GHC.Tc.Gen.HsType

Typechecking user-specified MonoTypes

Documentation

kcClassSigType :: SkolemInfo -> [Located Name] -> LHsSigType GhcRn -> TcM ()

tcClassSigType :: SkolemInfo -> [Located Name] -> LHsSigType GhcRn -> TcM Type

tcHsSigType :: UserTypeCtxt -> LHsSigType GhcRn -> TcM Type

tcHsSigWcType :: UserTypeCtxt -> LHsSigWcType GhcRn -> TcM Type

tcHsPartialSigType :: UserTypeCtxt -> LHsSigWcType GhcRn -> TcM ([(Name, TcTyVar)], Maybe TcType, [(Name, InvisTVBinder)], TcThetaType, TcType)

tcStandaloneKindSig :: LStandaloneKindSig GhcRn -> TcM (Name, Kind)

funsSigCtxt :: [Located Name] -> UserTypeCtxt

addSigCtxt :: UserTypeCtxt -> LHsType GhcRn -> TcM a -> TcM a

pprSigCtxt :: UserTypeCtxt -> LHsType GhcRn -> SDoc

tcHsClsInstType :: UserTypeCtxt -> LHsSigType GhcRn -> TcM Type

tcHsDeriv :: LHsSigType GhcRn -> TcM ([TyVar], Class, [Type], [Kind])

tcDerivStrategy

Arguments

:: Maybe (LDerivStrategy GhcRn)

The deriving strategy

-> TcM (Maybe (LDerivStrategy GhcTc), [TyVar])

The typechecked deriving strategy and the tyvars that it binds (if using ViaStrategy).

Typecheck a deriving strategy. For most deriving strategies, this is a no-op, but for the via strategy, this requires typechecking the via type.

tcHsTypeApp :: LHsWcType GhcRn -> Kind -> TcM Type

Type-check a visible type application

data UserTypeCtxt

Constructors

FunSigCtxt Name Bool

InfSigCtxt Name

ExprSigCtxt

KindSigCtxt

StandaloneKindSigCtxt Name

TypeAppCtxt

ConArgCtxt Name

TySynCtxt Name

PatSynCtxt Name

PatSigCtxt

RuleSigCtxt Name

ForSigCtxt Name

DefaultDeclCtxt

InstDeclCtxt Bool

SpecInstCtxt

GenSigCtxt

GhciCtxt Bool

ClassSCCtxt Name

SigmaCtxt

DataTyCtxt Name

DerivClauseCtxt

TyVarBndrKindCtxt Name

DataKindCtxt Name

TySynKindCtxt Name

TyFamResKindCtxt Name

bindImplicitTKBndrs_Tv :: [Name] -> TcM a -> TcM ([TcTyVar], a)

bindImplicitTKBndrs_Skol :: [Name] -> TcM a -> TcM ([TcTyVar], a)

bindImplicitTKBndrs_Q_Tv :: [Name] -> TcM a -> TcM ([TcTyVar], a)

bindImplicitTKBndrs_Q_Skol :: [Name] -> TcM a -> TcM ([TcTyVar], a)

bindExplicitTKBndrs_Tv :: OutputableBndrFlag flag => [LHsTyVarBndr flag GhcRn] -> TcM a -> TcM ([VarBndr TyVar flag], a)

bindExplicitTKBndrs_Skol :: OutputableBndrFlag flag => [LHsTyVarBndr flag GhcRn] -> TcM a -> TcM ([VarBndr TyVar flag], a)

bindExplicitTKBndrs_Q_Tv :: ContextKind -> [LHsTyVarBndr () GhcRn] -> TcM a -> TcM ([TcTyVar], a)

bindExplicitTKBndrs_Q_Skol :: ContextKind -> [LHsTyVarBndr () GhcRn] -> TcM a -> TcM ([TcTyVar], a)

data ContextKind

Describes the kind expected in a certain context.

Constructors

TheKind Kind

a specific kind

AnyKind

any kind will do

OpenKind

something of the form TYPE _

bindTyClTyVars :: Name -> (TcTyCon -> [TyConBinder] -> Kind -> TcM a) -> TcM a

Used for the type variables of a type or class decl in the "kind checking" and "type checking" pass, but not in the initial-kind run.

tcFamTyPats :: TyCon -> HsTyPats GhcRn -> TcM (TcType, TcKind)

etaExpandAlgTyCon :: [TyConBinder] -> Kind -> TcM ([TyConBinder], Kind)

tcbVisibilities :: TyCon -> [Type] -> [TyConBndrVis]

zonkAndScopedSort :: [TcTyVar] -> TcM [TcTyVar]

data InitialKindStrategy

Constructors

InitialKindCheck SAKS_or_CUSK

InitialKindInfer

data SAKS_or_CUSK

Constructors

SAKS Kind

CUSK

Instances

Outputable SAKS_or_CUSK

Defined in GHC.Tc.Gen.HsType

Methods

ppr :: SAKS_or_CUSK -> SDoc

kcDeclHeader

Arguments

:: InitialKindStrategy

-> Name

of the thing being checked

-> TyConFlavour

What sort of TyCon is being checked

-> LHsQTyVars GhcRn

Binders in the header

-> TcM ContextKind

The result kind

-> TcM TcTyCon

A suitably-kinded TcTyCon

tcNamedWildCardBinders :: [Name] -> ([(Name, TcTyVar)] -> TcM a) -> TcM a

tcHsLiftedType :: LHsType GhcRn -> TcM TcType

tcHsOpenType :: LHsType GhcRn -> TcM TcType

tcHsLiftedTypeNC :: LHsType GhcRn -> TcM TcType

tcHsOpenTypeNC :: LHsType GhcRn -> TcM TcType

tcInferLHsTypeKind :: LHsType GhcRn -> TcM (TcType, TcKind)

tcInferLHsType :: LHsType GhcRn -> TcM TcType

tcInferLHsTypeUnsaturated :: LHsType GhcRn -> TcM (TcType, TcKind)

tcCheckLHsType :: LHsType GhcRn -> ContextKind -> TcM TcType

tcHsMbContext :: Maybe (LHsContext GhcRn) -> TcM [PredType]

tcHsContext :: LHsContext GhcRn -> TcM [PredType]

tcLHsPredType :: LHsType GhcRn -> TcM PredType

kindGeneralizeAll :: TcType -> TcM [KindVar]

• Specialised verison of kindGeneralizeSome, but with empty WantedConstraints, so no filtering is needed i.e. kindGeneraliseAll = kindGeneralizeSome emptyWC

kindGeneralizeSome

Arguments

:: WantedConstraints

-> TcType

needn't be zonked

-> TcM [KindVar]

Generalize some of the free variables in the given type. All such variables should be *kind* variables; any type variables should be explicitly quantified (with a forall) before now.

The WantedConstraints are un-solved kind constraints. Generally they'll be reported as errors later, but meanwhile we refrain from quantifying over any variable free in these unsolved constraints. See Note [Failure in local type signatures].

But in all cases, generalize only those variables whose TcLevel is strictly greater than the ambient level. This "strictly greater than" means that you likely need to push the level before creating whatever type gets passed here.

Any variable whose level is greater than the ambient level but is not selected to be generalized will be promoted. (See [Promoting unification variables] in GHC.Tc.Solver and Note [Recipe for checking a signature].)

The resulting KindVar are the variables to quantify over, in the correct, well-scoped order. They should generally be Inferred, not Specified, but that's really up to the caller of this function.

kindGeneralizeNone :: TcType -> TcM ()

Specialized version of kindGeneralizeSome, but where no variables can be generalized, but perhaps some may neeed to be promoted. Use this variant when it is unknowable whether metavariables might later be constrained.

To see why this promotion is needed, see Note [Recipe for checking a signature], and especially Note [Promotion in signatures].

tcLHsKindSig :: UserTypeCtxt -> LHsKind GhcRn -> TcM Kind

checkDataKindSig :: DataSort -> Kind -> TcM ()

Checks that the return kind in a data declaration's kind signature is permissible. There are three cases:

If dealing with a data, newtype, data instance, or newtype instance declaration, check that the return kind is Type.

If the declaration is a newtype or newtype instance and the UnliftedNewtypes extension is enabled, this check is slightly relaxed so that a return kind of the form TYPE r (for some r) is permitted. See Note [Implementation of UnliftedNewtypes] in GHC.Tc.TyCl.

If dealing with a data family declaration, check that the return kind is either of the form:

1. TYPE r (for some r), or
2. k (where k is a bare kind variable; see #12369)

See also Note [Datatype return kinds] in GHC.Tc.TyCl

data DataSort

A description of whether something is a

• data or newtype (DataDeclSort)
• data instance or newtype instance (DataInstanceSort)
• data family (DataFamilySort)

At present, this data type is only consumed by checkDataKindSig.

Constructors

DataDeclSort NewOrData

DataInstanceSort NewOrData

DataFamilySort

checkClassKindSig :: Kind -> TcM ()

Checks that the result kind of a class is exactly Constraint, rejecting type synonyms and type families that reduce to Constraint. See #16826.

tcMult :: HsArrow GhcRn -> TcM Mult

tcHsPatSigType :: UserTypeCtxt -> HsPatSigType GhcRn -> TcM ([(Name, TcTyVar)], [(Name, TcTyVar)], TcType)

funAppCtxt :: (Outputable fun, Outputable arg) => fun -> arg -> Int -> SDoc

Make an appropriate message for an error in a function argument. Used for both expressions and types.

addTyConFlavCtxt :: Name -> TyConFlavour -> TcM a -> TcM a

Add a "In the data declaration for T" or some such.