rosa/Json.hs
2014-11-20 21:39:25 +01:00

35 lines
963 B
Haskell

module Json where
import Data.Aeson
import Data.Aeson.Types (parse)
import Data.Text (Text, unpack)
import Data.List (intercalate)
import qualified Data.Vector as V
import qualified Data.HashMap.Strict as H
-- Get the JSON value of a key
(|.) :: Object -> Text -> Value
obj |. key = case parse (.: key) obj of
Success val -> val
Error err -> toJSON err
-- Get the String value of a key
(|:) :: Object -> Text -> String
obj |: key = repr (obj |. key) 0
-- Create a String representation of a JSON Value
repr :: Value -> Int -> String
repr val lev =
case val of
Array x -> intercalate ", " $ mapl (\i -> repr i lev) x
Object x -> concat $ map (dump x) $ H.keys x
String x -> unpack x
Number x -> show x
Bool x -> show x
Null -> "null"
where
indent = '\n' : (concat . replicate lev) " "
dump o k = concat [indent, unpack k, ": ", repr (o |. k) (lev+1)]
mapl f v = V.toList $ V.map f v