UserTypeCtxt(..), pprUserTypeCtxt,
TcTyVarDetails(..), BoxInfo(..), pprTcTyVarDetails,
MetaDetails(Flexi, Indirect), SkolemInfo(..), pprSkolTvBinding, pprSkolInfo,
- isImmutableTyVar, isSkolemTyVar, isMetaTyVar, isBoxyTyVar, isSigTyVar, isExistentialTyVar,
+ isImmutableTyVar, isSkolemTyVar, isMetaTyVar, isBoxyTyVar,
+ isSigTyVar, isExistentialTyVar, isTyConableTyVar,
metaTvRef,
isFlexi, isIndirect,
tcTyVarsOfType, tcTyVarsOfTypes, exactTyVarsOfType, exactTyVarsOfTypes,
pprKind, pprParendKind,
- pprType, pprParendType, pprTyThingCategory,
+ pprType, pprParendType, pprTypeApp, pprTyThingCategory,
pprPred, pprTheta, pprThetaArrow, pprClassPred
) where
%************************************************************************
\begin{code}
-isImmutableTyVar, isSkolemTyVar, isExistentialTyVar, isBoxyTyVar, isMetaTyVar :: TyVar -> Bool
+isImmutableTyVar :: TyVar -> Bool
+
isImmutableTyVar tv
| isTcTyVar tv = isSkolemTyVar tv
| otherwise = True
+isTyConableTyVar, isSkolemTyVar, isExistentialTyVar,
+ isBoxyTyVar, isMetaTyVar :: TcTyVar -> Bool
+
+isTyConableTyVar tv
+ -- True of a meta-type variable tha can be filled in
+ -- with a type constructor application; in particular,
+ -- not a SigTv
+ = ASSERT( isTcTyVar tv)
+ case tcTyVarDetails tv of
+ MetaTv BoxTv _ -> True
+ MetaTv TauTv _ -> True
+ MetaTv (SigTv {}) _ -> False
+ SkolemTv {} -> False
+
isSkolemTyVar tv
= ASSERT( isTcTyVar tv )
case tcTyVarDetails tv of
isTauTyCon :: TyCon -> Bool
-- Returns False for type synonyms whose expansion is a polytype
isTauTyCon tc
- | isSynTyCon tc && not (isOpenTyCon tc) = isTauTy (snd (synTyConDefn tc))
- | otherwise = True
+ | isClosedSynTyCon tc = isTauTy (snd (synTyConDefn tc))
+ | otherwise = True
---------------
isBoxyTy :: TcType -> Bool