-
+%
% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[TcType]{Types used in the typechecker}
newtypes, and predicates are meaningful.
* look through usage types
-The "tc" prefix is for "typechechecker", because the type checker
+The "tc" prefix is for "TypeChecker", because the type checker
is the principal client.
\begin{code}
isClassPred, isTyVarClassPred, isEqPred,
mkDictTy, tcSplitPredTy_maybe,
isPredTy, isDictTy, tcSplitDFunTy, tcSplitDFunHead, predTyUnique,
- mkClassPred, isInheritablePred, isLinearPred, isIPPred, mkPredName,
+ mkClassPred, isInheritablePred, isIPPred, mkPredName,
dataConsStupidTheta, isRefineableTy,
---------------------------------
-- friends:
import TypeRep ( Type(..), funTyCon, Kind ) -- friend
-import Type ( -- Re-exports
- tyVarsOfType, tyVarsOfTypes, tyVarsOfPred,
- tyVarsOfTheta, Kind, PredType(..), KindVar,
- ThetaType, isUnliftedTypeKind, unliftedTypeKind,
- argTypeKind,
- liftedTypeKind, openTypeKind, mkArrowKind,
- tySuperKind, isLiftedTypeKind,
- mkArrowKinds, mkForAllTy, mkForAllTys,
- defaultKind, isSubArgTypeKind, isSubOpenTypeKind,
- mkFunTy, mkFunTys, zipFunTys,
- mkTyConApp, mkAppTy,
- mkAppTys, applyTy, applyTys,
- mkTyVarTy, mkTyVarTys, mkTyConTy, mkPredTy,
- mkPredTys, isUnLiftedType,
- isUnboxedTupleType, isPrimitiveType,
- splitTyConApp_maybe,
- tidyTopType, tidyType, tidyPred, tidyTypes,
- tidyFreeTyVars, tidyOpenType, tidyOpenTypes,
- tidyTyVarBndr, tidyOpenTyVar,
- tidyOpenTyVars, tidyKind,
- isSubKind, tcView,
-
- tcEqType, tcEqTypes, tcCmpType, tcCmpTypes,
- tcEqPred, tcCmpPred, tcEqTypeX, eqKind,
-
- TvSubst(..),
- TvSubstEnv, emptyTvSubst, mkTvSubst, zipTyEnv,
- mkOpenTvSubst, zipOpenTvSubst, zipTopTvSubst, mkTopTvSubst,
- getTvSubstEnv, setTvSubstEnv, getTvInScope, extendTvInScope,
- extendTvSubst, extendTvSubstList, isInScope, notElemTvSubst,
- substTy, substTys, substTyWith, substTheta,
- substTyVar, substTyVarBndr, substPred, lookupTyVar,
-
- typeKind, repType, coreView, repSplitAppTy_maybe,
- pprKind, pprParendKind,
- pprType, pprParendType, pprTyThingCategory,
- pprPred, pprTheta, pprThetaArrow, pprClassPred
- )
-import TyCon ( TyCon, isUnLiftedTyCon, isSynTyCon, synTyConDefn, tyConUnique )
+import Type
+import TyCon ( TyCon, isUnLiftedTyCon, isSynTyCon, isOpenTyCon,
+ synTyConDefn, tyConUnique )
import DataCon ( DataCon, dataConStupidTheta, dataConResTys )
import Class ( Class )
-import Var ( TyVar, Id, isTcTyVar, mkTcTyVar, tyVarName, tyVarKind, tcTyVarDetails )
+import Var ( TyVar, Id, isCoVar, isTcTyVar, mkTcTyVar, tyVarName, tyVarKind, tcTyVarDetails )
import ForeignCall ( Safety, DNType(..) )
import Unify ( tcMatchTys )
import VarSet
import OccName ( OccName, mkDictOcc, mkOccName, tvName )
import PrelNames -- Lots (e.g. in isFFIArgumentTy)
import TysWiredIn ( unitTyCon, charTyCon, listTyCon )
-import BasicTypes ( IPName(..), Arity, ipNameName )
+import BasicTypes ( Arity, ipNameName )
import SrcLoc ( SrcLoc, SrcSpan )
import Util ( equalLength )
import Maybes ( maybeToBool, expectJust, mapCatMaybes )
import ListSetOps ( hasNoDups )
import List ( nubBy )
import Outputable
-import DATA_IOREF
+
+import Data.IORef
\end{code}
-- The rest are for non-scoped skolems
| ClsSkol Class -- Bound at a class decl
| InstSkol Id -- Bound at an instance decl
+ | FamInstSkol TyCon -- Bound at a family instance decl
| PatSkol DataCon -- An existential type variable bound by a pattern for
SrcSpan -- a data constructor with an existential type. E.g.
-- data T = forall a. Eq a => MkT a
kindVarRef :: KindVar -> IORef MetaDetails
kindVarRef tc =
+ ASSERT ( isTcTyVar tc )
case tcTyVarDetails tc of
MetaTv TauTv ref -> ref
other -> pprPanic "kindVarRef" (ppr tc)
-- Print info about the binding of a skolem tyvar,
-- or nothing if we don't have anything useful to say
pprSkolTvBinding tv
- = ppr_details (tcTyVarDetails tv)
+ = ASSERT ( isTcTyVar tv )
+ ppr_details (tcTyVarDetails tv)
where
ppr_details (MetaTv TauTv _) = quotes (ppr tv) <+> ptext SLIT("is a meta type variable")
ppr_details (MetaTv BoxTv _) = quotes (ppr tv) <+> ptext SLIT("is a boxy type variable")
pprSkolInfo :: SkolemInfo -> SDoc
pprSkolInfo (SigSkol ctxt) = ptext SLIT("is bound by") <+> pprUserTypeCtxt ctxt
pprSkolInfo (ClsSkol cls) = ptext SLIT("is bound by the class declaration for") <+> quotes (ppr cls)
-pprSkolInfo (InstSkol df) = ptext SLIT("is bound by the instance declaration at") <+> ppr (getSrcLoc df)
-pprSkolInfo (ArrowSkol loc) = ptext SLIT("is bound by the arrow form at") <+> ppr loc
+pprSkolInfo (InstSkol df) =
+ ptext SLIT("is bound by the instance declaration at") <+> ppr (getSrcLoc df)
+pprSkolInfo (FamInstSkol tc) =
+ ptext SLIT("is bound by the family instance declaration at") <+>
+ ppr (getSrcLoc tc)
+pprSkolInfo (ArrowSkol loc) =
+ ptext SLIT("is bound by the arrow form at") <+> ppr loc
pprSkolInfo (PatSkol dc loc) = sep [ptext SLIT("is bound by the pattern for") <+> quotes (ppr dc),
nest 2 (ptext SLIT("at") <+> ppr loc)]
pprSkolInfo (GenSkol tvs ty loc) = sep [sep [ptext SLIT("is bound by the polymorphic type"),
isTauTyCon :: TyCon -> Bool
-- Returns False for type synonyms whose expansion is a polytype
-isTauTyCon tc | isSynTyCon tc = isTauTy (snd (synTyConDefn tc))
- | otherwise = True
+isTauTyCon tc
+ | isSynTyCon tc && not (isOpenTyCon tc) = isTauTy (snd (synTyConDefn tc))
+ | otherwise = True
---------------
isBoxyTy :: TcType -> Bool
tcSplitForAllTys ty = split ty ty []
where
split orig_ty ty tvs | Just ty' <- tcView ty = split orig_ty ty' tvs
- split orig_ty (ForAllTy tv ty) tvs = split ty ty (tv:tvs)
- split orig_ty t tvs = (reverse tvs, orig_ty)
+ split orig_ty (ForAllTy tv ty) tvs
+ | not (isCoVar tv) = split ty ty (tv:tvs)
+ split orig_ty t tvs = (reverse tvs, orig_ty)
tcIsForAllTy ty | Just ty' <- tcView ty = tcIsForAllTy ty'
-tcIsForAllTy (ForAllTy tv ty) = True
+tcIsForAllTy (ForAllTy tv ty) = not (isCoVar tv)
tcIsForAllTy t = False
tcSplitPhiTy :: Type -> (ThetaType, Type)
tcSplitPhiTy ty = split ty ty []
where
split orig_ty ty tvs | Just ty' <- tcView ty = split orig_ty ty' tvs
+
+ split orig_ty (ForAllTy tv ty) ts
+ | isCoVar tv = split ty ty (eq_pred:ts)
+ where
+ PredTy eq_pred = tyVarKind tv
split orig_ty (FunTy arg res) ts
| Just p <- tcSplitPredTy_maybe arg = split res res (p:ts)
split orig_ty ty ts = (reverse ts, orig_ty)
-----------------------
tcTyConAppTyCon :: Type -> TyCon
-tcTyConAppTyCon ty = fst (tcSplitTyConApp ty)
+tcTyConAppTyCon ty = case tcSplitTyConApp_maybe ty of
+ Just (tc, _) -> tc
+ Nothing -> pprPanic "tcTyConAppTyCon" (pprType ty)
tcTyConAppArgs :: Type -> [Type]
-tcTyConAppArgs ty = snd (tcSplitTyConApp ty)
+tcTyConAppArgs ty = case tcSplitTyConApp_maybe ty of
+ Just (_, args) -> args
+ Nothing -> pprPanic "tcTyConAppArgs" (pprType ty)
tcSplitTyConApp :: Type -> (TyCon, [Type])
tcSplitTyConApp ty = case tcSplitTyConApp_maybe ty of
getClassPredTys (ClassP clas tys) = (clas, tys)
getClassPredTys other = panic "getClassPredTys"
-isEqPred :: PredType -> Bool
-isEqPred (EqPred {}) = True
-isEqPred _ = False
-
mkDictTy :: Class -> [Type] -> Type
mkDictTy clas tys = mkPredTy (ClassP clas tys)
-- which can be free in g's rhs, and shared by both calls to g
isInheritablePred (ClassP _ _) = True
isInheritablePred other = False
-
-isLinearPred :: TcPredType -> Bool
-isLinearPred (IParam (Linear n) _) = True
-isLinearPred other = False
\end{code}
--------------------- Equality predicates ---------------------------------
tcTyVarsOfType (PredTy sty) = tcTyVarsOfPred sty
tcTyVarsOfType (FunTy arg res) = tcTyVarsOfType arg `unionVarSet` tcTyVarsOfType res
tcTyVarsOfType (AppTy fun arg) = tcTyVarsOfType fun `unionVarSet` tcTyVarsOfType arg
-tcTyVarsOfType (ForAllTy tyvar ty) = tcTyVarsOfType ty `delVarSet` tyvar
+tcTyVarsOfType (ForAllTy tyvar ty) = (tcTyVarsOfType ty `delVarSet` tyvar)
+ `unionVarSet` tcTyVarsOfTyVar tyvar
-- We do sometimes quantify over skolem TcTyVars
+tcTyVarsOfTyVar :: TcTyVar -> TyVarSet
+tcTyVarsOfTyVar tv | isCoVar tv = tcTyVarsOfType (tyVarKind tv)
+ | otherwise = emptyVarSet
+
tcTyVarsOfTypes :: [Type] -> TyVarSet
tcTyVarsOfTypes tys = foldr (unionVarSet.tcTyVarsOfType) emptyVarSet tys
go (FunTy arg res) = go arg `unionVarSet` go res
go (AppTy fun arg) = go fun `unionVarSet` go arg
go (ForAllTy tyvar ty) = delVarSet (go ty) tyvar
+ `unionVarSet` go_tv tyvar
go_pred (IParam _ ty) = go ty
go_pred (ClassP _ tys) = exactTyVarsOfTypes tys
go_pred (EqPred ty1 ty2) = go ty1 `unionVarSet` go ty2
+ go_tv tyvar | isCoVar tyvar = go (tyVarKind tyvar)
+ | otherwise = emptyVarSet
+
exactTyVarsOfTypes :: [TcType] -> TyVarSet
exactTyVarsOfTypes tys = foldr (unionVarSet . exactTyVarsOfType) emptyVarSet tys
\end{code}
projects / ghc-hetmet.git / blobdiff