Safe Haskell	Safe-Inferred
Language	Haskell2010

GHC.Tc.Errors.Hole

Synopsis

findValidHoleFits :: TidyEnv -> [Implication] -> [Ct] -> Hole -> TcM (TidyEnv, SDoc)
tcCheckHoleFit :: TypedHole -> TcSigmaType -> TcSigmaType -> TcM (Bool, HsWrapper)
withoutUnification :: FV -> TcM a -> TcM a
tcSubsumes :: TcSigmaType -> TcSigmaType -> TcM Bool
isFlexiTyVar :: TcTyVar -> TcM Bool
tcFilterHoleFits :: Maybe Int -> TypedHole -> (TcType, [TcTyVar]) -> [HoleFitCandidate] -> TcM (Bool, [HoleFit])
getLocalBindings :: TidyEnv -> CtLoc -> TcM [Id]
pprHoleFit :: HoleFitDispConfig -> HoleFit -> SDoc
addHoleFitDocs :: [HoleFit] -> TcM [HoleFit]
getHoleFitSortingAlg :: TcM HoleFitSortingAlg
getHoleFitDispConfig :: TcM HoleFitDispConfig
data HoleFitDispConfig = HFDC {
- showWrap :: Bool
- showWrapVars :: Bool
- showType :: Bool
- showProv :: Bool
- showMatches :: Bool
}
data HoleFitSortingAlg
- = HFSNoSorting
- | HFSBySize
- | HFSBySubsumption
relevantCts :: Type -> [Ct] -> [Ct]
zonkSubs :: TidyEnv -> [HoleFit] -> TcM (TidyEnv, [HoleFit])
sortHoleFitsByGraph :: [HoleFit] -> TcM [HoleFit]
sortHoleFitsBySize :: [HoleFit] -> TcM [HoleFit]
data HoleFitPlugin = HoleFitPlugin {
- candPlugin :: CandPlugin
- fitPlugin :: FitPlugin
}
data HoleFitPluginR = forall s.HoleFitPluginR {
- hfPluginInit :: TcM (TcRef s)
- hfPluginRun :: TcRef s -> HoleFitPlugin
- hfPluginStop :: TcRef s -> TcM ()
}

Documentation

findValidHoleFits Source #

Arguments

:: TidyEnv	The tidy_env for zonking
-> [Implication]	Enclosing implications for givens
-> [Ct]	The unsolved simple constraints in the implication for the hole.
-> Hole
-> TcM (TidyEnv, SDoc)

tcCheckHoleFit Source #

Arguments

:: TypedHole	The hole to check against
-> TcSigmaType	The type to check against (possibly modified, e.g. refined)
-> TcSigmaType	The type to check whether fits.
-> TcM (Bool, HsWrapper)	Whether it was a match, and the wrapper from hole_ty to ty.

A tcSubsumes which takes into account relevant constraints, to fix trac #14273. This makes sure that when checking whether a type fits the hole, the type has to be subsumed by type of the hole as well as fulfill all constraints on the type of the hole.

withoutUnification :: FV -> TcM a -> TcM a Source #

Takes a list of free variables and restores any Flexi type variables in free_vars after the action is run.

tcSubsumes :: TcSigmaType -> TcSigmaType -> TcM Bool Source #

Reports whether first type (ty_a) subsumes the second type (ty_b), discarding any errors. Subsumption here means that the ty_b can fit into the ty_a, i.e. `tcSubsumes a b == True` if b is a subtype of a.

isFlexiTyVar :: TcTyVar -> TcM Bool Source #

Checks whether a MetaTyVar is flexible or not.

tcFilterHoleFits Source #

Arguments

:: Maybe Int	How many we should output, if limited
-> TypedHole	The hole to filter against
-> (TcType, [TcTyVar])	The type to check for fits and a list of refinement variables (free type variables in the type) for emulating additional holes.
-> [HoleFitCandidate]	The candidates to check whether fit.
-> TcM (Bool, [HoleFit])	We return whether or not we stopped due to hitting the limit and the fits we found.

tcFilterHoleFits filters the candidates by whether, given the implications and the relevant constraints, they can be made to match the type by running the type checker. Stops after finding limit matches.

getLocalBindings :: TidyEnv -> CtLoc -> TcM [Id] Source #

pprHoleFit :: HoleFitDispConfig -> HoleFit -> SDoc Source #

addHoleFitDocs :: [HoleFit] -> TcM [HoleFit] Source #

getHoleFitSortingAlg :: TcM HoleFitSortingAlg Source #

getHoleFitDispConfig :: TcM HoleFitDispConfig Source #

data HoleFitDispConfig Source #

Constructors

HFDC
Fields showWrap :: Bool showWrapVars :: Bool showType :: Bool showProv :: Bool showMatches :: Bool

data HoleFitSortingAlg Source #

Constructors

HFSNoSorting
HFSBySize
HFSBySubsumption

Instances

Instances details

Eq HoleFitSortingAlg Source #
Instance details Defined in GHC.Tc.Errors.Hole Methods (==) :: HoleFitSortingAlg -> HoleFitSortingAlg -> Bool # (/=) :: HoleFitSortingAlg -> HoleFitSortingAlg -> Bool #
Ord HoleFitSortingAlg Source #
Instance details Defined in GHC.Tc.Errors.Hole Methods compare :: HoleFitSortingAlg -> HoleFitSortingAlg -> Ordering # (<) :: HoleFitSortingAlg -> HoleFitSortingAlg -> Bool # (<=) :: HoleFitSortingAlg -> HoleFitSortingAlg -> Bool # (>) :: HoleFitSortingAlg -> HoleFitSortingAlg -> Bool # (>=) :: HoleFitSortingAlg -> HoleFitSortingAlg -> Bool # max :: HoleFitSortingAlg -> HoleFitSortingAlg -> HoleFitSortingAlg # min :: HoleFitSortingAlg -> HoleFitSortingAlg -> HoleFitSortingAlg #

relevantCts :: Type -> [Ct] -> [Ct] Source #

zonkSubs :: TidyEnv -> [HoleFit] -> TcM (TidyEnv, [HoleFit]) Source #

sortHoleFitsByGraph :: [HoleFit] -> TcM [HoleFit] Source #

sortHoleFitsBySize :: [HoleFit] -> TcM [HoleFit] Source #

Sort by size uses as a measure for relevance the sizes of the different types needed to instantiate the fit to the type of the hole. This is much quicker than sorting by subsumption, and gives reasonable results in most cases.

data HoleFitPlugin Source #

A HoleFitPlugin is a pair of candidate and fit plugins.

Constructors

HoleFitPlugin
Fields candPlugin :: CandPlugin fitPlugin :: FitPlugin

data HoleFitPluginR Source #

HoleFitPluginR adds a TcRef to hole fit plugins so that plugins can track internal state. Note the existential quantification, ensuring that the state cannot be modified from outside the plugin.

Constructors

forall s. HoleFitPluginR
Fields hfPluginInit :: TcM (TcRef s) Initializes the TcRef to be passed to the plugin hfPluginRun :: TcRef s -> HoleFitPlugin The function defining the plugin itself hfPluginStop :: TcRef s -> TcM () Cleanup of state, guaranteed to be called even on error