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GHC 9.10.3 · lts/ghc-9.10.x · 248f8f0 · 2026-10-05

Modulererebase-1.21.2Haskell2010

Data.Void

  • 1 type
  • 2 values
datadata Void
#

Uninhabited data type

Instances33Eq, Data, Ord, Read, Show, Ix, …
valueabsurd :: Void -> a
#

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

Example2 expressions
let x :: Either Void Int; x = Right 5:{case x of    Right r -> r    Left l  -> absurd l:}5
valuevacuous :: 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.