Sample code for JSON parsing using Aeson in Haskell! From the blog post -> http://blog.raynes.me/blog/2012/11/27/easy-json-parsing-in-haskell-with-aeson/

ParseJson.hs

{-# LANGUAGE OverloadedStrings #-}
module PraseJsonSample where

import Data.Aeson             ((.:), (.:?), decode, FromJSON(..), Value(..))
import Control.Applicative    ((<$>), (<*>))
import Data.Time.Format       (parseTime)
import Data.Time.Clock        (UTCTime)
import System.Locale          (defaultTimeLocale)
import Control.Monad          (liftM)
import qualified Data.HashMap.Strict as HM
import qualified Data.ByteString.Lazy.Char8 as BS

parseRHTime :: String -> Maybe UTCTime
parseRHTime = parseTime defaultTimeLocale "%FT%X%QZ"

data Paste = Paste { getLines    :: Integer
                   , getDate     :: Maybe UTCTime
                   , getID       :: String
                   , getLanguage :: String
                   , getPrivate  :: Bool
                   , getURL      :: String
                   , getUser     :: Maybe String
                   , getBody     :: String
                   } deriving (Show)

instance FromJSON Paste where
  parseJSON (Object v) =
    Paste <$>
    (v .: "lines")                  <*>
    liftM parseRHTime (v .: "date") <*>
    (v .: "paste-id")               <*>
    (v .: "language")               <*>
    (v .: "private")                <*>
    (v .: "url")                    <*>
    (v .:? "user")                  <*>
    (v .: "contents")

sampleJson :: String
sampleJson = "{\"lines\":1,\"date\":\"2012-01-04T01:44:22.964Z\",\"paste-id\":\"1\",\"fork\":null,\"random-id\":\"f1fc1181fb294950ca4df7008\",\"language\":\"Clojure\",\"private\":false,\"url\":\"https://www.refheap.com/paste/1\",\"user\":\"raynes\",\"contents\":\"(begin)\"}"

main :: IO ()
main = do
  let (Just paste) = decode $ BS.pack sampleJson
  putStrLn $ show $ getDate paste
  putStrLn $ show $ getLines paste