X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypes%2FType.lhs;h=eb159f7d022bb37a4493f8fb60ae5218329a4d14;hb=1181f398e73359a2e6387364b4fe270d4cc78f36;hp=0a1887be16263757708830726c09286f7f7bc5ad;hpb=69e14f75a4b031e489b7774914e5a176409cea78;p=ghc-hetmet.git diff --git a/ghc/compiler/types/Type.lhs b/ghc/compiler/types/Type.lhs index 0a1887b..eb159f7 100644 --- a/ghc/compiler/types/Type.lhs +++ b/ghc/compiler/types/Type.lhs @@ -1,319 +1,145 @@ % % (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, PredType, TauType, ThetaType, Kind, TyVarSubst, - superKind, superBoxity, -- :: SuperKind - - boxedKind, -- :: Kind :: BX - anyBoxKind, -- :: Kind :: BX - typeCon, -- :: KindCon :: BX -> KX - anyBoxCon, -- :: KindCon :: BX - - boxedTypeKind, unboxedTypeKind, openTypeKind, -- Kind :: superKind + superKind, superBoxity, -- KX and BX respectively + liftedBoxity, unliftedBoxity, -- :: BX + openKindCon, -- :: KX + typeCon, -- :: BX -> KX + liftedTypeKind, unliftedTypeKind, openTypeKind, -- :: KX + mkArrowKind, mkArrowKinds, -- :: KX -> KX -> KX + isTypeKind, + 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, + funResultTy, funArgTy, zipFunTys, - mkTyConApp, mkTyConTy, splitTyConApp_maybe, - splitAlgTyConApp_maybe, splitAlgTyConApp, splitRepTyConApp_maybe, - mkDictTy, splitDictTy_maybe, isDictTy, + mkTyConApp, mkTyConTy, + tyConAppTyCon, tyConAppArgs, + splitTyConApp_maybe, splitTyConApp, - mkSynTy, isSynTy, deNoteType, + mkUTy, splitUTy, splitUTy_maybe, + isUTy, uaUTy, unUTy, liftUTy, mkUTyM, + isUsageKind, isUsage, isUTyVar, - mkUsgTy, isUsgTy{- dont use -}, isNotUsgTy, splitUsgTy, unUsgTy, tyUsg, + mkSynTy, + + repType, splitRepFunTys, typePrimRep, mkForAllTy, mkForAllTys, splitForAllTy_maybe, splitForAllTys, - isForAllTy, applyTy, applyTys, mkPiType, + applyTy, applyTys, isForAllTy, + + -- Source types + SourceType(..), sourceTypeRep, mkPredTy, mkPredTys, - TauType, RhoType, SigmaType, ThetaType, - isTauTy, - mkRhoTy, splitRhoTy, - mkSigmaTy, splitSigmaTy, + -- Newtypes + splitNewType_maybe, -- Lifting and boxity - isUnLiftedType, isUnboxedType, isUnboxedTupleType, isAlgType, isDataType, - typePrimRep, + isUnLiftedType, isUnboxedTupleType, isAlgType, isStrictType, isPrimitiveType, -- Free variables - tyVarsOfType, tyVarsOfTypes, namesOfType, typeKind, - addFreeTyVars, + tyVarsOfType, tyVarsOfTypes, tyVarsOfPred, tyVarsOfTheta, + usageAnnOfType, typeKind, addFreeTyVars, -- Tidying up for printing - tidyType, tidyTypes, - tidyOpenType, tidyOpenTypes, - tidyTyVar, tidyTyVars, - tidyTopType + tidyType, tidyTypes, + tidyOpenType, tidyOpenTypes, + tidyTyVarBndr, tidyFreeTyVars, + tidyOpenTyVar, tidyOpenTyVars, + tidyTopType, tidyPred, + + -- Comparison + eqType, eqKind, eqUsage, + + -- 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 #-} PprType( pprType ) -- Only called in debug messages -import {-# SOURCE #-} Subst ( mkTyVarSubst, substTy ) +import {-# SOURCE #-} Subst ( substTyWith ) -- 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 NameSet -import Class ( classTyCon, Class ) -import TyCon ( TyCon, KindCon, - mkFunTyCon, mkKindCon, mkSuperKindCon, - matchesTyCon, isUnboxedTupleTyCon, isUnLiftedTyCon, - isFunTyCon, isDataTyCon, isNewTyCon, - isAlgTyCon, isSynTyCon, tyConArity, - tyConKind, tyConDataCons, getSynTyConDefn, - tyConPrimRep, tyConClass_maybe +import Name ( NamedThing(..), mkLocalName, tidyOccName ) +import Class ( classTyCon ) +import TyCon ( TyCon, isRecursiveTyCon, isPrimTyCon, + isUnboxedTupleTyCon, isUnLiftedTyCon, + isFunTyCon, isNewTyCon, newTyConRep, + isAlgTyCon, isSynTyCon, tyConArity, + tyConKind, getSynTyConDefn, + tyConPrimRep, ) -- others -import BasicTypes ( Unused ) -import SrcLoc ( mkBuiltinSrcLoc, noSrcLoc ) -import PrelMods ( pREL_GHC ) +import CmdLineOpts ( opt_DictsStrict ) import Maybes ( maybeToBool ) -import PrimRep ( PrimRep(..), isFollowableRep ) -import Unique -- quite a few *Keys -import Util ( thenCmp, mapAccumL, seqList, ($!) ) +import SrcLoc ( noSrcLoc ) +import PrimRep ( PrimRep(..) ) +import Unique ( Uniquable(..) ) +import Util ( mapAccumL, seqList ) 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 - | 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) + | k2 `eqKind` openTypeKind = True + | otherwise = k1 `eqType` k2 + +defaultKind :: Kind -> Kind +-- Used when generalising: default kind '?' to '*' +defaultKind kind | kind `eqKind` openTypeKind = liftedTypeKind + | otherwise = kind + +isTypeKind :: Kind -> Bool +-- True of kind * and *# +isTypeKind k = case splitTyConApp_maybe k of + Just (tc,[k]) -> tc == typeCon + other -> False \end{code} - %************************************************************************ %* * \subsection{Constructor-specific functions} @@ -332,19 +158,25 @@ mkTyVarTys :: [TyVar] -> [Type] mkTyVarTys = map mkTyVarTy -- a common use of mkTyVarTy getTyVar :: String -> Type -> TyVar -getTyVar msg (TyVarTy tv) = tv -getTyVar msg (NoteTy _ t) = getTyVar msg t -getTyVar msg other = panic ("getTyVar: " ++ msg) +getTyVar msg (TyVarTy tv) = tv +getTyVar msg (SourceTy p) = getTyVar msg (sourceTypeRep 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 other = Nothing +getTyVar_maybe (TyVarTy tv) = Just tv +getTyVar_maybe (NoteTy _ t) = getTyVar_maybe t +getTyVar_maybe (SourceTy p) = getTyVar_maybe (sourceTypeRep 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 other = False +isTyVarTy (TyVarTy tv) = True +isTyVarTy (NoteTy _ ty) = isTyVarTy ty +isTyVarTy (SourceTy p) = isTyVarTy (sourceTypeRep p) +isTyVarTy ty@(UsageTy _ _) = pprPanic "isTyVarTy: UTy:" (pprType ty) +isTyVarTy other = False \end{code} @@ -356,38 +188,47 @@ 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 (isSourceTy orig_ty1) ) -- Source types 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 (isSourceTy orig_ty1) ) -- Source types 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 (SourceTy p) = splitAppTy_maybe (sourceTypeRep 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 +241,11 @@ 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 (SourceTy p) args = split orig_ty (sourceTypeRep 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 +256,24 @@ 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 (SourceTy p) = splitFunTy (sourceTypeRep 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 (SourceTy p) = splitFunTy_maybe (sourceTypeRep p) +splitFunTy_maybe ty@(UsageTy _ _) = pprPanic "splitFunTy_maybe: UTy:" (pprType ty) splitFunTy_maybe other = Nothing splitFunTys :: Type -> ([Type], Type) @@ -428,44 +281,57 @@ 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 (SourceTy p) = split args orig_ty (sourceTypeRep 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) -splitFunTysN msg orig_n orig_ty = split orig_n [] orig_ty orig_ty - where - 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 ty = pprPanic ("splitFunTysN: " ++ msg) (int orig_n <+> pprType orig_ty) - zipFunTys :: Outputable a => [a] -> Type -> ([(a,Type)], Type) zipFunTys orig_xs orig_ty = split [] orig_xs orig_ty orig_ty where 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 (SourceTy p) = split acc xs nty (sourceTypeRep 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 (SourceTy p) = funResultTy (sourceTypeRep 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 (SourceTy p) = funArgTy (sourceTypeRep p) +funArgTy (UsageTy _ ty) = funArgTy ty +funArgTy ty = pprPanic "funArgTy" (pprType ty) \end{code} --------------------------------------------------------------------- TyConApp ~~~~~~~~ +@mkTyConApp@ is a key function, because it builds a TyConApp, FunTy or SourceTy, +as apppropriate. \begin{code} mkTyConApp :: TyCon -> [Type] -> Type +-- Assumes TyCon is not a SynTyCon; use mkSynTy instead for those mkTyConApp tycon tys - | isFunTyCon tycon && length tys == 2 - = case tys of - (ty1:ty2:_) -> FunTy ty1 ty2 + | isFunTyCon tycon, [ty1,ty2] <- tys + = FunTy (mkUTyM ty1) (mkUTyM ty2) + + | isNewTyCon tycon, -- A saturated newtype application; + not (isRecursiveTyCon tycon), -- Not recursive (we don't use SourceTypes for them) + length tys == tyConArity tycon -- use the SourceType form + = SourceTy (NType tycon tys) | otherwise = ASSERT(not (isSynTyCon tycon)) + UASSERT2( not (any isUTy tys), ppr tycon <+> fsep (map pprType tys) ) TyConApp tycon tys mkTyConTy :: TyCon -> Type @@ -476,104 +342,52 @@ 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 = fst (splitTyConApp ty) + +tyConAppArgs :: Type -> [Type] +tyConAppArgs ty = snd (splitTyConApp 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 (SourceTy p) = splitTyConApp_maybe (sourceTypeRep 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. - -splitAlgTyConApp_maybe :: Type -> Maybe (TyCon, [Type], [DataCon]) -splitAlgTyConApp_maybe (TyConApp tc tys) - | isAlgTyCon tc && - tyConArity tc == length tys = Just (tc, tys, tyConDataCons tc) -splitAlgTyConApp_maybe (NoteTy _ ty) = splitAlgTyConApp_maybe ty -splitAlgTyConApp_maybe other = Nothing - -splitAlgTyConApp :: Type -> (TyCon, [Type], [DataCon]) - -- Here the "algebraic" property is an *assertion* -splitAlgTyConApp (TyConApp tc tys) = ASSERT( isAlgTyCon tc && tyConArity tc == length tys ) - (tc, tys, tyConDataCons tc) -splitAlgTyConApp (NoteTy _ ty) = splitAlgTyConApp ty \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 ~~~~~ \begin{code} -mkSynTy syn_tycon tys - = ASSERT( isSynTyCon syn_tycon ) - ASSERT( isNotUsgTy body ) - NoteTy (SynNote (TyConApp syn_tycon tys)) - (substTy (mkTyVarSubst tyvars tys) body) +mkSynTy tycon tys + | n_args == arity -- Exactly saturated + = mk_syn tys + | n_args > arity -- Over-saturated + = foldl AppTy (mk_syn (take arity tys)) (drop arity tys) + | otherwise -- Un-saturated + = TyConApp tycon tys + -- For the un-saturated case we build TyConApp directly + -- (mkTyConApp ASSERTs that the tc isn't a SynTyCon). + -- Here we are relying on checkValidType to find + -- the error. What we can't do is use mkSynTy with + -- too few arg tys, because that is utterly bogus. + where - (tyvars, body) = getSynTyConDefn syn_tycon - -isSynTy (NoteTy (SynNote _) _) = True -isSynTy other = False - -deNoteType :: Type -> Type - -- Sorry for the cute name -deNoteType ty@(TyVarTy tyvar) = ty -deNoteType (TyConApp tycon tys) = TyConApp tycon (map deNoteType tys) -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) + mk_syn tys = NoteTy (SynNote (TyConApp tycon tys)) + (substTyWith tyvars tys body) + + (tyvars, body) = ASSERT( isSynTyCon tycon ) getSynTyConDefn tycon + arity = tyConArity tycon + n_args = length tys \end{code} Notes on type synonyms @@ -591,74 +405,44 @@ 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 + ~~~~~~~~~~~~~~~~~~~~ +repType looks through + (a) for-alls, and + (b) synonyms + (c) predicates + (d) usage annotations + (e) [recursive] newtypes +It's useful in the back end. ---------------------------------------------------------------------- - 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) +Remember, non-recursive newtypes get expanded as part of the SourceTy case, +but recursive ones are represented by TyConApps and have to be expanded +by steam. \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 (SourceTy p) = repType (sourceTypeRep p) +repType (UsageTy _ ty) = repType ty +repType (TyConApp tc tys) | isNewTyCon tc && length tys == tyConArity tc + = repType (newTypeRep tc tys) +repType ty = 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 \end{code} @@ -667,148 +451,214 @@ 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 (SourceTy p) = splitFAT_m (sourceTypeRep 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 (SourceTy p) tvs = split orig_ty (sourceTypeRep 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. - -\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} +-- (mkPiType now in CoreUtils) -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 (SourceTy p) arg = applyTy (sourceTypeRep 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 ) + substTyWith [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) $ + substTyWith 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 (SourceTy p) args = split (sourceTypeRep 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 +--------------------------------------------------------------------- + UsageTy + ~~~~~~~ - ************* CHECK WITH KEITH ************** +Constructing and taking apart usage types. - 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" --} -\end{code} +\begin{code} +mkUTy :: Type -> Type -> Type +mkUTy u ty + = ASSERT2( typeKind u `eqKind` 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 -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. +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 -%************************************************************************ -%* * -\subsection{Stuff to do with the source-language types} -%* * -%************************************************************************ +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 -\begin{code} -type RhoType = Type -type TauType = Type -type ThetaType = [(Class, [Type])] -type SigmaType = Type -\end{code} +isUTy :: Type -> Bool + -- has usage annotation +isUTy = maybeToBool . splitUTy_maybe -@isTauTy@ tests for nested for-alls. +uaUTy :: Type -> Type + -- extract annotation +uaUTy = fst . splitUTy + +unUTy :: Type -> Type + -- extract unannotated type +unUTy = snd . splitUTy +\end{code} \begin{code} -isTauTy :: Type -> Bool -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 +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} -mkRhoTy :: [(Class, [Type])] -> Type -> Type -mkRhoTy theta ty = foldr (\(c,t) r -> FunTy (mkDictTy c t) r) ty theta +mkUTyM :: Type -> Type + -- put TOP (no info) annotation on unannotated type +mkUTyM ty = mkUTy usMany ty +\end{code} -splitRhoTy :: Type -> ([(Class, [Type])], 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) +\begin{code} +isUsageKind :: Kind -> Bool +isUsageKind k + = ASSERT( typeKind k `eqKind` superKind ) + k `eqKind` usageTypeKind + +isUsage :: Type -> Bool +isUsage ty + = isUsageKind (typeKind ty) + +isUTyVar :: Var -> Bool +isUTyVar v + = isUsageKind (tyVarKind v) \end{code} +%************************************************************************ +%* * +\subsection{Source types} +%* * +%************************************************************************ -\begin{code} -mkSigmaTy tyvars theta tau = mkForAllTys tyvars (mkRhoTy theta tau) +A "source type" is a type that is a separate type as far as the type checker is +concerned, but which has low-level representation as far as the back end is concerned. -splitSigmaTy :: Type -> ([TyVar], [(Class, [Type])], Type) -splitSigmaTy ty = - (tyvars, theta, tau) - where - (tyvars,rho) = splitForAllTys ty - (theta,tau) = splitRhoTy rho +Source types are always lifted. + +The key function is sourceTypeRep which gives the representation of a source type: + +\begin{code} +mkPredTy :: PredType -> Type +mkPredTy pred = SourceTy pred + +mkPredTys :: ThetaType -> [Type] +mkPredTys preds = map SourceTy preds + +sourceTypeRep :: SourceType -> Type +-- Convert a predicate to its "representation type"; +-- the type of evidence for that predicate, which is actually passed at runtime +sourceTypeRep (IParam n ty) = ty +sourceTypeRep (ClassP clas tys) = mkTyConApp (classTyCon clas) tys + -- Note the mkTyConApp; the classTyCon might be a newtype! +sourceTypeRep (NType tc tys) = newTypeRep tc tys + -- ToDo: Consider caching this substitution in a NType + +isSourceTy :: Type -> Bool +isSourceTy (NoteTy _ ty) = isSourceTy ty +isSourceTy (UsageTy _ ty) = isSourceTy ty +isSourceTy (SourceTy sty) = True +isSourceTy _ = False + + +splitNewType_maybe :: Type -> Maybe Type +-- Newtypes that are recursive are reprsented by TyConApp, just +-- as they always were. Occasionally we want to find their representation type. +-- NB: remember that in this module, non-recursive newtypes are transparent + +splitNewType_maybe ty + = case splitTyConApp_maybe ty of + Just (tc,tys) | isNewTyCon tc -> ASSERT( length tys == tyConArity tc ) + -- The assert should hold because repType should + -- only be applied to *types* (of kind *) + Just (newTypeRep tc tys) + other -> Nothing + +-- A local helper function (not exported) +newTypeRep new_tycon tys = case newTyConRep new_tycon of + (tvs, rep_ty) -> substTyWith tvs tys rep_ty \end{code} @@ -827,13 +677,25 @@ 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 (SourceTy _) = 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} @@ -842,38 +704,57 @@ typeKind (ForAllTy tv ty) = typeKind ty ~~~~~~~~~~~~~~~~~~~~~~~~ \begin{code} 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 (SourceTy sty) = tyVarsOfSourceType sty 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 = tyVarsOfSourceType -- Just a subtype + +tyVarsOfSourceType :: SourceType -> TyVarSet +tyVarsOfSourceType (IParam n ty) = tyVarsOfType ty +tyVarsOfSourceType (ClassP clas tys) = tyVarsOfTypes tys +tyVarsOfSourceType (NType tc tys) = tyVarsOfTypes tys + +tyVarsOfTheta :: ThetaType -> TyVarSet +tyVarsOfTheta = foldr (unionVarSet . tyVarsOfSourceType) 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 - --- Find the free names of a type, including the type constructors and classes it mentions -namesOfType :: Type -> NameSet -namesOfType (TyVarTy tv) = unitNameSet (getName tv) -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 (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) - -namesOfTypes tys = foldr (unionNameSets . namesOfType) emptyNameSet tys +addFreeTyVars ty@(NoteTy (FTVNote _) _) = ty +addFreeTyVars ty = NoteTy (FTVNote (tyVarsOfType ty)) ty +\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 (SourceTy p) = goT (sourceTypeRep 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} @@ -889,28 +770,34 @@ an interface file. It doesn't change the uniques at all, just the print names. \begin{code} -tidyTyVar :: TidyEnv -> TyVar -> (TidyEnv, TyVar) -tidyTyVar env@(tidy_env, subst) tyvar - = case lookupVarEnv subst tyvar of - - Just tyvar' -> -- Already substituted - (env, tyvar') - - Nothing -> -- Make a new nice name for it - - case tidyOccName tidy_env (getOccName name) of - (tidy', occ') -> -- New occname reqd - ((tidy', subst'), tyvar') - where - subst' = extendVarEnv subst tyvar tyvar' - tyvar' = setTyVarName tyvar name' - name' = mkLocalName (getUnique name) occ' noSrcLoc - -- Note: make a *user* tyvar, so it printes nicely - -- Could extract src loc, but no need. +tidyTyVarBndr :: TidyEnv -> TyVar -> (TidyEnv, TyVar) +tidyTyVarBndr (tidy_env, subst) tyvar + = case tidyOccName tidy_env (getOccName name) of + (tidy', occ') -> -- New occname reqd + ((tidy', subst'), tyvar') + where + subst' = extendVarEnv subst tyvar tyvar' + tyvar' = setTyVarName tyvar name' + name' = mkLocalName (getUnique name) occ' noSrcLoc + -- Note: make a *user* tyvar, so it printes nicely + -- Could extract src loc, but no need. where name = tyVarName 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 = fst (tidyOpenTyVars env (varSetElems tyvars)) + +tidyOpenTyVars :: TidyEnv -> [TyVar] -> (TidyEnv, [TyVar]) +tidyOpenTyVars env tyvars = mapAccumL tidyOpenTyVar env tyvars + +tidyOpenTyVar :: TidyEnv -> TyVar -> (TidyEnv, TyVar) +-- Treat a new tyvar as a binder, and give it a fresh tidy name +tidyOpenTyVar env@(tidy_env, subst) tyvar + = case lookupVarEnv subst tyvar of + Just tyvar' -> (env, tyvar') -- Already substituted + Nothing -> tidyTyVarBndr env tyvar -- Treat it as a binder tidyType :: TidyEnv -> Type -> Type tidyType env@(tidy_env, subst) ty @@ -922,21 +809,30 @@ tidyType env@(tidy_env, subst) ty 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 (SourceTy sty) = SourceTy (tidySourceType env sty) 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 (ForAllTy tv ty) = ForAllTy tvp $! (tidyType envp ty) + where + (envp, tvp) = tidyTyVarBndr env tv + go (UsageTy u ty) = (UsageTy $! (go u)) $! (go ty) go_note (SynNote ty) = SynNote $! (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 -> SourceType -> SourceType +tidyPred = tidySourceType + +tidySourceType :: TidyEnv -> SourceType -> SourceType +tidySourceType env (IParam n ty) = IParam n (tidyType env ty) +tidySourceType env (ClassP clas tys) = ClassP clas (tidyTypes env tys) +tidySourceType env (NType tc tys) = NType tc (tidyTypes env tys) \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 +840,7 @@ 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 +850,27 @@ 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 (SourceTy _) = False -- All source types are lifted +isUnLiftedType other = False isUnboxedTupleType :: Type -> Bool isUnboxedTupleType ty = case splitTyConApp_maybe ty of @@ -981,76 +883,109 @@ isAlgType ty = case splitTyConApp_maybe ty of Just (tc, ty_args) -> ASSERT( length ty_args == tyConArity tc ) isAlgTyCon tc other -> False +\end{code} --- Should only be applied to *types*; hence the assert -isDataType :: Type -> Bool -isDataType ty = case splitTyConApp_maybe ty of +@isStrictType@ computes whether an argument (or let RHS) should +be computed strictly or lazily, based only on its type. +Works just like isUnLiftedType, except that it has a special case +for dictionaries. Since it takes account of ClassP, you might think +this function should be in TcType, but isStrictType is used by DataCon, +which is below TcType in the hierarchy, so it's convenient to put it here. + +\begin{code} +isStrictType (ForAllTy tv ty) = isStrictType ty +isStrictType (NoteTy _ ty) = isStrictType ty +isStrictType (TyConApp tc _) = isUnLiftedTyCon tc +isStrictType (UsageTy _ ty) = isStrictType ty +isStrictType (SourceTy (ClassP clas _)) = opt_DictsStrict && not (isNewTyCon (classTyCon clas)) + -- We may be strict in dictionary types, but only if it + -- has more than one component. + -- [Being strict in a single-component dictionary risks + -- poking the dictionary component, which is wrong.] +isStrictType other = False +\end{code} + +\begin{code} +isPrimitiveType :: Type -> Bool +-- Returns types that are opaque to Haskell. +-- Most of these are unlifted, but now that we interact with .NET, we +-- may have primtive (foreign-imported) types that are lifted +isPrimitiveType ty = case splitTyConApp_maybe ty of Just (tc, ty_args) -> ASSERT( length ty_args == tyConArity tc ) - isDataTyCon tc + isPrimTyCon tc other -> False - -typePrimRep :: Type -> PrimRep -typePrimRep ty = case splitTyConApp_maybe ty of - Just (tc, ty_args) -> tyConPrimRep tc - other -> PtrRep \end{code} + %************************************************************************ %* * -\subsection{Equality on types} +\subsection{Sequencing 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 } +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 (SourceTy 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 :: SourceType -> () +seqPred (ClassP c tys) = c `seq` seqTypes tys +seqPred (NType tc tys) = tc `seq` seqTypes tys +seqPred (IParam n ty) = n `seq` seqType ty +\end{code} -instance Ord Type where - compare ty1 ty2 = cmpTy ty1 ty2 -cmpTy :: Type -> Type -> Ordering -cmpTy ty1 ty2 - = cmp emptyVarEnv ty1 ty2 - where - -- 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 - - -- 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 - - -- Deal with the rest: TyVarTy < AppTy < FunTy < TyConApp < ForAllTy - cmp env (AppTy _ _) (TyVarTy _) = GT - - cmp env (FunTy _ _) (TyVarTy _) = GT - cmp env (FunTy _ _) (AppTy _ _) = GT - - cmp env (TyConApp _ _) (TyVarTy _) = GT - cmp env (TyConApp _ _) (AppTy _ _) = GT - cmp env (TyConApp _ _) (FunTy _ _) = GT - - cmp env (ForAllTy _ _) other = GT - - cmp env _ _ = LT +%************************************************************************ +%* * +\subsection{Equality on types} +%* * +%************************************************************************ - 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} +Comparison; don't use instances so that we know where it happens. +Look through newtypes but not usage types. +\begin{code} +eqType t1 t2 = eq_ty emptyVarEnv t1 t2 +eqKind = eqType -- No worries about looking +eqUsage = eqType -- through source types for these two + +-- Look through Notes +eq_ty env (NoteTy _ t1) t2 = eq_ty env t1 t2 +eq_ty env t1 (NoteTy _ t2) = eq_ty env t1 t2 + +-- Look through SourceTy. This is where the looping danger comes from +eq_ty env (SourceTy sty1) t2 = eq_ty env (sourceTypeRep sty1) t2 +eq_ty env t1 (SourceTy sty2) = eq_ty env t1 (sourceTypeRep sty2) + +-- The rest is plain sailing +eq_ty env (TyVarTy tv1) (TyVarTy tv2) = case lookupVarEnv env tv1 of + Just tv1a -> tv1a == tv2 + Nothing -> tv1 == tv2 +eq_ty env (ForAllTy tv1 t1) (ForAllTy tv2 t2) + | tv1 == tv2 = eq_ty (delVarEnv env tv1) t1 t2 + | otherwise = eq_ty (extendVarEnv env tv1 tv2) t1 t2 +eq_ty env (AppTy s1 t1) (AppTy s2 t2) = (eq_ty env s1 s2) && (eq_ty env t1 t2) +eq_ty env (FunTy s1 t1) (FunTy s2 t2) = (eq_ty env s1 s2) && (eq_ty env t1 t2) +eq_ty env (UsageTy _ t1) (UsageTy _ t2) = eq_ty env t1 t2 +eq_ty env (TyConApp tc1 tys1) (TyConApp tc2 tys2) = (tc1 == tc2) && (eq_tys env tys1 tys2) +eq_ty env t1 t2 = False + +eq_tys env [] [] = True +eq_tys env (t1:tys1) (t2:tys2) = (eq_ty env t1 t2) && (eq_tys env tys1 tys2) +eq_tys env tys1 tys2 = False +\end{code}