tsurushuu

fromResult :: Result a -> Maybe a
fromResult (Ok k) = Just k
fromResult (Error e) = Nothing

maybeFromObj :: JSON a => String -> JSObject JSValue -> Maybe a
maybeFromObj k o = maybe (Nothing) (fromResult . readJSON) (lookup k (fromJSObject o))

tsurushuu

import System.IO (hPutStrLn, stderr)
import Control.Exception (catch, IOException, SomeException)
import Prelude hiding (catch)

readFileWithDefault :: FilePath -> String -> IO String
readFileWithDefault filepath defaultString =
    catch
    (readFile filepath)
    (\e -> do
       return (e::SomeException)