parseURI' x = case parseURI x of
    Nothing -> fail ("URI " ++ x ++ " is unparseable")
    Just x -> return x
parseURI' x = case parseURI x of
    Nothing -> fail ("URI " ++ x ++ " is unparseable")
    Just x -> return x
parseURI' x = case parseURI x of
    Nothing -> fail ("URI " ++ x ++ " is unparseable")
    Just x -> return x