base-4.14.0.0: Basic libraries
Copyright(c) The University of Glasgow CWI 2001--2004
LicenseBSD-style (see the file libraries/base/LICENSE)
Maintainerlibraries@haskell.org
Stabilityexperimental
Portabilityportable
Safe HaskellTrustworthy
LanguageHaskell2010

Data.Typeable

Description

The Typeable class reifies types to some extent by associating type representations to types. These type representations can be compared, and one can in turn define a type-safe cast operation. To this end, an unsafe cast is guarded by a test for type (representation) equivalence. The module Data.Dynamic uses Typeable for an implementation of dynamics. The module Data.Data uses Typeable and type-safe cast (but not dynamics) to support the "Scrap your boilerplate" style of generic programming.

Compatibility Notes

Since GHC 8.2, GHC has supported type-indexed type representations. Data.Typeable provides type representations which are qualified over this index, providing an interface very similar to the Typeable notion seen in previous releases. For the type-indexed interface, see Type.Reflection.

Since GHC 7.10, all types automatically have Typeable instances derived. This is in contrast to previous releases where Typeable had to be explicitly derived using the DeriveDataTypeable language extension.

Since GHC 7.8, Typeable is poly-kinded. The changes required for this might break some old programs involving Typeable. More details on this, including how to fix your code, can be found on the PolyTypeable wiki page

Synopsis

The Typeable class

class Typeable (a :: k) Source #

The class Typeable allows a concrete representation of a type to be calculated.

Minimal complete definition

typeRep#

typeOf :: forall a. Typeable a => a -> TypeRep Source #

Observe a type representation for the type of a value.

typeRep :: forall proxy a. Typeable a => proxy a -> TypeRep Source #

Takes a value of type a and returns a concrete representation of that type.

Since: base-4.7.0.0

Propositional equality

data a :~: b where infix 4 Source #

Propositional equality. If a :~: b is inhabited by some terminating value, then the type a is the same as the type b. To use this equality in practice, pattern-match on the a :~: b to get out the Refl constructor; in the body of the pattern-match, the compiler knows that a ~ b.

@since 4.7.0.0. Kind k explicitly quantified since 4.15.0.0.

Constructors

Refl :: a :~: a 

Instances

Instances details
Category ((:~:) :: k -> k -> Type) #

Since: base-4.7.0.0

Instance details

Defined in Control.Category

Methods

id :: forall (a :: k0). a :~: a Source #

(.) :: forall (b :: k0) (c :: k0) (a :: k0). (b :~: c) -> (a :~: b) -> a :~: c Source #

TestEquality ((:~:) a :: k -> Type) #

Since: base-4.7.0.0

Instance details

Defined in Data.Type.Equality

Methods

testEquality :: forall (a0 :: k0) (b :: k0). (a :~: a0) -> (a :~: b) -> Maybe (a0 :~: b) Source #

TestCoercion ((:~:) a :: k -> Type) #

Since: base-4.7.0.0

Instance details

Defined in Data.Type.Coercion

Methods

testCoercion :: forall (a0 :: k0) (b :: k0). (a :~: a0) -> (a :~: b) -> Maybe (Coercion a0 b) Source #

a ~ b => Bounded (a :~: b) #

Since: base-4.7.0.0

Instance details

Defined in Data.Type.Equality

Methods

minBound :: a :~: b Source #

maxBound :: a :~: b Source #

a ~ b => Enum (a :~: b) #

Since: base-4.7.0.0

Instance details

Defined in Data.Type.Equality

Methods

succ :: (a :~: b) -> a :~: b Source #

pred :: (a :~: b) -> a :~: b Source #

toEnum :: Int -> a :~: b Source #

fromEnum :: (a :~: b) -> Int Source #

enumFrom :: (a :~: b) -> [a :~: b] Source #

enumFromThen :: (a :~: b) -> (a :~: b) -> [a :~: b] Source #

enumFromTo :: (a :~: b) -> (a :~: b) -> [a :~: b] Source #

enumFromThenTo :: (a :~: b) -> (a :~: b) -> (a :~: b) -> [a :~: b] Source #

Eq (a :~: b) #

Since: base-4.7.0.0

Instance details

Defined in Data.Type.Equality

Methods

(==) :: (a :~: b) -> (a :~: b) -> Bool Source #

(/=) :: (a :~: b) -> (a :~: b) -> Bool Source #

(a ~ b, Data a) => Data (a :~: b) #

Since: base-4.7.0.0

Instance details

Defined in Data.Data

Methods

gfoldl :: (forall d b0. Data d => c (d -> b0) -> d -> c b0) -> (forall g. g -> c g) -> (a :~: b) -> c (a :~: b) Source #

gunfold :: (forall b0 r. Data b0 => c (b0 -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (a :~: b) Source #

toConstr :: (a :~: b) -> Constr Source #

dataTypeOf :: (a :~: b) -> DataType Source #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (a :~: b)) Source #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (a :~: b)) Source #

gmapT :: (forall b0. Data b0 => b0 -> b0) -> (a :~: b) -> a :~: b Source #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> (a :~: b) -> r Source #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> (a :~: b) -> r Source #

gmapQ :: (forall d. Data d => d -> u) -> (a :~: b) -> [u] Source #

gmapQi :: Int -> (forall d. Data d => d -> u) -> (a :~: b) -> u Source #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> (a :~: b) -> m (a :~: b) Source #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> (a :~: b) -> m (a :~: b) Source #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> (a :~: b) -> m (a :~: b) Source #

Ord (a :~: b) #

Since: base-4.7.0.0

Instance details

Defined in Data.Type.Equality

Methods

compare :: (a :~: b) -> (a :~: b) -> Ordering Source #

(<) :: (a :~: b) -> (a :~: b) -> Bool Source #

(<=) :: (a :~: b) -> (a :~: b) -> Bool Source #

(>) :: (a :~: b) -> (a :~: b) -> Bool Source #

(>=) :: (a :~: b) -> (a :~: b) -> Bool Source #

max :: (a :~: b) -> (a :~: b) -> a :~: b Source #

min :: (a :~: b) -> (a :~: b) -> a :~: b Source #

a ~ b => Read (a :~: b) #

Since: base-4.7.0.0

Instance details

Defined in Data.Type.Equality

Show (a :~: b) #

Since: base-4.7.0.0

Instance details

Defined in Data.Type.Equality

Methods

showsPrec :: Int -> (a :~: b) -> ShowS Source #

show :: (a :~: b) -> String Source #

showList :: [a :~: b] -> ShowS Source #

data a :~~: b where infix 4 Source #

Kind heterogeneous propositional equality. Like :~:, a :~~: b is inhabited by a terminating value if and only if a is the same type as b.

@since 4.10.0.0. Kinds k1 and k2 explicitly quantified since 4.15.0.0.

Constructors

HRefl :: a :~~: a 

Instances

Instances details
Category ((:~~:) :: k -> k -> Type) #

Since: base-4.10.0.0

Instance details

Defined in Control.Category

Methods

id :: forall (a :: k0). a :~~: a Source #

(.) :: forall (b :: k0) (c :: k0) (a :: k0). (b :~~: c) -> (a :~~: b) -> a :~~: c Source #

TestEquality ((:~~:) a :: k -> Type) #

Since: base-4.10.0.0

Instance details

Defined in Data.Type.Equality

Methods

testEquality :: forall (a0 :: k0) (b :: k0). (a :~~: a0) -> (a :~~: b) -> Maybe (a0 :~: b) Source #

TestCoercion ((:~~:) a :: k -> Type) #

Since: base-4.10.0.0

Instance details

Defined in Data.Type.Coercion

Methods

testCoercion :: forall (a0 :: k0) (b :: k0). (a :~~: a0) -> (a :~~: b) -> Maybe (Coercion a0 b) Source #

a ~~ b => Bounded (a :~~: b) #

Since: base-4.10.0.0

Instance details

Defined in Data.Type.Equality

Methods

minBound :: a :~~: b Source #

maxBound :: a :~~: b Source #

a ~~ b => Enum (a :~~: b) #

Since: base-4.10.0.0

Instance details

Defined in Data.Type.Equality

Methods

succ :: (a :~~: b) -> a :~~: b Source #

pred :: (a :~~: b) -> a :~~: b Source #

toEnum :: Int -> a :~~: b Source #

fromEnum :: (a :~~: b) -> Int Source #

enumFrom :: (a :~~: b) -> [a :~~: b] Source #

enumFromThen :: (a :~~: b) -> (a :~~: b) -> [a :~~: b] Source #

enumFromTo :: (a :~~: b) -> (a :~~: b) -> [a :~~: b] Source #

enumFromThenTo :: (a :~~: b) -> (a :~~: b) -> (a :~~: b) -> [a :~~: b] Source #

Eq (a :~~: b) #

Since: base-4.10.0.0

Instance details

Defined in Data.Type.Equality

Methods

(==) :: (a :~~: b) -> (a :~~: b) -> Bool Source #

(/=) :: (a :~~: b) -> (a :~~: b) -> Bool Source #

(Typeable i, Typeable j, Typeable a, Typeable b, a ~~ b) => Data (a :~~: b) #

Since: base-4.10.0.0

Instance details

Defined in Data.Data

Methods

gfoldl :: (forall d b0. Data d => c (d -> b0) -> d -> c b0) -> (forall g. g -> c g) -> (a :~~: b) -> c (a :~~: b) Source #

gunfold :: (forall b0 r. Data b0 => c (b0 -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (a :~~: b) Source #

toConstr :: (a :~~: b) -> Constr Source #

dataTypeOf :: (a :~~: b) -> DataType Source #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (a :~~: b)) Source #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (a :~~: b)) Source #

gmapT :: (forall b0. Data b0 => b0 -> b0) -> (a :~~: b) -> a :~~: b Source #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> (a :~~: b) -> r Source #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> (a :~~: b) -> r Source #

gmapQ :: (forall d. Data d => d -> u) -> (a :~~: b) -> [u] Source #

gmapQi :: Int -> (forall d. Data d => d -> u) -> (a :~~: b) -> u Source #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> (a :~~: b) -> m (a :~~: b) Source #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> (a :~~: b) -> m (a :~~: b) Source #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> (a :~~: b) -> m (a :~~: b) Source #

Ord (a :~~: b) #

Since: base-4.10.0.0

Instance details

Defined in Data.Type.Equality

Methods

compare :: (a :~~: b) -> (a :~~: b) -> Ordering Source #

(<) :: (a :~~: b) -> (a :~~: b) -> Bool Source #

(<=) :: (a :~~: b) -> (a :~~: b) -> Bool Source #

(>) :: (a :~~: b) -> (a :~~: b) -> Bool Source #

(>=) :: (a :~~: b) -> (a :~~: b) -> Bool Source #

max :: (a :~~: b) -> (a :~~: b) -> a :~~: b Source #

min :: (a :~~: b) -> (a :~~: b) -> a :~~: b Source #

a ~~ b => Read (a :~~: b) #

Since: base-4.10.0.0

Instance details

Defined in Data.Type.Equality

Show (a :~~: b) #

Since: base-4.10.0.0

Instance details

Defined in Data.Type.Equality

Methods

showsPrec :: Int -> (a :~~: b) -> ShowS Source #

show :: (a :~~: b) -> String Source #

showList :: [a :~~: b] -> ShowS Source #

Type-safe cast

cast :: forall a b. (Typeable a, Typeable b) => a -> Maybe b Source #

The type-safe cast operation

eqT :: forall a b. (Typeable a, Typeable b) => Maybe (a :~: b) Source #

Extract a witness of equality of two types

Since: base-4.7.0.0

gcast :: forall a b c. (Typeable a, Typeable b) => c a -> Maybe (c b) Source #

A flexible variation parameterised in a type constructor

Generalized casts for higher-order kinds

gcast1 :: forall c t t' a. (Typeable t, Typeable t') => c (t a) -> Maybe (c (t' a)) Source #

Cast over k1 -> k2

gcast2 :: forall c t t' a b. (Typeable t, Typeable t') => c (t a b) -> Maybe (c (t' a b)) Source #

Cast over k1 -> k2 -> k3

A canonical proxy type

data Proxy t Source #

Proxy is a type that holds no data, but has a phantom parameter of arbitrary type (or even kind). Its use is to provide type information, even though there is no value available of that type (or it may be too costly to create one).

Historically, Proxy :: Proxy a is a safer alternative to the undefined :: a idiom.

>>> Proxy :: Proxy (Void, Int -> Int)
Proxy

Proxy can even hold types of higher kinds,

>>> Proxy :: Proxy Either
Proxy
>>> Proxy :: Proxy Functor
Proxy
>>> Proxy :: Proxy complicatedStructure
Proxy

Constructors

Proxy 

Instances

Instances details
Generic1 (Proxy :: k -> Type) # 
Instance details

Defined in GHC.Generics

Associated Types

type Rep1 Proxy :: k -> Type Source #

Methods

from1 :: forall (a :: k0). Proxy a -> Rep1 Proxy a Source #

to1 :: forall (a :: k0). Rep1 Proxy a -> Proxy a Source #

Monad (Proxy :: Type -> Type) #

Since: base-4.7.0.0

Instance details

Defined in Data.Proxy

Methods

(>>=) :: Proxy a -> (a -> Proxy b) -> Proxy b Source #

(>>) :: Proxy a -> Proxy b -> Proxy b Source #

return :: a -> Proxy a Source #

Functor (Proxy :: Type -> Type) #

Since: base-4.7.0.0

Instance details

Defined in Data.Proxy

Methods

fmap :: (a -> b) -> Proxy a -> Proxy b Source #

(<$) :: a -> Proxy b -> Proxy a Source #

Applicative (Proxy :: Type -> Type) #

Since: base-4.7.0.0

Instance details

Defined in Data.Proxy

Methods

pure :: a -> Proxy a Source #

(<*>) :: Proxy (a -> b) -> Proxy a -> Proxy b Source #

liftA2 :: (a -> b -> c) -> Proxy a -> Proxy b -> Proxy c Source #

(*>) :: Proxy a -> Proxy b -> Proxy b Source #

(<*) :: Proxy a -> Proxy b -> Proxy a Source #

Foldable (Proxy :: Type -> Type) #

Since: base-4.7.0.0

Instance details

Defined in Data.Foldable

Methods

fold :: Monoid m => Proxy m -> m Source #

foldMap :: Monoid m => (a -> m) -> Proxy a -> m Source #

foldMap' :: Monoid m => (a -> m) -> Proxy a -> m Source #

foldr :: (a -> b -> b) -> b -> Proxy a -> b Source #

foldr' :: (a -> b -> b) -> b -> Proxy a -> b Source #

foldl :: (b -> a -> b) -> b -> Proxy a -> b Source #

foldl' :: (b -> a -> b) -> b -> Proxy a -> b Source #

foldr1 :: (a -> a -> a) -> Proxy a -> a Source #

foldl1 :: (a -> a -> a) -> Proxy a -> a Source #

toList :: Proxy a -> [a] Source #

null :: Proxy a -> Bool Source #

length :: Proxy a -> Int Source #

elem :: Eq a => a -> Proxy a -> Bool Source #

maximum :: Ord a => Proxy a -> a Source #

minimum :: Ord a => Proxy a -> a Source #

sum :: Num a => Proxy a -> a Source #

product :: Num a => Proxy a -> a Source #

Traversable (Proxy :: Type -> Type) #

Since: base-4.7.0.0

Instance details

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Proxy a -> f (Proxy b) Source #

sequenceA :: Applicative f => Proxy (f a) -> f (Proxy a) Source #

mapM :: Monad m => (a -> m b) -> Proxy a -> m (Proxy b) Source #

sequence :: Monad m => Proxy (m a) -> m (Proxy a) Source #

MonadPlus (Proxy :: Type -> Type) #

Since: base-4.9.0.0

Instance details

Defined in Data.Proxy

Methods

mzero :: Proxy a Source #

mplus :: Proxy a -> Proxy a -> Proxy a Source #

Alternative (Proxy :: Type -> Type) #

Since: base-4.9.0.0

Instance details

Defined in Data.Proxy

Methods

empty :: Proxy a Source #

(<|>) :: Proxy a -> Proxy a -> Proxy a Source #

some :: Proxy a -> Proxy [a] Source #

many :: Proxy a -> Proxy [a] Source #

MonadZip (Proxy :: Type -> Type) #

Since: base-4.9.0.0

Instance details

Defined in Control.Monad.Zip

Methods

mzip :: Proxy a -> Proxy b -> Proxy (a, b) Source #

mzipWith :: (a -> b -> c) -> Proxy a -> Proxy b -> Proxy c Source #

munzip :: Proxy (a, b) -> (Proxy a, Proxy b) Source #

Show1 (Proxy :: Type -> Type) #

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Classes

Methods

liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Proxy a -> ShowS Source #

liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Proxy a] -> ShowS Source #

Read1 (Proxy :: Type -> Type) #

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Classes

Ord1 (Proxy :: Type -> Type) #

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Classes

Methods

liftCompare :: (a -> b -> Ordering) -> Proxy a -> Proxy b -> Ordering Source #

Eq1 (Proxy :: Type -> Type) #

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Classes

Methods

liftEq :: (a -> b -> Bool) -> Proxy a -> Proxy b -> Bool Source #

Contravariant (Proxy :: Type -> Type) # 
Instance details

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a) -> Proxy a -> Proxy a' Source #

(>$) :: b -> Proxy b -> Proxy a Source #

Bounded (Proxy t) #

Since: base-4.7.0.0

Instance details

Defined in Data.Proxy

Enum (Proxy s) #

Since: base-4.7.0.0

Instance details

Defined in Data.Proxy

Methods

succ :: Proxy s -> Proxy s Source #

pred :: Proxy s -> Proxy s Source #

toEnum :: Int -> Proxy s Source #

fromEnum :: Proxy s -> Int Source #

enumFrom :: Proxy s -> [Proxy s] Source #

enumFromThen :: Proxy s -> Proxy s -> [Proxy s] Source #

enumFromTo :: Proxy s -> Proxy s -> [Proxy s] Source #

enumFromThenTo :: Proxy s -> Proxy s -> Proxy s -> [Proxy s] Source #

Eq (Proxy s) #

Since: base-4.7.0.0

Instance details

Defined in Data.Proxy

Methods

(==) :: Proxy s -> Proxy s -> Bool Source #

(/=) :: Proxy s -> Proxy s -> Bool Source #

Data t => Data (Proxy t) #

Since: base-4.7.0.0

Instance details

Defined in Data.Data

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Proxy t -> c (Proxy t) Source #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Proxy t) Source #

toConstr :: Proxy t -> Constr Source #

dataTypeOf :: Proxy t -> DataType Source #

dataCast1 :: Typeable t0 => (forall d. Data d => c (t0 d)) -> Maybe (c (Proxy t)) Source #

dataCast2 :: Typeable t0 => (forall d e. (Data d, Data e) => c (t0 d e)) -> Maybe (c (Proxy t)) Source #

gmapT :: (forall b. Data b => b -> b) -> Proxy t -> Proxy t Source #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Proxy t -> r Source #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Proxy t -> r Source #

gmapQ :: (forall d. Data d => d -> u) -> Proxy t -> [u] Source #

gmapQi :: Int -> (forall d. Data d => d -> u) -> Proxy t -> u Source #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Proxy t -> m (Proxy t) Source #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Proxy t -> m (Proxy t) Source #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Proxy t -> m (Proxy t) Source #

Ord (Proxy s) #

Since: base-4.7.0.0

Instance details

Defined in Data.Proxy

Methods

compare :: Proxy s -> Proxy s -> Ordering Source #

(<) :: Proxy s -> Proxy s -> Bool Source #

(<=) :: Proxy s -> Proxy s -> Bool Source #

(>) :: Proxy s -> Proxy s -> Bool Source #

(>=) :: Proxy s -> Proxy s -> Bool Source #

max :: Proxy s -> Proxy s -> Proxy s Source #

min :: Proxy s -> Proxy s -> Proxy s Source #

Read (Proxy t) #

Since: base-4.7.0.0

Instance details

Defined in Data.Proxy

Show (Proxy s) #

Since: base-4.7.0.0

Instance details

Defined in Data.Proxy

Ix (Proxy s) #

Since: base-4.7.0.0

Instance details

Defined in Data.Proxy

Methods

range :: (Proxy s, Proxy s) -> [Proxy s] Source #

index :: (Proxy s, Proxy s) -> Proxy s -> Int Source #

unsafeIndex :: (Proxy s, Proxy s) -> Proxy s -> Int Source #

inRange :: (Proxy s, Proxy s) -> Proxy s -> Bool Source #

rangeSize :: (Proxy s, Proxy s) -> Int Source #

unsafeRangeSize :: (Proxy s, Proxy s) -> Int Source #

Generic (Proxy t) # 
Instance details

Defined in GHC.Generics

Associated Types

type Rep (Proxy t) :: Type -> Type Source #

Methods

from :: Proxy t -> Rep (Proxy t) x Source #

to :: Rep (Proxy t) x -> Proxy t Source #

Semigroup (Proxy s) #

Since: base-4.9.0.0

Instance details

Defined in Data.Proxy

Methods

(<>) :: Proxy s -> Proxy s -> Proxy s Source #

sconcat :: NonEmpty (Proxy s) -> Proxy s Source #

stimes :: Integral b => b -> Proxy s -> Proxy s Source #

Monoid (Proxy s) #

Since: base-4.7.0.0

Instance details

Defined in Data.Proxy

Methods

mempty :: Proxy s Source #

mappend :: Proxy s -> Proxy s -> Proxy s Source #

mconcat :: [Proxy s] -> Proxy s Source #

type Rep1 (Proxy :: k -> Type) #

Since: base-4.6.0.0

Instance details

Defined in GHC.Generics

type Rep1 (Proxy :: k -> Type) = D1 ('MetaData "Proxy" "Data.Proxy" "base" 'False) (C1 ('MetaCons "Proxy" 'PrefixI 'False) (U1 :: k -> Type))
type Rep (Proxy t) #

Since: base-4.6.0.0

Instance details

Defined in GHC.Generics

type Rep (Proxy t) = D1 ('MetaData "Proxy" "Data.Proxy" "base" 'False) (C1 ('MetaCons "Proxy" 'PrefixI 'False) (U1 :: Type -> Type))

Type representations

type TypeRep = SomeTypeRep Source #

A quantified type representation.

rnfTypeRep :: TypeRep -> () Source #

Force a TypeRep to normal form.

showsTypeRep :: TypeRep -> ShowS Source #

Show a type representation

mkFunTy :: TypeRep -> TypeRep -> TypeRep Source #

Build a function type.

Observing type representations

funResultTy :: TypeRep -> TypeRep -> Maybe TypeRep Source #

Applies a type to a function type. Returns: Just u if the first argument represents a function of type t -> u and the second argument represents a function of type t. Otherwise, returns Nothing.

splitTyConApp :: TypeRep -> (TyCon, [TypeRep]) Source #

Splits a type constructor application. Note that if the type constructor is polymorphic, this will not return the kinds that were used.

typeRepArgs :: TypeRep -> [TypeRep] Source #

Observe the argument types of a type representation

typeRepTyCon :: TypeRep -> TyCon Source #

Observe the type constructor of a quantified type representation.

typeRepFingerprint :: TypeRep -> Fingerprint Source #

Takes a value of type a and returns a concrete representation of that type.

Since: base-4.7.0.0

Type constructors

data TyCon Source #

Instances

Instances details
Eq TyCon 
Instance details

Defined in GHC.Classes

Methods

(==) :: TyCon -> TyCon -> Bool Source #

(/=) :: TyCon -> TyCon -> Bool Source #

Ord TyCon 
Instance details

Defined in GHC.Classes

Show TyCon #

Since: base-2.1

Instance details

Defined in GHC.Show

For backwards compatibility

typeOf1 :: forall t (a :: Type). Typeable t => t a -> TypeRep Source #

typeOf2 :: forall t (a :: Type) (b :: Type). Typeable t => t a b -> TypeRep Source #

typeOf3 :: forall t (a :: Type) (b :: Type) (c :: Type). Typeable t => t a b c -> TypeRep Source #

typeOf4 :: forall t (a :: Type) (b :: Type) (c :: Type) (d :: Type). Typeable t => t a b c d -> TypeRep Source #

typeOf5 :: forall t (a :: Type) (b :: Type) (c :: Type) (d :: Type) (e :: Type). Typeable t => t a b c d e -> TypeRep Source #

typeOf6 :: forall t (a :: Type) (b :: Type) (c :: Type) (d :: Type) (e :: Type) (f :: Type). Typeable t => t a b c d e f -> TypeRep Source #

typeOf7 :: forall t (a :: Type) (b :: Type) (c :: Type) (d :: Type) (e :: Type) (f :: Type) (g :: Type). Typeable t => t a b c d e f g -> TypeRep Source #