Re: [Haskell-cafe] Why does this work: 'instance Num (Show a) where'

Is there a corresponding Show datatype? At least with 7.8.3, having just that line gives the following error: The first argument of ‘Num’ should have kind ‘*’, but ‘Show a’ has kind ‘Constraint’ In the instance declaration for ‘Num (Show a)’ On 4 November 2014 19:30, Tom Ellis wrote:

This is accepted by GHC 7.6.3. Is this a bug? What does it mean?

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