重叠的aeson实例

{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE OverloadedStrings #-}

import Data.Aeson (ToJSON, FromJSON, encode, decode)
import GHC.Generics (Generic)

data Person = Person
  { name :: String
  , age :: Int
  } deriving (Generic)

data Employee = Employee
  { name :: String
  , age :: Int
  , position :: String
  } deriving (Generic)

newtype NewPerson = NewPerson Person
newtype NewEmployee = NewEmployee Employee

instance ToJSON NewPerson where
  toJSON (NewPerson person) = toJSON person

instance FromJSON NewPerson where
  parseJSON json = NewPerson <$> parseJSON json

instance ToJSON NewEmployee where
  toJSON (NewEmployee employee) = toJSON employee

instance FromJSON NewEmployee where
  parseJSON json = NewEmployee <$> parseJSON json

main :: IO ()
main = do
  let person = Person "John Doe" 30
      employee = Employee "Jane Smith" 25 "Manager"
  
  putStrLn $ "Person JSON: " ++ show (encode (NewPerson person))
  putStrLn $ "Employee JSON: " ++ show (encode (NewEmployee employee))