GHC.Core.Predicate

Documentation

data Pred

A predicate in the solver. The solver tries to prove Wanted predicates from Given ones.

Constructors

ClassPred Class [Type]

A typeclass predicate.

EqPred EqRel Type Type

A type equality predicate.

IrredPred PredType

An irreducible predicate.

ForAllPred [TyVar] [PredType] PredType

A quantified predicate.

See Note [Quantified constraints] in GHC.Tc.Solver.Solve

classifyPredType :: PredType -> Pred

isPredTy :: HasDebugCallStack => Type -> Bool

isEvVarType :: Type -> Bool

data EqRel

A choice of equality relation. This is separate from the type Role because Phantom does not define a (non-trivial) equality relation.

Constructors

NomEq

ReprEq

Instances

Outputable EqRel

Defined in GHC.Core.Predicate

Methods

ppr :: EqRel -> SDoc

Eq EqRel

Defined in GHC.Core.Predicate

Methods

(==) :: EqRel -> EqRel -> Bool

(/=) :: EqRel -> EqRel -> Bool

Ord EqRel

Defined in GHC.Core.Predicate

Methods

compare :: EqRel -> EqRel -> Ordering

(<) :: EqRel -> EqRel -> Bool

(<=) :: EqRel -> EqRel -> Bool

(>) :: EqRel -> EqRel -> Bool

(>=) :: EqRel -> EqRel -> Bool

max :: EqRel -> EqRel -> EqRel

min :: EqRel -> EqRel -> EqRel

eqRelRole :: EqRel -> Role

isEqPrimPred :: PredType -> Bool

isEqPred :: PredType -> Bool

getEqPredTys :: PredType -> (Type, Type)

getEqPredTys_maybe :: PredType -> Maybe (Role, Type, Type)

getEqPredRole :: PredType -> Role

predTypeEqRel :: PredType -> EqRel

Get the equality relation relevant for a pred type.

mkPrimEqPred :: Type -> Type -> Type

Creates a primitive nominal type equality predicate. t1 ~# t2 Invariant: the types are not Coercions

mkReprPrimEqPred :: Type -> Type -> Type

Creates a primitive representational type equality predicate. t1 ~R# t2 Invariant: the types are not Coercions

mkPrimEqPredRole :: Role -> Type -> Type -> PredType

Makes a lifted equality predicate at the given role

mkNomPrimEqPred :: Kind -> Type -> Type -> Type

Creates a primitive nominal type equality predicate with an explicit (but homogeneous) kind: (~#) k k ty1 ty2

mkClassPred :: Class -> [Type] -> PredType

isDictTy :: Type -> Bool

typeDeterminesValue :: Type -> Bool

isClassPred :: PredType -> Bool

isEqualityClass :: Class -> Bool

isCTupleClass :: Class -> Bool

getClassPredTys :: HasDebugCallStack => PredType -> (Class, [Type])

getClassPredTys_maybe :: PredType -> Maybe (Class, [Type])

classMethodTy :: Id -> Type

classMethodInstTy :: Id -> [Type] -> Type

isIPLikePred :: Type -> Bool

mentionsIP :: Type -> Class -> [Type] -> Bool

isIPTyCon :: TyCon -> Bool

isIPClass :: Class -> Bool

isCallStackTy :: Type -> Bool

Is a type a CallStack?

isCallStackPred :: Class -> [Type] -> Maybe FastString

Is a PredType a CallStack implicit parameter?

If so, return the name of the parameter.

isCallStackPredTy :: Type -> Bool

isExceptionContextPred :: Class -> [Type] -> Maybe FastString

Is a PredType an ExceptionContext implicit parameter?

If so, return the name of the parameter.

isIPPred_maybe :: Class -> [Type] -> Maybe (Type, Type)

Decomposes a predicate if it is an implicit parameter. Does not look in superclasses. See also [Local implicit parameters].

type DictId = EvId

Dictionary Identifier

isEvVar :: Var -> Bool

isDictId :: Id -> Bool