Safe Haskell  None 

Language  GHC2021 
Main functions for manipulating types and typerelated things
Synopsis
 data Type
 data ForAllTyFlag where
 Invisible !Specificity
 Required
 pattern Specified :: ForAllTyFlag
 pattern Inferred :: ForAllTyFlag
 data FunTyFlag
 data Specificity
 type KindOrType = Type
 type PredType = Type
 type ThetaType = [PredType]
 type FRRType = Type
 data Var
 type TyVar = Var
 isTyVar :: Var > Bool
 type TyCoVar = Id
 data PiTyBinder
 type ForAllTyBinder = VarBndr TyCoVar ForAllTyFlag
 type TyVarBinder = VarBndr TyVar ForAllTyFlag
 type Mult = Type
 data Scaled a
 type KnotTied (ty :: k) = ty
 type RuntimeRepType = Type
 mkTyVarTy :: TyVar > Type
 mkTyVarTys :: [TyVar] > [Type]
 getTyVar :: HasDebugCallStack => Type > TyVar
 getTyVar_maybe :: Type > Maybe TyVar
 repGetTyVar_maybe :: Type > Maybe TyVar
 getCastedTyVar_maybe :: Type > Maybe (TyVar, CoercionN)
 tyVarKind :: TyVar > Kind
 varType :: Var > Kind
 mkAppTy :: Type > Type > Type
 mkAppTys :: Type > [Type] > Type
 splitAppTy :: Type > (Type, Type)
 splitAppTys :: HasDebugCallStack => Type > (Type, [Type])
 splitAppTysNoView :: HasDebugCallStack => Type > (Type, [Type])
 splitAppTy_maybe :: Type > Maybe (Type, Type)
 splitAppTyNoView_maybe :: HasDebugCallStack => Type > Maybe (Type, Type)
 tcSplitAppTyNoView_maybe :: Type > Maybe (Type, Type)
 mkFunTy :: HasDebugCallStack => FunTyFlag > Mult > Type > Type > Type
 mkVisFunTy :: HasDebugCallStack => Mult > Type > Type > Type
 mkVisFunTyMany :: HasDebugCallStack => Type > Type > Type
 mkVisFunTysMany :: [Type] > Type > Type
 mkScaledFunTys :: HasDebugCallStack => [Scaled Type] > Type > Type
 mkInvisFunTy :: HasDebugCallStack => Type > Type > Type
 mkInvisFunTys :: HasDebugCallStack => [Type] > Type > Type
 tcMkVisFunTy :: Mult > Type > Type > Type
 tcMkScaledFunTys :: [Scaled Type] > Type > Type
 tcMkInvisFunTy :: TypeOrConstraint > Type > Type > Type
 splitFunTy :: Type > (Mult, Type, Type)
 splitFunTy_maybe :: Type > Maybe (FunTyFlag, Mult, Type, Type)
 splitFunTys :: Type > ([Scaled Type], Type)
 funResultTy :: HasDebugCallStack => Type > Type
 funArgTy :: HasDebugCallStack => Type > Type
 funTyConAppTy_maybe :: FunTyFlag > Type > Type > Type > Maybe (TyCon, [Type])
 funTyFlagTyCon :: FunTyFlag > TyCon
 tyConAppFunTy_maybe :: HasDebugCallStack => TyCon > [Type] > Maybe Type
 tyConAppFunCo_maybe :: HasDebugCallStack => Role > TyCon > [Coercion] > Maybe Coercion
 mkFunctionType :: HasDebugCallStack => Mult > Type > Type > Type
 mkScaledFunctionTys :: [Scaled Type] > Type > Type
 chooseFunTyFlag :: HasDebugCallStack => Type > Type > FunTyFlag
 mkTyConApp :: TyCon > [Type] > Type
 mkTyConTy :: TyCon > Type
 tyConAppTyCon_maybe :: Type > Maybe TyCon
 tyConAppTyConPicky_maybe :: Type > Maybe TyCon
 tyConAppArgs_maybe :: Type > Maybe [Type]
 tyConAppTyCon :: HasDebugCallStack => Type > TyCon
 tyConAppArgs :: HasDebugCallStack => Type > [Type]
 splitTyConApp_maybe :: HasDebugCallStack => Type > Maybe (TyCon, [Type])
 splitTyConAppNoView_maybe :: HasDebugCallStack => Type > Maybe (TyCon, [Type])
 splitTyConApp :: Type > (TyCon, [Type])
 tcSplitTyConApp :: Type > (TyCon, [Type])
 tcSplitTyConApp_maybe :: HasDebugCallStack => Type > Maybe (TyCon, [Type])
 mkForAllTy :: ForAllTyBinder > Type > Type
 mkForAllTys :: [ForAllTyBinder] > Type > Type
 mkInvisForAllTys :: [InvisTVBinder] > Type > Type
 mkTyCoInvForAllTys :: [TyCoVar] > Type > Type
 mkSpecForAllTy :: TyVar > Type > Type
 mkSpecForAllTys :: [TyVar] > Type > Type
 mkVisForAllTys :: [TyVar] > Type > Type
 mkTyCoForAllTy :: TyCoVar > ForAllTyFlag > Type > Type
 mkTyCoForAllTys :: [ForAllTyBinder] > Type > Type
 mkTyCoInvForAllTy :: TyCoVar > Type > Type
 mkInfForAllTy :: TyVar > Type > Type
 mkInfForAllTys :: [TyVar] > Type > Type
 splitForAllTyCoVars :: Type > ([TyCoVar], Type)
 splitForAllTyVars :: Type > ([TyVar], Type)
 splitForAllReqTyBinders :: Type > ([ReqTyBinder], Type)
 splitForAllInvisTyBinders :: Type > ([InvisTyBinder], Type)
 splitForAllForAllTyBinders :: Type > ([ForAllTyBinder], Type)
 splitForAllForAllTyBinder_maybe :: Type > Maybe (ForAllTyBinder, Type)
 splitForAllTyCoVar_maybe :: Type > Maybe (TyCoVar, Type)
 splitForAllTyCoVar :: Type > (TyCoVar, Type)
 splitForAllTyVar_maybe :: Type > Maybe (TyVar, Type)
 splitForAllCoVar_maybe :: Type > Maybe (CoVar, Type)
 splitPiTy_maybe :: Type > Maybe (PiTyBinder, Type)
 splitPiTy :: Type > (PiTyBinder, Type)
 splitPiTys :: Type > ([PiTyBinder], Type)
 getRuntimeArgTys :: Type > [(Scaled Type, FunTyFlag)]
 mkTyConBindersPreferAnon :: [TyVar] > TyCoVarSet > [TyConBinder]
 mkPiTy :: HasDebugCallStack => PiTyBinder > Type > Type
 mkPiTys :: HasDebugCallStack => [PiTyBinder] > Type > Type
 piResultTy :: HasDebugCallStack => Type > Type > Type
 piResultTys :: HasDebugCallStack => Type > [Type] > Type
 applyTysX :: HasDebugCallStack => [TyVar] > Type > [Type] > Type
 dropForAlls :: Type > Type
 mkFamilyTyConApp :: TyCon > [Type] > Type
 buildSynTyCon :: Name > [KnotTied TyConBinder] > Kind > [Role] > KnotTied Type > TyCon
 mkNumLitTy :: Integer > Type
 isNumLitTy :: Type > Maybe Integer
 mkStrLitTy :: FastString > Type
 isStrLitTy :: Type > Maybe FastString
 mkCharLitTy :: Char > Type
 isCharLitTy :: Type > Maybe Char
 isLitTy :: Type > Maybe TyLit
 isPredTy :: HasDebugCallStack => Type > Bool
 getRuntimeRep :: HasDebugCallStack => Type > RuntimeRepType
 splitRuntimeRep_maybe :: RuntimeRepType > Maybe (TyCon, [Type])
 kindRep_maybe :: HasDebugCallStack => Kind > Maybe RuntimeRepType
 kindRep :: HasDebugCallStack => Kind > RuntimeRepType
 getLevity :: HasDebugCallStack => Type > Type
 levityType_maybe :: LevityType > Maybe Levity
 mkCastTy :: Type > Coercion > Type
 mkCoercionTy :: Coercion > Type
 splitCastTy_maybe :: Type > Maybe (Type, Coercion)
 type ErrorMsgType = Type
 userTypeError_maybe :: Type > Maybe ErrorMsgType
 deepUserTypeError_maybe :: Type > Maybe ErrorMsgType
 pprUserTypeErrorTy :: ErrorMsgType > SDoc
 coAxNthLHS :: forall (br :: BranchFlag). CoAxiom br > Int > Type
 stripCoercionTy :: Type > Coercion
 splitInvisPiTys :: Type > ([PiTyBinder], Type)
 splitInvisPiTysN :: Int > Type > ([PiTyBinder], Type)
 invisibleTyBndrCount :: Type > Int
 filterOutInvisibleTypes :: TyCon > [Type] > [Type]
 filterOutInferredTypes :: TyCon > [Type] > [Type]
 partitionInvisibleTypes :: TyCon > [Type] > ([Type], [Type])
 partitionInvisibles :: [(a, ForAllTyFlag)] > ([a], [a])
 tyConForAllTyFlags :: TyCon > [Type] > [ForAllTyFlag]
 appTyForAllTyFlags :: Type > [Type] > [ForAllTyFlag]
 data TyCoMapper env (m :: Type > Type) = TyCoMapper {}
 mapTyCo :: Monad m => TyCoMapper () m > (Type > m Type, [Type] > m [Type], Coercion > m Coercion, [Coercion] > m [Coercion])
 mapTyCoX :: Monad m => TyCoMapper env m > (env > Type > m Type, env > [Type] > m [Type], env > Coercion > m Coercion, env > [Coercion] > m [Coercion])
 data TyCoFolder env a = TyCoFolder {
 tcf_view :: Type > Maybe Type
 tcf_tyvar :: env > TyVar > a
 tcf_covar :: env > CoVar > a
 tcf_hole :: env > CoercionHole > a
 tcf_tycobinder :: env > TyCoVar > ForAllTyFlag > env
 foldTyCo :: Monoid a => TyCoFolder env a > env > (Type > a, [Type] > a, Coercion > a, [Coercion] > a)
 noView :: Type > Maybe Type
 newTyConInstRhs :: TyCon > [Type] > Type
 mkForAllTyBinder :: vis > TyCoVar > VarBndr TyCoVar vis
 mkForAllTyBinders :: vis > [TyCoVar] > [VarBndr TyCoVar vis]
 mkTyVarBinder :: vis > TyVar > VarBndr TyVar vis
 mkTyVarBinders :: vis > [TyVar] > [VarBndr TyVar vis]
 tyVarSpecToBinders :: [VarBndr a Specificity] > [VarBndr a ForAllTyFlag]
 isAnonPiTyBinder :: PiTyBinder > Bool
 binderVar :: VarBndr tv argf > tv
 binderVars :: [VarBndr tv argf] > [tv]
 binderType :: VarBndr TyCoVar argf > Type
 binderFlag :: VarBndr tv argf > argf
 binderFlags :: [VarBndr tv argf] > [argf]
 piTyBinderType :: PiTyBinder > Type
 namedPiTyBinder_maybe :: PiTyBinder > Maybe TyCoVar
 anonPiTyBinderType_maybe :: PiTyBinder > Maybe Type
 isVisibleForAllTyFlag :: ForAllTyFlag > Bool
 isInvisibleForAllTyFlag :: ForAllTyFlag > Bool
 isVisiblePiTyBinder :: PiTyBinder > Bool
 isInvisiblePiTyBinder :: PiTyBinder > Bool
 isNamedPiTyBinder :: PiTyBinder > Bool
 tyConBindersPiTyBinders :: [TyConBinder] > [PiTyBinder]
 isTyVarTy :: Type > Bool
 isFunTy :: Type > Bool
 isCoercionTy :: Type > Bool
 isCoercionTy_maybe :: Type > Maybe Coercion
 isForAllTy :: Type > Bool
 isForAllTy_ty :: Type > Bool
 isForAllTy_co :: Type > Bool
 isForAllTy_invis_ty :: Type > Bool
 isPiTy :: Type > Bool
 isTauTy :: Type > Bool
 isFamFreeTy :: Type > Bool
 isAtomicTy :: Type > Bool
 isValidJoinPointType :: JoinArity > Type > Bool
 tyConAppNeedsKindSig :: Bool > TyCon > Int > Bool
 mkTYPEapp :: RuntimeRepType > Type
 mkTYPEapp_maybe :: RuntimeRepType > Maybe Type
 mkCONSTRAINTapp :: RuntimeRepType > Type
 mkCONSTRAINTapp_maybe :: RuntimeRepType > Maybe Type
 mkBoxedRepApp_maybe :: LevityType > Maybe Type
 mkTupleRepApp_maybe :: Type > Maybe Type
 typeOrConstraintKind :: TypeOrConstraint > RuntimeRepType > Kind
 sORTKind_maybe :: Kind > Maybe (TypeOrConstraint, Type)
 typeTypeOrConstraint :: HasDebugCallStack => Type > TypeOrConstraint
 typeLevity :: HasDebugCallStack => Type > Levity
 typeLevity_maybe :: HasDebugCallStack => Type > Maybe Levity
 tyConIsTYPEorCONSTRAINT :: TyCon > Bool
 isLiftedTypeKind :: Kind > Bool
 isUnliftedTypeKind :: Kind > Bool
 pickyIsLiftedTypeKind :: Kind > Bool
 isLiftedRuntimeRep :: RuntimeRepType > Bool
 isUnliftedRuntimeRep :: RuntimeRepType > Bool
 runtimeRepLevity_maybe :: RuntimeRepType > Maybe Levity
 isBoxedRuntimeRep :: RuntimeRepType > Bool
 isLiftedLevity :: Type > Bool
 isUnliftedLevity :: Type > Bool
 isUnliftedType :: HasDebugCallStack => Type > Bool
 isBoxedType :: Type > Bool
 isUnboxedTupleType :: Type > Bool
 isUnboxedSumType :: Type > Bool
 kindBoxedRepLevity_maybe :: Type > Maybe Levity
 mightBeLiftedType :: Type > Bool
 mightBeUnliftedType :: Type > Bool
 definitelyLiftedType :: Type > Bool
 definitelyUnliftedType :: Type > Bool
 isAlgType :: Type > Bool
 isDataFamilyAppType :: Type > Bool
 isPrimitiveType :: Type > Bool
 isStrictType :: HasDebugCallStack => Type > Bool
 isTerminatingType :: HasDebugCallStack => Type > Bool
 isLevityTy :: Type > Bool
 isLevityVar :: TyVar > Bool
 isRuntimeRepTy :: Type > Bool
 isRuntimeRepVar :: TyVar > Bool
 isRuntimeRepKindedTy :: Type > Bool
 dropRuntimeRepArgs :: [Type] > [Type]
 isMultiplicityTy :: Type > Bool
 isMultiplicityVar :: TyVar > Bool
 unrestricted :: a > Scaled a
 linear :: a > Scaled a
 tymult :: a > Scaled a
 mkScaled :: Mult > a > Scaled a
 irrelevantMult :: Scaled a > a
 scaledSet :: Scaled a > b > Scaled b
 pattern OneTy :: Mult
 pattern ManyTy :: Mult
 isOneTy :: Mult > Bool
 isManyTy :: Mult > Bool
 isLinearType :: Type > Bool
 type Kind = Type
 typeKind :: HasDebugCallStack => Type > Kind
 typeHasFixedRuntimeRep :: HasDebugCallStack => Type > Bool
 tcIsLiftedTypeKind :: Kind > Bool
 isConstraintKind :: Kind > Bool
 isConstraintLikeKind :: Kind > Bool
 returnsConstraintKind :: Kind > Bool
 tcIsBoxedTypeKind :: Kind > Bool
 isTypeLikeKind :: Kind > Bool
 liftedTypeKind :: Type
 unliftedTypeKind :: Type
 tyCoFVsOfType :: Type > FV
 tyCoFVsBndr :: ForAllTyBinder > FV > FV
 tyCoFVsVarBndr :: Var > FV > FV
 tyCoFVsVarBndrs :: [Var] > FV > FV
 tyCoVarsOfType :: Type > TyCoVarSet
 tyCoVarsOfTypes :: [Type] > TyCoVarSet
 tyCoVarsOfTypeDSet :: Type > DTyCoVarSet
 coVarsOfType :: Type > CoVarSet
 coVarsOfTypes :: [Type] > CoVarSet
 anyFreeVarsOfType :: (TyCoVar > Bool) > Type > Bool
 anyFreeVarsOfTypes :: (TyCoVar > Bool) > [Type] > Bool
 noFreeVarsOfType :: Type > Bool
 expandTypeSynonyms :: Type > Type
 typeSize :: Type > Int
 occCheckExpand :: [Var] > Type > Maybe Type
 closeOverKindsDSet :: DTyVarSet > DTyVarSet
 closeOverKindsList :: [TyVar] > [TyVar]
 closeOverKinds :: TyCoVarSet > TyCoVarSet
 scopedSort :: [TyCoVar] > [TyCoVar]
 tyCoVarsOfTypeWellScoped :: Type > [TyVar]
 tyCoVarsOfTypesWellScoped :: [Type] > [TyVar]
 seqType :: Type > ()
 seqTypes :: [Type] > ()
 coreView :: Type > Maybe Type
 coreFullView :: Type > Type
 rewriterView :: Type > Maybe Type
 tyConsOfType :: Type > UniqSet TyCon
 type TvSubstEnv = TyVarEnv Type
 type IdSubstEnv = IdEnv CoreExpr
 data Subst = Subst InScopeSet IdSubstEnv TvSubstEnv CvSubstEnv
 emptyTvSubstEnv :: TvSubstEnv
 emptySubst :: Subst
 mkEmptySubst :: InScopeSet > Subst
 mkTCvSubst :: InScopeSet > TvSubstEnv > CvSubstEnv > Subst
 zipTvSubst :: HasDebugCallStack => [TyVar] > [Type] > Subst
 mkTvSubstPrs :: [(TyVar, Type)] > Subst
 zipTCvSubst :: HasDebugCallStack => [TyCoVar] > [Type] > Subst
 notElemSubst :: Var > Subst > Bool
 getTvSubstEnv :: Subst > TvSubstEnv
 zapSubst :: Subst > Subst
 getSubstInScope :: Subst > InScopeSet
 setInScope :: Subst > InScopeSet > Subst
 getSubstRangeTyCoFVs :: Subst > VarSet
 extendSubstInScope :: Subst > Var > Subst
 extendSubstInScopeList :: Subst > [Var] > Subst
 extendSubstInScopeSet :: Subst > VarSet > Subst
 extendTCvSubst :: Subst > TyCoVar > Type > Subst
 extendCvSubst :: Subst > CoVar > Coercion > Subst
 extendTvSubst :: Subst > TyVar > Type > Subst
 extendTvSubstList :: Subst > [(TyVar, Type)] > Subst
 extendTvSubstAndInScope :: Subst > TyVar > Type > Subst
 extendTCvSubstList :: Subst > [Var] > [Type] > Subst
 extendTvSubstWithClone :: Subst > TyVar > TyVar > Subst
 extendTCvSubstWithClone :: Subst > TyCoVar > TyCoVar > Subst
 isInScope :: Var > Subst > Bool
 composeTCvSubst :: Subst > Subst > Subst
 zipTyEnv :: HasDebugCallStack => [TyVar] > [Type] > TvSubstEnv
 zipCoEnv :: HasDebugCallStack => [CoVar] > [Coercion] > CvSubstEnv
 isEmptySubst :: Subst > Bool
 unionSubst :: Subst > Subst > Subst
 isEmptyTCvSubst :: Subst > Bool
 substTy :: HasDebugCallStack => Subst > Type > Type
 substTys :: HasDebugCallStack => Subst > [Type] > [Type]
 substScaledTy :: HasDebugCallStack => Subst > Scaled Type > Scaled Type
 substScaledTys :: HasDebugCallStack => Subst > [Scaled Type] > [Scaled Type]
 substTyWith :: HasDebugCallStack => [TyVar] > [Type] > Type > Type
 substTysWith :: HasDebugCallStack => [TyVar] > [Type] > [Type] > [Type]
 substTheta :: HasDebugCallStack => Subst > ThetaType > ThetaType
 substTyAddInScope :: HasDebugCallStack => Subst > Type > Type
 substTyUnchecked :: Subst > Type > Type
 substTysUnchecked :: Subst > [Type] > [Type]
 substScaledTyUnchecked :: HasDebugCallStack => Subst > Scaled Type > Scaled Type
 substScaledTysUnchecked :: Subst > [Scaled Type] > [Scaled Type]
 substThetaUnchecked :: Subst > ThetaType > ThetaType
 substTyWithUnchecked :: [TyVar] > [Type] > Type > Type
 substCo :: HasDebugCallStack => Subst > Coercion > Coercion
 substCoUnchecked :: Subst > Coercion > Coercion
 substCoWithUnchecked :: [TyVar] > [Type] > Coercion > Coercion
 substTyVarBndr :: HasDebugCallStack => Subst > TyVar > (Subst, TyVar)
 substTyVarBndrs :: HasDebugCallStack => Subst > [TyVar] > (Subst, [TyVar])
 substTyVar :: Subst > TyVar > Type
 substTyVars :: Subst > [TyVar] > [Type]
 substVarBndr :: HasDebugCallStack => Subst > TyCoVar > (Subst, TyCoVar)
 substVarBndrs :: HasDebugCallStack => Subst > [TyCoVar] > (Subst, [TyCoVar])
 substTyCoBndr :: Subst > PiTyBinder > (Subst, PiTyBinder)
 substTyVarToTyVar :: HasDebugCallStack => Subst > TyVar > TyVar
 cloneTyVarBndr :: Subst > TyVar > Unique > (Subst, TyVar)
 cloneTyVarBndrs :: Subst > [TyVar] > UniqSupply > (Subst, [TyVar])
 lookupTyVar :: Subst > TyVar > Maybe Type
 tidyType :: TidyEnv > Type > Type
 tidyTypes :: TidyEnv > [Type] > [Type]
 tidyOpenType :: TidyEnv > Type > Type
 tidyOpenTypes :: TidyEnv > [Type] > [Type]
 tidyOpenTypeX :: TidyEnv > Type > (TidyEnv, Type)
 tidyOpenTypesX :: TidyEnv > [Type] > (TidyEnv, [Type])
 tidyVarBndr :: TidyEnv > TyCoVar > (TidyEnv, TyCoVar)
 tidyVarBndrs :: TidyEnv > [TyCoVar] > (TidyEnv, [TyCoVar])
 tidyFreeTyCoVars :: TidyEnv > [TyCoVar] > TidyEnv
 tidyFreeTyCoVarX :: TidyEnv > TyCoVar > (TidyEnv, TyCoVar)
 tidyFreeTyCoVarsX :: TidyEnv > [TyCoVar] > (TidyEnv, [TyCoVar])
 tidyTyCoVarOcc :: TidyEnv > TyCoVar > TyCoVar
 tidyTopType :: Type > Type
 tidyForAllTyBinder :: TidyEnv > VarBndr TyCoVar vis > (TidyEnv, VarBndr TyCoVar vis)
 tidyForAllTyBinders :: TidyEnv > [VarBndr TyCoVar vis] > (TidyEnv, [VarBndr TyCoVar vis])
 isTYPEorCONSTRAINT :: Kind > Bool
 isConcreteType :: Type > Bool
 isFixedRuntimeRepKind :: HasDebugCallStack => Kind > Bool
Main data types representing Types
Types are any, but at least one, of:
 Boxed
 Iff its representation is a pointer to an object on the GC'd heap. Operationally, heap objects can be entered as a means of evaluation.
 Lifted
 Iff it has bottom as an element: An instance of a lifted type might diverge when evaluated. GHC Haskell's unboxed types are unlifted. An unboxed, but lifted type is not very useful. (Example: A byterepresented type, where evaluating 0xff computes the 12345678th collatz number modulo 0xff.) Only lifted types may be unified with a type variable.
 Algebraic
 Iff it is a type with one or more constructors, whether
declared with
data
ornewtype
. An algebraic type is one that can be deconstructed with a case expression. There are algebraic types that are not lifted types, like unlifted data types or unboxed tuples.  Data
 Iff it is a type declared with
data
, or a boxed tuple. There are also unlifted data types.  Primitive
 Iff it is a builtin type that can't be expressed in Haskell.
 Unlifted
 Anything that isn't lifted is considered unlifted.
Currently, all primitive types are unlifted, but that's not necessarily
the case: for example, Int
could be primitive.
Some primitive types are unboxed, such as Int#
, whereas some are boxed
but unlifted (such as ByteArray#
). The only primitive types that we
classify as algebraic are the unboxed tuples.
Some examples of type classifications that may make this a bit clearer are:
Type primitive boxed lifted algebraic  Int# Yes No No No ByteArray# Yes Yes No No (# a, b #) Yes No No Yes (# a  b #) Yes No No Yes ( a, b ) No Yes Yes Yes [a] No Yes Yes Yes
A source type is a type that is a separate type as far as the type checker is concerned, but which has a more lowlevel representation as far as CoretoCore passes and the rest of the back end is concerned.
You don't normally have to worry about this, as the utility functions in this module will automatically convert a source into a representation type if they are spotted, to the best of its abilities. If you don't want this to happen, use the equivalent functions from the TcType module.
Instances
Outputable Type Source #  
Data Type Source #  
Defined in GHC.Core.TyCo.Rep gfoldl :: (forall d b. Data d => c (d > b) > d > c b) > (forall g. g > c g) > Type > c Type # gunfold :: (forall b r. Data b => c (b > r) > c r) > (forall r. r > c r) > Constr > c Type # dataTypeOf :: Type > DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) > Maybe (c Type) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) > Maybe (c Type) # gmapT :: (forall b. Data b => b > b) > Type > Type # gmapQl :: (r > r' > r) > r > (forall d. Data d => d > r') > Type > r # gmapQr :: forall r r'. (r' > r > r) > r > (forall d. Data d => d > r') > Type > r # gmapQ :: (forall d. Data d => d > u) > Type > [u] # gmapQi :: Int > (forall d. Data d => d > u) > Type > u # gmapM :: Monad m => (forall d. Data d => d > m d) > Type > m Type # gmapMp :: MonadPlus m => (forall d. Data d => d > m d) > Type > m Type # gmapMo :: MonadPlus m => (forall d. Data d => d > m d) > Type > m Type #  
Eq (DeBruijn Type) Source #  
data ForAllTyFlag Source #
ForAllTyFlag
Is something required to appear in source Haskell (Required
),
permitted by request (Specified
) (visible type application), or
prohibited entirely from appearing in source Haskell (Inferred
)?
See Note [VarBndrs, ForAllTyBinders, TyConBinders, and visibility] in GHC.Core.TyCo.Rep
pattern Specified :: ForAllTyFlag  
pattern Inferred :: ForAllTyFlag 
Instances
The nondependent version of ForAllTyFlag
.
See Note [FunTyFlag]
Appears here partly so that it's together with its friends ForAllTyFlag
and ForallVisFlag, but also because it is used in IfaceType, rather
early in the compilation chain
Instances
Binary FunTyFlag Source #  
Outputable FunTyFlag Source #  
Data FunTyFlag Source #  
Defined in GHC.Types.Var gfoldl :: (forall d b. Data d => c (d > b) > d > c b) > (forall g. g > c g) > FunTyFlag > c FunTyFlag # gunfold :: (forall b r. Data b => c (b > r) > c r) > (forall r. r > c r) > Constr > c FunTyFlag # toConstr :: FunTyFlag > Constr # dataTypeOf :: FunTyFlag > DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) > Maybe (c FunTyFlag) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) > Maybe (c FunTyFlag) # gmapT :: (forall b. Data b => b > b) > FunTyFlag > FunTyFlag # gmapQl :: (r > r' > r) > r > (forall d. Data d => d > r') > FunTyFlag > r # gmapQr :: forall r r'. (r' > r > r) > r > (forall d. Data d => d > r') > FunTyFlag > r # gmapQ :: (forall d. Data d => d > u) > FunTyFlag > [u] # gmapQi :: Int > (forall d. Data d => d > u) > FunTyFlag > u # gmapM :: Monad m => (forall d. Data d => d > m d) > FunTyFlag > m FunTyFlag # gmapMp :: MonadPlus m => (forall d. Data d => d > m d) > FunTyFlag > m FunTyFlag # gmapMo :: MonadPlus m => (forall d. Data d => d > m d) > FunTyFlag > m FunTyFlag #  
Eq FunTyFlag Source #  
Ord FunTyFlag Source #  
Defined in GHC.Types.Var 
data Specificity Source #
Whether an Invisible
argument may appear in source Haskell.
InferredSpec  the argument may not appear in source Haskell, it is only inferred. 
SpecifiedSpec  the argument may appear in source Haskell, but isn't required. 
Instances
type KindOrType = Type Source #
The key representation of types within the compiler
A type of the form p
of constraint kind represents a value whose type is
the Haskell predicate p
, where a predicate is what occurs before
the =>
in a Haskell type.
We use PredType
as documentation to mark those types that we guarantee to
have this kind.
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"
Variable
Essentially a typed Name
, that may also contain some additional information
about the Var
and its use sites.
Instances
NamedThing Var Source #  
HasOccName Var Source #  
Uniquable Var Source #  
Outputable Var Source #  
OutputableBndr Var Source #  
Defined in GHC.Core.Ppr pprBndr :: BindingSite > Var > SDoc Source # pprPrefixOcc :: Var > SDoc Source # pprInfixOcc :: Var > SDoc Source # bndrIsJoin_maybe :: Var > JoinPointHood Source #  
Data Var Source #  
Defined in GHC.Types.Var gfoldl :: (forall d b. Data d => c (d > b) > d > c b) > (forall g. g > c g) > Var > c Var # gunfold :: (forall b r. Data b => c (b > r) > c r) > (forall r. r > c r) > Constr > c Var # dataTypeOf :: Var > DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) > Maybe (c Var) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) > Maybe (c Var) # gmapT :: (forall b. Data b => b > b) > Var > Var # gmapQl :: (r > r' > r) > r > (forall d. Data d => d > r') > Var > r # gmapQr :: forall r r'. (r' > r > r) > r > (forall d. Data d => d > r') > Var > r # gmapQ :: (forall d. Data d => d > u) > Var > [u] # gmapQi :: Int > (forall d. Data d => d > u) > Var > u # gmapM :: Monad m => (forall d. Data d => d > m d) > Var > m Var # gmapMp :: MonadPlus m => (forall d. Data d => d > m d) > Var > m Var # gmapMo :: MonadPlus m => (forall d. Data d => d > m d) > Var > m Var #  
Eq Var Source #  
Ord Var Source #  
Eq (DeBruijn CoreAlt) Source #  
Eq (DeBruijn CoreExpr) Source #  
Eq (DeBruijn Var) Source #  
OutputableBndr (Id, TagSig) Source #  
Defined in GHC.Stg.InferTags.TagSig pprBndr :: BindingSite > (Id, TagSig) > SDoc Source # pprPrefixOcc :: (Id, TagSig) > SDoc Source # pprInfixOcc :: (Id, TagSig) > SDoc Source # bndrIsJoin_maybe :: (Id, TagSig) > JoinPointHood Source #  
type Anno Id Source #  
Defined in GHC.Hs.Extension 
isTyVar :: Var > Bool Source #
Is this a typelevel (i.e., computationally irrelevant, thus erasable)
variable? Satisfies isTyVar = not . isId
.
data PiTyBinder Source #
A PiTyBinder
represents an argument to a function. PiTyBinders can be
dependent (Named
) or nondependent (Anon
). They may also be visible or
not. See Note [PiTyBinders]
Instances
Outputable PiTyBinder Source #  
Defined in GHC.Types.Var ppr :: PiTyBinder > SDoc Source #  
Data PiTyBinder Source #  
Defined in GHC.Types.Var gfoldl :: (forall d b. Data d => c (d > b) > d > c b) > (forall g. g > c g) > PiTyBinder > c PiTyBinder # gunfold :: (forall b r. Data b => c (b > r) > c r) > (forall r. r > c r) > Constr > c PiTyBinder # toConstr :: PiTyBinder > Constr # dataTypeOf :: PiTyBinder > DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) > Maybe (c PiTyBinder) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) > Maybe (c PiTyBinder) # gmapT :: (forall b. Data b => b > b) > PiTyBinder > PiTyBinder # gmapQl :: (r > r' > r) > r > (forall d. Data d => d > r') > PiTyBinder > r # gmapQr :: forall r r'. (r' > r > r) > r > (forall d. Data d => d > r') > PiTyBinder > r # gmapQ :: (forall d. Data d => d > u) > PiTyBinder > [u] # gmapQi :: Int > (forall d. Data d => d > u) > PiTyBinder > u # gmapM :: Monad m => (forall d. Data d => d > m d) > PiTyBinder > m PiTyBinder # gmapMp :: MonadPlus m => (forall d. Data d => d > m d) > PiTyBinder > m PiTyBinder # gmapMo :: MonadPlus m => (forall d. Data d => d > m d) > PiTyBinder > m PiTyBinder # 
type ForAllTyBinder = VarBndr TyCoVar ForAllTyFlag Source #
Variable Binder
A ForAllTyBinder
is the binder of a ForAllTy
It's convenient to define this synonym here rather its natural
home in GHC.Core.TyCo.Rep, because it's used in GHC.Core.DataCon.hsboot
A TyVarBinder
is a binder with only TyVar
type TyVarBinder = VarBndr TyVar ForAllTyFlag Source #
Mult is a type alias for Type.
Mult must contain Type because multiplicity variables are mere type variables (of kind Multiplicity) in Haskell. So the simplest implementation is to make Mult be Type.
Multiplicities can be formed with:  One: GHC.Types.One (= oneDataCon)  Many: GHC.Types.Many (= manyDataCon)  Multiplication: GHC.Types.MultMul (= multMulTyCon)
So that Mult feels a bit more structured, we provide pattern synonyms and smart constructors for these.
A shorthand for data with an attached Mult
element (the multiplicity).
Instances
Outputable a => Outputable (Scaled a) Source #  
Data a => Data (Scaled a) Source #  
Defined in GHC.Core.TyCo.Rep gfoldl :: (forall d b. Data d => c (d > b) > d > c b) > (forall g. g > c g) > Scaled a > c (Scaled a) # gunfold :: (forall b r. Data b => c (b > r) > c r) > (forall r. r > c r) > Constr > c (Scaled a) # toConstr :: Scaled a > Constr # dataTypeOf :: Scaled a > DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) > Maybe (c (Scaled a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) > Maybe (c (Scaled a)) # gmapT :: (forall b. Data b => b > b) > Scaled a > Scaled a # gmapQl :: (r > r' > r) > r > (forall d. Data d => d > r') > Scaled a > r # gmapQr :: forall r r'. (r' > r > r) > r > (forall d. Data d => d > r') > Scaled a > r # gmapQ :: (forall d. Data d => d > u) > Scaled a > [u] # gmapQi :: Int > (forall d. Data d => d > u) > Scaled a > u # gmapM :: Monad m => (forall d. Data d => d > m d) > Scaled a > m (Scaled a) # gmapMp :: MonadPlus m => (forall d. Data d => d > m d) > Scaled a > m (Scaled a) # gmapMo :: MonadPlus m => (forall d. Data d => d > m d) > Scaled a > m (Scaled a) # 
type KnotTied (ty :: k) = ty Source #
A type labeled KnotTied
might have knottied tycons in it. See
Note [Type checking recursive type and class declarations] in
GHC.Tc.TyCl
type RuntimeRepType = Type Source #
Type synonym used for types of kind RuntimeRep.
Constructing and deconstructing types
mkTyVarTys :: [TyVar] > [Type] Source #
getTyVar :: HasDebugCallStack => Type > TyVar Source #
Attempts to obtain the type variable underlying a Type
, and panics with the
given message if this is not a type variable type. See also getTyVar_maybe
getTyVar_maybe :: Type > Maybe TyVar Source #
Attempts to obtain the type variable underlying a Type
repGetTyVar_maybe :: Type > Maybe TyVar Source #
Attempts to obtain the type variable underlying a Type
, without
any expansion
getCastedTyVar_maybe :: Type > Maybe (TyVar, CoercionN) Source #
If the type is a tyvar, possibly under a cast, returns it, along with the coercion. Thus, the co is :: kind tv ~N kind ty
splitAppTy :: Type > (Type, Type) Source #
Attempts to take a type application apart, as in splitAppTy_maybe
,
and panics if this is not possible
splitAppTys :: HasDebugCallStack => Type > (Type, [Type]) Source #
Recursively splits a type as far as is possible, leaving a residual type being applied to and the type arguments applied to it. Never fails, even if that means returning an empty list of type applications.
splitAppTysNoView :: HasDebugCallStack => Type > (Type, [Type]) Source #
Like splitAppTys
, but doesn't look through type synonyms
splitAppTy_maybe :: Type > Maybe (Type, Type) Source #
Attempt to take a type application apart, whether it is a function, type constructor, or plain type application. Note that type family applications are NEVER unsaturated by this!
splitAppTyNoView_maybe :: HasDebugCallStack => Type > Maybe (Type, Type) Source #
Does the AppTy split as in splitAppTy_maybe
, but assumes that
any coreView stuff is already done
tcSplitAppTyNoView_maybe :: Type > Maybe (Type, Type) Source #
Just like splitAppTyNoView_maybe, but does not split (c => t) See Note [Decomposing fat arrow c=>t]
mkVisFunTy :: HasDebugCallStack => Mult > Type > Type > Type Source #
mkVisFunTyMany :: HasDebugCallStack => Type > Type > Type infixr 3 Source #
Make nested arrow types  Special, common, case: Arrow type with mult Many
mkScaledFunTys :: HasDebugCallStack => [Scaled Type] > Type > Type Source #
mkInvisFunTy :: HasDebugCallStack => Type > Type > Type infixr 3 Source #
mkInvisFunTys :: HasDebugCallStack => [Type] > Type > Type Source #
tcMkInvisFunTy :: TypeOrConstraint > Type > Type > Type Source #
splitFunTy :: Type > (Mult, Type, Type) Source #
Attempts to extract the multiplicity, argument and result types from a type,
and panics if that is not possible. See also splitFunTy_maybe
splitFunTy_maybe :: Type > Maybe (FunTyFlag, Mult, Type, Type) Source #
Attempts to extract the multiplicity, argument and result types from a type
funResultTy :: HasDebugCallStack => Type > Type Source #
Extract the function result type and panic if that is not possible
funArgTy :: HasDebugCallStack => Type > Type Source #
Extract the function argument type and panic if that is not possible
Just like piResultTys
but for a single argument
Try not to iterate piResultTy
, because it's inefficient to substitute
one variable at a time; instead use 'piResultTys"
funTyConAppTy_maybe :: FunTyFlag > Type > Type > Type > Maybe (TyCon, [Type]) Source #
Given the components of a FunTy figure out the corresponding TyConApp.
funTyFlagTyCon :: FunTyFlag > TyCon Source #
tyConAppFunTy_maybe :: HasDebugCallStack => TyCon > [Type] > Maybe Type Source #
Return Just if this TyConApp should be represented as a FunTy
tyConAppFunCo_maybe :: HasDebugCallStack => Role > TyCon > [Coercion] > Maybe Coercion Source #
Return Just if this TyConAppCo should be represented as a FunCo
mkFunctionType :: HasDebugCallStack => Mult > Type > Type > Type Source #
This one works out the FunTyFlag from the argument type See GHC.Types.Var Note [FunTyFlag]
mkScaledFunctionTys :: [Scaled Type] > Type > Type Source #
Like mkFunctionType, compute the FunTyFlag from the arguments
chooseFunTyFlag :: HasDebugCallStack => Type > Type > FunTyFlag Source #
See GHC.Types.Var Note [FunTyFlag]
mkTyConTy :: TyCon > Type Source #
(mkTyConTy tc) returns (TyConApp tc []) but arranges to share that TyConApp among all calls See Note [Sharing nullary TyConApps] So it's just an alias for tyConNullaryTy!
tyConAppTyCon_maybe :: Type > Maybe TyCon Source #
The same as fst . splitTyConApp
We can shortcut the FunTy case
tyConAppTyConPicky_maybe :: Type > Maybe TyCon Source #
Retrieve the tycon heading this type, if there is one. Does not look through synonyms.
tyConAppTyCon :: HasDebugCallStack => Type > TyCon Source #
tyConAppArgs :: HasDebugCallStack => Type > [Type] Source #
splitTyConApp_maybe :: HasDebugCallStack => Type > Maybe (TyCon, [Type]) Source #
Attempts to tease a type apart into a type constructor and the application of a number of arguments to that constructor
splitTyConAppNoView_maybe :: HasDebugCallStack => Type > Maybe (TyCon, [Type]) Source #
splitTyConApp :: Type > (TyCon, [Type]) Source #
Attempts to tease a type apart into a type constructor and the application
of a number of arguments to that constructor. Panics if that is not possible.
See also splitTyConApp_maybe
tcSplitTyConApp_maybe :: HasDebugCallStack => Type > Maybe (TyCon, [Type]) Source #
tcSplitTyConApp_maybe splits a type constructor application into its type constructor and applied types.
Differs from splitTyConApp_maybe in that it does *not* split types headed with (=>), as that's not a TyCon in the typechecker.
Note that this may fail (in funTyConAppTy_maybe) in the case
of a FunTy
with an argument of unknown kind FunTy
(e.g. `FunTy (a :: k) Int`, since the kind of a
isn't of
the form `TYPE rep`. This isn't usually a problem but may
be temporarily the case during canonicalization:
see Note [Decomposing FunTy] in GHC.Tc.Solver.Equality
and Note [The Purely Kinded Type Invariant (PKTI)] in GHC.Tc.Gen.HsType,
Wrinkle around FunTy
Consequently, you may need to zonk your type before using this function.
mkForAllTy :: ForAllTyBinder > Type > Type Source #
Like mkTyCoForAllTy
, but does not check the occurrence of the binder
See Note [Unused coercion variable in ForAllTy]
mkForAllTys :: [ForAllTyBinder] > Type > Type Source #
Wraps foralls over the type using the provided TyCoVar
s from left to right
mkInvisForAllTys :: [InvisTVBinder] > Type > Type Source #
Wraps foralls over the type using the provided InvisTVBinder
s from left to right
mkTyCoInvForAllTys :: [TyCoVar] > Type > Type Source #
Like mkForAllTys
, but assumes all variables are dependent and
Inferred
, a common case
mkSpecForAllTy :: TyVar > Type > Type Source #
Like mkForAllTy
, but assumes the variable is dependent and Specified
,
a common case
mkSpecForAllTys :: [TyVar] > Type > Type Source #
Like mkForAllTys
, but assumes all variables are dependent and
Specified
, a common case
mkVisForAllTys :: [TyVar] > Type > Type Source #
Like mkForAllTys, but assumes all variables are dependent and visible
mkTyCoForAllTy :: TyCoVar > ForAllTyFlag > Type > Type Source #
Make a dependent forall over a TyCoVar
mkTyCoForAllTys :: [ForAllTyBinder] > Type > Type Source #
Make a dependent forall over a TyCoVar
mkTyCoInvForAllTy :: TyCoVar > Type > Type Source #
Make a dependent forall over an Inferred
variable
mkInfForAllTy :: TyVar > Type > Type Source #
Like mkTyCoInvForAllTy
, but tv should be a tyvar
mkInfForAllTys :: [TyVar] > Type > Type Source #
Like mkTyCoInvForAllTys
, but tvs should be a list of tyvar
splitForAllTyCoVars :: Type > ([TyCoVar], Type) Source #
Take a ForAllTy apart, returning the list of tycovars and the result type. This always succeeds, even if it returns only an empty list. Note that the result type returned may have free variables that were bound by a forall.
splitForAllTyVars :: Type > ([TyVar], Type) Source #
Like splitForAllTyCoVars
, but split only for tyvars.
This always succeeds, even if it returns only an empty list. Note that the
result type returned may have free variables that were bound by a forall.
splitForAllReqTyBinders :: Type > ([ReqTyBinder], Type) Source #
Like splitForAllTyCoVars
, but only splits ForAllTy
s with Required
type
variable binders. Furthermore, each returned tyvar is annotated with ()
.
splitForAllInvisTyBinders :: Type > ([InvisTyBinder], Type) Source #
Like splitForAllTyCoVars
, but only splits ForAllTy
s with Invisible
type
variable binders. Furthermore, each returned tyvar is annotated with its
Specificity
.
splitForAllForAllTyBinders :: Type > ([ForAllTyBinder], Type) Source #
Take a ForAllTy apart, returning the binders and result type
splitForAllForAllTyBinder_maybe :: Type > Maybe (ForAllTyBinder, Type) Source #
Attempts to take a ForAllTy apart, returning the full ForAllTyBinder
splitForAllTyCoVar_maybe :: Type > Maybe (TyCoVar, Type) Source #
Attempts to take a ForAllTy apart, returning the Var
splitForAllTyCoVar :: Type > (TyCoVar, Type) Source #
Take a forall type apart, or panics if that is not possible.
splitForAllTyVar_maybe :: Type > Maybe (TyVar, Type) Source #
Attempts to take a ForAllTy apart, but only if the binder is a TyVar
splitForAllCoVar_maybe :: Type > Maybe (CoVar, Type) Source #
Like splitForAllTyCoVar_maybe
, but only returns Just if it is a covar binder.
splitPiTy_maybe :: Type > Maybe (PiTyBinder, Type) Source #
Attempts to take a forall type apart; works with proper foralls and functions
splitPiTys :: Type > ([PiTyBinder], Type) Source #
Split off all PiTyBinders to a type, splitting both proper foralls and functions
getRuntimeArgTys :: Type > [(Scaled Type, FunTyFlag)] Source #
Extracts a list of runtime arguments from a function type, looking through newtypes to the right of arrows.
Examples:
newtype Identity a = I a getRuntimeArgTys (Int > Bool > Double) == [(Int, FTF_T_T), (Bool, FTF_T_T)] getRuntimeArgTys (Identity Int > Bool > Double) == [(Identity Int, FTF_T_T), (Bool, FTF_T_T)] getRuntimeArgTys (Int > Identity (Bool > Identity Double)) == [(Int, FTF_T_T), (Bool, FTF_T_T)] getRuntimeArgTys (forall a. Show a => Identity a > a > Int > Bool) == [(Show a, FTF_C_T), (Identity a, FTF_T_T),(a, FTF_T_T),(Int, FTF_T_T)]
Note that, in the last case, the returned types might mention an outofscope type variable. This function is used only when we really care about the kinds of the returned types, so this is OK.
 *Warning**: this function can return an infinite list. For example:
newtype N a = MkN (a > N a) getRuntimeArgTys (N a) == repeat (a, FTF_T_T)
mkTyConBindersPreferAnon Source #
:: [TyVar]  binders 
> TyCoVarSet  free variables of result 
> [TyConBinder] 
Given a list of typelevel vars and the free vars of a result kind, makes PiTyBinders, preferring anonymous binders if the variable is, in fact, not dependent. e.g. mkTyConBindersPreferAnon (k:*),(b:k),(c:k) We want (k:*) Named, (b:k) Anon, (c:k) Anon
All noncoercion binders are visible.
mkPiTy :: HasDebugCallStack => PiTyBinder > Type > Type Source #
mkPiTys :: HasDebugCallStack => [PiTyBinder] > Type > Type Source #
piResultTy :: HasDebugCallStack => Type > Type > Type Source #
piResultTys :: HasDebugCallStack => Type > [Type] > Type Source #
(piResultTys f_ty [ty1, .., tyn]) gives the type of (f ty1 .. tyn)
where f :: f_ty
piResultTys
is interesting because:
1. f_ty
may have more foralls than there are args
2. Less obviously, it may have fewer foralls
For case 2. think of:
piResultTys (forall a.a) [forall b.b, Int]
This really can happen, but only (I think) in situations involving
undefined. For example:
undefined :: forall a. a
Term: undefined (forall b. b>b)
Int
This term should have type (Int > Int), but notice that
there are more type args than foralls in undefined
s type.
dropForAlls :: Type > Type Source #
Drops all ForAllTys
mkFamilyTyConApp :: TyCon > [Type] > Type Source #
Given a family instance TyCon and its arg types, return the corresponding family type. E.g:
data family T a data instance T (Maybe b) = MkT b
Where the instance tycon is :RTL, so:
mkFamilyTyConApp :RTL Int = T (Maybe Int)
mkNumLitTy :: Integer > Type Source #
isNumLitTy :: Type > Maybe Integer Source #
Is this a numeric literal. We also look through type synonyms.
mkStrLitTy :: FastString > Type Source #
isStrLitTy :: Type > Maybe FastString Source #
Is this a symbol literal. We also look through type synonyms.
mkCharLitTy :: Char > Type Source #
isCharLitTy :: Type > Maybe Char Source #
Is this a char literal? We also look through type synonyms.
getRuntimeRep :: HasDebugCallStack => Type > RuntimeRepType Source #
Extract the RuntimeRep classifier of a type. For instance,
getRuntimeRep_maybe Int = LiftedRep
. Panics if this is not possible.
splitRuntimeRep_maybe :: RuntimeRepType > Maybe (TyCon, [Type]) Source #
(splitRuntimeRep_maybe rr) takes a Type rr :: RuntimeRep, and
returns the (TyCon,[Type]) for the RuntimeRep, if possible, where
the TyCon is one of the promoted DataCons of RuntimeRep.
Remember: the unique on TyCon that is a a promoted DataCon is the
same as the unique on the DataCon
See Note [Promoted data constructors] in GHC.Core.TyCon
May not be possible if rr
is a type variable or type
family application
kindRep_maybe :: HasDebugCallStack => Kind > Maybe RuntimeRepType Source #
Given a kind (TYPE rr) or (CONSTRAINT rr), extract its RuntimeRep classifier rr.
For example, kindRep_maybe * = Just LiftedRep
Returns Nothing
if the kind is not of form (TYPE rr)
kindRep :: HasDebugCallStack => Kind > RuntimeRepType Source #
Extract the RuntimeRep classifier of a type from its kind. For example,
kindRep * = LiftedRep
; Panics if this is not possible.
Treats * and Constraint as the same
getLevity :: HasDebugCallStack => Type > Type Source #
Extract the Levity
of a type. For example, getLevity Int = Lifted
,
or getLevity (Array# Int) = Unlifted
.
Panics if this is not possible. Does not look through type family applications.
levityType_maybe :: LevityType > Maybe Levity Source #
levityType_maybe
takes a Type of kind Levity, and returns its levity
May not be possible for a type variable or type family application
mkCastTy :: Type > Coercion > Type Source #
Make a CastTy
. The Coercion must be nominal. Checks the
Coercion for reflexivity, dropping it if it's reflexive.
See Note [Respecting definitional equality]
in GHC.Core.TyCo.Rep
mkCoercionTy :: Coercion > Type Source #
type ErrorMsgType = Type Source #
A type of kind ErrorMessage
(from the TypeError
module).
userTypeError_maybe :: Type > Maybe ErrorMsgType Source #
Is this type a custom user error? If so, give us the error message.
pprUserTypeErrorTy :: ErrorMsgType > SDoc Source #
Render a type corresponding to a user type error into a SDoc.
coAxNthLHS :: forall (br :: BranchFlag). CoAxiom br > Int > Type Source #
Get the type on the LHS of a coercion induced by a type/data family instance.
stripCoercionTy :: Type > Coercion Source #
splitInvisPiTys :: Type > ([PiTyBinder], Type) Source #
Like splitPiTys
, but returns only *invisible* binders, including constraints.
Stops at the first visible binder.
splitInvisPiTysN :: Int > Type > ([PiTyBinder], Type) Source #
Same as splitInvisPiTys
, but stop when
 you have found n
PiTyBinder
s,
 or you run out of invisible binders
invisibleTyBndrCount :: Type > Int Source #
partitionInvisibles :: [(a, ForAllTyFlag)] > ([a], [a]) Source #
Given a list of things paired with their visibilities, partition the things into (invisible things, visible things).
tyConForAllTyFlags :: TyCon > [Type] > [ForAllTyFlag] Source #
Given a TyCon
and a list of argument types to which the TyCon
is
applied, determine each argument's visibility
(Inferred
, Specified
, or Required
).
Wrinkle: consider the following scenario:
T :: forall k. k > k tyConForAllTyFlags T [forall m. m > m > m, S, R, Q]
After substituting, we get
T (forall m. m > m > m) :: (forall m. m > m > m) > forall n. n > n > n
Thus, the first argument is invisible, S
is visible, R
is invisible again,
and Q
is visible.
appTyForAllTyFlags :: Type > [Type] > [ForAllTyFlag] Source #
Given a Type
and a list of argument types to which the Type
is
applied, determine each argument's visibility
(Inferred
, Specified
, or Required
).
Most of the time, the arguments will be Required
, but not always. Consider
f :: forall a. a > Type
. In f Type Bool
, the first argument (Type
) is
Specified
and the second argument (Bool
) is Required
. It is precisely
this sort of higherrank situation in which appTyForAllTyFlags
comes in handy,
since f Type Bool
would be represented in Core using AppTy
s.
(See also #15792).
Analyzing types
data TyCoMapper env (m :: Type > Type) Source #
This describes how a "map" operation over a type/coercion should behave
TyCoMapper  

mapTyCo :: Monad m => TyCoMapper () m > (Type > m Type, [Type] > m [Type], Coercion > m Coercion, [Coercion] > m [Coercion]) Source #
mapTyCoX :: Monad m => TyCoMapper env m > (env > Type > m Type, env > [Type] > m [Type], env > Coercion > m Coercion, env > [Coercion] > m [Coercion]) Source #
data TyCoFolder env a Source #
TyCoFolder  

foldTyCo :: Monoid a => TyCoFolder env a > env > (Type > a, [Type] > a, Coercion > a, [Coercion] > a) Source #
newTyConInstRhs :: TyCon > [Type] > Type Source #
Unwrap one layer
of newtype on a type constructor and its
arguments, using an etareduced version of the newtype
if possible.
This requires tys to have at least newTyConInstArity tycon
elements.
Binders
mkTyVarBinder :: vis > TyVar > VarBndr TyVar vis Source #
Make a named binder
var
should be a type variable
mkTyVarBinders :: vis > [TyVar] > [VarBndr TyVar vis] Source #
Make many named binders Input vars should be type variables
tyVarSpecToBinders :: [VarBndr a Specificity] > [VarBndr a ForAllTyFlag] Source #
isAnonPiTyBinder :: PiTyBinder > Bool Source #
Does this binder bind a variable that is not erased? Returns
True
for anonymous binders.
binderVars :: [VarBndr tv argf] > [tv] Source #
binderFlag :: VarBndr tv argf > argf Source #
binderFlags :: [VarBndr tv argf] > [argf] Source #
piTyBinderType :: PiTyBinder > Type Source #
anonPiTyBinderType_maybe :: PiTyBinder > Maybe Type Source #
Extract a relevant type, if there is one.
isVisibleForAllTyFlag :: ForAllTyFlag > Bool Source #
Does this ForAllTyFlag
classify an argument that is written in Haskell?
isInvisibleForAllTyFlag :: ForAllTyFlag > Bool Source #
Does this ForAllTyFlag
classify an argument that is not written in Haskell?
isVisiblePiTyBinder :: PiTyBinder > Bool Source #
Does this binder bind a visible argument?
isInvisiblePiTyBinder :: PiTyBinder > Bool Source #
Does this binder bind an invisible argument?
isNamedPiTyBinder :: PiTyBinder > Bool Source #
tyConBindersPiTyBinders :: [TyConBinder] > [PiTyBinder] Source #
Predicates on types
isFunTy :: Type > Bool Source #
Is this a function? Note: `forall {b}. Show b => b > IO b` will not be considered a function by this function. It would merely be a forall wrapping a function type.
isCoercionTy :: Type > Bool Source #
isForAllTy :: Type > Bool Source #
Checks whether this is a proper forall (with a named binder)
isForAllTy_ty :: Type > Bool Source #
Like isForAllTy
, but returns True only if it is a tyvar binder
isForAllTy_co :: Type > Bool Source #
Like isForAllTy
, but returns True only if it is a covar binder
isForAllTy_invis_ty :: Type > Bool Source #
Like isForAllTy
, but returns True only if it is an inferred tyvar binder
isFamFreeTy :: Type > Bool Source #
isAtomicTy :: Type > Bool Source #
isValidJoinPointType :: JoinArity > Type > Bool Source #
Determine whether a type could be the type of a join point of given total
arity, according to the polymorphism rule. A join point cannot be polymorphic
in its return type, since given
join j a
b x y z = e1 in e2,
the types of e1 and e2 must be the same, and a and b are not in scope for e2.
(See Note [The polymorphism rule of join points] in GHC.Core.) Returns False
also if the type simply doesn't have enough arguments.
Note that we need to know how many arguments (type *and* value) the putative join point takes; for instance, if j :: forall a. a > Int then j could be a binary join point returning an Int, but it could *not* be a unary join point returning a > Int.
TODO: See Note [Excess polymorphism and join points]
:: Bool  Should specified binders count towards injective positions in the kind of the TyCon? (If you're using visible kind applications, then you want True here. 
> TyCon  
> Int  The number of args the 
> Bool  Does 
Does a TyCon
(that is applied to some number of arguments) need to be
ascribed with an explicit kind signature to resolve ambiguity if rendered as
a sourcesyntax type?
(See Note [When does a tycon application need an explicit kind signature?]
for a full explanation of what this function checks for.)
Spacesaving construction
mkTYPEapp :: RuntimeRepType > Type Source #
mkTYPEapp_maybe :: RuntimeRepType > Maybe Type Source #
Given a RuntimeRep
, applies TYPE
to it.
On the fly it rewrites
TYPE LiftedRep > liftedTypeKind (a synonym)
TYPE UnliftedRep > unliftedTypeKind (ditto)
TYPE ZeroBitRep > zeroBitTypeKind (ditto)
NB: no need to check for TYPE (BoxedRep Lifted), TYPE (BoxedRep Unlifted)
because those inner types should already have been rewritten
to LiftedRep and UnliftedRep respectively, by mkTyConApp
see Note [TYPE and CONSTRAINT] in GHC.Builtin.Types.Prim. See Note [Using synonyms to compress types] in GHC.Core.Type
mkCONSTRAINTapp :: RuntimeRepType > Type Source #
Just like mkTYPEapp
mkCONSTRAINTapp_maybe :: RuntimeRepType > Maybe Type Source #
Just like mkTYPEapp_maybe
mkTupleRepApp_maybe :: Type > Maybe Type Source #
Given a `[RuntimeRep]`, apply TupleRep
to it
On the fly, rewrite
TupleRep [] > zeroBitRepTy (a synonym)
See Note [TYPE and CONSTRAINT] in GHC.Builtin.Types.Prim.
See Note [Using synonyms to compress types] in GHC.Core.Type
Levity and boxity
sORTKind_maybe :: Kind > Maybe (TypeOrConstraint, Type) Source #
typeLevity :: HasDebugCallStack => Type > Levity Source #
typeLevity_maybe :: HasDebugCallStack => Type > Maybe Levity Source #
tyConIsTYPEorCONSTRAINT :: TyCon > Bool Source #
isLiftedTypeKind :: Kind > Bool Source #
Returns True if the argument is (lifted) Type or Constraint See Note [TYPE and CONSTRAINT] in GHC.Builtin.Types.Prim
isUnliftedTypeKind :: Kind > Bool Source #
Returns True if the kind classifies unlifted types (like 'Int#') and False otherwise. Note that this returns False for representationpolymorphic kinds, which may be specialized to a kind that classifies unlifted types.
pickyIsLiftedTypeKind :: Kind > Bool Source #
isLiftedRuntimeRep :: RuntimeRepType > Bool Source #
Check whether a type of kind RuntimeRep
is lifted.
 True of
LiftedRep :: RuntimeRep
 False of type variables, type family applications,
and of other reps such as
IntRep :: RuntimeRep
.
isUnliftedRuntimeRep :: RuntimeRepType > Bool Source #
Check whether a type of kind RuntimeRep
is unlifted.
 True of definitely unlifted
RuntimeRep
s such asUnliftedRep
,IntRep
,FloatRep
, ...  False of
LiftedRep
,  False for type variables and type family applications.
runtimeRepLevity_maybe :: RuntimeRepType > Maybe Levity Source #
Check whether a type (usually of kind RuntimeRep
) is lifted, unlifted,
or unknown. Returns Nothing if the type isn't of kind RuntimeRep
.
`runtimeRepLevity_maybe rr` returns:
isBoxedRuntimeRep :: RuntimeRepType > Bool Source #
See isBoxedRuntimeRep_maybe
.
isLiftedLevity :: Type > Bool Source #
isUnliftedLevity :: Type > Bool Source #
isUnliftedType :: HasDebugCallStack => Type > Bool Source #
Is the given type definitely unlifted? See Type for what an unlifted type is.
Panics on representationpolymorphic types; See mightBeUnliftedType
for
a more approximate predicate that behaves better in the presence of
representation polymorphism.
isBoxedType :: Type > Bool Source #
See Type for what a boxed type is.
Panics on representationpolymorphic types; See mightBeUnliftedType
for
a more approximate predicate that behaves better in the presence of
representation polymorphism.
isUnboxedTupleType :: Type > Bool Source #
isUnboxedSumType :: Type > Bool Source #
mightBeLiftedType :: Type > Bool Source #
mightBeUnliftedType :: Type > Bool Source #
definitelyLiftedType :: Type > Bool Source #
definitelyUnliftedType :: Type > Bool Source #
isAlgType :: Type > Bool Source #
See Type for what an algebraic type is. Should only be applied to types, as opposed to e.g. partially saturated type constructors
isDataFamilyAppType :: Type > Bool Source #
Check whether a type is a data family type
isPrimitiveType :: Type > Bool Source #
Returns true of types that are opaque to Haskell.
isStrictType :: HasDebugCallStack => Type > Bool Source #
Computes whether an argument (or let right hand side) should
be computed strictly or lazily, based only on its type.
Currently, it's just isUnliftedType
.
Panics on representationpolymorphic types.
isTerminatingType :: HasDebugCallStack => Type > Bool Source #
True = a term of this type cannot be bottom This identifies the types described by Note [NONBOTTOMDICTS invariant] in GHC.Core NB: unlifted types are not terminating types! e.g. you can write a term (loop 1)::Int# that diverges.
isRuntimeRepTy :: Type > Bool Source #
Is this the type RuntimeRep
?
isRuntimeRepVar :: TyVar > Bool Source #
Is a tyvar of type RuntimeRep
?
isRuntimeRepKindedTy :: Type > Bool Source #
Is this a type of kind RuntimeRep? (e.g. LiftedRep)
dropRuntimeRepArgs :: [Type] > [Type] Source #
Drops prefix of RuntimeRep constructors in TyConApp
s. Useful for e.g.
dropping 'LiftedRep arguments of unboxed tuple TyCon applications:
dropRuntimeRepArgs [ 'LiftedRep, 'IntRep , String, Int# ] == [String, Int#]
Multiplicity
isMultiplicityTy :: Type > Bool Source #
Is this the type Multiplicity
?
isMultiplicityVar :: TyVar > Bool Source #
Is a tyvar of type Multiplicity
?
unrestricted :: a > Scaled a Source #
Scale a payload by Many
irrelevantMult :: Scaled a > a Source #
isLinearType :: Type > Bool Source #
Main data types representing Kinds
Finding the kind of a type
typeHasFixedRuntimeRep :: HasDebugCallStack => Type > Bool Source #
Returns True if a type has a syntactically fixed runtime rep, as per Note [Fixed RuntimeRep] in GHC.Tc.Utils.Concrete.
This function is equivalent to `isFixedRuntimeRepKind . typeKind` but much faster.
Precondition: The type has kind (
TYPE
blah)
isConstraintKind :: Kind > Bool Source #
isConstraintLikeKind :: Kind > Bool Source #
returnsConstraintKind :: Kind > Bool Source #
tcIsBoxedTypeKind :: Kind > Bool Source #
Is this kind equivalent to TYPE (BoxedRep l)
for some l :: Levity
?
isTypeLikeKind :: Kind > Bool Source #
Is this kind equivalent to TYPE r
(for some unknown r)?
This considers Constraint
to be distinct from *
.
Common Kind
Type free variables
tyCoFVsOfType :: Type > FV Source #
The worker for tyCoFVsOfType
and tyCoFVsOfTypeList
.
The previous implementation used unionVarSet
which is O(n+m) and can
make the function quadratic.
It's exported, so that it can be composed with
other functions that compute free variables.
See Note [FV naming conventions] in GHC.Utils.FV.
Etaexpanded because that makes it run faster (apparently) See Note [FV eta expansion] in GHC.Utils.FV for explanation.
tyCoFVsBndr :: ForAllTyBinder > FV > FV Source #
tyCoVarsOfType :: Type > TyCoVarSet Source #
tyCoVarsOfTypes :: [Type] > TyCoVarSet Source #
tyCoVarsOfTypeDSet :: Type > DTyCoVarSet Source #
tyCoFVsOfType
that returns free variables of a type in a deterministic
set. For explanation of why using VarSet
is not deterministic see
Note [Deterministic FV] in GHC.Utils.FV.
coVarsOfType :: Type > CoVarSet Source #
coVarsOfTypes :: [Type] > CoVarSet Source #
noFreeVarsOfType :: Type > Bool Source #
expandTypeSynonyms :: Type > Type Source #
Expand out all type synonyms. Actually, it'd suffice to expand out just the ones that discard type variables (e.g. type Funny a = Int) But we don't know which those are currently, so we just expand all.
expandTypeSynonyms
only expands out type synonyms mentioned in the type,
not in the kinds of any TyCon or TyVar mentioned in the type.
Keep this synchronized with synonymTyConsOfType
Closing over kinds
closeOverKindsDSet :: DTyVarSet > DTyVarSet Source #
Add the kind variables free in the kinds of the tyvars in the given set. Returns a deterministic set.
closeOverKindsList :: [TyVar] > [TyVar] Source #
Add the kind variables free in the kinds of the tyvars in the given set. Returns a deterministically ordered list.
Wellscoped lists of variables
scopedSort :: [TyCoVar] > [TyCoVar] Source #
Do a topological sort on a list of tyvars, so that binders occur before occurrences E.g. given [ a::k, k::*, b::k ] it'll return a wellscoped list [ k::*, a::k, b::k ]
This is a deterministic sorting operation (that is, doesn't depend on Uniques).
It is also meant to be stable: that is, variables should not be reordered unnecessarily. This is specified in Note [ScopedSort] See also Note [Ordering of implicit variables] in GHC.Rename.HsType
tyCoVarsOfTypeWellScoped :: Type > [TyVar] Source #
Get the free vars of a type in scoped order
tyCoVarsOfTypesWellScoped :: [Type] > [TyVar] Source #
Get the free vars of types in scoped order
Forcing evaluation of types
Other views onto Types
coreView :: Type > Maybe Type Source #
This function strips off the top layer only of a type synonym
application (if any) its underlying representation type.
Returns Nothing
if there is nothing to look through.
This function does not look through type family applications.
By being nonrecursive and inlined, this case analysis gets efficiently joined onto the case analysis that the caller is already doing
coreFullView :: Type > Type Source #
Iterates coreView
until there is no more to synonym to expand.
NB: coreFullView is nonrecursive and can be inlined;
core_full_view is the recursive one
See Note [Inlining coreView].
tyConsOfType :: Type > UniqSet TyCon Source #
All type constructors occurring in the type; looking through type synonyms, but not newtypes. When it finds a Class, it returns the class TyCon.
Main type substitution data types
Type & coercion & id substitution
The Subst data type defined in this module contains substitution for tyvar, covar and id. However, operations on IdSubstEnv (mapping from Id to CoreExpr) that require the definition of the Expr data type are defined in GHC.Core.Subst to avoid circular module dependency.
Instances
Manipulating type substitutions
emptySubst :: Subst Source #
mkEmptySubst :: InScopeSet > Subst Source #
mkTCvSubst :: InScopeSet > TvSubstEnv > CvSubstEnv > Subst Source #
zipTvSubst :: HasDebugCallStack => [TyVar] > [Type] > Subst Source #
Generates the inscope set for the Subst
from the types in the incoming
environment. No CoVars or Ids, please!
mkTvSubstPrs :: [(TyVar, Type)] > Subst Source #
Generates the inscope set for the TCvSubst
from the types in the
incoming environment. No CoVars, please! The InScopeSet is just a thunk
so with a bit of luck it'll never be evaluated
zipTCvSubst :: HasDebugCallStack => [TyCoVar] > [Type] > Subst Source #
getTvSubstEnv :: Subst > TvSubstEnv Source #
zapSubst :: Subst > Subst Source #
Remove all substitutions that might have been built up while preserving the inscope set originally called zapSubstEnv
getSubstInScope :: Subst > InScopeSet Source #
Find the inscope set: see Note [The substitution invariant]
setInScope :: Subst > InScopeSet > Subst Source #
getSubstRangeTyCoFVs :: Subst > VarSet Source #
Returns the free variables of the types in the range of a substitution as a nondeterministic set.
extendSubstInScopeList :: Subst > [Var] > Subst Source #
Add the Var
s to the inscope set: see also extendInScope
extendSubstInScopeSet :: Subst > VarSet > Subst Source #
Add the Var
s to the inscope set: see also extendInScope
extendTvSubstList :: Subst > [(TyVar, Type)] > Subst Source #
Adds multiple TyVar
substitutions to the Subst
: see also extendTvSubst
composeTCvSubst :: Subst > Subst > Subst Source #
Composes two substitutions, applying the second one provided first, like in function composition. This function leaves IdSubstEnv untouched because IdSubstEnv is not used during substitution for types.
zipTyEnv :: HasDebugCallStack => [TyVar] > [Type] > TvSubstEnv Source #
The InScopeSet is just a thunk so with a bit of luck it'll never be evaluated
zipCoEnv :: HasDebugCallStack => [CoVar] > [Coercion] > CvSubstEnv Source #
isEmptySubst :: Subst > Bool Source #
isEmptyTCvSubst :: Subst > Bool Source #
Checks whether the tyvar and covar environments are empty.
This function should be used over isEmptySubst
when substituting
for types, because types currently do not contain expressions; we can
safely disregard the expression environment when deciding whether
to skip a substitution. Using isEmptyTCvSubst
gives us a nontrivial
performance boost (up to 70% less allocation for T18223)
Performing substitution on types and kinds
substTy :: HasDebugCallStack => Subst > Type > Type Source #
Substitute within a Type
The substitution has to satisfy the invariants described in
Note [The substitution invariant].
substTys :: HasDebugCallStack => Subst > [Type] > [Type] Source #
Substitute within several Type
s
The substitution has to satisfy the invariants described in
Note [The substitution invariant].
substScaledTy :: HasDebugCallStack => Subst > Scaled Type > Scaled Type Source #
substScaledTys :: HasDebugCallStack => Subst > [Scaled Type] > [Scaled Type] Source #
substTyWith :: HasDebugCallStack => [TyVar] > [Type] > Type > Type Source #
Type substitution, see zipTvSubst
substTysWith :: HasDebugCallStack => [TyVar] > [Type] > [Type] > [Type] Source #
Type substitution, see zipTvSubst
substTheta :: HasDebugCallStack => Subst > ThetaType > ThetaType Source #
Substitute within a ThetaType
The substitution has to satisfy the invariants described in
Note [The substitution invariant].
substTyAddInScope :: HasDebugCallStack => Subst > Type > Type Source #
Substitute within a Type
after adding the free variables of the type
to the inscope set. This is useful for the case when the free variables
aren't already in the inscope set or easily available.
See also Note [The substitution invariant].
substTyUnchecked :: Subst > Type > Type Source #
Substitute within a Type
disabling the sanity checks.
The problems that the sanity checks in substTy catch are described in
Note [The substitution invariant].
The goal of #11371 is to migrate all the calls of substTyUnchecked to
substTy and remove this function. Please don't use in new code.
substTysUnchecked :: Subst > [Type] > [Type] Source #
Substitute within several Type
s disabling the sanity checks.
The problems that the sanity checks in substTys catch are described in
Note [The substitution invariant].
The goal of #11371 is to migrate all the calls of substTysUnchecked to
substTys and remove this function. Please don't use in new code.
substScaledTyUnchecked :: HasDebugCallStack => Subst > Scaled Type > Scaled Type Source #
substThetaUnchecked :: Subst > ThetaType > ThetaType Source #
Substitute within a ThetaType
disabling the sanity checks.
The problems that the sanity checks in substTys catch are described in
Note [The substitution invariant].
The goal of #11371 is to migrate all the calls of substThetaUnchecked to
substTheta and remove this function. Please don't use in new code.
substTyWithUnchecked :: [TyVar] > [Type] > Type > Type Source #
Type substitution, see zipTvSubst
. Disables sanity checks.
The problems that the sanity checks in substTy catch are described in
Note [The substitution invariant].
The goal of #11371 is to migrate all the calls of substTyUnchecked to
substTy and remove this function. Please don't use in new code.
substCo :: HasDebugCallStack => Subst > Coercion > Coercion Source #
Substitute within a Coercion
The substitution has to satisfy the invariants described in
Note [The substitution invariant].
substCoUnchecked :: Subst > Coercion > Coercion Source #
Substitute within a Coercion
disabling sanity checks.
The problems that the sanity checks in substCo catch are described in
Note [The substitution invariant].
The goal of #11371 is to migrate all the calls of substCoUnchecked to
substCo and remove this function. Please don't use in new code.
substCoWithUnchecked :: [TyVar] > [Type] > Coercion > Coercion Source #
Coercion substitution, see zipTvSubst
. Disables sanity checks.
The problems that the sanity checks in substCo catch are described in
Note [The substitution invariant].
The goal of #11371 is to migrate all the calls of substCoUnchecked to
substCo and remove this function. Please don't use in new code.
substTyVarBndr :: HasDebugCallStack => Subst > TyVar > (Subst, TyVar) Source #
substTyVarBndrs :: HasDebugCallStack => Subst > [TyVar] > (Subst, [TyVar]) Source #
substVarBndr :: HasDebugCallStack => Subst > TyCoVar > (Subst, TyCoVar) Source #
substVarBndrs :: HasDebugCallStack => Subst > [TyCoVar] > (Subst, [TyCoVar]) Source #
substTyCoBndr :: Subst > PiTyBinder > (Subst, PiTyBinder) Source #
substTyVarToTyVar :: HasDebugCallStack => Subst > TyVar > TyVar Source #
cloneTyVarBndrs :: Subst > [TyVar] > UniqSupply > (Subst, [TyVar]) Source #
Tidying type related things up for printing
tidyType :: TidyEnv > Type > Type Source #
Tidy a Type
See Note [Strictness in tidyType and friends]
tidyTypes :: TidyEnv > [Type] > [Type] Source #
Tidy a list of Types
See Note [Strictness in tidyType and friends]
tidyOpenTypesX :: TidyEnv > [Type] > (TidyEnv, [Type]) Source #
Grabs the free type variables, tidies them
and then uses tidyType
to work over the type itself
tidyVarBndrs :: TidyEnv > [TyCoVar] > (TidyEnv, [TyCoVar]) Source #
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.
tidyFreeTyCoVars :: TidyEnv > [TyCoVar] > TidyEnv Source #
Add the free TyVar
s to the env in tidy form,
so that we can tidy the type they are free in
Precondition: input free vars are closed over kinds and
This function does a scopedSort, so that tidied variables
have tidied kinds.
See Note [Tidying is idempotent]
tidyFreeTyCoVarX :: TidyEnv > TyCoVar > (TidyEnv, TyCoVar) Source #
Treat a new TyCoVar
as a binder, and give it a fresh tidy name
using the environment if one has not already been allocated. See
also tidyVarBndr
See Note [Tidying is idempotent]
tidyTopType :: Type > Type Source #
Calls tidyType
on a toplevel type (i.e. with an empty tidying environment)
tidyForAllTyBinders :: TidyEnv > [VarBndr TyCoVar vis] > (TidyEnv, [VarBndr TyCoVar vis]) Source #
Kinds
isTYPEorCONSTRAINT :: Kind > Bool Source #
Does this classify a type allowed to have values? Responds True to things like *, TYPE Lifted, TYPE IntRep, TYPE v, Constraint.
True of a kind `TYPE _` or `CONSTRAINT _`
isConcreteType :: Type > Bool Source #
Tests whether the given type is concrete, i.e. it whether it consists only of concrete type constructors, concrete type variables, and applications.
See Note [Concrete types] in GHC.Tc.Utils.Concrete.
isFixedRuntimeRepKind :: HasDebugCallStack => Kind > Bool Source #
Checks that a kind of the form Type
, Constraint
or 'TYPE r
is concrete. See isConcreteType
.
Precondition: The type has kind `TYPE blah` or `CONSTRAINT blah`