Safe Haskell | Safe-Inferred |
---|---|
Language | Haskell2010 |
Monadic type operations
This module contains monadic operations over types that contain mutable type variables.
Synopsis
- type TcTyVar = Var
- type TcKind = Kind
- type TcType = Type
- type TcTauType = TcType
- type TcThetaType = ThetaType
- type TcTyVarSet = TyVarSet
- newFlexiTyVar :: Kind -> TcM TcTyVar
- newNamedFlexiTyVar :: FastString -> Kind -> TcM TcTyVar
- newFlexiTyVarTy :: Kind -> TcM TcType
- newFlexiTyVarTys :: Int -> Kind -> TcM [TcType]
- newOpenFlexiTyVar :: TcM TcTyVar
- newOpenFlexiTyVarTy :: TcM TcType
- newOpenTypeKind :: TcM TcKind
- newOpenBoxedTypeKind :: TcM TcKind
- newMetaKindVar :: TcM TcKind
- newMetaKindVars :: Int -> TcM [TcKind]
- newMetaTyVarTyAtLevel :: TcLevel -> TcKind -> TcM TcType
- newAnonMetaTyVar :: MetaInfo -> Kind -> TcM TcTyVar
- cloneMetaTyVar :: TcTyVar -> TcM TcTyVar
- newCycleBreakerTyVar :: TcKind -> TcM TcTyVar
- newMultiplicityVar :: TcM TcType
- readMetaTyVar :: TyVar -> TcM MetaDetails
- writeMetaTyVar :: TcTyVar -> TcType -> TcM ()
- writeMetaTyVarRef :: TcTyVar -> TcRef MetaDetails -> TcType -> TcM ()
- newTauTvDetailsAtLevel :: TcLevel -> TcM TcTyVarDetails
- newMetaDetails :: MetaInfo -> TcM TcTyVarDetails
- newMetaTyVarName :: FastString -> TcM Name
- isFilledMetaTyVar_maybe :: TcTyVar -> TcM (Maybe Type)
- isFilledMetaTyVar :: TyVar -> TcM Bool
- isUnfilledMetaTyVar :: TyVar -> TcM Bool
- newEvVar :: TcPredType -> TcRnIf gbl lcl EvVar
- newEvVars :: TcThetaType -> TcM [EvVar]
- newDict :: Class -> [TcType] -> TcM DictId
- newWanted :: CtOrigin -> Maybe TypeOrKind -> PredType -> TcM CtEvidence
- newWanteds :: CtOrigin -> ThetaType -> TcM [CtEvidence]
- cloneWanted :: Ct -> TcM Ct
- cloneWC :: WantedConstraints -> TcM WantedConstraints
- emitWanted :: CtOrigin -> TcPredType -> TcM EvTerm
- emitWantedEq :: CtOrigin -> TypeOrKind -> Role -> TcType -> TcType -> TcM Coercion
- emitWantedEvVar :: CtOrigin -> TcPredType -> TcM EvVar
- emitWantedEvVars :: CtOrigin -> [TcPredType] -> TcM [EvVar]
- emitDerivedEqs :: CtOrigin -> [(TcType, TcType)] -> TcM ()
- newTcEvBinds :: TcM EvBindsVar
- newNoTcEvBinds :: TcM EvBindsVar
- addTcEvBind :: EvBindsVar -> EvBind -> TcM ()
- emitNewExprHole :: OccName -> Type -> TcM HoleExprRef
- newCoercionHole :: TcPredType -> TcM CoercionHole
- fillCoercionHole :: CoercionHole -> Coercion -> TcM ()
- isFilledCoercionHole :: CoercionHole -> TcM Bool
- unpackCoercionHole :: CoercionHole -> TcM Coercion
- unpackCoercionHole_maybe :: CoercionHole -> TcM (Maybe Coercion)
- checkCoercionHole :: CoVar -> Coercion -> TcM Coercion
- newImplication :: TcM Implication
- newMetaTyVars :: [TyVar] -> TcM (TCvSubst, [TcTyVar])
- newMetaTyVarX :: TCvSubst -> TyVar -> TcM (TCvSubst, TcTyVar)
- newMetaTyVarsX :: TCvSubst -> [TyVar] -> TcM (TCvSubst, [TcTyVar])
- newMetaTyVarTyVarX :: TCvSubst -> TyVar -> TcM (TCvSubst, TcTyVar)
- newTyVarTyVar :: Name -> Kind -> TcM TcTyVar
- cloneTyVarTyVar :: Name -> Kind -> TcM TcTyVar
- newPatSigTyVar :: Name -> Kind -> TcM TcTyVar
- newSkolemTyVar :: Name -> Kind -> TcM TcTyVar
- newWildCardX :: TCvSubst -> TyVar -> TcM (TCvSubst, TcTyVar)
- data ExpType
- = Check TcType
- | Infer !InferResult
- type ExpSigmaType = ExpType
- type ExpRhoType = ExpType
- mkCheckExpType :: TcType -> ExpType
- newInferExpType :: TcM ExpType
- tcInfer :: (ExpSigmaType -> TcM a) -> TcM (a, TcSigmaType)
- readExpType :: ExpType -> TcM TcType
- readExpType_maybe :: ExpType -> TcM (Maybe TcType)
- readScaledExpType :: Scaled ExpType -> TcM (Scaled Type)
- expTypeToType :: ExpType -> TcM TcType
- scaledExpTypeToType :: Scaled ExpType -> TcM (Scaled TcType)
- checkingExpType_maybe :: ExpType -> Maybe TcType
- checkingExpType :: String -> ExpType -> TcType
- inferResultToType :: InferResult -> TcM Type
- fillInferResult :: TcType -> InferResult -> TcM TcCoercionN
- promoteTcType :: TcLevel -> TcType -> TcM (TcCoercionN, TcType)
- zonkTidyTcType :: TidyEnv -> TcType -> TcM (TidyEnv, TcType)
- zonkTidyTcTypes :: TidyEnv -> [TcType] -> TcM (TidyEnv, [TcType])
- zonkTidyOrigin :: TidyEnv -> CtOrigin -> TcM (TidyEnv, CtOrigin)
- tidyEvVar :: TidyEnv -> EvVar -> EvVar
- tidyCt :: TidyEnv -> Ct -> Ct
- tidyHole :: TidyEnv -> Hole -> Hole
- tidySkolemInfo :: TidyEnv -> SkolemInfo -> SkolemInfo
- zonkTcTyVar :: TcTyVar -> TcM TcType
- zonkTcTyVars :: [TcTyVar] -> TcM [TcType]
- zonkTcTyVarToTyVar :: HasDebugCallStack => TcTyVar -> TcM TcTyVar
- zonkInvisTVBinder :: VarBndr TcTyVar spec -> TcM (VarBndr TyVar spec)
- zonkTyCoVarsAndFV :: TyCoVarSet -> TcM TyCoVarSet
- zonkTcTypeAndFV :: TcType -> TcM DTyCoVarSet
- zonkDTyCoVarSetAndFV :: DTyCoVarSet -> TcM DTyCoVarSet
- zonkTyCoVarsAndFVList :: [TyCoVar] -> TcM [TyCoVar]
- zonkTcType :: TcType -> TcM TcType
- zonkTcTypes :: [TcType] -> TcM [TcType]
- zonkCo :: Coercion -> TcM Coercion
- zonkTyCoVarKind :: TyCoVar -> TcM TyCoVar
- zonkTyCoVarKindBinder :: VarBndr TyCoVar fl -> TcM (VarBndr TyCoVar fl)
- zonkEvVar :: EvVar -> TcM EvVar
- zonkWC :: WantedConstraints -> TcM WantedConstraints
- zonkImplication :: Implication -> TcM Implication
- zonkSimples :: Cts -> TcM Cts
- zonkId :: TcId -> TcM TcId
- zonkCoVar :: CoVar -> TcM CoVar
- zonkCt :: Ct -> TcM Ct
- zonkSkolemInfo :: SkolemInfo -> TcM SkolemInfo
- defaultTyVar :: Bool -> TcTyVar -> TcM Bool
- promoteMetaTyVarTo :: TcLevel -> TcTyVar -> TcM Bool
- promoteTyVarSet :: TcTyVarSet -> TcM Bool
- quantifyTyVars :: CandidatesQTvs -> TcM [TcTyVar]
- isQuantifiableTv :: TcLevel -> TcTyVar -> Bool
- skolemiseUnboundMetaTyVar :: TcTyVar -> TcM TyVar
- zonkAndSkolemise :: TcTyCoVar -> TcM TcTyCoVar
- skolemiseQuantifiedTyVar :: TcTyVar -> TcM TcTyVar
- doNotQuantifyTyVars :: CandidatesQTvs -> (TidyEnv -> TcM (TidyEnv, SDoc)) -> TcM ()
- candidateQTyVarsOfType :: TcType -> TcM CandidatesQTvs
- candidateQTyVarsOfKind :: TcKind -> TcM CandidatesQTvs
- candidateQTyVarsOfTypes :: [Type] -> TcM CandidatesQTvs
- candidateQTyVarsOfKinds :: [TcKind] -> TcM CandidatesQTvs
- data CandidatesQTvs = DV {}
- delCandidates :: CandidatesQTvs -> [Var] -> CandidatesQTvs
- candidateKindVars :: CandidatesQTvs -> TyVarSet
- partitionCandidates :: CandidatesQTvs -> (TyVar -> Bool) -> (TyVarSet, CandidatesQTvs)
- ensureNotLevPoly :: Type -> SDoc -> TcM ()
- checkForLevPoly :: SDoc -> Type -> TcM ()
- checkForLevPolyX :: Monad m => (SDoc -> m ()) -> SDoc -> Type -> m ()
- formatLevPolyErr :: Type -> SDoc
Documentation
type TcThetaType = ThetaType Source #
type TcTyVarSet = TyVarSet Source #
newNamedFlexiTyVar :: FastString -> Kind -> TcM TcTyVar Source #
Create a new flexi ty var with a specific name
newOpenFlexiTyVarTy :: TcM TcType Source #
Create a tyvar that can be a lifted or unlifted type. Returns alpha :: TYPE kappa, where both alpha and kappa are fresh
readMetaTyVar :: TyVar -> TcM MetaDetails Source #
writeMetaTyVarRef :: TcTyVar -> TcRef MetaDetails -> TcType -> TcM () Source #
newMetaTyVarName :: FastString -> TcM Name Source #
newWanted :: CtOrigin -> Maybe TypeOrKind -> PredType -> TcM CtEvidence Source #
newWanteds :: CtOrigin -> ThetaType -> TcM [CtEvidence] Source #
emitWanted :: CtOrigin -> TcPredType -> TcM EvTerm Source #
Emits a new Wanted. Deals with both equalities and non-equalities.
emitWantedEq :: CtOrigin -> TypeOrKind -> Role -> TcType -> TcType -> TcM Coercion Source #
Emits a new equality constraint
emitWantedEvVar :: CtOrigin -> TcPredType -> TcM EvVar Source #
Creates a new EvVar and immediately emits it as a Wanted. No equality predicates here.
emitWantedEvVars :: CtOrigin -> [TcPredType] -> TcM [EvVar] Source #
newNoTcEvBinds :: TcM EvBindsVar Source #
Creates an EvBindsVar incapable of holding any bindings. It still tracks covar usages (see comments on ebv_tcvs in GHC.Tc.Types.Evidence), thus must be made monadically
addTcEvBind :: EvBindsVar -> EvBind -> TcM () Source #
emitNewExprHole :: OccName -> Type -> TcM HoleExprRef Source #
Emit a new wanted expression hole
fillCoercionHole :: CoercionHole -> Coercion -> TcM () Source #
Put a value in a coercion hole
isFilledCoercionHole :: CoercionHole -> TcM Bool Source #
Is a coercion hole filled in?
unpackCoercionHole :: CoercionHole -> TcM Coercion Source #
Retrieve the contents of a coercion hole. Panics if the hole is unfilled
unpackCoercionHole_maybe :: CoercionHole -> TcM (Maybe Coercion) Source #
Retrieve the contents of a coercion hole, if it is filled
checkCoercionHole :: CoVar -> Coercion -> TcM Coercion Source #
Check that a coercion is appropriate for filling a hole. (The hole itself is needed only for printing.) Always returns the checked coercion, but this return value is necessary so that the input coercion is forced only when the output is forced.
newImplication :: TcM Implication Source #
Create a new Implication
with as many sensible defaults for its fields
as possible. Note that the ic_tclvl
, ic_binds
, and ic_info
fields do
not have sensible defaults, so they are initialized with lazy thunks that
will panic
if forced, so one should take care to initialize these fields
after creation.
This is monadic to look up the TcLclEnv
, which is used to initialize
ic_env
, and to set the -Winaccessible-code flag. See
Note [Avoid -Winaccessible-code when deriving] in GHC.Tc.TyCl.Instance.
An expected type to check against during type-checking. See Note [ExpType] in GHC.Tc.Utils.TcMType, where you'll also find manipulators.
Instances
type ExpSigmaType = ExpType Source #
type ExpRhoType = ExpType Source #
tcInfer :: (ExpSigmaType -> TcM a) -> TcM (a, TcSigmaType) Source #
Infer a type using a fresh ExpType See also Note [ExpType] in GHC.Tc.Utils.TcMType
readExpType_maybe :: ExpType -> TcM (Maybe TcType) Source #
Extract a type out of an ExpType, if one exists. But one should always exist. Unless you're quite sure you know what you're doing.
readScaledExpType :: Scaled ExpType -> TcM (Scaled Type) Source #
Same as readExpType, but for Scaled ExpTypes
expTypeToType :: ExpType -> TcM TcType Source #
Extracts the expected type if there is one, or generates a new TauTv if there isn't.
checkingExpType_maybe :: ExpType -> Maybe TcType Source #
Returns the expected type when in checking mode.
checkingExpType :: String -> ExpType -> TcType Source #
Returns the expected type when in checking mode. Panics if in inference mode.
inferResultToType :: InferResult -> TcM Type Source #
fillInferResult :: TcType -> InferResult -> TcM TcCoercionN Source #
promoteTcType :: TcLevel -> TcType -> TcM (TcCoercionN, TcType) Source #
tidySkolemInfo :: TidyEnv -> SkolemInfo -> SkolemInfo Source #
zonkTcTyVarToTyVar :: HasDebugCallStack => TcTyVar -> TcM TcTyVar Source #
zonkTcTypeAndFV :: TcType -> TcM DTyCoVarSet Source #
zonkSkolemInfo :: SkolemInfo -> TcM SkolemInfo Source #
promoteTyVarSet :: TcTyVarSet -> TcM Bool Source #
quantifyTyVars :: CandidatesQTvs -> TcM [TcTyVar] Source #
candidateQTyVarsOfType :: TcType -> TcM CandidatesQTvs Source #
Gathers free variables to use as quantification candidates (in
quantifyTyVars
). This might output the same var
in both sets, if it's used in both a type and a kind.
The variables to quantify must have a TcLevel strictly greater than
the ambient level. (See Wrinkle in Note [Naughty quantification candidates])
See Note [CandidatesQTvs determinism and order]
See Note [Dependent type variables]
candidateQTyVarsOfKind :: TcKind -> TcM CandidatesQTvs Source #
Like candidateQTyVarsOfType
, but consider every free variable
to be dependent. This is appropriate when generalizing a *kind*,
instead of a type. (That way, -XNoPolyKinds will default the variables
to Type.)
candidateQTyVarsOfTypes :: [Type] -> TcM CandidatesQTvs Source #
Like candidateQTyVarsOfType
, but over a list of types
The variables to quantify must have a TcLevel strictly greater than
the ambient level. (See Wrinkle in Note [Naughty quantification candidates])
data CandidatesQTvs Source #
Instances
Monoid CandidatesQTvs Source # | |
Defined in GHC.Tc.Utils.TcMType mempty :: CandidatesQTvs Source # mappend :: CandidatesQTvs -> CandidatesQTvs -> CandidatesQTvs Source # mconcat :: [CandidatesQTvs] -> CandidatesQTvs Source # | |
Semigroup CandidatesQTvs Source # | |
Defined in GHC.Tc.Utils.TcMType (<>) :: CandidatesQTvs -> CandidatesQTvs -> CandidatesQTvs Source # sconcat :: NonEmpty CandidatesQTvs -> CandidatesQTvs Source # stimes :: Integral b => b -> CandidatesQTvs -> CandidatesQTvs Source # | |
Outputable CandidatesQTvs Source # | |
Defined in GHC.Tc.Utils.TcMType ppr :: CandidatesQTvs -> SDoc Source # |
delCandidates :: CandidatesQTvs -> [Var] -> CandidatesQTvs Source #
partitionCandidates :: CandidatesQTvs -> (TyVar -> Bool) -> (TyVarSet, CandidatesQTvs) Source #
ensureNotLevPoly :: Type -> SDoc -> TcM () Source #
According to the rules around representation polymorphism (see https://gitlab.haskell.org/ghc/ghc/wikis/no-sub-kinds), no binder can have a representation-polymorphic type. This check ensures that we respect this rule. It is a bit regrettable that this error occurs in zonking, after which we should have reported all errors. But it's hard to see where else to do it, because this can be discovered only after all solving is done. And, perhaps most importantly, this isn't really a compositional property of a type system, so it's not a terrible surprise that the check has to go in an awkward spot.
formatLevPolyErr :: Type -> SDoc Source #