More fun with Aeson

JSON.hs

{-# LANGUAGE OverloadedStrings #-}

-- See 
-- http://stackoverflow.com/questions/7800272/trying-to-parse-recursive-json-am-i-on-the-right-track/7800464

import Control.Applicative
import Control.Monad
import Data.Aeson
import Data.Attoparsec
import qualified Data.ByteString as B
import Data.Map as M
import Data.Text
import qualified Data.Vector as V

data Outer = Outer {
  oName :: Text,
  oProducts :: M.Map Text Inner
} deriving Show

data Inner = Inner {
  iQA :: Text,
  iVM :: Text,
  iAvailable :: V.Vector Text
} deriving Show

instance FromJSON Outer where
    parseJSON (Object o) = Outer <$> o .: "name" <*> o .: "products"
    parseJSON _          = mzero

instance FromJSON Inner where
  parseJSON (Object o) = Inner <$> o .: "qa" <*> o .: "vm" <*> o .: "available"
  parseJSON _ = mzero

parseAll :: B.ByteString -> Outer
parseAll s = case (parse (fromJSON <$> json) s) of
  Done _ (Success e) -> e
  _                  -> error "Should not happen!"

main :: IO ()
main = do p <- parseAll <$> B.readFile "json.txt"
          print p

TestData.json

{
        "name": "versions",
        "products":
        {
                "IM":
                {
                        "qa":"5.0.01.004",
                        "vm":"5.0.01.003",
                        "available":
                        [
                                "3.1.02.003",
                                "3.9.0",
                                "3.9.1",
                                "3.9.2",
                                "4.0.01.004",
                                "4.0.01.005",
                                "4.1.00.001",
                                "4.1.00.002",
                                "4.1.01.001",
                                "4.1.01.002",
                                "4.1.01.003",
                                "4.2.00.001",
                                "4.2.00.002",
                                "4.2.01.001",
                                "4.2.01.002",
                                "4.2.01.003",
                                "4.2.01.004",
                                "4.3.00.001",
                                "4.3.00.002",
                                "4.3.00.003",
                                "4.3.00.004",
                                "4.3.00.005",
                                "4.3.01.001",
                                "5.0.00.001",
                                "5.0.00.002",
                                "5.0.00.003",
                                "5.0.00.004",
                                "5.0.00.005",
                                "5.0.00.006",
                                "5.0.01.001",
                                "5.0.01.002",
                                "5.0.01.003",
                                "5.0.01.004"
                        ]
                },
                "IB":
                {
                        "qa":"5.0.01.004",
                        "vm":"5.0.01.003",
                        "available":
                        [
                                "3.1.02.003",
                                "3.9.0",
                                "3.9.1",
                                "3.9.2",
                                "4.0.01.004",
                                "4.0.01.005",
                                "4.1.00.001",
                                "4.1.00.002",
                                "4.1.01.001",
                                "4.1.01.002",
                                "4.1.01.003",
                                "4.2.00.001",
                                "4.2.00.002",
                                "4.2.01.001",
                                "4.2.01.002",
                                "4.2.01.003",
                                "4.2.01.004",
                                "4.3.00.001",
                                "4.3.00.002",
                                "4.3.00.003",
                                "4.3.00.004",
                                "4.3.00.005",
                                "4.3.01.001",
                                "5.0.00.001",
                                "5.0.00.002",
                                "5.0.00.003",
                                "5.0.00.004",
                                "5.0.00.005",
                                "5.0.00.006",
                                "5.0.01.001",
                                "5.0.01.002",
                                "5.0.01.003",
                                "5.0.01.004"
                        ]
                }

                }
}

TestOutput.txt

$ ./Main json.txt   
Outer {oName = "versions", oProducts = fromList [("IB",Inner {iQA = "5.0.01.004", iVM = "5.0.01.003", iAvailable = fromList ["3.1.02.003","3.9.0","3.9.1","3.9.2","4.0.01.004","4.0.01.005","4.1.00.001","4.1.00.002","4.1.01.001","4.1.01.002","4.1.01.003","4.2.00.001","4.2.00.002","4.2.01.001","4.2.01.002","4.2.01.003","4.2.01.004","4.3.00.001","4.3.00.002","4.3.00.003","4.3.00.004","4.3.00.005","4.3.01.001","5.0.00.001","5.0.00.002","5.0.00.003","5.0.00.004","5.0.00.005","5.0.00.006","5.0.01.001","5.0.01.002","5.0.01.003","5.0.01.004"] :: Data.Vector.Vector}),("IM",Inner {iQA = "5.0.01.004", iVM = "5.0.01.003", iAvailable = fromList ["3.1.02.003","3.9.0","3.9.1","3.9.2","4.0.01.004","4.0.01.005","4.1.00.001","4.1.00.002","4.1.01.001","4.1.01.002","4.1.01.003","4.2.00.001","4.2.00.002","4.2.01.001","4.2.01.002","4.2.01.003","4.2.01.004","4.3.00.001","4.3.00.002","4.3.00.003","4.3.00.004","4.3.00.005","4.3.01.001","5.0.00.001","5.0.00.002","5.0.00.003","5.0.00.004","5.0.00.005","5.0.00.006","5.0.01.001","5.0.01.002","5.0.01.003","5.0.01.004"] :: Data.Vector.Vector})]}