GHC.Tc.Solver

Documentation

data InferMode

How should we choose which constraints to quantify over?

Constructors

ApplyMR

Apply the monomorphism restriction, never quantifying over any constraints

EagerDefaulting

See Note [TcRnExprMode] in GHC.Tc.Module, the :type +d case; this mode refuses to quantify over any defaultable constraint

NoRestrictions

Quantify over any constraint that satisfies pickQuantifiablePreds

Instances

Outputable InferMode

Defined in GHC.Tc.Solver

Methods

ppr :: InferMode -> SDoc

simplifyInfer :: TcLevel -> InferMode -> [TcIdSigInst] -> [(Name, TcTauType)] -> WantedConstraints -> TcM ([TcTyVar], [EvVar], TcEvBinds, Bool)

findInferredDiff :: TcThetaType -> TcThetaType -> TcM TcThetaType

growThetaTyVars :: ThetaType -> TyCoVarSet -> TyCoVarSet

simplifyAmbiguityCheck :: Type -> WantedConstraints -> TcM ()

simplifyDefault :: ThetaType -> TcM Bool

simplifyTop :: WantedConstraints -> TcM (Bag EvBind)

simplifyTopImplic :: Bag Implication -> TcM ()

simplifyInteractive :: WantedConstraints -> TcM (Bag EvBind)

solveEqualities :: String -> TcM a -> TcM a

Type-check a thing that emits only equality constraints, solving any constraints we can and re-emitting constraints that we can't. Use this variant only when we'll get another crack at it later See Note [Failure in local type signatures]

Panics if we solve any non-equality constraints. (In runTCSEqualities we use an error thunk for the evidence bindings.)

pushLevelAndSolveEqualities :: SkolemInfoAnon -> [TyConBinder] -> TcM a -> TcM a

pushLevelAndSolveEqualitiesX :: String -> TcM a -> TcM (TcLevel, WantedConstraints, a)

reportUnsolvedEqualities :: SkolemInfo -> [TcTyVar] -> TcLevel -> WantedConstraints -> TcM ()

simplifyWantedsTcM :: [CtEvidence] -> TcM WantedConstraints

tcCheckGivens :: InertSet -> Bag EvVar -> TcM (Maybe InertSet)

Return (Just new_inerts) if the Givens are satisfiable, Nothing if definitely contradictory.

See Note [Pattern match warnings with insoluble Givens] above.

tcCheckWanteds :: InertSet -> ThetaType -> TcM Bool

Return True if the Wanteds are soluble, False if not

tcNormalise :: InertSet -> Type -> TcM Type

Normalise a type as much as possible using the given constraints. See Note [tcNormalise].

captureTopConstraints :: TcM a -> TcM (a, WantedConstraints)

simplifyTopWanteds :: WantedConstraints -> TcS WantedConstraints

Simplify top-level constraints, but without reporting any unsolved constraints nor unsafe overlapping.

promoteTyVarSet :: HasDebugCallStack => TcTyVarSet -> TcM Bool

simplifyAndEmitFlatConstraints :: WantedConstraints -> TcM ()

solveWanteds :: WantedConstraints -> TcS WantedConstraints

approximateWC :: Bool -> WantedConstraints -> Cts