[Haskell-beginners] How to write the FromJSON instance for CUid

Hello, I try to write the instance for the CUid[1] type But I do not know what to do. instance FromJSON CUid where parseJSON = ... {-# INLINE parseJSON #-} Thansk for your help [1] https://hackage.haskell.org/package/base-4.11.1.0/docs/System-Posix-Types.ht...