[Haskell-cafe] Instance deriving for Void types.

Lyndon Maydwell maydwell at gmail.com
Tue Oct 29 04:15:47 UTC 2013

Hi Cafe.

I was wondering if it's possible to have automatic deriving for some
classes for the Void type. This would be classes that require a parameter
of the type in its functions. This should obviously be trivial as the
definition can be undefined since there's no way to supply a value of the

I guess the obvious one would be Show.

data Nada deriving Show

instance Show Nada where
  show _ = undefined

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