funTyCon,
-- Pretty-printing
- pprType, pprParendType, pprTyThingCategory,
- pprPred, pprTheta, pprThetaArrow, pprClassPred,
+ pprType, pprParendType, pprTyThingCategory,
+ pprPred, pprTheta, pprForAll, pprThetaArrow, pprClassPred,
-- Kinds
liftedTypeKind, unliftedTypeKind, openTypeKind,
data PredType
= ClassP Class [Type] -- Class predicate
| IParam (IPName Name) Type -- Implicit parameter
- | EqPred Type Type -- Equality predicate (ty1 :=: ty2)
+ | EqPred Type Type -- Equality predicate (ty1 ~ ty2)
type ThetaType = [PredType]
\end{code}
Note [Equality predicates]
~~~~~~~~~~~~~~~~~~~~~~~~~~
- forall a b. (a :=: S b) => a -> b
+ forall a b. (a ~ S b) => a -> b
could be represented by
ForAllTy a (ForAllTy b (FunTy (PredTy (EqPred a (S b))) ...))
OR
isLiftedTypeKind other = False
isCoercionKind :: Kind -> Bool
--- All coercions are of form (ty1 :=: ty2)
+-- All coercions are of form (ty1 ~ ty2)
-- This function is here rather than in Coercion,
-- because it's used in a knot-tied way to enforce invariants in Var
isCoercionKind (NoteTy _ k) = isCoercionKind k
pprPred :: PredType -> SDoc
pprPred (ClassP cls tys) = pprClassPred cls tys
pprPred (IParam ip ty) = ppr ip <> dcolon <> pprType ty
-pprPred (EqPred ty1 ty2) = sep [ppr ty1, nest 2 (ptext SLIT(":=:")), ppr ty2]
+pprPred (EqPred ty1 ty2) = sep [ppr ty1, nest 2 (ptext SLIT("~")), ppr ty2]
pprClassPred :: Class -> [Type] -> SDoc
pprClassPred clas tys = parenSymOcc (getOccName clas) (ppr clas)
ppr_type :: Prec -> Type -> SDoc
ppr_type p (TyVarTy tv) = ppr tv
-ppr_type p (PredTy pred) = braces (ppr pred)
+ppr_type p (PredTy pred) = ifPprDebug (ptext SLIT("<pred>")) <> (ppr pred)
ppr_type p (NoteTy other ty2) = ppr_type p ty2
ppr_type p (TyConApp tc tys) = ppr_tc_app p tc tys