Dear list members, I started looking into monadic programming in Haskell and I have some difficulties to come up with code that is concise, easy to read and easy on the eyes. In particular I would like to have a function "add" with following type signature: JSON a => MyData -> String -> a -> MyData. MyData holds a JSValue and add should add a key and a value to this JSON object. here is what I came up with and I am far from satisfied. Maybe someone can help me to simplify this... module Test where import Text.JSON import Data.Maybe (isJust, fromJust) import Control.Monad data MyData = MyData { json :: JSValue } deriving (Read, Show) jsObj :: JSValue -> Maybe (JSObject JSValue) jsObj (JSObject o) = Just o jsObj _ = Nothing add :: JSON a => MyData -> String -> a -> MyData add m k v = fromJust $ (return $ json m) >>= jsObj >>= (return . fromJSObject) >>= (return . ((k, showJSON v):)) >>= (return . toJSObject) >>= (return . showJSON) >>= \js -> (return $ m { json = js }) add2 :: JSON a => MyData -> String -> a -> MyData add2 m k v = fromJust $ (\js -> m { json = js }) `liftM` (showJSON `liftM` (toJSObject `liftM` (((k, showJSON v):) `liftM` (fromJSObject `liftM` (jsObj $ json m))))) add3 :: JSON a => MyData -> String -> a -> MyData add3 = undefined -- How to simplify add? What the code essentially does is that using functions from Text.JSON, it gets the list of key-value pairs and conses another pair to it before wrapping it again in the JSValue-Type. Many thanks, Levi