-
+%
% (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,
---------------------------------
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 )
-- 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"),
-----------------------
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
-- 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 ---------------------------------