[Haskell-cafe] Reverse Show instance
andrewcoppin at btinternet.com
Thu May 19 23:08:27 CEST 2011
Cannot deduce (Show x) from context (Show (x, y)).
Cannot deduce (Show y) from context (Show (x, y)).
From Prelude, we have
Show x, Show y => Show (x, y)
So clearly it works in the forward direction. But apparently not in the
Is this a bug or a feature? (I.e., is there some obscure possibility I
haven't thought of which means that doing the reverse inference would be
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