def next_callback(self, line, idx):
        marks = self.__marks
        if marks:
            buf = []
            prev = 0
            for start, end in self.__marks:
                buf.append(line[prev:start])
                buf.append(TURN_ON)
                buf.append(line[start:end])
                buf.append(TURN_OFF)
                prev = end
            buf.append(line[prev:])
            printout((self.__name, idx + 1, ''.join(buf)) % '%s:%d:%s')
            self.__marks[:] = ()
dataset/ETHPy150Open edgewall/trac/contrib/checkwiki.py/DefaultWikiChecker.next_callback/swapped operands of `%`