Safe Haskell	Safe-Inferred
Language	Haskell2010

Data.Void.Compat

Synopsis

Documentation

data Void #

Uninhabited data type

Since: base-4.8.0.0

Instances details

Semigroup Void	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: Void -> Void -> Void # sconcat :: NonEmpty Void -> Void # stimes :: Integral b => b -> Void -> Void #
Exception Void	Since: base-4.8.0.0
Instance details Defined in GHC.Exception.Type Methods toException :: Void -> SomeException # fromException :: SomeException -> Maybe Void # displayException :: Void -> String #
Read Void	Reading a `Void` value is always a parse error, considering `Void` as a data type with no constructors. Since: base-4.8.0.0
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Void # readList :: ReadS [Void] # readPrec :: ReadPrec Void # readListPrec :: ReadPrec [Void] #
Show Void	Since: base-4.8.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Void -> ShowS # show :: Void -> String # showList :: [Void] -> ShowS #
Eq Void	Since: base-4.8.0.0
Instance details Defined in GHC.Base Methods (==) :: Void -> Void -> Bool # (/=) :: Void -> Void -> Bool #
Ord Void	Since: base-4.8.0.0
Instance details Defined in GHC.Base Methods compare :: Void -> Void -> Ordering # (<) :: Void -> Void -> Bool # (<=) :: Void -> Void -> Bool # (>) :: Void -> Void -> Bool # (>=) :: Void -> Void -> Bool # max :: Void -> Void -> Void # min :: Void -> Void -> Void #

Since Void values logically don't exist, this witnesses the logical reasoning tool of "ex falso quodlibet".

>>> let x :: Either Void Int; x = Right 5
>>> :{
case x of
    Right r -> r
    Left l  -> absurd l
:}
5

Since: base-4.8.0.0

vacuous :: Functor f => f Void -> f a #

If Void is uninhabited then any Functor that holds only values of type Void is holding no values. It is implemented in terms of fmap absurd.

Since: base-4.8.0.0