[Haskell] "Never" GADT Function?

Ashley Yakeley ashley at semantic.org
Sat Jan 8 00:48:21 EST 2005

OK, so I've been playing around with GADTs in the CVS GHC. Consider this:

  data T a where
    BoolT :: T Bool
    IntT :: T Int

  neverT :: T Char -> x

Is it possible to write neverT without using undefined? Such functions 
are occasionally useful, especially when GADTs are being used as type 

Then again, I suppose it's the same situation for types with no 

Ashley Yakeley, Seattle WA

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