Data.Maybe.Singletons

Defines functions and datatypes relating to the singleton for Maybe, including singled versions of all the definitions in Data.Maybe.

Because many of these definitions are produced by Template Haskell, it is not possible to create proper Haddock documentation. Please look up the corresponding operation in Data.Maybe. Also, please excuse the apparent repeated variable names. This is due to an interaction between Template Haskell and Haddock.

Documentation

type family Sing :: k -> Type

The singleton kind-indexed type family.

Instances

type Sing

Defined in Data.Singletons.Base.Instances

type Sing = SBool

type Sing

Defined in Data.Singletons.Base.Instances

type Sing = SOrdering

type Sing

Defined in GHC.TypeLits.Singletons.Internal

type Sing = SNat

type Sing

Defined in GHC.TypeLits.Singletons.Internal

type Sing = SSymbol

type Sing

Defined in Data.Singletons.Base.Instances

type Sing = STuple0

type Sing

Defined in Data.Singletons.Base.Instances

type Sing = SVoid

type Sing

Defined in Data.Semigroup.Singletons.Internal

type Sing = SAll

type Sing

Defined in Data.Semigroup.Singletons.Internal

type Sing = SAny

type Sing

Defined in Data.Singletons.Base.TypeError

type Sing = SErrorMessage

type Sing

Defined in Data.Singletons.Base.Instances

type Sing = SList :: [a] -> Type

type Sing

Defined in Data.Singletons.Base.Instances

type Sing = SMaybe :: Maybe a -> Type

type Sing

A choice of singleton for the kind TYPE rep (for some RuntimeRep rep), an instantiation of which is the famous kind Type.

Conceivably, one could generalize this instance to `Sing @k` for any kind k, and remove all other Sing instances. We don't adopt this design, however, since it is far more convenient in practice to work with explicit singleton values than TypeReps (for instance, TypeReps are more difficult to pattern match on, and require extra runtime checks).

We cannot produce explicit singleton values for everything in TYPE rep, however, since it is an open kind, so we reach for TypeRep in this one particular case.

Defined in Data.Singletons.Base.TypeRepTYPE

type Sing = TypeRep :: TYPE rep -> Type

type Sing

Defined in Data.Semigroup.Singletons.Internal

type Sing = SMin :: Min a -> Type

type Sing

Defined in Data.Semigroup.Singletons.Internal

type Sing = SMax :: Max a -> Type

type Sing

Defined in Data.Semigroup.Singletons.Internal

type Sing = SFirst :: First a -> Type

type Sing

Defined in Data.Semigroup.Singletons.Internal

type Sing = SLast :: Last a -> Type

type Sing

Defined in Data.Semigroup.Singletons.Internal

type Sing = SWrappedMonoid :: WrappedMonoid m -> Type

type Sing

Defined in Data.Singletons.Base.Instances

type Sing = SIdentity :: Identity a -> Type

type Sing

Defined in Data.Monoid.Singletons

type Sing = SFirst :: First a -> Type

type Sing

Defined in Data.Monoid.Singletons

type Sing = SLast :: Last a -> Type

type Sing

Defined in Data.Semigroup.Singletons.Internal

type Sing = SDual :: Dual a -> Type

type Sing

Defined in Data.Semigroup.Singletons.Internal

type Sing = SSum :: Sum a -> Type

type Sing

Defined in Data.Semigroup.Singletons.Internal

type Sing = SProduct :: Product a -> Type

type Sing

Defined in Data.Ord.Singletons

type Sing = SDown :: Down a -> Type

type Sing

Defined in Data.Singletons.Base.Instances

type Sing = SNonEmpty :: NonEmpty a -> Type

type Sing

Defined in Data.Singletons.Base.Instances

type Sing = SEither :: Either a b -> Type

type Sing

Defined in Data.Singletons.Base.Instances

type Sing = STuple2 :: (a, b) -> Type

type Sing

Defined in Data.Semigroup.Singletons

type Sing = SArg :: Arg a b -> Type

type Sing

Defined in Data.Proxy.Singletons

type Sing = SProxy :: Proxy t -> Type

type Sing

Defined in Data.Singletons

type Sing = SWrappedSing :: WrappedSing a -> Type

type Sing

Defined in Data.Singletons

type Sing = SLambda :: (k1 ~> k2) -> Type

type Sing

Defined in Data.Singletons.Base.Instances

type Sing = STuple3 :: (a, b, c) -> Type

type Sing

Defined in Data.Functor.Const.Singletons

type Sing = SConst :: Const a b -> Type

type Sing

Defined in Data.Singletons.Base.Instances

type Sing = STuple4 :: (a, b, c, d) -> Type

type Sing

Defined in Data.Singletons.Base.Instances

type Sing = STuple5 :: (a, b, c, d, e) -> Type

type Sing

Defined in Data.Singletons.Base.Instances

type Sing = STuple6 :: (a, b, c, d, e, f) -> Type

type Sing

Defined in Data.Singletons.Base.Instances

type Sing = STuple7 :: (a, b, c, d, e, f, g) -> Type

data SMaybe :: forall (a :: Type). Maybe a -> Type where

Constructors

SNothing :: forall (a :: Type). SMaybe ('Nothing :: Maybe (a :: Type))

SJust :: forall (a :: Type) (n :: a). (Sing n) -> SMaybe ('Just n :: Maybe (a :: Type))

Instances

SDecide a => TestCoercion (SMaybe :: Maybe a -> Type)

Defined in Data.Singletons.Base.Instances

Methods

testCoercion :: forall (a0 :: k) (b :: k). SMaybe a0 -> SMaybe b -> Maybe (Coercion a0 b)

SDecide a => TestEquality (SMaybe :: Maybe a -> Type)

Defined in Data.Singletons.Base.Instances

Methods

testEquality :: forall (a0 :: k) (b :: k). SMaybe a0 -> SMaybe b -> Maybe (a0 :~: b)

ShowSing a => Show (SMaybe z)

Defined in Data.Singletons.Base.Instances

Methods

showsPrec :: Int -> SMaybe z -> ShowS

show :: SMaybe z -> String

showList :: [SMaybe z] -> ShowS

Singletons from Data.Maybe

maybe_ :: b -> (a -> b) -> Maybe a -> b

type family Maybe_ (a :: b) (a :: (~>) a b) (a :: Maybe a) :: b where ...

Equations

Maybe_ n _ 'Nothing = n

Maybe_ _ f ('Just x) = Apply f x

sMaybe_ :: forall b a (t :: b) (t :: (~>) a b) (t :: Maybe a). Sing t -> Sing t -> Sing t -> Sing (Apply (Apply (Apply Maybe_Sym0 t) t) t :: b)

The preceding two definitions are derived from the function maybe in Data.Maybe. The extra underscore is to avoid name clashes with the type Maybe.

type family IsJust (a :: Maybe a) :: Bool where ...

Equations

IsJust 'Nothing = FalseSym0

IsJust ('Just _) = TrueSym0

sIsJust :: forall a (t :: Maybe a). Sing t -> Sing (Apply IsJustSym0 t :: Bool)

type family IsNothing (a :: Maybe a) :: Bool where ...

Equations

IsNothing 'Nothing = TrueSym0

IsNothing ('Just _) = FalseSym0

sIsNothing :: forall a (t :: Maybe a). Sing t -> Sing (Apply IsNothingSym0 t :: Bool)

type family FromJust (a :: Maybe a) :: a where ...

Equations

FromJust 'Nothing = Apply ErrorSym0 "Maybe.fromJust: Nothing"

FromJust ('Just x) = x

sFromJust :: forall a (t :: Maybe a). Sing t -> Sing (Apply FromJustSym0 t :: a)

type family FromMaybe (a :: a) (a :: Maybe a) :: a where ...

Equations

FromMaybe d x = Case_6989586621679538946 d x x

sFromMaybe :: forall a (t :: a) (t :: Maybe a). Sing t -> Sing t -> Sing (Apply (Apply FromMaybeSym0 t) t :: a)

type family ListToMaybe (a :: [a]) :: Maybe a where ...

Equations

ListToMaybe '[] = NothingSym0

ListToMaybe ('(:) a _) = Apply JustSym0 a

sListToMaybe :: forall a (t :: [a]). Sing t -> Sing (Apply ListToMaybeSym0 t :: Maybe a)

type family MaybeToList (a :: Maybe a) :: [a] where ...

Equations

MaybeToList 'Nothing = NilSym0

MaybeToList ('Just x) = Apply (Apply (:@#@$) x) NilSym0

sMaybeToList :: forall a (t :: Maybe a). Sing t -> Sing (Apply MaybeToListSym0 t :: [a])

type family CatMaybes (a :: [Maybe a]) :: [a] where ...

Equations

CatMaybes '[] = NilSym0

CatMaybes ('(:) ('Just x) xs) = Apply (Apply (:@#@$) x) (Apply CatMaybesSym0 xs)

CatMaybes ('(:) 'Nothing xs) = Apply CatMaybesSym0 xs

sCatMaybes :: forall a (t :: [Maybe a]). Sing t -> Sing (Apply CatMaybesSym0 t :: [a])

type family MapMaybe (a :: (~>) a (Maybe b)) (a :: [a]) :: [b] where ...

Equations

MapMaybe _ '[] = NilSym0

MapMaybe f ('(:) x xs) = Case_6989586621679538921 f x xs (Let6989586621679538919Scrutinee_6989586621679538783Sym3 f x xs)

sMapMaybe :: forall a b (t :: (~>) a (Maybe b)) (t :: [a]). Sing t -> Sing t -> Sing (Apply (Apply MapMaybeSym0 t) t :: [b])

Defunctionalization symbols

type family NothingSym0 :: Maybe (a :: Type) where ...

Equations

NothingSym0 = 'Nothing

data JustSym0 :: (~>) a (Maybe (a :: Type))

Instances

SingI (JustSym0 :: TyFun a (Maybe a) -> Type)

Defined in Data.Singletons.Base.Instances

Methods

sing :: Sing JustSym0

SuppressUnusedWarnings (JustSym0 :: TyFun a (Maybe a) -> Type)

Defined in Data.Singletons.Base.Instances

Methods

suppressUnusedWarnings :: ()

type Apply (JustSym0 :: TyFun a (Maybe a) -> Type) (a6989586621679041801 :: a)

Defined in Data.Singletons.Base.Instances

type Apply (JustSym0 :: TyFun a (Maybe a) -> Type) (a6989586621679041801 :: a) = 'Just a6989586621679041801

type family JustSym1 (a6989586621679041801 :: a) :: Maybe (a :: Type) where ...

Equations

JustSym1 a6989586621679041801 = 'Just a6989586621679041801

data Maybe_Sym0 :: (~>) b ((~>) ((~>) a b) ((~>) (Maybe a) b))

Instances

SingI (Maybe_Sym0 :: TyFun b ((a ~> b) ~> (Maybe a ~> b)) -> Type)

Defined in Data.Maybe.Singletons

Methods

sing :: Sing Maybe_Sym0

SuppressUnusedWarnings (Maybe_Sym0 :: TyFun b ((a ~> b) ~> (Maybe a ~> b)) -> Type)

Defined in Data.Maybe.Singletons

Methods

suppressUnusedWarnings :: ()

type Apply (Maybe_Sym0 :: TyFun b ((a ~> b) ~> (Maybe a ~> b)) -> Type) (a6989586621679537122 :: b)

Defined in Data.Maybe.Singletons

type Apply (Maybe_Sym0 :: TyFun b ((a ~> b) ~> (Maybe a ~> b)) -> Type) (a6989586621679537122 :: b) = Maybe_Sym1 a6989586621679537122 :: TyFun (a ~> b) (Maybe a ~> b) -> Type

data Maybe_Sym1 (a6989586621679537122 :: b) :: (~>) ((~>) a b) ((~>) (Maybe a) b)

Instances

SingI d => SingI (Maybe_Sym1 d :: TyFun (a ~> b) (Maybe a ~> b) -> Type)

Defined in Data.Maybe.Singletons

Methods

sing :: Sing (Maybe_Sym1 d)

SuppressUnusedWarnings (Maybe_Sym1 a6989586621679537122 :: TyFun (a ~> b) (Maybe a ~> b) -> Type)

Defined in Data.Maybe.Singletons

Methods

suppressUnusedWarnings :: ()

type Apply (Maybe_Sym1 a6989586621679537122 :: TyFun (a ~> b) (Maybe a ~> b) -> Type) (a6989586621679537123 :: a ~> b)

Defined in Data.Maybe.Singletons

type Apply (Maybe_Sym1 a6989586621679537122 :: TyFun (a ~> b) (Maybe a ~> b) -> Type) (a6989586621679537123 :: a ~> b) = Maybe_Sym2 a6989586621679537122 a6989586621679537123

data Maybe_Sym2 (a6989586621679537122 :: b) (a6989586621679537123 :: (~>) a b) :: (~>) (Maybe a) b

Instances

(SingI d1, SingI d2) => SingI (Maybe_Sym2 d1 d2 :: TyFun (Maybe a) b -> Type)

Defined in Data.Maybe.Singletons

Methods

sing :: Sing (Maybe_Sym2 d1 d2)

SuppressUnusedWarnings (Maybe_Sym2 a6989586621679537122 a6989586621679537123 :: TyFun (Maybe a) b -> Type)

Defined in Data.Maybe.Singletons

Methods

suppressUnusedWarnings :: ()

type Apply (Maybe_Sym2 a6989586621679537122 a6989586621679537123 :: TyFun (Maybe a) b -> Type) (a6989586621679537124 :: Maybe a)

Defined in Data.Maybe.Singletons

type Apply (Maybe_Sym2 a6989586621679537122 a6989586621679537123 :: TyFun (Maybe a) b -> Type) (a6989586621679537124 :: Maybe a) = Maybe_ a6989586621679537122 a6989586621679537123 a6989586621679537124

type family Maybe_Sym3 (a6989586621679537122 :: b) (a6989586621679537123 :: (~>) a b) (a6989586621679537124 :: Maybe a) :: b where ...

Equations

Maybe_Sym3 a6989586621679537122 a6989586621679537123 a6989586621679537124 = Maybe_ a6989586621679537122 a6989586621679537123 a6989586621679537124

data IsJustSym0 :: (~>) (Maybe a) Bool

Instances

SingI (IsJustSym0 :: TyFun (Maybe a) Bool -> Type)

Defined in Data.Maybe.Singletons

Methods

sing :: Sing IsJustSym0

SuppressUnusedWarnings (IsJustSym0 :: TyFun (Maybe a) Bool -> Type)

Defined in Data.Maybe.Singletons

Methods

suppressUnusedWarnings :: ()

type Apply (IsJustSym0 :: TyFun (Maybe a) Bool -> Type) (a6989586621679538959 :: Maybe a)

Defined in Data.Maybe.Singletons

type Apply (IsJustSym0 :: TyFun (Maybe a) Bool -> Type) (a6989586621679538959 :: Maybe a) = IsJust a6989586621679538959

type family IsJustSym1 (a6989586621679538959 :: Maybe a) :: Bool where ...

Equations

IsJustSym1 a6989586621679538959 = IsJust a6989586621679538959

data IsNothingSym0 :: (~>) (Maybe a) Bool

Instances

SingI (IsNothingSym0 :: TyFun (Maybe a) Bool -> Type)

Defined in Data.Maybe.Singletons

Methods

sing :: Sing IsNothingSym0

SuppressUnusedWarnings (IsNothingSym0 :: TyFun (Maybe a) Bool -> Type)

Defined in Data.Maybe.Singletons

Methods

suppressUnusedWarnings :: ()

type Apply (IsNothingSym0 :: TyFun (Maybe a) Bool -> Type) (a6989586621679538956 :: Maybe a)

Defined in Data.Maybe.Singletons

type Apply (IsNothingSym0 :: TyFun (Maybe a) Bool -> Type) (a6989586621679538956 :: Maybe a) = IsNothing a6989586621679538956

type family IsNothingSym1 (a6989586621679538956 :: Maybe a) :: Bool where ...

Equations

IsNothingSym1 a6989586621679538956 = IsNothing a6989586621679538956

data FromJustSym0 :: (~>) (Maybe a) a

Instances

SingI (FromJustSym0 :: TyFun (Maybe a) a -> Type)

Defined in Data.Maybe.Singletons

Methods

sing :: Sing FromJustSym0

SuppressUnusedWarnings (FromJustSym0 :: TyFun (Maybe a) a -> Type)

Defined in Data.Maybe.Singletons

Methods

suppressUnusedWarnings :: ()

type Apply (FromJustSym0 :: TyFun (Maybe a) a -> Type) (a6989586621679538952 :: Maybe a)

Defined in Data.Maybe.Singletons

type Apply (FromJustSym0 :: TyFun (Maybe a) a -> Type) (a6989586621679538952 :: Maybe a) = FromJust a6989586621679538952

type family FromJustSym1 (a6989586621679538952 :: Maybe a) :: a where ...

Equations

FromJustSym1 a6989586621679538952 = FromJust a6989586621679538952

data FromMaybeSym0 :: (~>) a ((~>) (Maybe a) a)

Instances

SingI (FromMaybeSym0 :: TyFun a (Maybe a ~> a) -> Type)

Defined in Data.Maybe.Singletons

Methods

sing :: Sing FromMaybeSym0

SuppressUnusedWarnings (FromMaybeSym0 :: TyFun a (Maybe a ~> a) -> Type)

Defined in Data.Maybe.Singletons

Methods

suppressUnusedWarnings :: ()

type Apply (FromMaybeSym0 :: TyFun a (Maybe a ~> a) -> Type) (a6989586621679538942 :: a)

Defined in Data.Maybe.Singletons

type Apply (FromMaybeSym0 :: TyFun a (Maybe a ~> a) -> Type) (a6989586621679538942 :: a) = FromMaybeSym1 a6989586621679538942

data FromMaybeSym1 (a6989586621679538942 :: a) :: (~>) (Maybe a) a

Instances

SingI d => SingI (FromMaybeSym1 d :: TyFun (Maybe a) a -> Type)

Defined in Data.Maybe.Singletons

Methods

sing :: Sing (FromMaybeSym1 d)

SuppressUnusedWarnings (FromMaybeSym1 a6989586621679538942 :: TyFun (Maybe a) a -> Type)

Defined in Data.Maybe.Singletons

Methods

suppressUnusedWarnings :: ()

type Apply (FromMaybeSym1 a6989586621679538942 :: TyFun (Maybe a) a -> Type) (a6989586621679538943 :: Maybe a)

Defined in Data.Maybe.Singletons

type Apply (FromMaybeSym1 a6989586621679538942 :: TyFun (Maybe a) a -> Type) (a6989586621679538943 :: Maybe a) = FromMaybe a6989586621679538942 a6989586621679538943

type family FromMaybeSym2 (a6989586621679538942 :: a) (a6989586621679538943 :: Maybe a) :: a where ...

Equations

FromMaybeSym2 a6989586621679538942 a6989586621679538943 = FromMaybe a6989586621679538942 a6989586621679538943

data ListToMaybeSym0 :: (~>) [a] (Maybe a)

Instances

SingI (ListToMaybeSym0 :: TyFun [a] (Maybe a) -> Type)

Defined in Data.Maybe.Singletons

Methods

sing :: Sing ListToMaybeSym0

SuppressUnusedWarnings (ListToMaybeSym0 :: TyFun [a] (Maybe a) -> Type)

Defined in Data.Maybe.Singletons

Methods

suppressUnusedWarnings :: ()

type Apply (ListToMaybeSym0 :: TyFun [a] (Maybe a) -> Type) (a6989586621679538933 :: [a])

Defined in Data.Maybe.Singletons

type Apply (ListToMaybeSym0 :: TyFun [a] (Maybe a) -> Type) (a6989586621679538933 :: [a]) = ListToMaybe a6989586621679538933

type family ListToMaybeSym1 (a6989586621679538933 :: [a]) :: Maybe a where ...

Equations

ListToMaybeSym1 a6989586621679538933 = ListToMaybe a6989586621679538933

data MaybeToListSym0 :: (~>) (Maybe a) [a]

Instances

SingI (MaybeToListSym0 :: TyFun (Maybe a) [a] -> Type)

Defined in Data.Maybe.Singletons

Methods

sing :: Sing MaybeToListSym0

SuppressUnusedWarnings (MaybeToListSym0 :: TyFun (Maybe a) [a] -> Type)

Defined in Data.Maybe.Singletons

Methods

suppressUnusedWarnings :: ()

type Apply (MaybeToListSym0 :: TyFun (Maybe a) [a] -> Type) (a6989586621679538937 :: Maybe a)

Defined in Data.Maybe.Singletons

type Apply (MaybeToListSym0 :: TyFun (Maybe a) [a] -> Type) (a6989586621679538937 :: Maybe a) = MaybeToList a6989586621679538937

type family MaybeToListSym1 (a6989586621679538937 :: Maybe a) :: [a] where ...

Equations

MaybeToListSym1 a6989586621679538937 = MaybeToList a6989586621679538937

data CatMaybesSym0 :: (~>) [Maybe a] [a]

Instances

SingI (CatMaybesSym0 :: TyFun [Maybe a] [a] -> Type)

Defined in Data.Maybe.Singletons

Methods

sing :: Sing CatMaybesSym0

SuppressUnusedWarnings (CatMaybesSym0 :: TyFun [Maybe a] [a] -> Type)

Defined in Data.Maybe.Singletons

Methods

suppressUnusedWarnings :: ()

type Apply (CatMaybesSym0 :: TyFun [Maybe a] [a] -> Type) (a6989586621679538927 :: [Maybe a])

Defined in Data.Maybe.Singletons

type Apply (CatMaybesSym0 :: TyFun [Maybe a] [a] -> Type) (a6989586621679538927 :: [Maybe a]) = CatMaybes a6989586621679538927

type family CatMaybesSym1 (a6989586621679538927 :: [Maybe a]) :: [a] where ...

Equations

CatMaybesSym1 a6989586621679538927 = CatMaybes a6989586621679538927

data MapMaybeSym0 :: (~>) ((~>) a (Maybe b)) ((~>) [a] [b])

Instances

SingI (MapMaybeSym0 :: TyFun (a ~> Maybe b) ([a] ~> [b]) -> Type)

Defined in Data.Maybe.Singletons

Methods

sing :: Sing MapMaybeSym0

SuppressUnusedWarnings (MapMaybeSym0 :: TyFun (a ~> Maybe b) ([a] ~> [b]) -> Type)

Defined in Data.Maybe.Singletons

Methods

suppressUnusedWarnings :: ()

type Apply (MapMaybeSym0 :: TyFun (a ~> Maybe b) ([a] ~> [b]) -> Type) (a6989586621679538912 :: a ~> Maybe b)

Defined in Data.Maybe.Singletons

type Apply (MapMaybeSym0 :: TyFun (a ~> Maybe b) ([a] ~> [b]) -> Type) (a6989586621679538912 :: a ~> Maybe b) = MapMaybeSym1 a6989586621679538912

data MapMaybeSym1 (a6989586621679538912 :: (~>) a (Maybe b)) :: (~>) [a] [b]

Instances

SingI d => SingI (MapMaybeSym1 d :: TyFun [a] [b] -> Type)

Defined in Data.Maybe.Singletons

Methods

sing :: Sing (MapMaybeSym1 d)

SuppressUnusedWarnings (MapMaybeSym1 a6989586621679538912 :: TyFun [a] [b] -> Type)

Defined in Data.Maybe.Singletons

Methods

suppressUnusedWarnings :: ()

type Apply (MapMaybeSym1 a6989586621679538912 :: TyFun [a] [b] -> Type) (a6989586621679538913 :: [a])

Defined in Data.Maybe.Singletons

type Apply (MapMaybeSym1 a6989586621679538912 :: TyFun [a] [b] -> Type) (a6989586621679538913 :: [a]) = MapMaybe a6989586621679538912 a6989586621679538913

type family MapMaybeSym2 (a6989586621679538912 :: (~>) a (Maybe b)) (a6989586621679538913 :: [a]) :: [b] where ...

Equations

MapMaybeSym2 a6989586621679538912 a6989586621679538913 = MapMaybe a6989586621679538912 a6989586621679538913