Symbol

Symbol

data Symbol

(Kind) This is the kind of type-level symbols. Declared here because class IP needs it

Instances

SingKind Symbol

Since: base-4.9.0.0

Defined in GHC.Generics

Associated Types

type DemoteRep Symbol :: *

Methods

fromSing :: Sing a -> DemoteRep Symbol

KnownSymbol a => SingI (a :: Symbol)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

sing :: Sing a

KnownSymbol n => Reifies (n :: Symbol) String

Defined in Data.Reflection

Methods

reflect :: proxy n -> String

IsRecord (M1 S (MetaSel (Nothing :: Maybe Symbol) u ss ds) f) False

Defined in Data.Aeson.Types.Generic

data Sing (s :: Symbol)

Defined in GHC.Generics

data Sing (s :: Symbol) where

• SSym :: Sing s

type DemoteRep Symbol

Defined in GHC.Generics

type DemoteRep Symbol = String

class KnownSymbol (n :: Symbol)

This class gives the string associated with a type-level symbol. There are instances of the class for every concrete literal: "hello", etc.

Since: base-4.7.0.0

Minimal complete definition

symbolSing

symbolVal :: KnownSymbol n => proxy n -> String

Since: base-4.7.0.0

symbolVal' :: KnownSymbol n => Proxy# n -> String

Since: base-4.8.0.0

data SomeSymbol where

This type represents unknown type-level symbols.

Constructors

SomeSymbol :: SomeSymbol

Since: base-4.7.0.0

Instances

Eq SomeSymbol

Since: base-4.7.0.0

Defined in GHC.TypeLits

Methods

(==) :: SomeSymbol -> SomeSymbol -> Bool

(/=) :: SomeSymbol -> SomeSymbol -> Bool

Ord SomeSymbol

Since: base-4.7.0.0

Defined in GHC.TypeLits

Methods

compare :: SomeSymbol -> SomeSymbol -> Ordering

(<) :: SomeSymbol -> SomeSymbol -> Bool

(<=) :: SomeSymbol -> SomeSymbol -> Bool

(>) :: SomeSymbol -> SomeSymbol -> Bool

(>=) :: SomeSymbol -> SomeSymbol -> Bool

max :: SomeSymbol -> SomeSymbol -> SomeSymbol

min :: SomeSymbol -> SomeSymbol -> SomeSymbol

Read SomeSymbol

Since: base-4.7.0.0

Defined in GHC.TypeLits

Methods

readsPrec :: Int -> ReadS SomeSymbol

readList :: ReadS [SomeSymbol]

readPrec :: ReadPrec SomeSymbol

readListPrec :: ReadPrec [SomeSymbol]

Show SomeSymbol

Since: base-4.7.0.0

Defined in GHC.TypeLits

Methods

showsPrec :: Int -> SomeSymbol -> ShowS

show :: SomeSymbol -> String

showList :: [SomeSymbol] -> ShowS

someSymbolVal :: String -> SomeSymbol

Convert a string into an unknown type-level symbol.

Since: base-4.7.0.0

sameSymbol :: (KnownSymbol a, KnownSymbol b) => Proxy a -> Proxy b -> Maybe (a :~: b)

We either get evidence that this function was instantiated with the same type-level symbols, or Nothing.

Since: base-4.7.0.0

type family AppendSymbol (a :: Symbol) (b :: Symbol) :: Symbol where ...

Concatenation of type-level symbols.

Since: base-4.10.0.0

type family CmpSymbol (a :: Symbol) (b :: Symbol) :: Ordering where ...

Comparison of type-level symbols, as a function.

Since: base-4.7.0.0

type family (++) :: Symbol -> Symbol -> Symbol where ...

type family Take :: Nat -> Symbol -> Symbol where ...

type family Drop :: Nat -> Symbol -> Symbol where ...

type family Length :: Symbol -> Nat where ...

appendSymbol :: (KnownSymbol a, KnownSymbol b) :- KnownSymbol (a ++ b)

appendUnit1 :: Dict (("" ++ a) ~ a)

appendUnit2 :: Dict ((a ++ "") ~ a)

appendAssociates :: Dict (((a ++ b) ++ c) ~ (a ++ (b ++ c)))

takeSymbol :: (KnownNat n, KnownSymbol a) :- KnownSymbol (Take n a)

dropSymbol :: (KnownNat n, KnownSymbol a) :- KnownSymbol (Drop n a)

takeAppendDrop :: Dict ((Take n a ++ Drop n a) ~ a)

lengthSymbol :: KnownSymbol a :- KnownNat (Length a)

takeLength :: (Length a <= n) :- (Take n a ~ a)

take0 :: Dict (Take 0 a ~ "")

takeEmpty :: Dict (Take n "" ~ "")

dropLength :: (Length a <= n) :- (Drop n a ~ "")

drop0 :: Dict (Drop 0 a ~ a)

dropEmpty :: Dict (Drop n "" ~ "")

lengthTake :: Dict (Length (Take n a) <= n)

lengthDrop :: Dict (Length a <= (Length (Drop n a) + n))

dropDrop :: Dict (Drop n (Drop m a) ~ Drop (n + m) a)

takeTake :: Dict (Take n (Take m a) ~ Take (Min n m) a)