TcType

FunSigCtxt Name
ExprSigCtxt
ConArgCtxt Name
TySynCtxt Name
GenPatCtxt
LamPatSigCtxt
BindPatSigCtxt
ResSigCtxt
ForSigCtxt Name
DefaultDeclCtxt
SpecInstCtxt

pprUserTypeCtxt :: UserTypeCtxt -> SDoc

data TcTyVarDetails

Constructors

SkolemTv SkolemInfo
MetaTv BoxInfo (IORef MetaDetails)

data BoxInfo

Constructors

BoxTv
TauTv
SigTv SkolemInfo

pprTcTyVarDetails :: TcTyVarDetails -> SDoc

data MetaDetails

Constructors

Flexi
Indirect TcType

Instances

Outputable MetaDetails

data SkolemInfo

Constructors

SigSkol UserTypeCtxt
ClsSkol Class
InstSkol
FamInstSkol
PatSkol DataCon
ArrowSkol
RuleSkol RuleName
GenSkol [TcTyVar] TcType
RuntimeUnkSkol
UnkSkol

pprSkolTvBinding :: TcTyVar -> SDoc

pprSkolInfo :: SkolemInfo -> SDoc

isImmutableTyVar :: TyVar -> Bool

isSkolemTyVar :: TcTyVar -> Bool

isSigTyVar :: Var -> Bool

metaTvRef :: TyVar -> IORef MetaDetails

isIndirect :: MetaDetails -> Bool

isRuntimeUnk :: TyVar -> Bool

isUnk :: TyVar -> Bool

mkPhiTy :: [PredType] -> Type -> Type

mkSigmaTy :: [TyVar] -> [PredType] -> Type -> Type

tcView :: Type -> Maybe Type

Similar to coreView, but for the type checker, which just looks through synonyms

tcSplitForAllTys :: Type -> ([TyVar], Type)

tcSplitPhiTy :: Type -> (ThetaType, Type)

tcSplitPredFunTy_maybe :: Type -> Maybe (PredType, Type)

tcSplitFunTy_maybe :: Type -> Maybe (Type, Type)

tcSplitFunTys :: Type -> ([Type], Type)

tcFunArgTy :: Type -> Type

tcFunResultTy :: Type -> Type

tcSplitFunTysN :: TcRhoType -> Arity -> ([TcSigmaType], TcSigmaType)

tcSplitTyConApp :: Type -> (TyCon, [Type])

tcSplitTyConApp_maybe :: Type -> Maybe (TyCon, [Type])

tcTyConAppTyCon :: Type -> TyCon

tcTyConAppArgs :: Type -> [Type]

tcSplitAppTy_maybe :: Type -> Maybe (Type, Type)

tcSplitAppTy :: Type -> (Type, Type)

tcSplitAppTys :: Type -> (Type, [Type])

repSplitAppTy_maybe :: Type -> Maybe (Type, Type)

Does the AppTy split as in splitAppTy_maybe, but assumes that any Core view stuff is already done

tcInstHeadTyNotSynonym :: Type -> Bool

tcInstHeadTyAppAllTyVars :: Type -> Bool

tcGetTyVar_maybe :: Type -> Maybe TyVar

tcGetTyVar :: String -> Type -> TyVar

tcSplitSigmaTy :: Type -> ([TyVar], ThetaType, Type)

tcMultiSplitSigmaTy :: TcSigmaType -> ([([TyVar], ThetaType)], TcSigmaType)

tcEqType :: Type -> Type -> Bool

Type equality on source types. Does not look through newtypes or PredTypes, but it does look through type synonyms.

tcEqTypes :: [Type] -> [Type] -> Bool

tcEqPred :: PredType -> PredType -> Bool

tcCmpType :: Type -> Type -> Ordering

Type ordering on source types. Does not look through newtypes or PredTypes, but it does look through type synonyms.

tcCmpTypes :: [Type] -> [Type] -> Ordering

tcCmpPred :: PredType -> PredType -> Ordering

tcEqTypeX :: RnEnv2 -> Type -> Type -> Bool

eqKind :: Kind -> Kind -> Bool

isSigmaTy :: Type -> Bool

isOverloadedTy :: Type -> Bool

isRigidTy :: TcType -> Bool

isBoxyTy :: TcType -> Bool

isDoubleTy :: Type -> Bool

isStringTy :: Type -> Bool

isTauTy :: Type -> Bool

isTauTyCon :: TyCon -> Bool

tcIsTyVarTy :: Type -> Bool

tcIsForAllTy :: Type -> Bool

isOpenSynTyConApp :: TcTauType -> Bool

deNoteType :: Type -> Type

tyClsNamesOfType :: Type -> NameSet

tyClsNamesOfDFunHead :: Type -> NameSet

getDFunTyKey :: Type -> OccName

getClassPredTys_maybe :: PredType -> Maybe (Class, [Type])

getClassPredTys :: PredType -> (Class, [Type])

isClassPred :: PredType -> Bool

isTyVarClassPred :: PredType -> Bool

isEqPred :: PredType -> Bool

mkDictTy :: Class -> [Type] -> Type

tcSplitPredTy_maybe :: Type -> Maybe PredType

isPredTy :: Type -> Bool

isDictTy :: Type -> Bool

tcSplitDFunTy :: Type -> ([TyVar], [PredType], Class, [Type])

tcSplitDFunHead :: Type -> (Class, [Type])

predTyUnique :: PredType -> Unique

mkClassPred :: Class -> [Type] -> PredType

isInheritablePred :: PredType -> Bool

isIPPred :: PredType -> Bool

dataConsStupidTheta :: [DataCon] -> ThetaType

isRefineableTy :: TcType -> (Bool, Bool)

isRefineablePred :: TcPredType -> Bool

isFFIArgumentTy :: DynFlags -> Safety -> Type -> Bool

isFFIImportResultTy :: DynFlags -> Type -> Bool

isFFIExportResultTy :: Type -> Bool

isFFIExternalTy :: Type -> Bool

isFFIDynArgumentTy :: Type -> Bool

isFFIDynResultTy :: Type -> Bool

isFFILabelTy :: Type -> Bool

isFFIDotnetTy :: DynFlags -> Type -> Bool

isFFIDotnetObjTy :: Type -> Bool

isFFITy :: Type -> Bool

isFunPtrTy :: Type -> Bool

tcSplitIOType_maybe :: Type -> Maybe (TyCon, Type, CoercionI)

toDNType :: Type -> DNType

type Kind = Type

The key type representing kinds in the compiler. Invariant: a kind is always in one of these forms:

 FunTy k1 k2
 TyConApp PrimTyCon [...]
 TyVar kv   -- (during inference only)
 ForAll ... -- (for top-level coercions)

unliftedTypeKind :: Kind

See Type#kind_subtyping for details of the distinction between these Kinds

mkArrowKind :: Kind -> Kind -> Kind

Given two kinds k1 and k2, creates the Kind k1 -> k2

mkArrowKinds :: [Kind] -> Kind -> Kind

Iterated application of mkArrowKind

isLiftedTypeKind :: Kind -> Bool

isSubOpenTypeKind :: Kind -> Bool

True of any sub-kind of OpenTypeKind (i.e. anything except arrow)

isSubArgTypeKind :: Kind -> Bool

True of any sub-kind of ArgTypeKind

isSubKind :: Kind -> Kind -> Bool

k1 `isSubKind` k2 checks that k1 <: k2

defaultKind :: Kind -> Kind

Used when generalising: default kind ? and ?? to *. See Type#kind_subtyping for more information on what that means

kindVarRef :: KindVar -> IORef MetaDetails

mkKindVar :: Unique -> IORef MetaDetails -> KindVar

data Type

The key representation of types within the compiler

Instances

Outputable Type

data PredType

A type of the form PredTy p represents a value whose type is the Haskell predicate p, where a predicate is what occurs before the => in a Haskell type. It can be expanded into its representation, but:

The type checker must treat it as opaque
The rest of the compiler treats it as transparent

Consider these examples:

 f :: (Eq a) => a -> Int
 g :: (?x :: Int -> Int) => a -> Int
 h :: (r\l) => {r} => {l::Int | r}

Here the Eq a and ?x :: Int -> Int and rl are all called "predicates"

Constructors

ClassP Class [Type]	Class predicate e.g. `Eq a`
IParam (IPName Name) Type	Implicit parameter e.g. `?x :: Int`
EqPred Type Type	Equality predicate e.g `ty1 ~ ty2`

Instances

Eq PredType

Ord PredType

Outputable PredType

type ThetaType = [PredType]

A collection of PredTypes

mkForAllTy :: TyVar -> Type -> Type

mkForAllTys :: [TyVar] -> Type -> Type

Wraps foralls over the type using the provided TyVars from left to right

mkFunTy :: Type -> Type -> Type

Creates a function type from the given argument and result type

mkFunTys :: [Type] -> Type -> Type

zipFunTys :: Outputable a => [a] -> Type -> ([(a, Type)], Type)

Splits off argument types from the given type and associating them with the things in the input list from left to right. The final result type is returned, along with the resulting pairs of objects and types, albeit with the list of pairs in reverse order. Panics if there are not enough argument types for the input list.

mkTyConApp :: TyCon -> [Type] -> Type

A key function: builds a TyConApp or FunTy as apppropriate to its arguments. Applies its arguments to the constructor from left to right

mkAppTy :: Type -> Type -> Type

Applies a type to another, as in e.g. k a

mkAppTys :: Type -> [Type] -> Type

applyTy :: Type -> Type -> Type

Instantiate a forall type with one or more type arguments. Used when we have a polymorphic function applied to type args:

 f t1 t2

We use applyTys type-of-f [t1,t2] to compute the type of the expression. Panics if no application is possible.

applyTys :: Type -> [Type] -> Type

This function is interesting because:

1. The function may have more for-alls than there are args

2. Less obviously, it may have fewer for-alls

For case 2. think of:

 applyTys (forall a.a) [forall b.b, Int]

This really can happen, via dressing up polymorphic types with newtype clothing. Here's an example:

 newtype R = R (forall a. a->a)
 foo = case undefined :: R of
            R f -> f ()

mkTyVarTy :: TyVar -> Type

mkTyVarTys :: [TyVar] -> [Type]

mkTyConTy :: TyCon -> Type

Create the plain type constructor type which has been applied to no type arguments at all.

mkPredTy :: PredType -> Type

mkPredTys :: ThetaType -> [Type]

data TvSubst

Type substitution

The following invariants must hold of a TvSubst:

1. The in-scope set is needed only to guide the generation of fresh uniques

2. In particular, the kind of the type variables in the in-scope set is not relevant

3. The substition is only applied ONCE! This is because in general such application will not reached a fixed point.

Constructors

TvSubst InScopeSet TvSubstEnv

Instances

Outputable TvSubst

type TvSubstEnv = TyVarEnv Type

A substitition of Types for TyVars

emptyTvSubst :: TvSubst

substEqSpec :: TvSubst -> [(TyVar, Type)] -> [(TcType, TcType)]

mkOpenTvSubst :: TvSubstEnv -> TvSubst

Generates the in-scope set for the TvSubst from the types in the incoming environment, hence open

zipOpenTvSubst :: [TyVar] -> [Type] -> TvSubst

Generates the in-scope set for the TvSubst from the types in the incoming environment, hence open

zipTopTvSubst :: [TyVar] -> [Type] -> TvSubst

mkTopTvSubst :: [(TyVar, Type)] -> TvSubst

Called when doing top-level substitutions. Here we expect that the free vars of the range of the substitution will be empty.

notElemTvSubst :: TyVar -> TvSubst -> Bool

getTvSubstEnv :: TvSubst -> TvSubstEnv

setTvSubstEnv :: TvSubst -> TvSubstEnv -> TvSubst

getTvInScope :: TvSubst -> InScopeSet

extendTvInScope :: TvSubst -> [Var] -> TvSubst

lookupTyVar :: TvSubst -> TyVar -> Maybe Type

extendTvSubst :: TvSubst -> TyVar -> Type -> TvSubst

extendTvSubstList :: TvSubst -> [TyVar] -> [Type] -> TvSubst

isInScope :: Var -> TvSubst -> Bool

mkTvSubst :: InScopeSet -> TvSubstEnv -> TvSubst

zipTyEnv :: [TyVar] -> [Type] -> TvSubstEnv

substTy :: TvSubst -> Type -> Type

Substitute within a Type

substTys :: TvSubst -> [Type] -> [Type]

Substitute within several Types

substTyWith :: [TyVar] -> [Type] -> Type -> Type

Type substitution making use of an TvSubst that is assumed to be open, see zipOpenTvSubst

substTheta :: TvSubst -> ThetaType -> ThetaType

Substitute within a ThetaType

substTyVar :: TvSubst -> TyVar -> Type

substTyVars :: TvSubst -> [TyVar] -> [Type]

substTyVarBndr :: TvSubst -> TyVar -> (TvSubst, TyVar)

isUnLiftedType :: Type -> Bool

See Type#type_classification for what an unlifted type is

isUnboxedTupleType :: Type -> Bool

isPrimitiveType :: Type -> Bool

Returns true of types that are opaque to Haskell. Most of these are unlifted, but now that we interact with .NET, we may have primtive (foreign-imported) types that are lifted

tidyTopType :: Type -> Type

Calls tidyType on a top-level type (i.e. with an empty tidying environment)

tidyType :: TidyEnv -> Type -> Type

tidyPred :: TidyEnv -> PredType -> PredType

tidyTypes :: TidyEnv -> [Type] -> [Type]

tidyFreeTyVars :: TidyEnv -> TyVarSet -> TidyEnv

Add the free TyVars to the env in tidy form, so that we can tidy the type they are free in

tidyOpenType :: TidyEnv -> Type -> (TidyEnv, Type)

Grabs the free type variables, tidies them and then uses tidyType to work over the type itself

tidyOpenTypes :: TidyEnv -> [Type] -> (TidyEnv, [Type])

tidyTyVarBndr :: TidyEnv -> TyVar -> (TidyEnv, TyVar)

This tidies up a type for printing in an error message, or in an interface file.

It doesn't change the uniques at all, just the print names.

tidyOpenTyVar :: TidyEnv -> TyVar -> (TidyEnv, TyVar)

Treat a new TyVar as a binder, and give it a fresh tidy name using the environment if one has not already been allocated. See also tidyTyVarBndr

tidyOpenTyVars :: TidyEnv -> [TyVar] -> (TidyEnv, [TyVar])

tidySkolemTyVar :: TidyEnv -> TcTyVar -> (TidyEnv, TcTyVar)

typeKind :: Type -> Kind

tidyKind :: TidyEnv -> Kind -> (TidyEnv, Kind)

tyVarsOfType :: Type -> TyVarSet

NB: for type synonyms tyVarsOfType does not expand the synonym

tyVarsOfTypes :: [Type] -> TyVarSet

tyVarsOfPred :: PredType -> TyVarSet

tyVarsOfTheta :: ThetaType -> TyVarSet

tcTyVarsOfType :: Type -> TcTyVarSet

tcTyVarsOfTypes :: [Type] -> TyVarSet

exactTyVarsOfType :: TcType -> TyVarSet

exactTyVarsOfTypes :: [TcType] -> TyVarSet

pprParendKind :: Kind -> SDoc

pprParendType :: Type -> SDoc

pprTypeApp :: NamedThing a => a -> [Type] -> SDoc

pprTyThingCategory :: TyThing -> SDoc

pprPred :: PredType -> SDoc

pprTheta :: ThetaType -> SDoc

pprThetaArrow :: ThetaType -> SDoc

pprClassPred :: Class -> [Type] -> SDoc

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