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Data.Void

Copyright (C) 2008-2014 Edward Kmett
License BSD-style (see the file libraries/base/LICENSE)
Maintainer Edward Kmett <[email protected]>
Stability provisional
Portability portable
Safe Haskell Safe
Language Haskell2010

Description

A logically uninhabited data type, used to indicate that a given term should not exist.

Since: 4.8.0.0

data Void Source

Uninhabited data type

Since: 4.8.0.0

Instances

Eq Void
Data Void
Ord Void
Read Void

Reading a Void value is always a parse error, considering Void as a data type with no constructors.
Show Void
Ix Void
Generic Void
Exception Void
type Rep Void

absurd :: Void -> a Source

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

Since: 4.8.0.0

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

If Void is uninhabited then any Functor that holds only values of type Void is holding no values.

Since: 4.8.0.0

© The University of Glasgow and others
Licensed under a BSD-style license (see top of the page).
https://downloads.haskell.org/~ghc/7.10.3/docs/html/libraries/base-4.8.2.0/Data-Void.html