\begin{code}
module Type (
-- re-exports from TypeRep:
- Type,
+ Type, PredType, TauType, ThetaType,
Kind, TyVarSubst,
superKind, superBoxity, -- KX and BX respectively
typeCon, -- :: BX -> KX
liftedTypeKind, unliftedTypeKind, openTypeKind, -- :: KX
mkArrowKind, mkArrowKinds, -- :: KX -> KX -> KX
-
+ isTypeKind,
funTyCon,
usageKindCon, -- :: KX
mkAppTy, mkAppTys, splitAppTy, splitAppTys, splitAppTy_maybe,
- mkFunTy, mkFunTys, splitFunTy, splitFunTy_maybe, splitFunTys, splitFunTysN,
+ mkFunTy, mkFunTys, splitFunTy, splitFunTy_maybe, splitFunTys,
funResultTy, funArgTy, zipFunTys,
mkTyConApp, mkTyConTy,
tyConAppTyCon, tyConAppArgs,
splitTyConApp_maybe, splitTyConApp,
- splitAlgTyConApp_maybe, splitAlgTyConApp,
mkUTy, splitUTy, splitUTy_maybe,
isUTy, uaUTy, unUTy, liftUTy, mkUTyM,
isUsageKind, isUsage, isUTyVar,
- mkSynTy, deNoteType,
+ mkSynTy,
- repType, splitRepFunTys, splitNewType_maybe, typePrimRep,
+ repType, splitRepFunTys, typePrimRep,
mkForAllTy, mkForAllTys, splitForAllTy_maybe, splitForAllTys,
- applyTy, applyTys, hoistForAllTys, isForAllTy,
+ applyTy, applyTys, isForAllTy,
- -- Predicates and the like
- PredType(..), getClassPredTys_maybe, getClassPredTys,
- isPredTy, isClassPred, isTyVarClassPred,
- mkDictTy, mkPredTy, mkPredTys, splitPredTy_maybe, predTyUnique,
- splitDictTy, splitDictTy_maybe, isDictTy, predRepTy, splitDFunTy,
- mkClassPred, predMentionsIPs, inheritablePred, isIPPred, mkPredName,
+ -- Source types
+ SourceType(..), sourceTypeRep, mkPredTy, mkPredTys,
- -- Tau, Rho, Sigma
- TauType, RhoType, SigmaType, ThetaType,
- isTauTy, mkRhoTy, splitRhoTy, splitMethodTy,
- mkSigmaTy, isSigmaTy, splitSigmaTy,
- getDFunTyKey,
+ -- Newtypes
+ splitNewType_maybe,
-- Lifting and boxity
- isUnLiftedType, isUnboxedTupleType, isAlgType, isDataType, isNewType,
+ isUnLiftedType, isUnboxedTupleType, isAlgType, isStrictType, isPrimitiveType,
-- Free variables
tyVarsOfType, tyVarsOfTypes, tyVarsOfPred, tyVarsOfTheta,
- namesOfType, usageAnnOfType, typeKind, addFreeTyVars,
- namesOfDFunHead,
+ usageAnnOfType, typeKind, addFreeTyVars,
-- Tidying up for printing
- tidyType, tidyTypes,
- tidyOpenType, tidyOpenTypes,
- tidyTyVar, tidyTyVars, tidyFreeTyVars,
- tidyTopType, tidyPred,
+ tidyType, tidyTypes,
+ tidyOpenType, tidyOpenTypes,
+ tidyTyVarBndr, tidyFreeTyVars,
+ tidyOpenTyVar, tidyOpenTyVars,
+ tidyTopType, tidyPred,
+
+ -- Comparison
+ eqType, eqKind, eqUsage,
-- Seq
seqType, seqTypes
-- Other imports:
-import {-# SOURCE #-} DataCon( DataCon )
import {-# SOURCE #-} PprType( pprType ) -- Only called in debug messages
-import {-# SOURCE #-} Subst ( mkTyVarSubst, substTy )
+import {-# SOURCE #-} Subst ( substTyWith )
-- friends:
import Var ( Var, TyVar, tyVarKind, tyVarName, setTyVarName )
import VarEnv
import VarSet
-import OccName ( mkDictOcc )
-import Name ( Name, NamedThing(..), OccName, mkLocalName, tidyOccName )
-import NameSet
-import Class ( classTyCon, Class )
-import TyCon ( TyCon,
+import Name ( NamedThing(..), mkLocalName, tidyOccName )
+import Class ( classTyCon )
+import TyCon ( TyCon, isRecursiveTyCon, isPrimTyCon,
isUnboxedTupleTyCon, isUnLiftedTyCon,
- isFunTyCon, isDataTyCon, isNewTyCon, newTyConRep,
- isAlgTyCon, isSynTyCon, tyConArity,
- tyConKind, tyConDataCons, getSynTyConDefn,
- tyConPrimRep
+ isFunTyCon, isNewTyCon, newTyConRep,
+ isAlgTyCon, isSynTyCon, tyConArity,
+ tyConKind, getSynTyConDefn,
+ tyConPrimRep,
)
-- others
+import CmdLineOpts ( opt_DictsStrict )
import Maybes ( maybeToBool )
-import SrcLoc ( SrcLoc, noSrcLoc )
+import SrcLoc ( noSrcLoc )
import PrimRep ( PrimRep(..) )
-import Unique ( Unique, Uniquable(..) )
-import Util ( mapAccumL, seqList, thenCmp )
+import Unique ( Uniquable(..) )
+import Util ( mapAccumL, seqList )
import Outputable
import UniqSet ( sizeUniqSet ) -- Should come via VarSet
\end{code}
\begin{code}
hasMoreBoxityInfo :: Kind -> Kind -> Bool
hasMoreBoxityInfo k1 k2
- | k2 == openTypeKind = True
- | otherwise = k1 == k2
+ | k2 `eqKind` openTypeKind = True
+ | otherwise = k1 `eqType` k2
defaultKind :: Kind -> Kind
-- Used when generalising: default kind '?' to '*'
-defaultKind kind | kind == openTypeKind = liftedTypeKind
- | otherwise = kind
+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}
mkTyVarTys = map mkTyVarTy -- a common use of mkTyVarTy
getTyVar :: String -> Type -> TyVar
-getTyVar msg (TyVarTy tv) = tv
-getTyVar msg (PredTy p) = getTyVar msg (predRepTy p)
-getTyVar msg (NoteTy _ t) = getTyVar msg t
+getTyVar msg (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 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 (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
+getTyVar_maybe other = Nothing
isTyVarTy :: Type -> Bool
-isTyVarTy (TyVarTy tv) = True
-isTyVarTy (NoteTy _ ty) = isTyVarTy ty
-isTyVarTy (PredTy p) = isTyVarTy (predRepTy p)
+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
+isTyVarTy other = False
\end{code}
\begin{code}
mkAppTy orig_ty1 orig_ty2
- = ASSERT( not (isPredTy orig_ty1) ) -- Predicates are of kind *
+ = 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
-- returns to (Ratio Integer), which has needlessly lost
-- the Rational part.
mkAppTys orig_ty1 orig_tys2
- = ASSERT( not (isPredTy orig_ty1) ) -- Predicates are of kind *
+ = 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
splitAppTy_maybe (FunTy ty1 ty2) = Just (TyConApp funTyCon [unUTy ty1], unUTy ty2)
splitAppTy_maybe (AppTy ty1 ty2) = Just (ty1, ty2)
splitAppTy_maybe (NoteTy _ ty) = splitAppTy_maybe ty
-splitAppTy_maybe (PredTy p) = splitAppTy_maybe (predRepTy p)
+splitAppTy_maybe (SourceTy p) = splitAppTy_maybe (sourceTypeRep 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 (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)
splitFunTy :: Type -> (Type, Type)
splitFunTy (FunTy arg res) = (arg, res)
splitFunTy (NoteTy _ ty) = splitFunTy ty
-splitFunTy (PredTy p) = splitFunTy (predRepTy p)
+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 (PredTy p) = splitFunTy_maybe (predRepTy p)
+splitFunTy_maybe (SourceTy p) = splitFunTy_maybe (sourceTypeRep p)
splitFunTy_maybe ty@(UsageTy _ _) = pprPanic "splitFunTy_maybe: UTy:" (pprType ty)
splitFunTy_maybe other = Nothing
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 (SourceTy p) = split args orig_ty (sourceTypeRep p)
split args orig_ty (UsageTy _ _) = pprPanic "splitFunTys: UTy:" (pprType orig_ty)
split args orig_ty ty = (reverse args, orig_ty)
-splitFunTysN :: String -> Int -> Type -> ([Type], Type)
-splitFunTysN msg orig_n orig_ty = split orig_n [] orig_ty orig_ty
- where
- split 0 args syn_ty ty = (reverse args, syn_ty)
- split n args syn_ty (FunTy arg res) = split (n-1) (arg:args) res res
- split n args syn_ty (NoteTy _ ty) = split n args syn_ty ty
- split n args syn_ty (PredTy p) = split n args syn_ty (predRepTy p)
- split n args syn_ty (UsageTy _ _) = pprPanic "splitFunTysN: UTy:" (pprType orig_ty)
- split n args syn_ty ty = pprPanic ("splitFunTysN: " ++ msg) (int orig_n <+> pprType orig_ty)
-
zipFunTys :: Outputable a => [a] -> Type -> ([(a,Type)], Type)
zipFunTys orig_xs orig_ty = split [] orig_xs orig_ty orig_ty
where
split acc [] nty ty = (reverse acc, nty)
split acc (x:xs) nty (FunTy arg res) = split ((x,arg):acc) xs res res
split acc xs nty (NoteTy _ ty) = split acc xs nty ty
- split acc xs nty (PredTy p) = split acc xs nty (predRepTy p)
+ 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 (PredTy p) = funResultTy (predRepTy p)
+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 (PredTy p) = funArgTy (predRepTy p)
+funArgTy (SourceTy p) = funArgTy (sourceTypeRep p)
funArgTy (UsageTy _ ty) = funArgTy ty
funArgTy ty = pprPanic "funArgTy" (pprType ty)
\end{code}
---------------------------------------------------------------------
TyConApp
~~~~~~~~
+@mkTyConApp@ is a key function, because it builds a TyConApp, FunTy or SourceTy,
+as apppropriate.
\begin{code}
mkTyConApp :: TyCon -> [Type] -> Type
+-- Assumes TyCon is not a SynTyCon; use mkSynTy instead for those
mkTyConApp tycon tys
- | isFunTyCon tycon && length tys == 2
- = case tys of
- (ty1:ty2:_) -> FunTy (mkUTyM ty1) (mkUTyM ty2)
+ | isFunTyCon tycon, [ty1,ty2] <- tys
+ = FunTy (mkUTyM ty1) (mkUTyM ty2)
+
+ | isNewTyCon tycon, -- A saturated newtype application;
+ not (isRecursiveTyCon tycon), -- Not recursive (we don't use SourceTypes for them)
+ length tys == tyConArity tycon -- use the SourceType form
+ = SourceTy (NType tycon tys)
| otherwise
= ASSERT(not (isSynTyCon tycon))
-- including functions are returned as Just ..
tyConAppTyCon :: Type -> TyCon
-tyConAppTyCon ty = case splitTyConApp_maybe ty of
- Just (tc,_) -> tc
- Nothing -> pprPanic "tyConAppTyCon" (pprType ty)
+tyConAppTyCon ty = fst (splitTyConApp ty)
tyConAppArgs :: Type -> [Type]
-tyConAppArgs ty = case splitTyConApp_maybe ty of
- Just (_,args) -> args
- Nothing -> pprPanic "tyConAppArgs" (pprType ty)
+tyConAppArgs ty = snd (splitTyConApp ty)
splitTyConApp :: Type -> (TyCon, [Type])
splitTyConApp ty = case splitTyConApp_maybe ty of
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 (PredTy p) = splitTyConApp_maybe (predRepTy p)
+splitTyConApp_maybe (SourceTy p) = splitTyConApp_maybe (sourceTypeRep p)
splitTyConApp_maybe (UsageTy _ ty) = splitTyConApp_maybe ty
splitTyConApp_maybe other = Nothing
-
--- splitAlgTyConApp_maybe looks for
--- *saturated* applications of *algebraic* data types
--- "Algebraic" => newtype, data type, or dictionary (not function types)
--- We return the constructors too, so there had better be some.
-
-splitAlgTyConApp_maybe :: Type -> Maybe (TyCon, [Type], [DataCon])
-splitAlgTyConApp_maybe (TyConApp tc tys)
- | isAlgTyCon tc &&
- tyConArity tc == length tys = Just (tc, tys, tyConDataCons tc)
-splitAlgTyConApp_maybe (NoteTy _ ty) = splitAlgTyConApp_maybe ty
-splitAlgTyConApp_maybe (PredTy p) = splitAlgTyConApp_maybe (predRepTy p)
-splitAlgTyConApp_maybe (UsageTy _ ty)= splitAlgTyConApp_maybe ty
-splitAlgTyConApp_maybe other = Nothing
-
-splitAlgTyConApp :: Type -> (TyCon, [Type], [DataCon])
- -- Here the "algebraic" property is an *assertion*
-splitAlgTyConApp (TyConApp tc tys) = ASSERT( isAlgTyCon tc && tyConArity tc == length tys )
- (tc, tys, tyConDataCons tc)
-splitAlgTyConApp (NoteTy _ ty) = splitAlgTyConApp ty
-splitAlgTyConApp (PredTy p) = splitAlgTyConApp (predRepTy p)
-splitAlgTyConApp (UsageTy _ ty) = splitAlgTyConApp ty
-#ifdef DEBUG
-splitAlgTyConApp ty = pprPanic "splitAlgTyConApp" (pprType ty)
-#endif
\end{code}
~~~~~
\begin{code}
-mkSynTy syn_tycon tys
- = ASSERT( isSynTyCon syn_tycon )
- ASSERT( length tyvars == length tys )
- NoteTy (SynNote (TyConApp syn_tycon tys))
- (substTy (mkTyVarSubst tyvars tys) body)
+mkSynTy tycon tys
+ | n_args == arity -- Exactly saturated
+ = mk_syn tys
+ | n_args > arity -- Over-saturated
+ = foldl AppTy (mk_syn (take arity tys)) (drop arity tys)
+ | otherwise -- Un-saturated
+ = TyConApp tycon tys
+ -- For the un-saturated case we build TyConApp directly
+ -- (mkTyConApp ASSERTs that the tc isn't a SynTyCon).
+ -- Here we are relying on checkValidType to find
+ -- the error. What we can't do is use mkSynTy with
+ -- too few arg tys, because that is utterly bogus.
+
where
- (tyvars, body) = getSynTyConDefn syn_tycon
-
-deNoteType :: Type -> Type
- -- Remove synonyms, but not Preds
-deNoteType ty@(TyVarTy tyvar) = ty
-deNoteType (TyConApp tycon tys) = TyConApp tycon (map deNoteType tys)
-deNoteType (PredTy p) = PredTy (deNotePred p)
-deNoteType (NoteTy _ ty) = deNoteType ty
-deNoteType (AppTy fun arg) = AppTy (deNoteType fun) (deNoteType arg)
-deNoteType (FunTy fun arg) = FunTy (deNoteType fun) (deNoteType arg)
-deNoteType (ForAllTy tv ty) = ForAllTy tv (deNoteType ty)
-deNoteType (UsageTy u ty) = UsageTy u (deNoteType ty)
-
-deNotePred :: PredType -> PredType
-deNotePred (ClassP c tys) = ClassP c (map deNoteType tys)
-deNotePred (IParam n ty) = IParam n (deNoteType ty)
+ mk_syn tys = NoteTy (SynNote (TyConApp tycon tys))
+ (substTyWith tyvars tys body)
+
+ (tyvars, body) = ASSERT( isSynTyCon tycon ) getSynTyConDefn tycon
+ arity = tyConArity tycon
+ n_args = length tys
\end{code}
Notes on type synonyms
repType looks through
(a) for-alls, and
- (b) newtypes
- (c) synonyms
- (d) predicates
- (e) usage annotations
-It's useful in the back end where we're not
-interested in newtypes anymore.
+ (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}
repType :: Type -> Type
-repType (ForAllTy _ ty) = repType ty
-repType (NoteTy _ ty) = repType ty
-repType (PredTy p) = repType (predRepTy p)
-repType (UsageTy _ ty) = repType ty
-repType ty = case splitNewType_maybe ty of
- Just ty' -> repType ty' -- Still re-apply repType in case of for-all
- Nothing -> ty
+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
FunTy _ _ -> PtrRep
AppTy _ _ -> PtrRep -- ??
TyVarTy _ -> PtrRep
-
-splitNewType_maybe :: Type -> Maybe Type
--- Find the representation of a newtype, if it is one
--- Looks through multiple levels of newtype, but does not look through for-alls
-splitNewType_maybe (NoteTy _ ty) = splitNewType_maybe ty
-splitNewType_maybe (PredTy p) = splitNewType_maybe (predRepTy p)
-splitNewType_maybe (UsageTy _ ty) = splitNewType_maybe ty
-splitNewType_maybe (TyConApp tc tys) = case newTyConRep tc of
- Just rep_ty -> ASSERT( length tys == tyConArity tc )
- -- The assert should hold because repType should
- -- only be applied to *types* (of kind *)
- Just (applyTys rep_ty tys)
- Nothing -> Nothing
-splitNewType_maybe other = Nothing
\end{code}
splitForAllTy_maybe ty = splitFAT_m ty
where
splitFAT_m (NoteTy _ ty) = splitFAT_m ty
- splitFAT_m (PredTy p) = splitFAT_m (predRepTy p)
+ 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
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 (PredTy p) tvs = split orig_ty (predRepTy p) 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}
\begin{code}
applyTy :: Type -> Type -> Type
-applyTy (PredTy p) arg = applyTy (predRepTy p) arg
+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 )
- substTy (mkTyVarSubst [tv] [arg]) ty
+ substTyWith [tv] [arg] ty
applyTy (UsageTy u ty) arg = UsageTy u (applyTy ty arg)
applyTy other arg = panic "applyTy"
(case mu of
Just u -> UsageTy u
Nothing -> id) $
- substTy (mkTyVarSubst tvs arg_tys) ty
+ 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 (PredTy p) args = split (predRepTy p) 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
split other_ty args = panic "applyTys"
\end{code}
-\begin{code}
-hoistForAllTys :: Type -> Type
- -- Move all the foralls to the top
- -- e.g. T -> forall a. a ==> forall a. T -> a
- -- Careful: LOSES USAGE ANNOTATIONS!
-hoistForAllTys ty
- = case hoist ty of { (tvs, body) -> mkForAllTys tvs body }
- where
- hoist :: Type -> ([TyVar], Type)
- hoist ty = case splitFunTys ty of { (args, res) ->
- case splitForAllTys res of {
- ([], body) -> ([], ty) ;
- (tvs1, body1) -> case hoist body1 of { (tvs2,body2) ->
- (tvs1 ++ tvs2, mkFunTys args body2)
- }}}
-\end{code}
-
---------------------------------------------------------------------
UsageTy
\begin{code}
mkUTy :: Type -> Type -> Type
mkUTy u ty
- = ASSERT2( typeKind u == usageTypeKind, ptext SLIT("mkUTy:") <+> pprType u <+> pprType 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
\begin{code}
isUsageKind :: Kind -> Bool
isUsageKind k
- = ASSERT( typeKind k == superKind )
- k == usageTypeKind
+ = ASSERT( typeKind k `eqKind` superKind )
+ k `eqKind` usageTypeKind
isUsage :: Type -> Bool
isUsage ty
%************************************************************************
%* *
-\subsection{Predicates}
+\subsection{Source types}
%* *
%************************************************************************
-"Dictionary" types are just ordinary data types, but you can
-tell from the type constructor whether it's a dictionary or not.
-
-\begin{code}
-mkClassPred clas tys = UASSERT2( not (any isUTy tys), ppr clas <+> fsep (map pprType tys) )
- ClassP clas tys
-
-isClassPred (ClassP clas tys) = True
-isClassPred other = False
-
-isIPPred (IParam _ _) = True
-isIPPred other = False
+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.
-isTyVarClassPred (ClassP clas tys) = all isTyVarTy tys
-isTyVarClassPred other = False
+Source types are always lifted.
-getClassPredTys_maybe :: PredType -> Maybe (Class, [Type])
-getClassPredTys_maybe (ClassP clas tys) = Just (clas, tys)
-getClassPredTys_maybe _ = Nothing
-
-getClassPredTys :: PredType -> (Class, [Type])
-getClassPredTys (ClassP clas tys) = (clas, tys)
-
-inheritablePred :: PredType -> Bool
--- Can be inherited by a context. For example, consider
--- f x = let g y = (?v, y+x)
--- in (g 3 with ?v = 8,
--- g 4 with ?v = 9)
--- The point is that g's type must be quantifed over ?v:
--- g :: (?v :: a) => a -> a
--- but it doesn't need to be quantified over the Num a dictionary
--- which can be free in g's rhs, and shared by both calls to g
-inheritablePred (ClassP _ _) = True
-inheritablePred other = False
-
-predMentionsIPs :: PredType -> NameSet -> Bool
-predMentionsIPs (IParam n _) ns = n `elemNameSet` ns
-predMentionsIPs other ns = False
-
-mkDictTy :: Class -> [Type] -> Type
-mkDictTy clas tys = UASSERT2( not (any isUTy tys), ppr clas <+> fsep (map pprType tys) )
- mkPredTy (ClassP clas tys)
+The key function is sourceTypeRep which gives the representation of a source type:
+\begin{code}
mkPredTy :: PredType -> Type
-mkPredTy pred = PredTy pred
+mkPredTy pred = SourceTy pred
mkPredTys :: ThetaType -> [Type]
-mkPredTys preds = map PredTy preds
-
-predTyUnique :: PredType -> Unique
-predTyUnique (IParam n _) = getUnique n
-predTyUnique (ClassP clas tys) = getUnique clas
+mkPredTys preds = map SourceTy preds
-predRepTy :: PredType -> Type
+sourceTypeRep :: SourceType -> Type
-- Convert a predicate to its "representation type";
-- the type of evidence for that predicate, which is actually passed at runtime
-predRepTy (ClassP clas tys) = TyConApp (classTyCon clas) tys
-predRepTy (IParam n ty) = ty
-
-isPredTy :: Type -> Bool
-isPredTy (NoteTy _ ty) = isPredTy ty
-isPredTy (PredTy _) = True
-isPredTy (UsageTy _ ty)= isPredTy ty
-isPredTy _ = False
-
-isDictTy :: Type -> Bool
-isDictTy (NoteTy _ ty) = isDictTy ty
-isDictTy (PredTy (ClassP _ _)) = True
-isDictTy (UsageTy _ ty) = isDictTy ty
-isDictTy other = False
-
-splitPredTy_maybe :: Type -> Maybe PredType
-splitPredTy_maybe (NoteTy _ ty) = splitPredTy_maybe ty
-splitPredTy_maybe (PredTy p) = Just p
-splitPredTy_maybe (UsageTy _ ty)= splitPredTy_maybe ty
-splitPredTy_maybe other = Nothing
-
-splitDictTy :: Type -> (Class, [Type])
-splitDictTy (NoteTy _ ty) = splitDictTy ty
-splitDictTy (PredTy (ClassP clas tys)) = (clas, tys)
-
-splitDictTy_maybe :: Type -> Maybe (Class, [Type])
-splitDictTy_maybe (NoteTy _ ty) = splitDictTy_maybe ty
-splitDictTy_maybe (PredTy (ClassP clas tys)) = Just (clas, tys)
-splitDictTy_maybe other = Nothing
-
-splitDFunTy :: Type -> ([TyVar], [PredType], Class, [Type])
--- Split the type of a dictionary function
-splitDFunTy ty
- = case splitSigmaTy ty of { (tvs, theta, tau) ->
- case splitDictTy tau of { (clas, tys) ->
- (tvs, theta, clas, tys) }}
-
-namesOfDFunHead :: Type -> NameSet
--- Find the free type constructors and classes
--- of the head of the dfun instance type
--- The 'dfun_head_type' is because of
--- instance Foo a => Baz T where ...
--- The decl is an orphan if Baz and T are both not locally defined,
--- even if Foo *is* locally defined
-namesOfDFunHead dfun_ty = case splitSigmaTy dfun_ty of
- (tvs,_,head_ty) -> delListFromNameSet (namesOfType head_ty)
- (map getName tvs)
-
-mkPredName :: Unique -> SrcLoc -> PredType -> Name
-mkPredName uniq loc (ClassP cls tys) = mkLocalName uniq (mkDictOcc (getOccName cls)) loc
-mkPredName uniq loc (IParam name ty) = name
-\end{code}
-
-%************************************************************************
-%* *
-\subsection{Tau, sigma and rho}
-%* *
-%************************************************************************
-
-@isTauTy@ tests for nested for-alls.
-
-\begin{code}
-isTauTy :: Type -> Bool
-isTauTy (TyVarTy v) = True
-isTauTy (TyConApp _ tys) = all isTauTy tys
-isTauTy (AppTy a b) = isTauTy a && isTauTy b
-isTauTy (FunTy a b) = isTauTy a && isTauTy b
-isTauTy (PredTy p) = isTauTy (predRepTy p)
-isTauTy (NoteTy _ ty) = isTauTy ty
-isTauTy (UsageTy _ ty) = isTauTy ty
-isTauTy other = False
-\end{code}
-
-\begin{code}
-mkRhoTy :: [PredType] -> Type -> Type
-mkRhoTy theta ty = UASSERT2( not (isUTy ty), pprType ty )
- foldr (\p r -> FunTy (mkUTyM (mkPredTy p)) (mkUTyM r)) ty theta
-
-splitRhoTy :: Type -> ([PredType], Type)
-splitRhoTy ty = split ty ty []
- where
- split orig_ty (FunTy arg res) ts = case splitPredTy_maybe arg of
- Just p -> split res res (p:ts)
- Nothing -> (reverse ts, orig_ty)
- split orig_ty (NoteTy _ ty) ts = split orig_ty ty ts
- split orig_ty (UsageTy _ ty) ts = split orig_ty ty ts
- split orig_ty ty ts = (reverse ts, orig_ty)
-\end{code}
+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
-The type of a method for class C is always of the form:
- Forall a1..an. C a1..an => sig_ty
-where sig_ty is the type given by the method's signature, and thus in general
-is a ForallTy. At the point that splitMethodTy is called, it is expected
-that the outer Forall has already been stripped off. splitMethodTy then
-returns (C a1..an, sig_ty') where sig_ty' is sig_ty with any Notes or
-Usages stripped off.
+isSourceTy :: Type -> Bool
+isSourceTy (NoteTy _ ty) = isSourceTy ty
+isSourceTy (UsageTy _ ty) = isSourceTy ty
+isSourceTy (SourceTy sty) = True
+isSourceTy _ = False
-\begin{code}
-splitMethodTy :: Type -> (PredType, Type)
-splitMethodTy ty = split ty
- where
- split (FunTy arg res) = case splitPredTy_maybe arg of
- Just p -> (p, res)
- Nothing -> panic "splitMethodTy"
- split (NoteTy _ ty) = split ty
- split (UsageTy _ ty) = split ty
- split _ = panic "splitMethodTy"
-\end{code}
+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
-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)
-
-isSigmaTy :: Type -> Bool
-isSigmaTy (ForAllTy tyvar ty) = True
-isSigmaTy (FunTy a b) = isPredTy a
-isSigmaTy (NoteTy _ ty) = isSigmaTy ty
-isSigmaTy (UsageTy _ ty) = isSigmaTy ty
-isSigmaTy _ = False
-
-splitSigmaTy :: Type -> ([TyVar], [PredType], Type)
-splitSigmaTy ty =
- (tyvars, theta, tau)
- where
- (tyvars,rho) = splitForAllTys ty
- (theta,tau) = splitRhoTy rho
-\end{code}
-
-\begin{code}
-getDFunTyKey :: Type -> OccName -- Get some string from a type, to be used to
- -- construct a dictionary function name
-getDFunTyKey (TyVarTy tv) = getOccName tv
-getDFunTyKey (TyConApp tc _) = getOccName tc
-getDFunTyKey (AppTy fun _) = getDFunTyKey fun
-getDFunTyKey (NoteTy _ t) = getDFunTyKey t
-getDFunTyKey (FunTy arg _) = getOccName funTyCon
-getDFunTyKey (ForAllTy _ t) = getDFunTyKey t
-getDFunTyKey (UsageTy _ t) = getDFunTyKey t
--- PredTy shouldn't happen
+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}
typeKind (TyVarTy tyvar) = tyVarKind tyvar
typeKind (TyConApp tycon tys) = foldr (\_ k -> funResultTy k) (tyConKind tycon) tys
typeKind (NoteTy _ ty) = typeKind ty
-typeKind (PredTy _) = liftedTypeKind -- Predicates are always
+typeKind (SourceTy _) = liftedTypeKind -- Predicates are always
-- represented by lifted types
typeKind (AppTy fun arg) = funResultTy (typeKind fun)
Free variables of a type
~~~~~~~~~~~~~~~~~~~~~~~~
\begin{code}
-
tyVarsOfType :: Type -> TyVarSet
tyVarsOfType (TyVarTy tv) = unitVarSet tv
tyVarsOfType (TyConApp tycon tys) = tyVarsOfTypes tys
tyVarsOfType (NoteTy (FTVNote tvs) ty2) = tvs
tyVarsOfType (NoteTy (SynNote ty1) ty2) = tyVarsOfType ty1
-tyVarsOfType (PredTy p) = tyVarsOfPred p
+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
tyVarsOfTypes tys = foldr (unionVarSet.tyVarsOfType) emptyVarSet tys
tyVarsOfPred :: PredType -> TyVarSet
-tyVarsOfPred (ClassP clas tys) = tyVarsOfTypes tys
-tyVarsOfPred (IParam n ty) = tyVarsOfType ty
+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 . tyVarsOfPred) emptyVarSet
+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
-
--- Find the free names of a type, including the type constructors and classes it mentions
-namesOfType :: Type -> NameSet
-namesOfType (TyVarTy tv) = unitNameSet (getName tv)
-namesOfType (TyConApp tycon tys) = unitNameSet (getName tycon) `unionNameSets`
- namesOfTypes tys
-namesOfType (NoteTy (SynNote ty1) ty2) = namesOfType ty1
-namesOfType (NoteTy other_note ty2) = namesOfType ty2
-namesOfType (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 `delFromNameSet` getName tyvar
-namesOfType (UsageTy u ty) = namesOfType u `unionNameSets` namesOfType ty
-
-namesOfTypes tys = foldr (unionNameSets . namesOfType) emptyNameSet tys
\end{code}
Usage annotations of a type
goT (TyConApp tc tys) = concatMap goT tys
goT (FunTy sty1 sty2) = goS sty1 ++ goS sty2
goT (ForAllTy mv ty) = goT ty
- goT (PredTy p) = goT (predRepTy p)
+ goT (SourceTy p) = goT (sourceTypeRep p)
goT ty@(UsageTy _ _) = pprPanic "usageAnnOfType: unexpected usage:" (pprType ty)
goT (NoteTy note ty) = goT ty
It doesn't change the uniques at all, just the print names.
\begin{code}
-tidyTyVar :: TidyEnv -> TyVar -> (TidyEnv, TyVar)
-tidyTyVar env@(tidy_env, subst) tyvar
- = case lookupVarEnv subst tyvar of
-
- Just tyvar' -> -- Already substituted
- (env, tyvar')
-
- Nothing -> -- Make a new nice name for it
-
- case tidyOccName tidy_env (getOccName name) of
- (tidy', occ') -> -- New occname reqd
- ((tidy', subst'), tyvar')
- where
- subst' = extendVarEnv subst tyvar tyvar'
- tyvar' = setTyVarName tyvar name'
- name' = mkLocalName (getUnique name) occ' noSrcLoc
- -- Note: make a *user* tyvar, so it printes nicely
- -- Could extract src loc, but no need.
+tidyTyVarBndr :: TidyEnv -> TyVar -> (TidyEnv, TyVar)
+tidyTyVarBndr (tidy_env, subst) tyvar
+ = case tidyOccName tidy_env (getOccName name) of
+ (tidy', occ') -> -- New occname reqd
+ ((tidy', subst'), tyvar')
+ where
+ subst' = extendVarEnv subst tyvar tyvar'
+ tyvar' = setTyVarName tyvar name'
+ name' = mkLocalName (getUnique name) occ' noSrcLoc
+ -- Note: make a *user* tyvar, so it printes nicely
+ -- Could extract src loc, but no need.
where
name = tyVarName tyvar
-tidyTyVars :: TidyEnv -> [TyVar] -> (TidyEnv, [TyVar])
-tidyTyVars env tyvars = mapAccumL tidyTyVar env tyvars
-
tidyFreeTyVars :: TidyEnv -> TyVarSet -> TidyEnv
-- Add the free tyvars to the env in tidy form,
-- so that we can tidy the type they are free in
-tidyFreeTyVars env tyvars = foldl add env (varSetElems tyvars)
- where
- add env tv = fst (tidyTyVar env tv)
+tidyFreeTyVars env tyvars = fst (tidyOpenTyVars env (varSetElems tyvars))
+
+tidyOpenTyVars :: TidyEnv -> [TyVar] -> (TidyEnv, [TyVar])
+tidyOpenTyVars env tyvars = mapAccumL tidyOpenTyVar env tyvars
+
+tidyOpenTyVar :: TidyEnv -> TyVar -> (TidyEnv, TyVar)
+-- Treat a new tyvar as a binder, and give it a fresh tidy name
+tidyOpenTyVar env@(tidy_env, subst) tyvar
+ = case lookupVarEnv subst tyvar of
+ Just tyvar' -> (env, tyvar') -- Already substituted
+ Nothing -> tidyTyVarBndr env tyvar -- Treat it as a binder
tidyType :: TidyEnv -> Type -> Type
tidyType env@(tidy_env, subst) ty
Just tv' -> TyVarTy tv'
go (TyConApp tycon tys) = let args = map go tys
in args `seqList` TyConApp tycon args
- go (NoteTy note ty) = (NoteTy SAPPLY (go_note note)) SAPPLY (go ty)
- go (PredTy p) = PredTy (tidyPred env p)
- go (AppTy fun arg) = (AppTy SAPPLY (go fun)) SAPPLY (go arg)
- go (FunTy fun arg) = (FunTy SAPPLY (go fun)) SAPPLY (go arg)
- go (ForAllTy tv ty) = ForAllTy tvp SAPPLY (tidyType envp ty)
+ 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) = tidyTyVar env tv
- go (UsageTy u ty) = (UsageTy SAPPLY (go u)) SAPPLY (go ty)
+ (envp, tvp) = tidyTyVarBndr env tv
+ go (UsageTy u ty) = (UsageTy $! (go u)) $! (go ty)
- go_note (SynNote ty) = SynNote SAPPLY (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 -> PredType -> PredType
-tidyPred env (ClassP clas tys) = ClassP clas (tidyTypes env tys)
-tidyPred env (IParam n ty) = IParam n (tidyType env ty)
+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}
isUnLiftedType (NoteTy _ ty) = isUnLiftedType ty
isUnLiftedType (TyConApp tc _) = isUnLiftedTyCon tc
isUnLiftedType (UsageTy _ ty) = isUnLiftedType ty
-isUnLiftedType other = False
+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) -> ASSERT( length ty_args == tyConArity tc )
isAlgTyCon tc
other -> False
+\end{code}
--- Should only be applied to *types*; hence the assert
-isDataType :: Type -> Bool
-isDataType ty = case splitTyConApp_maybe ty of
- Just (tc, ty_args) -> ASSERT( length ty_args == tyConArity tc )
- isDataTyCon tc
- other -> False
+@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.
-isNewType :: Type -> Bool
-isNewType ty = case splitTyConApp_maybe ty of
+\begin{code}
+isStrictType (ForAllTy tv ty) = isStrictType ty
+isStrictType (NoteTy _ ty) = isStrictType ty
+isStrictType (TyConApp tc _) = isUnLiftedTyCon tc
+isStrictType (UsageTy _ ty) = isStrictType ty
+isStrictType (SourceTy (ClassP clas _)) = opt_DictsStrict && not (isNewTyCon (classTyCon clas))
+ -- We may be strict in dictionary types, but only if it
+ -- has more than one component.
+ -- [Being strict in a single-component dictionary risks
+ -- poking the dictionary component, which is wrong.]
+isStrictType other = False
+\end{code}
+
+\begin{code}
+isPrimitiveType :: Type -> Bool
+-- Returns types that are opaque to Haskell.
+-- Most of these are unlifted, but now that we interact with .NET, we
+-- may have primtive (foreign-imported) types that are lifted
+isPrimitiveType ty = case splitTyConApp_maybe ty of
Just (tc, ty_args) -> ASSERT( length ty_args == tyConArity tc )
- isNewTyCon tc
+ isPrimTyCon tc
other -> False
\end{code}
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 (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
seqNote (SynNote ty) = seqType ty
seqNote (FTVNote set) = sizeUniqSet set `seq` ()
-seqPred :: PredType -> ()
-seqPred (ClassP c tys) = c `seq` seqTypes tys
-seqPred (IParam n ty) = n `seq` seqType ty
+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}
%* *
%************************************************************************
+Comparison; don't use instances so that we know where it happens.
+Look through newtypes but not usage types.
\begin{code}
-instance Eq Type where
- ty1 == ty2 = case ty1 `compare` ty2 of { EQ -> True; other -> False }
-
-instance Ord Type where
- compare ty1 ty2 = cmpTy emptyVarEnv ty1 ty2
-
-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
-
- -- Get rid of NoteTy
-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
-cmpTy env (TyVarTy tv1) (TyVarTy tv2) = case lookupVarEnv env tv1 of
- Just tv1a -> tv1a `compare` tv2
- Nothing -> tv1 `compare` tv2
-
-cmpTy env (AppTy f1 a1) (AppTy f2 a2) = cmpTy env f1 f2 `thenCmp` cmpTy env a1 a2
-cmpTy env (FunTy f1 a1) (FunTy f2 a2) = cmpTy env f1 f2 `thenCmp` cmpTy env a1 a2
-cmpTy env (TyConApp tc1 tys1) (TyConApp tc2 tys2) = (tc1 `compare` tc2) `thenCmp` (cmpTys env tys1 tys2)
-cmpTy env (ForAllTy tv1 t1) (ForAllTy tv2 t2) = cmpTy (extendVarEnv env tv1 tv2) t1 t2
-cmpTy env (UsageTy u1 t1) (UsageTy u2 t2) = cmpTy env u1 u2 `thenCmp` cmpTy env t1 t2
-
- -- Deal with the rest: TyVarTy < AppTy < FunTy < TyConApp < ForAllTy < UsageTy
-cmpTy env (AppTy _ _) (TyVarTy _) = GT
-
-cmpTy env (FunTy _ _) (TyVarTy _) = GT
-cmpTy env (FunTy _ _) (AppTy _ _) = GT
-
-cmpTy env (TyConApp _ _) (TyVarTy _) = GT
-cmpTy env (TyConApp _ _) (AppTy _ _) = GT
-cmpTy env (TyConApp _ _) (FunTy _ _) = GT
-
-cmpTy env (ForAllTy _ _) (TyVarTy _) = GT
-cmpTy env (ForAllTy _ _) (AppTy _ _) = GT
-cmpTy env (ForAllTy _ _) (FunTy _ _) = GT
-cmpTy env (ForAllTy _ _) (TyConApp _ _) = GT
-
-cmpTy env (UsageTy _ _) other = GT
-
-cmpTy env _ _ = LT
-
-
-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
+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}
-\begin{code}
-instance Eq PredType where
- p1 == p2 = case p1 `compare` p2 of { EQ -> True; other -> False }
-
-instance Ord PredType where
- compare p1 p2 = cmpPred emptyVarEnv p1 p2
-
-cmpPred :: TyVarEnv TyVar -> PredType -> PredType -> Ordering
-cmpPred env (IParam n1 ty1) (IParam n2 ty2) = (n1 `compare` n2) `thenCmp` (cmpTy env ty1 ty2)
- -- Compare types as well as names for implicit parameters
- -- This comparison is used exclusively (I think) for the
- -- finite map built in TcSimplify
-cmpPred env (ClassP c1 tys1) (ClassP c2 tys2) = (c1 `compare` c2) `thenCmp` (cmpTys env tys1 tys2)
-cmpPred env (IParam _ _) (ClassP _ _) = LT
-cmpPred env (ClassP _ _) (IParam _ _) = GT
-\end{code}