On Tue, Aug 13, 2013 at 10:46 AM, Lukas Lehner <lehner.lukas@gmail.com> wrote:

That means ghc cannot infer the type.

Is there a way how to # print flatten (List []) ?

Or even more general, print [] without enforcing the type?

If you turn on the ExtendedDefaultRules extension ( `{-# LANGUAGE ExtendedDefaultRules #-}` pragma or `-X ExtendedDefaultRules` ghc option), ghc will infer () for the type just as ghci does. Note that this reduces type safety a bit, since ghc will now accept programs that have what otherwise would be type errors.

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brandon s allbery kf8nh                               sine nomine associates

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