users/grfn/xanthous/src/Xanthous/Util/JSON.hs


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module Xanthous.Util.JSON
  ( ReadShowJSON(..)
  ) where
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import Xanthous.Prelude
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import Data.Aeson
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newtype ReadShowJSON a = ReadShowJSON a
  deriving newtype (Read, Show)

instance Show a => ToJSON (ReadShowJSON a) where
  toJSON = toJSON . show

instance Read a => FromJSON (ReadShowJSON a) where
  parseJSON = withText "readable"
    $ maybe (fail "Could not read") pure . readMay