%
% (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
-
- boxedKind, -- :: Kind :: BX
- anyBoxKind, -- :: Kind :: BX
- typeCon, -- :: KindCon :: BX -> KX
- anyBoxCon, -- :: KindCon :: BX
-
- boxedTypeKind, unboxedTypeKind, openTypeKind, -- Kind :: superKind
-
- mkArrowKind, mkArrowKinds, hasMoreBoxityInfo,
+ superKind, superBoxity, -- KX and BX respectively
+ boxedBoxity, unboxedBoxity, -- :: BX
+ openKindCon, -- :: KX
+ typeCon, -- :: BX -> KX
+ boxedTypeKind, unboxedTypeKind, openTypeKind, -- :: KX
+ mkArrowKind, mkArrowKinds, -- :: KX -> KX -> KX
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, splitTyConApp_maybe,
- splitAlgTyConApp_maybe, splitAlgTyConApp, splitRepTyConApp_maybe,
- mkDictTy, splitDictTy_maybe, isDictTy,
+ splitAlgTyConApp_maybe, splitAlgTyConApp,
+
+ -- Predicates and the like
+ mkDictTy, mkDictTys, mkPredTy, splitPredTy_maybe,
+ splitDictTy, splitDictTy_maybe, isDictTy, predRepTy, splitDFunTy,
+
+ mkSynTy, isSynTy, deNoteType,
- mkSynTy, isSynTy, deNoteType,
+ repType, splitRepFunTys, splitNewType_maybe, typePrimRep,
- mkUsgTy, isUsgTy{- dont use -}, isNotUsgTy, splitUsgTy, unUsgTy, tyUsg,
+ UsageAnn(..), mkUsgTy, isUsgTy{- dont use -}, isNotUsgTy, splitUsgTy, unUsgTy, tyUsg,
+ mkUsForAllTy, mkUsForAllTys, splitUsForAllTys, substUsTy,
mkForAllTy, mkForAllTys, splitForAllTy_maybe, splitForAllTys,
- isForAllTy, applyTy, applyTys, mkPiType,
+ applyTy, applyTys, hoistForAllTys,
- TauType, RhoType, SigmaType, ThetaType,
- isTauTy,
- mkRhoTy, splitRhoTy,
- mkSigmaTy, splitSigmaTy,
+ TauType, RhoType, SigmaType, PredType(..), ThetaType,
+ ClassPred, ClassContext, mkClassPred,
+ getClassTys_maybe, ipName_maybe, classesOfPreds,
+ isTauTy, mkRhoTy, splitRhoTy,
+ mkSigmaTy, isSigmaTy, splitSigmaTy,
+ getDFunTyKey,
-- Lifting and boxity
- isUnLiftedType, isUnboxedType, isUnboxedTupleType, isAlgType, isDataType,
- typePrimRep,
+ isUnLiftedType, isUnboxedType, isUnboxedTupleType, isAlgType, isDataType, isNewType,
-- Free variables
- tyVarsOfType, tyVarsOfTypes, namesOfType, typeKind,
- addFreeTyVars,
+ tyVarsOfType, tyVarsOfTypes, tyVarsOfPred, tyVarsOfTheta,
+ namesOfType, typeKind, addFreeTyVars,
-- Tidying up for printing
tidyType, tidyTypes,
tidyOpenType, tidyOpenTypes,
tidyTyVar, tidyTyVars,
- tidyTopType
+ tidyTopType,
+
+ -- 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 ( TyVar, UVar,
+ tyVarKind, tyVarName, setTyVarName,
)
import VarEnv
import VarSet
-import Name ( NamedThing(..), Provenance(..), ExportFlag(..),
- mkWiredInTyConName, mkGlobalName, mkLocalName, mkKindOccFS, tcName,
- tidyOccName, TidyOccEnv
- )
+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 Class ( classTyCon, Class, ClassPred, ClassContext )
+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 SrcLoc ( noSrcLoc )
import PrimRep ( PrimRep(..), isFollowableRep )
-import Unique -- quite a few *Keys
-import Util ( thenCmp, mapAccumL, seqList, ($!) )
+import 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 = boxedTypeKind
+ | otherwise = kind
\end{code}
-
%************************************************************************
%* *
\subsection{Constructor-specific functions}
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 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 other = Nothing
isTyVarTy :: Type -> Bool
isTyVarTy (TyVarTy tv) = True
isTyVarTy (NoteTy _ ty) = isTyVarTy ty
+isTyVarTy (PredTy p) = isTyVarTy (predRepTy p)
isTyVarTy other = False
\end{code}
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
+ = ASSERT2( isNotUsgTy orig_ty1 && isNotUsgTy orig_ty2, pprType orig_ty1 <+> text "to" <+> pprType orig_ty2 )
+ ASSERT( not (isPredTy orig_ty1) ) -- Predicates are of kind *
+ mk_app orig_ty1
where
mk_app (NoteTy _ ty1) = mk_app ty1
mk_app (TyConApp tc tys) = mkTyConApp tc (tys ++ [orig_ty2])
-- 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
+ = ASSERT2( isNotUsgTy orig_ty1, pprType orig_ty1 )
+ ASSERT( not (isPredTy orig_ty1) ) -- Predicates are of kind *
+ mk_app orig_ty1
where
mk_app (NoteTy _ ty1) = mk_app ty1
mk_app (TyConApp tc tys) = mkTyConApp tc (tys ++ orig_tys2)
splitAppTy_maybe (FunTy ty1 ty2) = Just (TyConApp funTyCon [ty1], 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
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])
split orig_ty (TyConApp tc tc_args) args = (TyConApp tc [], tc_args ++ args)
mkFunTys :: [Type] -> Type -> Type
mkFunTys 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_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 other = Nothing
splitFunTys :: Type -> ([Type], Type)
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 ty = (reverse args, orig_ty)
splitFunTysN :: String -> Int -> Type -> ([Type], Type)
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 ty = pprPanic ("splitFunTysN: " ++ msg) (int orig_n <+> pprType orig_ty)
zipFunTys :: Outputable a => [a] -> Type -> ([(a,Type)], Type)
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 (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 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 ty = pprPanic "funArgTy" (pprType ty)
\end{code}
splitTyConApp_maybe (TyConApp tc tys) = Just (tc, tys)
splitTyConApp_maybe (FunTy arg res) = Just (funTyCon, [arg,res])
splitTyConApp_maybe (NoteTy _ ty) = splitTyConApp_maybe ty
+splitTyConApp_maybe (PredTy p) = splitTyConApp_maybe (predRepTy p)
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 other = Nothing
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)
+#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
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
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 p
deNoteType (NoteTy _ ty) = deNoteType ty
deNoteType (AppTy fun arg) = AppTy (deNoteType fun) (deNoteType arg)
deNoteType (FunTy fun arg) = FunTy (deNoteType fun) (deNoteType arg)
interfaces. Notably this plays a role in tcTySigs in TcBinds.lhs.
+ Representation types
+ ~~~~~~~~~~~~~~~~~~~~
+
+repType looks through
+ (a) for-alls, and
+ (b) newtypes
+ (c) synonyms
+ (d) predicates
+It's useful in the back end where we're not
+interested in newtypes anymore.
+
+\begin{code}
+repType :: Type -> Type
+repType (ForAllTy _ ty) = repType ty
+repType (NoteTy _ ty) = repType ty
+repType (PredTy p) = repType (predRepTy p)
+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)
+
+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 (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}
+
---------------------------------------------------------------------
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)
+Polymorphic Type_ (POPL'99) usage of "rho = generalised
+usage-annotated type; sigma = usage-annotated type; tau =
+usage-annotated type except on top"; unfortunately this conflicts with
+the rho/tau/theta/sigma usage in the rest of the compiler. (KSW
+1999-07)
\begin{code}
mkUsgTy :: UsageAnn -> Type -> Type
#ifndef USMANY
isUsgTy _ = True
#else
-isUsgTy (NoteTy (UsgNote _) _) = True
-isUsgTy other = False
+isUsgTy (NoteTy (UsgForAll _) ty) = isUsgTy ty
+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
+isNotUsgTy (NoteTy (UsgForAll _) _) = False
+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,
splitUsgTy_maybe :: Type -> Maybe (UsageAnn,Type)
splitUsgTy_maybe (NoteTy (UsgNote usg) ty2) = ASSERT( isNotUsgTy ty2 )
Just (usg,ty2)
-splitUsgTy_maybe ty = Nothing
+splitUsgTy_maybe ty@(NoteTy (UsgForAll _) _) = pprPanic "splitUsgTy_maybe:" $ pprType ty
+splitUsgTy_maybe ty = Nothing
splitUsgTy :: Type -> (UsageAnn,Type)
splitUsgTy ty = case splitUsgTy_maybe ty of
Just (_,ty1) -> ASSERT2( isNotUsgTy ty1, pprType ty )
ty1
Nothing -> ty
-\end{code}
+mkUsForAllTy :: UVar -> Type -> Type
+mkUsForAllTy uv ty = NoteTy (UsgForAll uv) ty
+
+mkUsForAllTys :: [UVar] -> Type -> Type
+mkUsForAllTys uvs ty = foldr (NoteTy . UsgForAll) ty uvs
+
+splitUsForAllTys :: Type -> ([UVar],Type)
+splitUsForAllTys ty = split ty []
+ where split (NoteTy (UsgForAll u) ty) uvs = split ty (u:uvs)
+ split other_ty uvs = (reverse uvs, other_ty)
+
+substUsTy :: VarEnv UsageAnn -> Type -> Type
+-- assumes range is fresh uvars, so no conflicts
+substUsTy ve (NoteTy note@(UsgNote (UsVar u))
+ ty ) = NoteTy (case lookupVarEnv ve u of
+ Just ua -> UsgNote ua
+ Nothing -> note)
+ (substUsTy ve ty)
+substUsTy ve (NoteTy (SynNote ty1) ty2) = NoteTy (SynNote (substUsTy ve ty1)) (substUsTy ve ty2)
+substUsTy ve (NoteTy note ty) = NoteTy note (substUsTy ve ty)
+
+substUsTy ve (PredTy (Class c tys)) = PredTy (Class c (map (substUsTy ve) tys))
+substUsTy ve (PredTy (IParam n ty)) = PredTy (IParam n (substUsTy ve ty))
+substUsTy ve (TyVarTy tv) = TyVarTy tv
+substUsTy ve (AppTy ty1 ty2) = AppTy (substUsTy ve ty1) (substUsTy ve ty2)
+substUsTy ve (FunTy ty1 ty2) = FunTy (substUsTy ve ty1) (substUsTy ve ty2)
+substUsTy ve (TyConApp tyc tys) = TyConApp tyc (map (substUsTy ve) tys)
+substUsTy ve (ForAllTy yv ty ) = ForAllTy yv (substUsTy ve ty)
+\end{code}
---------------------------------------------------------------------
return (tyvar, NoteTy (UsgNote usg) ty'')
Nothing -> 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 _ = Nothing
splitForAllTys :: Type -> ([TyVar], Type)
splitForAllTys ty = case splitUsgTy_maybe ty of
in (tvs, NoteTy (UsgNote usg) ty'')
Nothing -> 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 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
\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 (NoteTy note@(UsgNote _) fun) arg = NoteTy note (applyTy fun arg)
+applyTy (NoteTy note@(UsgForAll _) fun) arg = NoteTy note (applyTy fun arg)
+applyTy (PredTy p) arg = applyTy (predRepTy p) 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"
applyTys :: Type -> [Type] -> Type
applyTys fun_ty arg_tys
(tvs, ty) = split fun_ty arg_tys
split fun_ty [] = ([], fun_ty)
+ split (NoteTy note@(UsgNote _) fun_ty)
+ args = case split fun_ty args of
+ (tvs, ty) -> (tvs, NoteTy note ty)
+ split (NoteTy note@(UsgForAll _) fun_ty)
+ args = case split fun_ty args of
+ (tvs, ty) -> (tvs, NoteTy note ty)
split (NoteTy _ fun_ty) args = split fun_ty args
+ split (PredTy p) args = split (predRepTy p) 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 other_ty args = panic "applyTys"
-
-{- OLD version with bogus usage stuff
-
- ************* 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"
--}
\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.
+\begin{code}
+hoistForAllTys :: Type -> Type
+ -- Move all the foralls to the top
+ -- e.g. T -> forall a. a ==> forall a. T -> a
+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}
+
+
%************************************************************************
%* *
\subsection{Stuff to do with the source-language types}
+
+PredType and ThetaType are used in types for expressions and bindings.
+ClassPred and ClassContext are used in class and instance declarations.
%* *
%************************************************************************
+"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 = Class clas tys
+
+mkDictTy :: Class -> [Type] -> Type
+mkDictTy clas tys = mkPredTy (Class clas tys)
+
+mkDictTys :: ClassContext -> [Type]
+mkDictTys cxt = [mkDictTy cls tys | (cls,tys) <- cxt]
+
+mkPredTy :: PredType -> Type
+mkPredTy pred = PredTy pred
+
+predRepTy :: PredType -> Type
+-- Convert a predicate to its "representation type";
+-- the type of evidence for that predicate, which is actually passed at runtime
+predRepTy (Class clas tys) = TyConApp (classTyCon clas) tys
+predRepTy (IParam n ty) = ty
+
+isPredTy :: Type -> Bool
+isPredTy (NoteTy _ ty) = isPredTy ty
+isPredTy (PredTy _) = True
+isPredTy _ = False
+
+isDictTy :: Type -> Bool
+isDictTy (NoteTy _ ty) = isDictTy ty
+isDictTy (PredTy (Class _ _)) = True
+isDictTy other = False
+
+splitPredTy_maybe :: Type -> Maybe PredType
+splitPredTy_maybe (NoteTy _ ty) = splitPredTy_maybe ty
+splitPredTy_maybe (PredTy p) = Just p
+splitPredTy_maybe other = Nothing
+
+splitDictTy :: Type -> (Class, [Type])
+splitDictTy (NoteTy _ ty) = splitDictTy ty
+splitDictTy (PredTy (Class clas tys)) = (clas, tys)
+
+splitDictTy_maybe :: Type -> Maybe (Class, [Type])
+splitDictTy_maybe (NoteTy _ ty) = Just (splitDictTy ty)
+splitDictTy_maybe (PredTy (Class 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) }}
+
+getClassTys_maybe :: PredType -> Maybe ClassPred
+getClassTys_maybe (Class clas tys) = Just (clas, tys)
+getClassTys_maybe _ = Nothing
+
+ipName_maybe :: PredType -> Maybe Name
+ipName_maybe (IParam n _) = Just n
+ipName_maybe _ = Nothing
+
+classesOfPreds :: ThetaType -> ClassContext
+classesOfPreds theta = [(clas,tys) | Class clas tys <- theta]
\end{code}
@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 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 = foldr (\p r -> FunTy (mkPredTy p) 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 ty ts = (reverse ts, orig_ty)
\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 _ = False
+
+splitSigmaTy :: Type -> ([TyVar], [PredType], Type)
splitSigmaTy ty =
(tyvars, theta, tau)
where
(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
+-- PredTy shouldn't happen
+\end{code}
+
%************************************************************************
%* *
typeKind (TyVarTy tyvar) = tyVarKind tyvar
typeKind (TyConApp tycon tys) = foldr (\_ k -> funResultTy k) (tyConKind tycon) tys
typeKind (NoteTy _ ty) = typeKind ty
+typeKind (PredTy _) = boxedTypeKind -- Predicates are always
+ -- represented by boxed 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 = boxedTypeKind
+ 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 boxed 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
\end{code}
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 (NoteTy (UsgForAll _) 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
tyVarsOfTypes :: [Type] -> TyVarSet
tyVarsOfTypes tys = foldr (unionVarSet.tyVarsOfType) emptyVarSet tys
+tyVarsOfPred :: PredType -> TyVarSet
+tyVarsOfPred (Class 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 (NoteTy note@(UsgNote _) ty) = NoteTy note (addFreeTyVars ty)
+addFreeTyVars (NoteTy note@(UsgForAll _) 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
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)
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 (go_pred 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_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
+ go_note note@(UsgForAll _) = note -- Uvar binder is already tidy
+
+ go_pred (Class c tys) = Class c (tidyTypes env tys)
+ go_pred (IParam n ty) = IParam n (go ty)
-tidyTypes env tys = map (tidyType env) tys
+tidyTypes env tys = map (tidyType 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}
\end{code}
+
%************************************************************************
%* *
\subsection{Boxedness and liftedness}
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 other = False
isUnboxedTupleType :: Type -> Bool
isUnboxedTupleType 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
+
+seqTypes :: [Type] -> ()
+seqTypes [] = ()
+seqTypes (ty:tys) = seqType ty `seq` seqTypes tys
+
+seqNote :: TyNote -> ()
+seqNote (SynNote ty) = seqType ty
+seqNote (FTVNote set) = sizeUniqSet set `seq` ()
+seqNote (UsgNote usg) = usg `seq` ()
+
+seqPred :: PredType -> ()
+seqPred (Class 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
-- Deal with the rest: TyVarTy < AppTy < FunTy < TyConApp < ForAllTy
- cmp env (AppTy _ _) (TyVarTy _) = GT
+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 _ _) 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 t) (IParam n2 t2) = n1 `compare` n2
+ -- Just compare the names!
+cmpPred env (Class c1 tys1) (Class c2 tys2) = (c1 `compare` c2) `thenCmp` (cmpTys env tys1 tys2)
+cmpPred env (IParam _ _) (Class _ _) = LT
+cmpPred env (Class _ _) (IParam _ _) = GT
+\end{code}
projects / ghc-hetmet.git / blobdiff