parseOne
  :: Monad m
  => Parser b
  -> PP.Parser ByteString m (Either PA.ParsingError b)
parseOne p = do
  mex <- PA.parse p
  return $ fromMaybe (Left $ PA.ParsingError [] "no input!") mex
parseOne
  :: Monad m
  => Parser b
  -> PP.Parser ByteString m (Either PA.ParsingError b)
parseOne p = do
  mex <- PA.parse p
  return $ fromMaybe (Left $ PA.ParsingError [] "no input!") mex
parseOne p = do
  mex <- PA.parse p
  return $ fromMaybe (Left $ PA.ParsingError [] "no input!") mex