Safe Haskell	None
Language	Haskell2010

TcUnify

Synopsis

tcWrapResult :: HsExpr GhcRn -> HsExpr GhcTcId -> TcSigmaType -> ExpRhoType -> TcM (HsExpr GhcTcId)
tcWrapResultO :: CtOrigin -> HsExpr GhcRn -> HsExpr GhcTcId -> TcSigmaType -> ExpRhoType -> TcM (HsExpr GhcTcId)
tcSkolemise :: UserTypeCtxt -> TcSigmaType -> ([TcTyVar] -> TcType -> TcM result) -> TcM (HsWrapper, result)
tcSkolemiseET :: UserTypeCtxt -> ExpSigmaType -> (ExpRhoType -> TcM result) -> TcM (HsWrapper, result)
tcSubTypeHR :: CtOrigin -> Maybe (HsExpr GhcRn) -> TcSigmaType -> ExpRhoType -> TcM HsWrapper
tcSubTypeO :: CtOrigin -> UserTypeCtxt -> TcSigmaType -> ExpRhoType -> TcM HsWrapper
tcSubType_NC :: UserTypeCtxt -> TcSigmaType -> TcSigmaType -> TcM HsWrapper
tcSubTypeDS :: CtOrigin -> UserTypeCtxt -> TcSigmaType -> ExpRhoType -> TcM HsWrapper
tcSubTypeDS_NC_O :: CtOrigin -> UserTypeCtxt -> Maybe (HsExpr GhcRn) -> TcSigmaType -> ExpRhoType -> TcM HsWrapper
tcSubTypeET :: CtOrigin -> UserTypeCtxt -> ExpSigmaType -> TcSigmaType -> TcM HsWrapper
checkConstraints :: SkolemInfo -> [TcTyVar] -> [EvVar] -> TcM result -> TcM (TcEvBinds, result)
buildImplicationFor :: TcLevel -> SkolemInfo -> [TcTyVar] -> [EvVar] -> WantedConstraints -> TcM (Bag Implication, TcEvBinds)
unifyType :: Maybe (HsExpr GhcRn) -> TcTauType -> TcTauType -> TcM TcCoercionN
unifyTheta :: TcThetaType -> TcThetaType -> TcM [TcCoercionN]
unifyKind :: Maybe (HsType GhcRn) -> TcKind -> TcKind -> TcM CoercionN
uType :: TypeOrKind -> CtOrigin -> TcType -> TcType -> TcM Coercion
promoteTcType :: TcLevel -> TcType -> TcM (TcCoercion, TcType)
swapOverTyVars :: TcTyVar -> TcTyVar -> Bool
canSolveByUnification :: TcLevel -> TcTyVar -> TcType -> Bool
tcInferInst :: (ExpRhoType -> TcM a) -> TcM (a, TcRhoType)
tcInferNoInst :: (ExpSigmaType -> TcM a) -> TcM (a, TcSigmaType)
matchExpectedListTy :: TcRhoType -> TcM (TcCoercionN, TcRhoType)
matchExpectedPArrTy :: TcRhoType -> TcM (TcCoercionN, TcRhoType)
matchExpectedTyConApp :: TyCon -> TcRhoType -> TcM (TcCoercionN, [TcSigmaType])
matchExpectedAppTy :: TcRhoType -> TcM (TcCoercion, (TcSigmaType, TcSigmaType))
matchExpectedFunTys :: forall a. SDoc -> Arity -> ExpRhoType -> ([ExpSigmaType] -> ExpRhoType -> TcM a) -> TcM (a, HsWrapper)
matchActualFunTys :: SDoc -> CtOrigin -> Maybe (HsExpr GhcRn) -> Arity -> TcSigmaType -> TcM (HsWrapper, [TcSigmaType], TcSigmaType)
matchActualFunTysPart :: SDoc -> CtOrigin -> Maybe (HsExpr GhcRn) -> Arity -> TcSigmaType -> [TcSigmaType] -> Arity -> TcM (HsWrapper, [TcSigmaType], TcSigmaType)
matchExpectedFunKind :: Outputable fun => fun -> TcKind -> TcM (Coercion, TcKind, TcKind)
occCheckExpand :: TcTyVar -> TcType -> Maybe TcType
metaTyVarUpdateOK :: DynFlags -> TcTyVar -> TcType -> Maybe TcType
occCheckForErrors :: DynFlags -> TcTyVar -> Type -> OccCheckResult ()
data OccCheckResult a
- = OC_OK a
- | OC_Bad
- | OC_Occurs

Documentation

tcWrapResult :: HsExpr GhcRn -> HsExpr GhcTcId -> TcSigmaType -> ExpRhoType -> TcM (HsExpr GhcTcId) Source #

tcWrapResultO :: CtOrigin -> HsExpr GhcRn -> HsExpr GhcTcId -> TcSigmaType -> ExpRhoType -> TcM (HsExpr GhcTcId) Source #

Sometimes we don't have a HsExpr Name to hand, and this is more convenient.

tcSkolemise Source #

Arguments

:: UserTypeCtxt
-> TcSigmaType
-> ([TcTyVar] -> TcType -> TcM result)	These are only ever used for scoped type variables.
-> TcM (HsWrapper, result)	The expression has type: spec_ty -> expected_ty

Take an "expected type" and strip off quantifiers to expose the type underneath, binding the new skolems for the thing_inside. The returned HsWrapper has type specific_ty -> expected_ty.

tcSkolemiseET :: UserTypeCtxt -> ExpSigmaType -> (ExpRhoType -> TcM result) -> TcM (HsWrapper, result) Source #

Variant of tcSkolemise that takes an ExpType

tcSubTypeHR Source #

Arguments

:: CtOrigin	of the actual type
-> Maybe (HsExpr GhcRn)	If present, it has type ty_actual
-> TcSigmaType
-> ExpRhoType
-> TcM HsWrapper

Call this variant when you are in a higher-rank situation and you know the right-hand type is deeply skolemised.

tcSubTypeO Source #

Arguments

:: CtOrigin	of the actual type
-> UserTypeCtxt	of the expected type
-> TcSigmaType
-> ExpRhoType
-> TcM HsWrapper

tcSubType_NC :: UserTypeCtxt -> TcSigmaType -> TcSigmaType -> TcM HsWrapper Source #

tcSubTypeDS :: CtOrigin -> UserTypeCtxt -> TcSigmaType -> ExpRhoType -> TcM HsWrapper Source #

tcSubTypeDS_NC_O :: CtOrigin -> UserTypeCtxt -> Maybe (HsExpr GhcRn) -> TcSigmaType -> ExpRhoType -> TcM HsWrapper Source #

tcSubTypeET :: CtOrigin -> UserTypeCtxt -> ExpSigmaType -> TcSigmaType -> TcM HsWrapper Source #

checkConstraints :: SkolemInfo -> [TcTyVar] -> [EvVar] -> TcM result -> TcM (TcEvBinds, result) Source #

buildImplicationFor :: TcLevel -> SkolemInfo -> [TcTyVar] -> [EvVar] -> WantedConstraints -> TcM (Bag Implication, TcEvBinds) Source #

unifyType Source #

Arguments

:: Maybe (HsExpr GhcRn)	If present, has type `ty1`
-> TcTauType
-> TcTauType
-> TcM TcCoercionN

unifyTheta :: TcThetaType -> TcThetaType -> TcM [TcCoercionN] Source #

unifyKind :: Maybe (HsType GhcRn) -> TcKind -> TcKind -> TcM CoercionN Source #

uType :: TypeOrKind -> CtOrigin -> TcType -> TcType -> TcM Coercion Source #

promoteTcType :: TcLevel -> TcType -> TcM (TcCoercion, TcType) Source #

swapOverTyVars :: TcTyVar -> TcTyVar -> Bool Source #

canSolveByUnification :: TcLevel -> TcTyVar -> TcType -> Bool Source #

tcInferInst :: (ExpRhoType -> TcM a) -> TcM (a, TcRhoType) Source #

tcInferNoInst :: (ExpSigmaType -> TcM a) -> TcM (a, TcSigmaType) Source #

Infer a type using a fresh ExpType See also Note [ExpType] in TcMType Does not attempt to instantiate the inferred type

matchExpectedListTy :: TcRhoType -> TcM (TcCoercionN, TcRhoType) Source #

matchExpectedPArrTy :: TcRhoType -> TcM (TcCoercionN, TcRhoType) Source #

matchExpectedTyConApp :: TyCon -> TcRhoType -> TcM (TcCoercionN, [TcSigmaType]) Source #

matchExpectedAppTy :: TcRhoType -> TcM (TcCoercion, (TcSigmaType, TcSigmaType)) Source #

matchExpectedFunTys :: forall a. SDoc -> Arity -> ExpRhoType -> ([ExpSigmaType] -> ExpRhoType -> TcM a) -> TcM (a, HsWrapper) Source #

matchActualFunTys :: SDoc -> CtOrigin -> Maybe (HsExpr GhcRn) -> Arity -> TcSigmaType -> TcM (HsWrapper, [TcSigmaType], TcSigmaType) Source #

matchActualFunTysPart :: SDoc -> CtOrigin -> Maybe (HsExpr GhcRn) -> Arity -> TcSigmaType -> [TcSigmaType] -> Arity -> TcM (HsWrapper, [TcSigmaType], TcSigmaType) Source #

Variant of matchActualFunTys that works when supplied only part (that is, to the right of some arrows) of the full function type

matchExpectedFunKind Source #

Arguments

:: Outputable fun
=> fun	type, only for errors
-> TcKind	function kind
-> TcM (Coercion, TcKind, TcKind)	co :: old_kind ~ arg -> res

Breaks apart a function kind into its pieces.

occCheckExpand :: TcTyVar -> TcType -> Maybe TcType Source #

metaTyVarUpdateOK :: DynFlags -> TcTyVar -> TcType -> Maybe TcType Source #

occCheckForErrors :: DynFlags -> TcTyVar -> Type -> OccCheckResult () Source #

data OccCheckResult a Source #

Constructors

OC_OK a
OC_Bad
OC_Occurs

Instances

Monad OccCheckResult Source #
Instance details Methods (>>=) :: OccCheckResult a -> (a -> OccCheckResult b) -> OccCheckResult b # (>>) :: OccCheckResult a -> OccCheckResult b -> OccCheckResult b # return :: a -> OccCheckResult a # fail :: String -> OccCheckResult a #
Functor OccCheckResult Source #
Instance details Methods fmap :: (a -> b) -> OccCheckResult a -> OccCheckResult b # (<$) :: a -> OccCheckResult b -> OccCheckResult a #
Applicative OccCheckResult Source #
Instance details Methods pure :: a -> OccCheckResult a # (<>) :: OccCheckResult (a -> b) -> OccCheckResult a -> OccCheckResult b # liftA2 :: (a -> b -> c) -> OccCheckResult a -> OccCheckResult b -> OccCheckResult c # (>) :: OccCheckResult a -> OccCheckResult b -> OccCheckResult b # (<*) :: OccCheckResult a -> OccCheckResult b -> OccCheckResult a #