-- | Runs an IO action while transforming any error into 'Bad'
-- values. It also accepts an optional value to use in case the error
-- is just does not exist.
catchIOErrors :: Maybe a         -- ^ Optional default
              -> IO a            -- ^ Action to run
              -> IO (Result a)
catchIOErrors def action =
  Control.Exception.catch
        (do
          result <- action
          return (Ok result)
        ) (\err -> let bad_result = Bad (show err)
                   in return $ if isDoesNotExistError err
                                 then maybe bad_result Ok def
                                 else bad_result)
catchIOErrors :: Maybe a         -- ^ Optional default
              -> IO a            -- ^ Action to run
              -> IO (Result a)
catchIOErrors def action =
  Control.Exception.catch
        (do
          result <- action
          return (Ok result)
        ) (\err -> let bad_result = Bad (show err)
                   in return $ if isDoesNotExistError err
                                 then maybe bad_result Ok def
                                 else bad_result)
catchIOErrors def action =
  Control.Exception.catch
        (do
          result <- action
          return (Ok result)
        ) (\err -> let bad_result = Bad (show err)
                   in return $ if isDoesNotExistError err
                                 then maybe bad_result Ok def
                                 else bad_result)