Haskell: Quick JSON Parse using Aeson

JSON_Parse.hs

import Data.ByteString.Lazy.Internal
import Data.Aeson
import Control.Applicative

data Person = Person String Int deriving (Show) 

instance FromJSON Person where
  parseJSON (Object p) =
    Person <$> 
      (p .: "name") <*> 
      (p .: "age")

decode (packChars "{\"name\": \"Chris\", \"age\": 30}") :: Maybe Person
--> Just (Person "Chris" 30)

instance ToJSON Person where
  toJSON (Person name age) =
    object [ "name" .= name
           , "age"  .= age
           ]
 
encode $ Just (Person "Chris" 30)
--> "{\"age\":30,\"name\":\"Chris\"}"

-- Let's decode an encoded Person to make sure we get back the same thing
decode $ encode $ Just $ Person "Chris" 30 :: Maybe Person
--> Just (Person "Chris" 30)   -- yep!