-\begin{code}
-#include "HsVersions.h"
+%
+% (c) The GRASP/AQUA Project, Glasgow University, 1998
+%
+\section[Type]{Type - public interface}
+\begin{code}
module Type (
- GenType(..), SYN_IE(Type), SYN_IE(TauType),
- mkTyVarTy, mkTyVarTys,
- getTyVar, getTyVar_maybe, isTyVarTy,
- mkAppTy, mkAppTys, splitAppTy,
- mkFunTy, mkFunTys,
- splitFunTy, splitFunTyExpandingDicts, splitFunTyExpandingDictsAndPeeking,
- getFunTy_maybe, getFunTyExpandingDicts_maybe,
- mkTyConTy, getTyCon_maybe, applyTyCon,
- mkSynTy,
- mkForAllTy, mkForAllTys, getForAllTy_maybe, getForAllTyExpandingDicts_maybe, splitForAllTy,
- mkForAllUsageTy, getForAllUsageTy,
- applyTy,
-#ifdef DEBUG
- expandTy, -- only let out for debugging (ToDo: rm?)
-#endif
- isPrimType, isUnboxedType, typePrimRep,
+ -- re-exports from TypeRep:
+ Type, PredType, TauType, ThetaType,
+ Kind, TyVarSubst,
- SYN_IE(RhoType), SYN_IE(SigmaType), SYN_IE(ThetaType),
- mkDictTy,
- mkRhoTy, splitRhoTy, mkTheta,
- mkSigmaTy, splitSigmaTy,
+ 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,
- maybeAppTyCon, getAppTyCon,
- maybeAppDataTyCon, getAppDataTyCon, getAppSpecDataTyCon,
- maybeAppDataTyConExpandingDicts, maybeAppSpecDataTyConExpandingDicts,
- getAppDataTyConExpandingDicts, getAppSpecDataTyConExpandingDicts,
- maybeBoxedPrimType,
+ usageKindCon, -- :: KX
+ usageTypeKind, -- :: KX
+ usOnceTyCon, usManyTyCon, -- :: $
+ usOnce, usMany, -- :: $
- matchTy, matchTys, eqTy, eqSimpleTy, eqSimpleTheta,
+ -- exports from this module:
+ hasMoreBoxityInfo, defaultKind,
- instantiateTy, instantiateTauTy, instantiateUsage,
- applyTypeEnvToTy,
+ mkTyVarTy, mkTyVarTys, getTyVar, getTyVar_maybe, isTyVarTy,
- isTauTy,
+ mkAppTy, mkAppTys, splitAppTy, splitAppTys, splitAppTy_maybe,
- tyVarsOfType, tyVarsOfTypes, typeKind
- ) where
+ mkFunTy, mkFunTys, splitFunTy, splitFunTy_maybe, splitFunTys,
+ funResultTy, funArgTy, zipFunTys,
-IMP_Ubiq()
-IMPORT_DELOOPER(IdLoop) -- for paranoia checking
-IMPORT_DELOOPER(TyLoop) -- for paranoia checking
-IMPORT_DELOOPER(PrelLoop) -- for paranoia checking
+ mkTyConApp, mkTyConTy,
+ tyConAppTyCon, tyConAppArgs,
+ splitTyConApp_maybe, splitTyConApp,
--- friends:
-import Class ( classSig, classOpLocalType, GenClass{-instances-} )
-import Kind ( mkBoxedTypeKind, resultKind, notArrowKind, Kind )
-import TyCon ( mkFunTyCon, mkTupleTyCon, isFunTyCon,
- isPrimTyCon, isDataTyCon, isSynTyCon, maybeNewTyCon, isNewTyCon,
- tyConKind, tyConDataCons, getSynTyConDefn, TyCon )
-import TyVar ( tyVarKind, GenTyVar{-instances-}, SYN_IE(GenTyVarSet),
- emptyTyVarSet, unionTyVarSets, minusTyVarSet,
- unitTyVarSet, nullTyVarEnv, lookupTyVarEnv, delFromTyVarEnv,
- addOneToTyVarEnv, SYN_IE(TyVarEnv), SYN_IE(TyVar) )
-import Usage ( usageOmega, GenUsage, SYN_IE(Usage), SYN_IE(UVar), SYN_IE(UVarEnv),
- nullUVarEnv, addOneToUVarEnv, lookupUVarEnv, eqUVar,
- eqUsage )
+ mkUTy, splitUTy, splitUTy_maybe,
+ isUTy, uaUTy, unUTy, liftUTy, mkUTyM,
+ isUsageKind, isUsage, isUTyVar,
--- others
-import Maybes ( maybeToBool, assocMaybe )
-import PrimRep ( PrimRep(..) )
-import Unique -- quite a few *Keys
-import Util ( thenCmp, zipEqual, assoc,
- panic, panic#, assertPanic, pprTrace{-ToDo:rm-}, pprPanic{-ToDo:rm-},
- Ord3(..){-instances-}
- )
--- ToDo:rm all these
-import {-mumble-}
- Pretty
-import {-mumble-}
- PprStyle
-import {-mumble-}
- PprType --(pprType )
-import {-mumble-}
- UniqFM (ufmToList )
-import {-mumble-}
- Outputable
-\end{code}
+ mkSynTy,
-Data types
-~~~~~~~~~~
+ repType, splitRepFunTys, typePrimRep,
-\begin{code}
-type Type = GenType TyVar UVar -- Used after typechecker
-
-data GenType tyvar uvar -- Parameterised over type and usage variables
- = TyVarTy tyvar
-
- | AppTy
- (GenType tyvar uvar)
- (GenType tyvar uvar)
-
- | TyConTy -- Constants of a specified kind
- TyCon -- Must *not* be a SynTyCon
- (GenUsage uvar) -- Usage gives uvar of the full application,
- -- iff the full application is of kind Type
- -- c.f. the Usage field in TyVars
-
- | SynTy -- Synonyms must be saturated, and contain their expansion
- TyCon -- Must be a SynTyCon
- [GenType tyvar uvar]
- (GenType tyvar uvar) -- Expansion!
-
- | ForAllTy
- tyvar
- (GenType tyvar uvar) -- TypeKind
-
- | ForAllUsageTy
- uvar -- Quantify over this
- [uvar] -- Bounds; the quantified var must be
- -- less than or equal to all these
- (GenType tyvar uvar)
-
- -- Two special cases that save a *lot* of administrative
- -- overhead:
-
- | FunTy -- BoxedTypeKind
- (GenType tyvar uvar) -- Both args are of TypeKind
- (GenType tyvar uvar)
- (GenUsage uvar)
-
- | DictTy -- TypeKind
- Class -- Class
- (GenType tyvar uvar) -- Arg has kind TypeKind
- (GenUsage uvar)
-\end{code}
+ mkForAllTy, mkForAllTys, splitForAllTy_maybe, splitForAllTys,
+ applyTy, applyTys, isForAllTy,
-\begin{code}
-type RhoType = Type
-type TauType = Type
-type ThetaType = [(Class, Type)]
-type SigmaType = Type
-\end{code}
+ -- Source types
+ SourceType(..), sourceTypeRep, mkPredTy, mkPredTys,
+ -- Newtypes
+ splitNewType_maybe,
-Expand abbreviations
-~~~~~~~~~~~~~~~~~~~~
-Removes just the top level of any abbreviations.
+ -- Lifting and boxity
+ isUnLiftedType, isUnboxedTupleType, isAlgType, isStrictType, isPrimitiveType,
-\begin{code}
-expandTy :: Type -> Type -- Restricted to Type due to Dict expansion
+ -- Free variables
+ tyVarsOfType, tyVarsOfTypes, tyVarsOfPred, tyVarsOfTheta,
+ usageAnnOfType, typeKind, addFreeTyVars,
-expandTy (FunTy t1 t2 u) = AppTy (AppTy (TyConTy mkFunTyCon u) t1) t2
-expandTy (SynTy _ _ t) = expandTy t
-expandTy (DictTy clas ty u)
- = case all_arg_tys of
+ -- Tidying up for printing
+ tidyType, tidyTypes,
+ tidyOpenType, tidyOpenTypes,
+ tidyTyVarBndr, tidyFreeTyVars,
+ tidyOpenTyVar, tidyOpenTyVars,
+ tidyTopType, tidyPred,
- [] -> voidTy -- Empty dictionary represented by Void
+ -- Comparison
+ eqType, eqKind, eqUsage,
- [arg_ty] -> expandTy arg_ty -- just the <whatever> itself
+ -- Seq
+ seqType, seqTypes
- -- The extra expandTy is to make sure that
- -- the result isn't still a dict, which it might be
- -- if the original guy was a dict with one superdict and
- -- no methods!
+ ) where
- other -> ASSERT(not (null all_arg_tys))
- foldl AppTy (TyConTy (mkTupleTyCon (length all_arg_tys)) u) all_arg_tys
+#include "HsVersions.h"
- -- A tuple of 'em
- -- Note: length of all_arg_tys can be 0 if the class is
- -- CCallable, CReturnable (and anything else
- -- *really weird* that the user writes).
- where
- (tyvar, super_classes, ops) = classSig clas
- super_dict_tys = map mk_super_ty super_classes
- class_op_tys = map mk_op_ty ops
- all_arg_tys = super_dict_tys ++ class_op_tys
- mk_super_ty sc = DictTy sc ty usageOmega
- mk_op_ty op = instantiateTy [(tyvar,ty)] (classOpLocalType op)
-
-expandTy ty = ty
-\end{code}
+-- We import the representation and primitive functions from TypeRep.
+-- Many things are reexported, but not the representation!
-Simple construction and analysis functions
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-\begin{code}
-mkTyVarTy :: t -> GenType t u
-mkTyVarTys :: [t] -> [GenType t y]
-mkTyVarTy = TyVarTy
-mkTyVarTys = map mkTyVarTy -- a common use of mkTyVarTy
+import TypeRep
-getTyVar :: String -> GenType t u -> t
-getTyVar msg (TyVarTy tv) = tv
-getTyVar msg (SynTy _ _ t) = getTyVar msg t
-getTyVar msg other = panic ("getTyVar: " ++ msg)
+-- Other imports:
-getTyVar_maybe :: GenType t u -> Maybe t
-getTyVar_maybe (TyVarTy tv) = Just tv
-getTyVar_maybe (SynTy _ _ t) = getTyVar_maybe t
-getTyVar_maybe other = Nothing
+import {-# SOURCE #-} PprType( pprType ) -- Only called in debug messages
+import {-# SOURCE #-} Subst ( substTyWith )
-isTyVarTy :: GenType t u -> Bool
-isTyVarTy (TyVarTy tv) = True
-isTyVarTy (SynTy _ _ t) = isTyVarTy t
-isTyVarTy other = False
-\end{code}
+-- friends:
+import Var ( Var, TyVar, tyVarKind, tyVarName, setTyVarName )
+import VarEnv
+import VarSet
+
+import Name ( NamedThing(..), mkLocalName, tidyOccName )
+import Class ( classTyCon )
+import TyCon ( TyCon, isRecursiveTyCon, isPrimTyCon,
+ isUnboxedTupleTyCon, isUnLiftedTyCon,
+ isFunTyCon, isNewTyCon, newTyConRep,
+ isAlgTyCon, isSynTyCon, tyConArity,
+ tyConKind, getSynTyConDefn,
+ tyConPrimRep,
+ )
-\begin{code}
-mkAppTy = AppTy
+-- others
+import CmdLineOpts ( opt_DictsStrict )
+import Maybes ( maybeToBool )
+import SrcLoc ( noSrcLoc )
+import PrimRep ( PrimRep(..) )
+import Unique ( Uniquable(..) )
+import Util ( mapAccumL, seqList )
+import Outputable
+import UniqSet ( sizeUniqSet ) -- Should come via VarSet
+\end{code}
-mkAppTys :: GenType t u -> [GenType t u] -> GenType t u
-mkAppTys t ts = foldl AppTy t ts
-splitAppTy :: GenType t u -> (GenType t u, [GenType t u])
-splitAppTy t = go t []
- where
- go (AppTy t arg) ts = go t (arg:ts)
- go (FunTy fun arg u) ts = (TyConTy mkFunTyCon u, fun:arg:ts)
- go (SynTy _ _ t) ts = go t ts
- go t ts = (t,ts)
-\end{code}
+%************************************************************************
+%* *
+\subsection{Stuff to do with kinds.}
+%* *
+%************************************************************************
\begin{code}
--- NB mkFunTy, mkFunTys puts in Omega usages, for now at least
-mkFunTy arg res = FunTy arg res usageOmega
-
-mkFunTys :: [GenType t u] -> GenType t u -> GenType t u
-mkFunTys ts t = foldr (\ f a -> FunTy f a usageOmega) t ts
-
- -- getFunTy_maybe and splitFunTy *must* have the general type given, which
- -- means they *can't* do the DictTy jiggery-pokery that
- -- *is* sometimes required. Hence we also have the ExpandingDicts variants
- -- The relationship between these
- -- two functions is like that between eqTy and eqSimpleTy.
- -- ToDo: NUKE when we do dicts via newtype
-
-getFunTy_maybe :: GenType t u -> Maybe (GenType t u, GenType t u)
-getFunTy_maybe (FunTy arg result _) = Just (arg,result)
-getFunTy_maybe (AppTy (AppTy (TyConTy tycon _) arg) res)
- | isFunTyCon tycon = Just (arg, res)
-getFunTy_maybe (SynTy _ _ t) = getFunTy_maybe t
-getFunTy_maybe other = Nothing
-
-getFunTyExpandingDicts_maybe :: Bool -- True <=> peek inside newtype applicatons
- -> Type
- -> Maybe (Type, Type)
-
-getFunTyExpandingDicts_maybe peek (FunTy arg result _) = Just (arg,result)
-getFunTyExpandingDicts_maybe peek
- (AppTy (AppTy (TyConTy tycon _) arg) res) | isFunTyCon tycon = Just (arg, res)
-getFunTyExpandingDicts_maybe peek (SynTy _ _ t) = getFunTyExpandingDicts_maybe peek t
-getFunTyExpandingDicts_maybe peek ty@(DictTy _ _ _) = getFunTyExpandingDicts_maybe peek (expandTy ty)
-getFunTyExpandingDicts_maybe peek other
- | not peek = Nothing -- that was easy
- | otherwise
- = case (maybeAppTyCon other) of
- Nothing -> Nothing
- Just (tc, arg_tys)
- | not (isNewTyCon tc) -> Nothing
- | otherwise ->
- let
- [newtype_con] = tyConDataCons tc -- there must be exactly one...
- [inside_ty] = dataConArgTys newtype_con arg_tys
- in
- getFunTyExpandingDicts_maybe peek inside_ty
-
-splitFunTy :: GenType t u -> ([GenType t u], GenType t u)
-splitFunTyExpandingDicts :: Type -> ([Type], Type)
-splitFunTyExpandingDictsAndPeeking :: Type -> ([Type], Type)
-
-splitFunTy t = split_fun_ty getFunTy_maybe t
-splitFunTyExpandingDicts t = split_fun_ty (getFunTyExpandingDicts_maybe False) t
-splitFunTyExpandingDictsAndPeeking t = split_fun_ty (getFunTyExpandingDicts_maybe True) t
-
-split_fun_ty get t = go t []
- where
- go t ts = case (get t) of
- Just (arg,res) -> go res (arg:ts)
- Nothing -> (reverse ts, t)
+hasMoreBoxityInfo :: Kind -> Kind -> Bool
+hasMoreBoxityInfo k1 k2
+ | 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}
-\begin{code}
--- NB applyTyCon puts in usageOmega, for now at least
-mkTyConTy tycon
- = ASSERT(not (isSynTyCon tycon))
- TyConTy tycon usageOmega
-applyTyCon :: TyCon -> [GenType t u] -> GenType t u
-applyTyCon tycon tys
- = --ASSERT (not (isSynTyCon tycon))
- (if (not (isSynTyCon tycon)) then \x->x else pprTrace "applyTyCon:" (pprTyCon PprDebug tycon)) $
- foldl AppTy (TyConTy tycon usageOmega) tys
+%************************************************************************
+%* *
+\subsection{Constructor-specific functions}
+%* *
+%************************************************************************
-getTyCon_maybe :: GenType t u -> Maybe TyCon
---getTyConExpandingDicts_maybe :: Type -> Maybe TyCon
-getTyCon_maybe (TyConTy tycon _) = Just tycon
-getTyCon_maybe (SynTy _ _ t) = getTyCon_maybe t
-getTyCon_maybe other_ty = Nothing
+---------------------------------------------------------------------
+ TyVarTy
+ ~~~~~~~
+\begin{code}
+mkTyVarTy :: TyVar -> Type
+mkTyVarTy = TyVarTy
+
+mkTyVarTys :: [TyVar] -> [Type]
+mkTyVarTys = map mkTyVarTy -- a common use of mkTyVarTy
---getTyConExpandingDicts_maybe (TyConTy tycon _) = Just tycon
---getTyConExpandingDicts_maybe (SynTy _ _ t) = getTyConExpandingDicts_maybe t
---getTyConExpandingDicts_maybe ty@(DictTy _ _ _) = getTyConExpandingDicts_maybe (expandTy ty)
---getTyConExpandingDicts_maybe other_ty = Nothing
+getTyVar :: String -> Type -> TyVar
+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 (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 (SourceTy p) = isTyVarTy (sourceTypeRep p)
+isTyVarTy ty@(UsageTy _ _) = pprPanic "isTyVarTy: UTy:" (pprType ty)
+isTyVarTy other = False
\end{code}
+
+---------------------------------------------------------------------
+ AppTy
+ ~~~~~
+We need to be pretty careful with AppTy to make sure we obey the
+invariant that a TyConApp is always visibly so. mkAppTy maintains the
+invariant: use it.
+
\begin{code}
-mkSynTy syn_tycon tys
- = ASSERT(isSynTyCon syn_tycon)
- SynTy syn_tycon tys (instantiateTauTy (zipEqual "mkSynTy" tyvars tys) body)
+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 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
+ = 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
- (tyvars, body) = getSynTyConDefn syn_tycon
+ mk_app (NoteTy _ ty1) = mk_app ty1
+ mk_app (TyConApp tc tys) = mkTyConApp tc (tys ++ 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 [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)
+splitAppTy ty = case splitAppTy_maybe ty of
+ Just pr -> pr
+ Nothing -> panic "splitAppTy"
+
+splitAppTys :: Type -> (Type, [Type])
+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 [], [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}
-Tau stuff
-~~~~~~~~~
-\begin{code}
-isTauTy :: GenType t u -> Bool
-isTauTy (TyVarTy v) = True
-isTauTy (TyConTy _ _) = True
-isTauTy (AppTy a b) = isTauTy a && isTauTy b
-isTauTy (FunTy a b _) = isTauTy a && isTauTy b
-isTauTy (SynTy _ _ ty) = isTauTy ty
-isTauTy other = False
-\end{code}
-Rho stuff
-~~~~~~~~~
-NB mkRhoTy and mkDictTy put in usageOmega, for now at least
+---------------------------------------------------------------------
+ FunTy
+ ~~~~~
\begin{code}
-mkDictTy :: Class -> GenType t u -> GenType t u
-mkDictTy clas ty = DictTy clas ty usageOmega
-
-mkRhoTy :: [(Class, GenType t u)] -> GenType t u -> GenType t u
-mkRhoTy theta ty =
- foldr (\(c,t) r -> FunTy (DictTy c t usageOmega) r usageOmega) ty theta
-
-splitRhoTy :: GenType t u -> ([(Class,GenType t u)], GenType t u)
-splitRhoTy t =
- go t []
- where
- go (FunTy (DictTy c t _) r _) ts = go r ((c,t):ts)
- go (AppTy (AppTy (TyConTy tycon _) (DictTy c t _)) r) ts
- | isFunTyCon tycon
- = go r ((c,t):ts)
- go (SynTy _ _ t) ts = go t ts
- go t ts = (reverse ts, t)
-
-
-mkTheta :: [Type] -> ThetaType
- -- recover a ThetaType from the types of some dictionaries
-mkTheta dict_tys
- = map cvt dict_tys
+mkFunTy :: Type -> Type -> Type
+mkFunTy arg res = UASSERT2( isUTy arg && isUTy res, pprType arg <+> pprType res )
+ FunTy arg res
+
+mkFunTys :: [Type] -> Type -> Type
+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)
+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)
+
+zipFunTys :: Outputable a => [a] -> Type -> ([(a,Type)], Type)
+zipFunTys orig_xs orig_ty = split [] orig_xs orig_ty orig_ty
where
- cvt (DictTy clas ty _) = (clas, ty)
- cvt other = pprPanic "mkTheta:" (pprType PprDebug other)
+ 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}
-Forall stuff
-~~~~~~~~~~~~
-\begin{code}
-mkForAllTy = ForAllTy
-
-mkForAllTys :: [t] -> GenType t u -> GenType t u
-mkForAllTys tyvars ty = foldr ForAllTy ty tyvars
-
-getForAllTy_maybe :: GenType t u -> Maybe (t,GenType t u)
-getForAllTy_maybe (SynTy _ _ t) = getForAllTy_maybe t
-getForAllTy_maybe (ForAllTy tyvar t) = Just(tyvar,t)
-getForAllTy_maybe _ = Nothing
-
-getForAllTyExpandingDicts_maybe :: Type -> Maybe (TyVar, Type)
-getForAllTyExpandingDicts_maybe (SynTy _ _ t) = getForAllTyExpandingDicts_maybe t
-getForAllTyExpandingDicts_maybe (ForAllTy tyvar t) = Just(tyvar,t)
-getForAllTyExpandingDicts_maybe ty@(DictTy _ _ _) = getForAllTyExpandingDicts_maybe (expandTy ty)
-getForAllTyExpandingDicts_maybe _ = Nothing
-
-splitForAllTy :: GenType t u-> ([t], GenType t u)
-splitForAllTy t = go t []
- where
- go (ForAllTy tv t) tvs = go t (tv:tvs)
- go (SynTy _ _ t) tvs = go t tvs
- go t tvs = (reverse tvs, t)
-\end{code}
+---------------------------------------------------------------------
+ TyConApp
+ ~~~~~~~~
+@mkTyConApp@ is a key function, because it builds a TyConApp, FunTy or SourceTy,
+as apppropriate.
\begin{code}
-mkForAllUsageTy :: u -> [u] -> GenType t u -> GenType t u
-mkForAllUsageTy = ForAllUsageTy
+mkTyConApp :: TyCon -> [Type] -> Type
+-- Assumes TyCon is not a SynTyCon; use mkSynTy instead for those
+mkTyConApp tycon tys
+ | isFunTyCon tycon, [ty1,ty2] <- tys
+ = FunTy (mkUTyM ty1) (mkUTyM ty2)
-getForAllUsageTy :: GenType t u -> Maybe (u,[u],GenType t u)
-getForAllUsageTy (ForAllUsageTy uvar bounds t) = Just(uvar,bounds,t)
-getForAllUsageTy (SynTy _ _ t) = getForAllUsageTy t
-getForAllUsageTy _ = Nothing
+ | 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
+mkTyConTy tycon = ASSERT( not (isSynTyCon tycon) )
+ TyConApp tycon []
+
+-- splitTyConApp "looks through" synonyms, because they don't
+-- 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, [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
\end{code}
-Applied tycons (includes FunTyCons)
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-\begin{code}
-maybeAppTyCon
- :: GenType tyvar uvar
- -> Maybe (TyCon, -- the type constructor
- [GenType tyvar uvar]) -- types to which it is applied
-
-maybeAppTyCon ty
- = case (getTyCon_maybe app_ty) of
- Nothing -> Nothing
- Just tycon -> Just (tycon, arg_tys)
- where
- (app_ty, arg_tys) = splitAppTy ty
+---------------------------------------------------------------------
+ SynTy
+ ~~~~~
-getAppTyCon
- :: GenType tyvar uvar
- -> (TyCon, -- the type constructor
- [GenType tyvar uvar]) -- types to which it is applied
+\begin{code}
+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.
-getAppTyCon ty
- = case maybeAppTyCon ty of
- Just stuff -> stuff
-#ifdef DEBUG
- Nothing -> panic "Type.getAppTyCon" -- (ppr PprShowAll ty)
-#endif
+ where
+ 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}
-Applied data tycons (give back constrs)
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-\begin{code}
-maybeAppDataTyCon
- :: GenType (GenTyVar any) uvar
- -> Maybe (TyCon, -- the type constructor
- [GenType (GenTyVar any) uvar], -- types to which it is applied
- [Id]) -- its family of data-constructors
-maybeAppDataTyConExpandingDicts, maybeAppSpecDataTyConExpandingDicts
- :: Type -> Maybe (TyCon, [Type], [Id])
+Notes on type synonyms
+~~~~~~~~~~~~~~~~~~~~~~
+The various "split" functions (splitFunTy, splitRhoTy, splitForAllTy) try
+to return type synonyms whereever possible. Thus
-maybeAppDataTyCon ty = maybe_app_data_tycon (\x->x) ty
-maybeAppDataTyConExpandingDicts ty = maybe_app_data_tycon expandTy ty
-maybeAppSpecDataTyConExpandingDicts ty = maybe_app_data_tycon expandTy ty
+ type Foo a = a -> a
+we want
+ splitFunTys (a -> Foo a) = ([a], Foo a)
+not ([a], a -> a)
-maybe_app_data_tycon expand ty
- = let
- expanded_ty = expand ty
- (app_ty, arg_tys) = splitAppTy expanded_ty
- in
- case (getTyCon_maybe app_ty) of
- Just tycon | --pprTrace "maybe_app:" (ppCat [ppr PprDebug (isDataTyCon tycon), ppr PprDebug (notArrowKind (typeKind expanded_ty))]) $
- isDataTyCon tycon &&
- notArrowKind (typeKind expanded_ty)
- -- Must be saturated for ty to be a data type
- -> Just (tycon, arg_tys, tyConDataCons tycon)
-
- other -> Nothing
-
-getAppDataTyCon, getAppSpecDataTyCon
- :: GenType (GenTyVar any) uvar
- -> (TyCon, -- the type constructor
- [GenType (GenTyVar any) uvar], -- types to which it is applied
- [Id]) -- its family of data-constructors
-getAppDataTyConExpandingDicts, getAppSpecDataTyConExpandingDicts
- :: Type -> (TyCon, [Type], [Id])
-
-getAppDataTyCon ty = get_app_data_tycon maybeAppDataTyCon ty
-getAppDataTyConExpandingDicts ty = --pprTrace "getAppDataTyConEx...:" (pprType PprDebug ty) $
- get_app_data_tycon maybeAppDataTyConExpandingDicts ty
-
--- these should work like the UniTyFuns.getUniDataSpecTyCon* things of old (ToDo)
-getAppSpecDataTyCon = getAppDataTyCon
-getAppSpecDataTyConExpandingDicts = getAppDataTyConExpandingDicts
-
-get_app_data_tycon maybe ty
- = case maybe ty of
- Just stuff -> stuff
-#ifdef DEBUG
- Nothing -> panic "Type.getAppDataTyCon" -- (pprGenType PprShowAll ty)
-#endif
+The reason is that we then get better (shorter) type signatures in
+interfaces. Notably this plays a role in tcTySigs in TcBinds.lhs.
-maybeBoxedPrimType :: Type -> Maybe (Id, Type)
+ Representation types
+ ~~~~~~~~~~~~~~~~~~~~
-maybeBoxedPrimType ty
- = case (maybeAppDataTyCon ty) of -- Data type,
- Just (tycon, tys_applied, [data_con]) -- with exactly one constructor
- -> case (dataConArgTys data_con tys_applied) of
- [data_con_arg_ty] -- Applied to exactly one type,
- | isPrimType data_con_arg_ty -- which is primitive
- -> Just (data_con, data_con_arg_ty)
- other_cases -> Nothing
- other_cases -> Nothing
-\end{code}
+repType looks through
+ (a) for-alls, and
+ (b) synonyms
+ (c) predicates
+ (d) usage annotations
+ (e) [recursive] newtypes
+It's useful in the back end.
+
+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}
-splitSigmaTy :: GenType t u -> ([t], [(Class,GenType t u)], GenType t u)
-splitSigmaTy ty =
- (tyvars, theta, tau)
- where
- (tyvars,rho) = splitForAllTy ty
- (theta,tau) = splitRhoTy rho
+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)
-mkSigmaTy tyvars theta tau = mkForAllTys tyvars (mkRhoTy theta tau)
+typePrimRep :: Type -> PrimRep
+typePrimRep ty = case repType ty of
+ TyConApp tc _ -> tyConPrimRep tc
+ FunTy _ _ -> PtrRep
+ AppTy _ _ -> PtrRep -- ??
+ TyVarTy _ -> PtrRep
\end{code}
-Finding the kind of a type
-~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+---------------------------------------------------------------------
+ ForAllTy
+ ~~~~~~~~
+
\begin{code}
-typeKind :: GenType (GenTyVar any) u -> Kind
-
-typeKind (TyVarTy tyvar) = tyVarKind tyvar
-typeKind (TyConTy tycon usage) = tyConKind tycon
-typeKind (SynTy _ _ ty) = typeKind ty
-typeKind (FunTy fun arg _) = mkBoxedTypeKind
-typeKind (DictTy clas arg _) = mkBoxedTypeKind
-typeKind (AppTy fun arg) = resultKind (typeKind fun)
-typeKind (ForAllTy _ _) = mkBoxedTypeKind
-typeKind (ForAllUsageTy _ _ _) = mkBoxedTypeKind
+mkForAllTy :: TyVar -> Type -> Type
+mkForAllTy tyvar ty
+ = mkForAllTys [tyvar] ty
+
+mkForAllTys :: [TyVar] -> Type -> Type
+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 = splitFAT_m ty
+ where
+ 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 = 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 (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 now in CoreUtils)
+
+Applying a for-all to its arguments. Lift usage annotation as required.
-Free variables of a type
-~~~~~~~~~~~~~~~~~~~~~~~~
\begin{code}
-tyVarsOfType :: GenType (GenTyVar flexi) uvar -> GenTyVarSet flexi
-
-tyVarsOfType (TyVarTy tv) = unitTyVarSet tv
-tyVarsOfType (TyConTy tycon usage) = emptyTyVarSet
-tyVarsOfType (SynTy _ tys ty) = tyVarsOfTypes tys
-tyVarsOfType (FunTy arg res _) = tyVarsOfType arg `unionTyVarSets` tyVarsOfType res
-tyVarsOfType (AppTy fun arg) = tyVarsOfType fun `unionTyVarSets` tyVarsOfType arg
-tyVarsOfType (DictTy clas ty _) = tyVarsOfType ty
-tyVarsOfType (ForAllTy tyvar ty) = tyVarsOfType ty `minusTyVarSet` unitTyVarSet tyvar
-tyVarsOfType (ForAllUsageTy _ _ ty) = tyVarsOfType ty
-
-tyVarsOfTypes :: [GenType (GenTyVar flexi) uvar] -> GenTyVarSet flexi
-tyVarsOfTypes tys = foldr (unionTyVarSets.tyVarsOfType) emptyTyVarSet tys
+applyTy :: Type -> Type -> Type
+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
+ = 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
+ (mu, tvs, ty) = split fun_ty arg_tys
+
+ split fun_ty [] = (Nothing, [], fun_ty)
+ split (NoteTy _ fun_ty) args = split fun_ty args
+ 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}
-Instantiating a type
-~~~~~~~~~~~~~~~~~~~~
-\begin{code}
-applyTy :: GenType (GenTyVar flexi) uvar
- -> GenType (GenTyVar flexi) uvar
- -> GenType (GenTyVar flexi) uvar
+---------------------------------------------------------------------
+ UsageTy
+ ~~~~~~~
-applyTy (SynTy _ _ fun) arg = applyTy fun arg
-applyTy (ForAllTy tv ty) arg = instantiateTy [(tv,arg)] ty
-applyTy other arg = panic "applyTy"
-\end{code}
+Constructing and taking apart usage types.
\begin{code}
-instantiateTy :: [(GenTyVar flexi, GenType (GenTyVar flexi) uvar)]
- -> GenType (GenTyVar flexi) uvar
- -> GenType (GenTyVar flexi) uvar
+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
-instantiateTauTy :: Eq tv =>
- [(tv, GenType tv' u)]
- -> GenType tv u
- -> GenType tv' u
+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
-applyTypeEnvToTy :: TyVarEnv Type -> SigmaType -> SigmaType
+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
--- instantiateTauTy works only (a) on types with no ForAlls,
--- and when (b) all the type variables are being instantiated
--- In return it is more polymorphic than instantiateTy
+isUTy :: Type -> Bool
+ -- has usage annotation
+isUTy = maybeToBool . splitUTy_maybe
-instant_help ty lookup_tv deflt_tv choose_tycon
- if_usage if_forall bound_forall_tv_BAD deflt_forall_tv
- = go ty
- where
- go (TyVarTy tv) = case (lookup_tv tv) of
- Nothing -> deflt_tv tv
- Just ty -> ty
- go ty@(TyConTy tycon usage) = choose_tycon ty tycon usage
- go (SynTy tycon tys ty) = SynTy tycon (map go tys) (go ty)
- go (FunTy arg res usage) = FunTy (go arg) (go res) usage
- go (AppTy fun arg) = AppTy (go fun) (go arg)
- go (DictTy clas ty usage) = DictTy clas (go ty) usage
- go (ForAllUsageTy uvar bds ty) = if_usage $
- ForAllUsageTy uvar bds (go ty)
- go (ForAllTy tv ty) = if_forall $
- (if (bound_forall_tv_BAD && maybeToBool (lookup_tv tv)) then
- trace "instantiateTy: unexpected forall hit"
- else
- \x->x) ForAllTy (deflt_forall_tv tv) (go ty)
-
-instantiateTy tenv ty
- = instant_help ty lookup_tv deflt_tv choose_tycon
- if_usage if_forall bound_forall_tv_BAD deflt_forall_tv
- where
- lookup_tv tv = case [ty | (tv',ty) <- tenv, tv == tv'] of
- [] -> Nothing
- [ty] -> Just ty
- _ -> panic "instantiateTy:lookup_tv"
-
- deflt_tv tv = TyVarTy tv
- choose_tycon ty _ _ = ty
- if_usage ty = ty
- if_forall ty = ty
- bound_forall_tv_BAD = True
- deflt_forall_tv tv = tv
-
-instantiateTauTy tenv ty
- = instant_help ty lookup_tv deflt_tv choose_tycon
- if_usage if_forall bound_forall_tv_BAD deflt_forall_tv
- where
- lookup_tv tv = case [ty | (tv',ty) <- tenv, tv == tv'] of
- [] -> Nothing
- [ty] -> Just ty
- _ -> panic "instantiateTauTy:lookup_tv"
-
- deflt_tv tv = panic "instantiateTauTy"
- choose_tycon _ tycon usage = TyConTy tycon usage
- if_usage ty = panic "instantiateTauTy:ForAllUsageTy"
- if_forall ty = panic "instantiateTauTy:ForAllTy"
- bound_forall_tv_BAD = panic "instantiateTauTy:bound_forall_tv"
- deflt_forall_tv tv = panic "instantiateTauTy:deflt_forall_tv"
-
-
--- applyTypeEnv applies a type environment to a type.
--- It can handle shadowing; for example:
--- f = /\ t1 t2 -> \ d ->
--- letrec f' = /\ t1 -> \x -> ...(f' t1 x')...
--- in f' t1
--- Here, when we clone t1 to t1', say, we'll come across shadowing
--- when applying the clone environment to the type of f'.
---
--- As a sanity check, we should also check that name capture
--- doesn't occur, but that means keeping track of the free variables of the
--- range of the TyVarEnv, which I don't do just yet.
---
--- We don't use instant_help because we need to carry in the environment
-
-applyTypeEnvToTy tenv ty
- = go tenv ty
- where
- go tenv ty@(TyVarTy tv) = case (lookupTyVarEnv tenv tv) of
- Nothing -> ty
- Just ty -> ty
- go tenv ty@(TyConTy tycon usage) = ty
- go tenv (SynTy tycon tys ty) = SynTy tycon (map (go tenv) tys) (go tenv ty)
- go tenv (FunTy arg res usage) = FunTy (go tenv arg) (go tenv res) usage
- go tenv (AppTy fun arg) = AppTy (go tenv fun) (go tenv arg)
- go tenv (DictTy clas ty usage) = DictTy clas (go tenv ty) usage
- go tenv (ForAllUsageTy uvar bds ty) = ForAllUsageTy uvar bds (go tenv ty)
- go tenv (ForAllTy tv ty) = ForAllTy tv (go tenv' ty)
- where
- tenv' = case lookupTyVarEnv tenv tv of
- Nothing -> tenv
- Just _ -> delFromTyVarEnv tenv tv
+uaUTy :: Type -> Type
+ -- extract annotation
+uaUTy = fst . splitUTy
+
+unUTy :: Type -> Type
+ -- extract unannotated type
+unUTy = snd . splitUTy
+\end{code}
+
+\begin{code}
+liftUTy :: (Type -> Type) -> Type -> Type
+ -- lift outer usage annot over operation on unannotated types
+liftUTy f ty
+ = let
+ (u,ty') = splitUTy ty
+ in
+ mkUTy u (f ty')
\end{code}
\begin{code}
-instantiateUsage
- :: Ord3 u => [(u, GenType t u')] -> GenType t u -> GenType t u'
+mkUTyM :: Type -> Type
+ -- put TOP (no info) annotation on unannotated type
+mkUTyM ty = mkUTy usMany ty
+\end{code}
-instantiateUsage = panic "instantiateUsage: not implemented"
+\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}
-At present there are no unboxed non-primitive types, so
-isUnboxedType is the same as isPrimType.
+%************************************************************************
+%* *
+\subsection{Source types}
+%* *
+%************************************************************************
+
+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.
+
+Source types are always lifted.
-We're a bit cavalier about finding out whether something is
-primitive/unboxed or not. Rather than deal with the type
-arguemnts we just zoom into the function part of the type.
-That is, given (T a) we just recurse into the "T" part,
-ignoring "a".
+The key function is sourceTypeRep which gives the representation of a source type:
\begin{code}
-isPrimType, isUnboxedType :: Type -> Bool
+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}
-isPrimType (AppTy ty _) = isPrimType ty
-isPrimType (SynTy _ _ ty) = isPrimType ty
-isPrimType (TyConTy tycon _) = case maybeNewTyCon tycon of
- Just (tyvars, ty) -> isPrimType ty
- Nothing -> isPrimTyCon tycon
-isPrimType _ = False
+%************************************************************************
+%* *
+\subsection{Kinds and free variables}
+%* *
+%************************************************************************
-isUnboxedType = isPrimType
+---------------------------------------------------------------------
+ Finding the kind of a type
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~
+\begin{code}
+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) = 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}
-This is *not* right: it is a placeholder (ToDo 96/03 WDP):
+
+---------------------------------------------------------------------
+ Free variables of a type
+ ~~~~~~~~~~~~~~~~~~~~~~~~
\begin{code}
-typePrimRep :: Type -> PrimRep
+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 (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
+addFreeTyVars :: Type -> Type
+addFreeTyVars ty@(NoteTy (FTVNote _) _) = ty
+addFreeTyVars ty = NoteTy (FTVNote (tyVarsOfType ty)) ty
+\end{code}
+
+Usage annotations of a type
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
-typePrimRep (SynTy _ _ ty) = typePrimRep ty
-typePrimRep (AppTy ty _) = typePrimRep ty
-typePrimRep (TyConTy tc _)
- | isPrimTyCon tc = case (assocMaybe tc_primrep_list (uniqueOf tc)) of
- Just xx -> xx
- Nothing -> pprPanic "typePrimRep:" (pprTyCon PprDebug tc)
-
- | otherwise = case maybeNewTyCon tc of
- Just (tyvars, ty) | isPrimType ty -> typePrimRep ty
- _ -> PtrRep -- Default
-
-typePrimRep _ = PtrRep -- the "default"
-
-tc_primrep_list
- = [(addrPrimTyConKey, AddrRep)
- ,(arrayPrimTyConKey, ArrayRep)
- ,(byteArrayPrimTyConKey, ByteArrayRep)
- ,(charPrimTyConKey, CharRep)
- ,(doublePrimTyConKey, DoubleRep)
- ,(floatPrimTyConKey, FloatRep)
- ,(foreignObjPrimTyConKey, ForeignObjRep)
- ,(intPrimTyConKey, IntRep)
- ,(mutableArrayPrimTyConKey, ArrayRep)
- ,(mutableByteArrayPrimTyConKey, ByteArrayRep)
- ,(stablePtrPrimTyConKey, StablePtrRep)
- ,(statePrimTyConKey, VoidRep)
- ,(synchVarPrimTyConKey, PtrRep)
- ,(voidTyConKey, VoidRep)
- ,(wordPrimTyConKey, WordRep)
- ]
+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}
+
%************************************************************************
%* *
-\subsection{Matching on types}
+\subsection{TidyType}
%* *
%************************************************************************
-Matching is a {\em unidirectional} process, matching a type against a
-template (which is just a type with type variables in it). The
-matcher assumes that there are no repeated type variables in the
-template, so that it simply returns a mapping of type variables to
-types. It also fails on nested foralls.
+tidyTy tidies up a type for printing in an error message, or in
+an interface file.
-@matchTys@ matches corresponding elements of a list of templates and
-types.
+It doesn't change the uniques at all, just the print names.
\begin{code}
-matchTy :: GenType t1 u1 -- Template
- -> GenType t2 u2 -- Proposed instance of template
- -> Maybe [(t1,GenType t2 u2)] -- Matching substitution
+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
-matchTys :: [GenType t1 u1] -- Templates
- -> [GenType t2 u2] -- Proposed instance of template
- -> Maybe [(t1,GenType t2 u2)] -- Matching substitution
+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))
-matchTy ty1 ty2 = match [] [] ty1 ty2
-matchTys tys1 tys2 = match' [] (zipEqual "matchTys" tys1 tys2)
+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
+ = go ty
+ where
+ go (TyVarTy tv) = case lookupVarEnv subst tv of
+ Nothing -> TyVarTy tv
+ 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 (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 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
+
+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}
-@match@ is the main function.
+
+@tidyOpenType@ grabs the free type variables, tidies them
+and then uses @tidyType@ to work over the type itself
\begin{code}
-match :: [(t1, GenType t2 u2)] -- r, the accumulating result
- -> [(GenType t1 u1, GenType t2 u2)] -- w, the work list
- -> GenType t1 u1 -> GenType t2 u2 -- Current match pair
- -> Maybe [(t1, GenType t2 u2)]
-
-match r w (TyVarTy v) ty = match' ((v,ty) : r) w
-match r w (FunTy fun1 arg1 _) (FunTy fun2 arg2 _) = match r ((fun1,fun2):w) arg1 arg2
-match r w (AppTy fun1 arg1) (AppTy fun2 arg2) = match r ((fun1,fun2):w) arg1 arg2
-match r w (TyConTy con1 _) (TyConTy con2 _) | con1 == con2 = match' r w
-match r w (DictTy clas1 ty1 _) (DictTy clas2 ty2 _) | clas1 == clas2 = match r w ty1 ty2
-match r w (SynTy _ _ ty1) ty2 = match r w ty1 ty2
-match r w ty1 (SynTy _ _ ty2) = match r w ty1 ty2
-
- -- With type synonyms, we have to be careful for the exact
- -- same reasons as in the unifier. Please see the
- -- considerable commentary there before changing anything
- -- here! (WDP 95/05)
-
--- Catch-all fails
-match _ _ _ _ = Nothing
-
-match' r [] = Just r
-match' r ((ty1,ty2):w) = match r w ty1 ty2
+tidyOpenType :: TidyEnv -> Type -> (TidyEnv, Type)
+tidyOpenType env ty
+ = (env', tidyType env' ty)
+ where
+ env' = tidyFreeTyVars env (tyVarsOfType ty)
+
+tidyOpenTypes :: TidyEnv -> [Type] -> (TidyEnv, [Type])
+tidyOpenTypes env tys = mapAccumL tidyOpenType env tys
+
+tidyTopType :: Type -> Type
+tidyTopType ty = tidyType emptyTidyEnv ty
\end{code}
+
+
%************************************************************************
%* *
-\subsection{Equality on types}
+\subsection{Liftedness}
%* *
%************************************************************************
-The functions eqSimpleTy and eqSimpleTheta are polymorphic in the types t
-and u, but ONLY WORK FOR SIMPLE TYPES (ie. they panic if they see
-dictionaries or polymorphic types). The function eqTy has a more
-specific type, but does the `right thing' for all types.
-
\begin{code}
-eqSimpleTheta :: (Eq t,Eq u) =>
- [(Class,GenType t u)] -> [(Class,GenType t u)] -> Bool
+isUnLiftedType :: Type -> Bool
+ -- 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
+ Just (tc, ty_args) -> isUnboxedTupleTyCon tc
+ other -> False
+
+-- Should only be applied to *types*; hence the assert
+isAlgType :: Type -> Bool
+isAlgType ty = case splitTyConApp_maybe ty of
+ Just (tc, ty_args) -> ASSERT( length ty_args == tyConArity tc )
+ isAlgTyCon tc
+ other -> False
+\end{code}
+
+@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.
-eqSimpleTheta [] [] = True
-eqSimpleTheta ((c1,t1):th1) ((c2,t2):th2) =
- c1==c2 && t1 `eqSimpleTy` t2 && th1 `eqSimpleTheta` th2
-eqSimpleTheta other1 other2 = False
+\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}
-eqSimpleTy :: (Eq t,Eq u) => GenType t u -> GenType t u -> Bool
-
-(TyVarTy tv1) `eqSimpleTy` (TyVarTy tv2) =
- tv1 == tv2
-(AppTy f1 a1) `eqSimpleTy` (AppTy f2 a2) =
- f1 `eqSimpleTy` f2 && a1 `eqSimpleTy` a2
-(TyConTy tc1 u1) `eqSimpleTy` (TyConTy tc2 u2) =
- tc1 == tc2 --ToDo: later: && u1 == u2
-
-(FunTy f1 a1 u1) `eqSimpleTy` (FunTy f2 a2 u2) =
- f1 `eqSimpleTy` f2 && a1 `eqSimpleTy` a2 && u1 == u2
-(FunTy f1 a1 u1) `eqSimpleTy` t2 =
- -- Expand t1 just in case t2 matches that version
- (AppTy (AppTy (TyConTy mkFunTyCon u1) f1) a1) `eqSimpleTy` t2
-t1 `eqSimpleTy` (FunTy f2 a2 u2) =
- -- Expand t2 just in case t1 matches that version
- t1 `eqSimpleTy` (AppTy (AppTy (TyConTy mkFunTyCon u2) f2) a2)
-
-(SynTy tc1 ts1 t1) `eqSimpleTy` (SynTy tc2 ts2 t2) =
- (tc1 == tc2 && and (zipWith eqSimpleTy ts1 ts2) && length ts1 == length ts2)
- || t1 `eqSimpleTy` t2
-(SynTy _ _ t1) `eqSimpleTy` t2 =
- t1 `eqSimpleTy` t2 -- Expand the abbrevation and try again
-t1 `eqSimpleTy` (SynTy _ _ t2) =
- t1 `eqSimpleTy` t2 -- Expand the abbrevation and try again
-
-(DictTy _ _ _) `eqSimpleTy` _ = panic "eqSimpleTy: got DictTy"
-_ `eqSimpleTy` (DictTy _ _ _) = panic "eqSimpleTy: got DictTy"
-
-(ForAllTy _ _) `eqSimpleTy` _ = panic "eqSimpleTy: got ForAllTy"
-_ `eqSimpleTy` (ForAllTy _ _) = panic "eqSimpleTy: got ForAllTy"
-
-(ForAllUsageTy _ _ _) `eqSimpleTy` _ = panic "eqSimpleTy: got ForAllUsageTy"
-_ `eqSimpleTy` (ForAllUsageTy _ _ _) = panic "eqSimpleTy: got ForAllUsageTy"
-
-_ `eqSimpleTy` _ = False
+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 )
+ isPrimTyCon tc
+ other -> False
\end{code}
-Types are ordered so we can sort on types in the renamer etc. DNT: Since
-this class is also used in CoreLint and other such places, we DO expand out
-Fun/Syn/Dict types (if necessary).
+
+%************************************************************************
+%* *
+\subsection{Sequencing on types
+%* *
+%************************************************************************
\begin{code}
-eqTy :: Type -> Type -> Bool
+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}
-eqTy t1 t2 =
- eq nullTyVarEnv nullUVarEnv t1 t2
- where
- eq tve uve (TyVarTy tv1) (TyVarTy tv2) =
- tv1 == tv2 ||
- case (lookupTyVarEnv tve tv1) of
- Just tv -> tv == tv2
- Nothing -> False
- eq tve uve (AppTy f1 a1) (AppTy f2 a2) =
- eq tve uve f1 f2 && eq tve uve a1 a2
- eq tve uve (TyConTy tc1 u1) (TyConTy tc2 u2) =
- tc1 == tc2 -- ToDo: LATER: && eqUsage uve u1 u2
-
- eq tve uve (FunTy f1 a1 u1) (FunTy f2 a2 u2) =
- eq tve uve f1 f2 && eq tve uve a1 a2 && eqUsage uve u1 u2
- eq tve uve (FunTy f1 a1 u1) t2 =
- -- Expand t1 just in case t2 matches that version
- eq tve uve (AppTy (AppTy (TyConTy mkFunTyCon u1) f1) a1) t2
- eq tve uve t1 (FunTy f2 a2 u2) =
- -- Expand t2 just in case t1 matches that version
- eq tve uve t1 (AppTy (AppTy (TyConTy mkFunTyCon u2) f2) a2)
-
- eq tve uve (DictTy c1 t1 u1) (DictTy c2 t2 u2)
- | c1 == c2
- = eq tve uve t1 t2 && eqUsage uve u1 u2
- -- NB we use a guard for c1==c2 so that if they aren't equal we
- -- fall through into expanding the type. Why? Because brain-dead
- -- people might write
- -- class Foo a => Baz a where {}
- -- and that means that a Foo dictionary and a Baz dictionary are identical
- -- Sigh. Let's hope we don't spend too much time in here!
-
- eq tve uve t1@(DictTy _ _ _) t2 =
- eq tve uve (expandTy t1) t2 -- Expand the dictionary and try again
- eq tve uve t1 t2@(DictTy _ _ _) =
- eq tve uve t1 (expandTy t2) -- Expand the dictionary and try again
-
- eq tve uve (SynTy tc1 ts1 t1) (SynTy tc2 ts2 t2) =
- (tc1 == tc2 && and (zipWith (eq tve uve) ts1 ts2) && length ts1 == length ts2)
- || eq tve uve t1 t2
- eq tve uve (SynTy _ _ t1) t2 =
- eq tve uve t1 t2 -- Expand the abbrevation and try again
- eq tve uve t1 (SynTy _ _ t2) =
- eq tve uve t1 t2 -- Expand the abbrevation and try again
-
- eq tve uve (ForAllTy tv1 t1) (ForAllTy tv2 t2) =
- eq (addOneToTyVarEnv tve tv1 tv2) uve t1 t2
- eq tve uve (ForAllUsageTy u1 b1 t1) (ForAllUsageTy u2 b2 t2) =
- eqBounds uve b1 b2 && eq tve (addOneToUVarEnv uve u1 u2) t1 t2
-
- eq _ _ _ _ = False
-
- eqBounds uve [] [] = True
- eqBounds uve (u1:b1) (u2:b2) = eqUVar uve u1 u2 && eqBounds uve b1 b2
- eqBounds uve _ _ = False
+
+%************************************************************************
+%* *
+\subsection{Equality on types}
+%* *
+%************************************************************************
+
+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}
+