void

A Haskell 98 logically uninhabited data type

http://github.com/ekmett/void

Version on this page:0.7.2
LTS Haskell 24.28:0.7.4
Stackage Nightly 2026-01-19:0.7.4
Latest on Hackage:0.7.4

See all snapshots void appears in

BSD-3-Clause licensed by Edward A. Kmett
Maintained by Edward A. Kmett
This version can be pinned in stack with:void-0.7.2@sha256:e07cd23407914833bc8bf726ad27fe4696c2e38685bc00031a2ca632230124ca,1527

Module documentation for 0.7.2

Depends on 1 package(full list with versions):
base
Used by 3 packages in nightly-2018-03-13(full list with versions):
graphs, optparse-generic, pipes

void

Hackage Build Status

This package provides a canonical ‘uninhabited’ data type for Haskell. This arises in a surprisingly wide array of situations in practice.

Contact Information

Contributions and bug reports are welcome!

Please feel free to contact me through github or on the #haskell IRC channel on irc.freenode.net.

-Edward Kmett

Changes

0.7.2

  • Only depend on deepseq, hashable, and semigroups if using GHC 7.8 or earlier.
  • Cleaned up spurious “redundant constraint” warnings on GHC 8+

0.7.1

  • Support semigroups 0.17 on older GHCs
  • Backported NFData’s semigroup instance to older GHCs.

0.7

  • adapt to Data.Void being moved into base-4.8
  • vacuousM removed

0.6

  • instance Exception Void
  • instance Generic Void
  • instance Hashable Void

0.5.12

  • Fixed compatibility with GHC 7.2 (#6)
  • Added CHANGELOG.markdown and README.markdown