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  • Glasgow Haskell CompilerGlasgow Haskell Compiler
  • GHCGHC
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  • #2431
Closed
Open
Issue created Jul 10, 2008 by RalfHinze@trac-RalfHinze

Allow empty case analysis

Using -XEmptyDataDecls I can declare an (almost) empty data type.

  data Void

However, I can't use an empty case to discriminate values of the empty type.

This does not work:

  get :: Void -> a

Only the type signature, but no body. [This would be useful also in other circumstances.]

  get :: Void -> a
  get v = case v of { }

An empty case in the body.

Edited Mar 09, 2019 by Simon Peyton Jones
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