[Haskell-cafe] aeson- deriveJSON error

Bas van Dijk v.dijk.bas at gmail.com
Sat Jan 26 15:20:16 CET 2013

On 26 January 2013 14:47,  <jims at stuttard.org> wrote:
> ghc doesn't seem to be unifying deriveJSON (String->String)
> parameter with id :: a -> a.

It seems you're using aeson HEAD. Note that the deriveJSON from the
released aeson- as the type:

  deriveJSON :: (String -> String) -> Name -> Q [Dec]

But in aeson-HEAD it has the following type:

  deriveJSON :: Options -> Name -> Q [Dec]



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