> Maybe (Class, [Type]) +splitDictTy_maybe (NoteTy _ ty) = splitDictTy_maybe ty +splitDictTy_maybe (PredTy (ClassP clas tys)) = Just (clas, tys) +splitDictTy_maybe other = Nothing + +splitDFunTy :: Type -> ([TyVar], [PredType], Class, [Type]) +-- Split the type of a dictionary function +splitDFunTy ty + = case splitSigmaTy ty of { (tvs, theta, tau) -> + case splitDictTy tau of { (clas, tys) -> + (tvs, theta, clas, tys) }} + +namesOfDFunHead :: Type -> NameSet +-- Find the free type constructors and classes +-- of the head of the dfun instance type +-- The 'dfun_head_type' is because of +-- instance Foo a => Baz T where ... +-- The decl is an orphan if Baz and T are both not locally defined, +-- even if Foo *is* locally defined +namesOfDFunHead dfun_ty = case splitSigmaTy dfun_ty of + (tvs,_,head_ty) -> delListFromNameSet (namesOfType head_ty) + (map getName tvs) + +mkPredName :: Unique -> SrcLoc -> PredType -> Name +mkPredName uniq loc (ClassP cls tys) = mkLocalName uniq (mkDictOcc (getOccName cls)) loc +mkPredName uniq loc (IParam name ty) = name \end{code} +%************************************************************************ +%* * +\subsection{Tau, sigma and rho} +%* * +%************************************************************************ + @isTauTy@ tests for nested for-alls. \begin{code} isTauTy :: Type -> Bool -isTauTy (TyVarTy v) = True +isTauTy (TyVarTy v) = True isTauTy (TyConApp _ tys) = all isTauTy tys -isTauTy (AppTy a b) = isTauTy a && isTauTy b -isTauTy (FunTy a b) = isTauTy a && isTauTy b -isTauTy (NoteTy _ ty) = isTauTy ty -isTauTy other = False +isTauTy (AppTy a b) = isTauTy a && isTauTy b +isTauTy (FunTy a b) = isTauTy a && isTauTy b +isTauTy (PredTy p) = isTauTy (predRepTy p) +isTauTy (NoteTy _ ty) = isTauTy ty +isTauTy (UsageTy _ ty) = isTauTy ty +isTauTy other = False \end{code} \begin{code} -mkRhoTy :: [(Class, [Type])] -> Type -> Type -mkRhoTy theta ty = foldr (\(c,t) r -> FunTy (mkDictTy c t) r) ty theta +mkRhoTy :: [PredType] -> Type -> Type +mkRhoTy theta ty = UASSERT2( not (isUTy ty), pprType ty ) + foldr (\p r -> FunTy (mkUTyM (mkPredTy p)) (mkUTyM r)) ty theta -splitRhoTy :: Type -> ([(Class, [Type])], Type) +splitRhoTy :: Type -> ([PredType], Type) splitRhoTy ty = split ty ty [] where - split orig_ty (FunTy arg res) ts = case splitDictTy_maybe arg of - Just pair -> split res res (pair:ts) - Nothing -> (reverse ts, orig_ty) - split orig_ty (NoteTy _ ty) ts = split orig_ty ty ts - split orig_ty ty ts = (reverse ts, orig_ty) + split orig_ty (FunTy arg res) ts = case splitPredTy_maybe arg of + Just p -> split res res (p:ts) + Nothing -> (reverse ts, orig_ty) + split orig_ty (NoteTy _ ty) ts = split orig_ty ty ts + split orig_ty (UsageTy _ ty) ts = split orig_ty ty ts + split orig_ty ty ts = (reverse ts, orig_ty) +\end{code} + +The type of a method for class C is always of the form: + Forall a1..an. C a1..an => sig_ty +where sig_ty is the type given by the method's signature, and thus in general +is a ForallTy. At the point that splitMethodTy is called, it is expected +that the outer Forall has already been stripped off. splitMethodTy then +returns (C a1..an, sig_ty') where sig_ty' is sig_ty with any Notes or +Usages stripped off. + +\begin{code} +splitMethodTy :: Type -> (PredType, Type) +splitMethodTy ty = split ty + where + split (FunTy arg res) = case splitPredTy_maybe arg of + Just p -> (p, res) + Nothing -> panic "splitMethodTy" + split (NoteTy _ ty) = split ty + split (UsageTy _ ty) = split ty + split _ = panic "splitMethodTy" \end{code} +isSigmaType returns true of any qualified type. It doesn't *necessarily* have +any foralls. E.g. + f :: (?x::Int) => Int -> Int \begin{code} mkSigmaTy tyvars theta tau = mkForAllTys tyvars (mkRhoTy theta tau) -splitSigmaTy :: Type -> ([TyVar], [(Class, [Type])], Type) +isSigmaTy :: Type -> Bool +isSigmaTy (ForAllTy tyvar ty) = True +isSigmaTy (FunTy a b) = isPredTy a +isSigmaTy (NoteTy _ ty) = isSigmaTy ty +isSigmaTy (UsageTy _ ty) = isSigmaTy ty +isSigmaTy _ = False + +splitSigmaTy :: Type -> ([TyVar], [PredType], Type) splitSigmaTy ty = (tyvars, theta, tau) where @@ -811,6 +863,19 @@ splitSigmaTy ty = (theta,tau) = splitRhoTy rho \end{code} +\begin{code} +getDFunTyKey :: Type -> OccName -- Get some string from a type, to be used to + -- construct a dictionary function name +getDFunTyKey (TyVarTy tv) = getOccName tv +getDFunTyKey (TyConApp tc _) = getOccName tc +getDFunTyKey (AppTy fun _) = getDFunTyKey fun +getDFunTyKey (NoteTy _ t) = getDFunTyKey t +getDFunTyKey (FunTy arg _) = getOccName funTyCon +getDFunTyKey (ForAllTy _ t) = getDFunTyKey t +getDFunTyKey (UsageTy _ t) = getDFunTyKey t +-- PredTy shouldn't happen +\end{code} + %************************************************************************ %* * @@ -827,13 +892,25 @@ typeKind :: Type -> Kind typeKind (TyVarTy tyvar) = tyVarKind tyvar typeKind (TyConApp tycon tys) = foldr (\_ k -> funResultTy k) (tyConKind tycon) tys typeKind (NoteTy _ ty) = typeKind ty +typeKind (PredTy _) = liftedTypeKind -- Predicates are always + -- represented by lifted types typeKind (AppTy fun arg) = funResultTy (typeKind fun) -typeKind (FunTy arg res) = boxedTypeKind -- A function is boxed regardless of its result type - -- No functions at the type level, hence we don't need - -- to say (typeKind res). +typeKind (FunTy arg res) = fix_up (typeKind res) + where + fix_up (TyConApp tycon _) | tycon == typeCon + || tycon == openKindCon = liftedTypeKind + fix_up (NoteTy _ kind) = fix_up kind + fix_up kind = kind + -- The basic story is + -- typeKind (FunTy arg res) = typeKind res + -- But a function is lifted regardless of its result type + -- Hence the strange fix-up. + -- Note that 'res', being the result of a FunTy, can't have + -- a strange kind like (*->*). typeKind (ForAllTy tv ty) = typeKind ty +typeKind (UsageTy _ ty) = typeKind ty -- we don't have separate kinds for ann/unann \end{code} @@ -841,26 +918,32 @@ typeKind (ForAllTy tv ty) = typeKind ty Free variables of a type ~~~~~~~~~~~~~~~~~~~~~~~~ \begin{code} -tyVarsOfType :: Type -> TyVarSet +tyVarsOfType :: Type -> TyVarSet tyVarsOfType (TyVarTy tv) = unitVarSet tv tyVarsOfType (TyConApp tycon tys) = tyVarsOfTypes tys tyVarsOfType (NoteTy (FTVNote tvs) ty2) = tvs tyVarsOfType (NoteTy (SynNote ty1) ty2) = tyVarsOfType ty1 -tyVarsOfType (NoteTy (UsgNote _) ty) = tyVarsOfType ty +tyVarsOfType (PredTy p) = tyVarsOfPred p tyVarsOfType (FunTy arg res) = tyVarsOfType arg `unionVarSet` tyVarsOfType res tyVarsOfType (AppTy fun arg) = tyVarsOfType fun `unionVarSet` tyVarsOfType arg tyVarsOfType (ForAllTy tyvar ty) = tyVarsOfType ty `minusVarSet` unitVarSet tyvar +tyVarsOfType (UsageTy u ty) = tyVarsOfType u `unionVarSet` tyVarsOfType ty tyVarsOfTypes :: [Type] -> TyVarSet tyVarsOfTypes tys = foldr (unionVarSet.tyVarsOfType) emptyVarSet tys +tyVarsOfPred :: PredType -> TyVarSet +tyVarsOfPred (ClassP clas tys) = tyVarsOfTypes tys +tyVarsOfPred (IParam n ty) = tyVarsOfType ty + +tyVarsOfTheta :: ThetaType -> TyVarSet +tyVarsOfTheta = foldr (unionVarSet . tyVarsOfPred) emptyVarSet + -- Add a Note with the free tyvars to the top of the type --- (but under a usage if there is one) addFreeTyVars :: Type -> Type -addFreeTyVars (NoteTy note@(UsgNote _) ty) = NoteTy note (addFreeTyVars ty) -addFreeTyVars ty@(NoteTy (FTVNote _) _) = ty -addFreeTyVars ty = NoteTy (FTVNote (tyVarsOfType ty)) ty +addFreeTyVars ty@(NoteTy (FTVNote _) _) = ty +addFreeTyVars ty = NoteTy (FTVNote (tyVarsOfType ty)) ty -- Find the free names of a type, including the type constructors and classes it mentions namesOfType :: Type -> NameSet @@ -869,13 +952,38 @@ namesOfType (TyConApp tycon tys) = unitNameSet (getName tycon) `unionNameSets` namesOfTypes tys namesOfType (NoteTy (SynNote ty1) ty2) = namesOfType ty1 namesOfType (NoteTy other_note ty2) = namesOfType ty2 +namesOfType (PredTy p) = namesOfType (predRepTy p) namesOfType (FunTy arg res) = namesOfType arg `unionNameSets` namesOfType res namesOfType (AppTy fun arg) = namesOfType fun `unionNameSets` namesOfType arg -namesOfType (ForAllTy tyvar ty) = namesOfType ty `minusNameSet` unitNameSet (getName tyvar) +namesOfType (ForAllTy tyvar ty) = namesOfType ty `delFromNameSet` getName tyvar +namesOfType (UsageTy u ty) = namesOfType u `unionNameSets` namesOfType ty namesOfTypes tys = foldr (unionNameSets . namesOfType) emptyNameSet tys \end{code} +Usage annotations of a type +~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Get a list of usage annotations of a type, *in left-to-right pre-order*. + +\begin{code} +usageAnnOfType :: Type -> [Type] +usageAnnOfType ty + = goS ty + where + goT (TyVarTy _) = [] + goT (AppTy ty1 ty2) = goT ty1 ++ goT ty2 + goT (TyConApp tc tys) = concatMap goT tys + goT (FunTy sty1 sty2) = goS sty1 ++ goS sty2 + goT (ForAllTy mv ty) = goT ty + goT (PredTy p) = goT (predRepTy p) + goT ty@(UsageTy _ _) = pprPanic "usageAnnOfType: unexpected usage:" (pprType ty) + goT (NoteTy note ty) = goT ty + + goS sty = case splitUTy sty of + (u,tty) -> u : goT tty +\end{code} + %************************************************************************ %* * @@ -910,8 +1018,16 @@ tidyTyVar env@(tidy_env, subst) tyvar where name = tyVarName tyvar +tidyTyVars :: TidyEnv -> [TyVar] -> (TidyEnv, [TyVar]) tidyTyVars env tyvars = mapAccumL tidyTyVar env tyvars +tidyFreeTyVars :: TidyEnv -> TyVarSet -> TidyEnv +-- Add the free tyvars to the env in tidy form, +-- so that we can tidy the type they are free in +tidyFreeTyVars env tyvars = foldl add env (varSetElems tyvars) + where + add env tv = fst (tidyTyVar env tv) + tidyType :: TidyEnv -> Type -> Type tidyType env@(tidy_env, subst) ty = go ty @@ -921,22 +1037,27 @@ tidyType env@(tidy_env, subst) ty Just tv' -> TyVarTy tv' go (TyConApp tycon tys) = let args = map go tys in args `seqList` TyConApp tycon args - go (NoteTy note ty) = (NoteTy $! (go_note note)) $! (go ty) - go (AppTy fun arg) = (AppTy $! (go fun)) $! (go arg) - go (FunTy fun arg) = (FunTy $! (go fun)) $! (go arg) - go (ForAllTy tv ty) = ForAllTy tv' $! (tidyType env' ty) - where - (env', tv') = tidyTyVar env tv + go (NoteTy note ty) = (NoteTy SAPPLY (go_note note)) SAPPLY (go ty) + go (PredTy p) = PredTy (tidyPred env p) + go (AppTy fun arg) = (AppTy SAPPLY (go fun)) SAPPLY (go arg) + go (FunTy fun arg) = (FunTy SAPPLY (go fun)) SAPPLY (go arg) + go (ForAllTy tv ty) = ForAllTy tvp SAPPLY (tidyType envp ty) + where + (envp, tvp) = tidyTyVar env tv + go (UsageTy u ty) = (UsageTy SAPPLY (go u)) SAPPLY (go ty) - go_note (SynNote ty) = SynNote $! (go ty) + go_note (SynNote ty) = SynNote SAPPLY (go ty) go_note note@(FTVNote ftvs) = note -- No need to tidy the free tyvars - go_note note@(UsgNote _) = note -- Usage annotation is already tidy -tidyTypes env tys = map (tidyType env) tys +tidyTypes env tys = map (tidyType env) tys + +tidyPred :: TidyEnv -> PredType -> PredType +tidyPred env (ClassP clas tys) = ClassP clas (tidyTypes env tys) +tidyPred env (IParam n ty) = IParam n (tidyType env ty) \end{code} -@tidyOpenType@ grabs the free type varibles, tidies them +@tidyOpenType@ grabs the free type variables, tidies them and then uses @tidyType@ to work over the type itself \begin{code} @@ -944,8 +1065,7 @@ tidyOpenType :: TidyEnv -> Type -> (TidyEnv, Type) tidyOpenType env ty = (env', tidyType env' ty) where - env' = foldl go env (varSetElems (tyVarsOfType ty)) - go env tyvar = fst (tidyTyVar env tyvar) + env' = tidyFreeTyVars env (tyVarsOfType ty) tidyOpenTypes :: TidyEnv -> [Type] -> (TidyEnv, [Type]) tidyOpenTypes env tys = mapAccumL tidyOpenType env tys @@ -955,20 +1075,26 @@ tidyTopType ty = tidyType emptyTidyEnv ty \end{code} + %************************************************************************ %* * -\subsection{Boxedness and liftedness} +\subsection{Liftedness} %* * %************************************************************************ \begin{code} -isUnboxedType :: Type -> Bool -isUnboxedType ty = not (isFollowableRep (typePrimRep ty)) - isUnLiftedType :: Type -> Bool -isUnLiftedType ty = case splitTyConApp_maybe ty of - Just (tc, ty_args) -> isUnLiftedTyCon tc - other -> False + -- isUnLiftedType returns True for forall'd unlifted types: + -- x :: forall a. Int# + -- I found bindings like these were getting floated to the top level. + -- They are pretty bogus types, mind you. It would be better never to + -- construct them + +isUnLiftedType (ForAllTy tv ty) = isUnLiftedType ty +isUnLiftedType (NoteTy _ ty) = isUnLiftedType ty +isUnLiftedType (TyConApp tc _) = isUnLiftedTyCon tc +isUnLiftedType (UsageTy _ ty) = isUnLiftedType ty +isUnLiftedType other = False isUnboxedTupleType :: Type -> Bool isUnboxedTupleType ty = case splitTyConApp_maybe ty of @@ -989,68 +1115,123 @@ isDataType ty = case splitTyConApp_maybe ty of isDataTyCon tc other -> False -typePrimRep :: Type -> PrimRep -typePrimRep ty = case splitTyConApp_maybe ty of - Just (tc, ty_args) -> tyConPrimRep tc - other -> PtrRep +isNewType :: Type -> Bool +isNewType ty = case splitTyConApp_maybe ty of + Just (tc, ty_args) -> ASSERT( length ty_args == tyConArity tc ) + isNewTyCon tc + other -> False +\end{code} + + +%************************************************************************ +%* * +\subsection{Sequencing on types +%* * +%************************************************************************ + +\begin{code} +seqType :: Type -> () +seqType (TyVarTy tv) = tv `seq` () +seqType (AppTy t1 t2) = seqType t1 `seq` seqType t2 +seqType (FunTy t1 t2) = seqType t1 `seq` seqType t2 +seqType (NoteTy note t2) = seqNote note `seq` seqType t2 +seqType (PredTy p) = seqPred p +seqType (TyConApp tc tys) = tc `seq` seqTypes tys +seqType (ForAllTy tv ty) = tv `seq` seqType ty +seqType (UsageTy u ty) = seqType u `seq` seqType ty + +seqTypes :: [Type] -> () +seqTypes [] = () +seqTypes (ty:tys) = seqType ty `seq` seqTypes tys + +seqNote :: TyNote -> () +seqNote (SynNote ty) = seqType ty +seqNote (FTVNote set) = sizeUniqSet set `seq` () + +seqPred :: PredType -> () +seqPred (ClassP c tys) = c `seq` seqTypes tys +seqPred (IParam n ty) = n `seq` seqType ty \end{code} + %************************************************************************ %* * \subsection{Equality on types} %* * %************************************************************************ -For the moment at least, type comparisons don't work if -there are embedded for-alls. \begin{code} instance Eq Type where - ty1 == ty2 = case ty1 `cmpTy` ty2 of { EQ -> True; other -> False } + ty1 == ty2 = case ty1 `compare` ty2 of { EQ -> True; other -> False } instance Ord Type where - compare ty1 ty2 = cmpTy ty1 ty2 + compare ty1 ty2 = cmpTy emptyVarEnv ty1 ty2 -cmpTy :: Type -> Type -> Ordering -cmpTy ty1 ty2 - = cmp emptyVarEnv ty1 ty2 - where +cmpTy :: TyVarEnv TyVar -> Type -> Type -> Ordering -- The "env" maps type variables in ty1 to type variables in ty2 -- So when comparing for-alls.. (forall tv1 . t1) (forall tv2 . t2) -- we in effect substitute tv2 for tv1 in t1 before continuing - lookup env tv1 = case lookupVarEnv env tv1 of - Just tv2 -> tv2 - Nothing -> tv1 -- Get rid of NoteTy - cmp env (NoteTy _ ty1) ty2 = cmp env ty1 ty2 - cmp env ty1 (NoteTy _ ty2) = cmp env ty1 ty2 - +cmpTy env (NoteTy _ ty1) ty2 = cmpTy env ty1 ty2 +cmpTy env ty1 (NoteTy _ ty2) = cmpTy env ty1 ty2 + + -- Get rid of PredTy +cmpTy env (PredTy p1) (PredTy p2) = cmpPred env p1 p2 +cmpTy env (PredTy p1) ty2 = cmpTy env (predRepTy p1) ty2 +cmpTy env ty1 (PredTy p2) = cmpTy env ty1 (predRepTy p2) + -- Deal with equal constructors - cmp env (TyVarTy tv1) (TyVarTy tv2) = lookup env tv1 `compare` tv2 - cmp env (AppTy f1 a1) (AppTy f2 a2) = cmp env f1 f2 `thenCmp` cmp env a1 a2 - cmp env (FunTy f1 a1) (FunTy f2 a2) = cmp env f1 f2 `thenCmp` cmp env a1 a2 - cmp env (TyConApp tc1 tys1) (TyConApp tc2 tys2) = (tc1 `compare` tc2) `thenCmp` (cmps env tys1 tys2) - cmp env (ForAllTy tv1 t1) (ForAllTy tv2 t2) = cmp (extendVarEnv env tv1 tv2) t1 t2 +cmpTy env (TyVarTy tv1) (TyVarTy tv2) = case lookupVarEnv env tv1 of + Just tv1a -> tv1a `compare` tv2 + Nothing -> tv1 `compare` tv2 + +cmpTy env (AppTy f1 a1) (AppTy f2 a2) = cmpTy env f1 f2 `thenCmp` cmpTy env a1 a2 +cmpTy env (FunTy f1 a1) (FunTy f2 a2) = cmpTy env f1 f2 `thenCmp` cmpTy env a1 a2 +cmpTy env (TyConApp tc1 tys1) (TyConApp tc2 tys2) = (tc1 `compare` tc2) `thenCmp` (cmpTys env tys1 tys2) +cmpTy env (ForAllTy tv1 t1) (ForAllTy tv2 t2) = cmpTy (extendVarEnv env tv1 tv2) t1 t2 +cmpTy env (UsageTy u1 t1) (UsageTy u2 t2) = cmpTy env u1 u2 `thenCmp` cmpTy env t1 t2 - -- Deal with the rest: TyVarTy < AppTy < FunTy < TyConApp < ForAllTy - cmp env (AppTy _ _) (TyVarTy _) = GT + -- Deal with the rest: TyVarTy < AppTy < FunTy < TyConApp < ForAllTy < UsageTy +cmpTy env (AppTy _ _) (TyVarTy _) = GT - cmp env (FunTy _ _) (TyVarTy _) = GT - cmp env (FunTy _ _) (AppTy _ _) = GT +cmpTy env (FunTy _ _) (TyVarTy _) = GT +cmpTy env (FunTy _ _) (AppTy _ _) = GT - cmp env (TyConApp _ _) (TyVarTy _) = GT - cmp env (TyConApp _ _) (AppTy _ _) = GT - cmp env (TyConApp _ _) (FunTy _ _) = GT +cmpTy env (TyConApp _ _) (TyVarTy _) = GT +cmpTy env (TyConApp _ _) (AppTy _ _) = GT +cmpTy env (TyConApp _ _) (FunTy _ _) = GT - cmp env (ForAllTy _ _) other = GT +cmpTy env (ForAllTy _ _) (TyVarTy _) = GT +cmpTy env (ForAllTy _ _) (AppTy _ _) = GT +cmpTy env (ForAllTy _ _) (FunTy _ _) = GT +cmpTy env (ForAllTy _ _) (TyConApp _ _) = GT + +cmpTy env (UsageTy _ _) other = GT - cmp env _ _ = LT +cmpTy env _ _ = LT - cmps env [] [] = EQ - cmps env (t:ts) [] = GT - cmps env [] (t:ts) = LT - cmps env (t1:t1s) (t2:t2s) = cmp env t1 t2 `thenCmp` cmps env t1s t2s -\end{code} +cmpTys env [] [] = EQ +cmpTys env (t:ts) [] = GT +cmpTys env [] (t:ts) = LT +cmpTys env (t1:t1s) (t2:t2s) = cmpTy env t1 t2 `thenCmp` cmpTys env t1s t2s +\end{code} +\begin{code} +instance Eq PredType where + p1 == p2 = case p1 `compare` p2 of { EQ -> True; other -> False } + +instance Ord PredType where + compare p1 p2 = cmpPred emptyVarEnv p1 p2 + +cmpPred :: TyVarEnv TyVar -> PredType -> PredType -> Ordering +cmpPred env (IParam n1 ty1) (IParam n2 ty2) = (n1 `compare` n2) `thenCmp` (cmpTy env ty1 ty2) + -- Compare types as well as names for implicit parameters + -- This comparison is used exclusively (I think) for the + -- finite map built in TcSimplify +cmpPred env (ClassP c1 tys1) (ClassP c2 tys2) = (c1 `compare` c2) `thenCmp` (cmpTys env tys1 tys2) +cmpPred env (IParam _ _) (ClassP _ _) = LT +cmpPred env (ClassP _ _) (IParam _ _) = GT +\end{code}