def expand_to_neighboring_punct(i, is_puncts):
    """
    >>> expand_to_neighboring_punct(0, [False, True, True])
    (0, 3)
    >>> expand_to_neighboring_punct(2, [True, True, False])
    (0, 3)
    >>> expand_to_neighboring_punct(1, [False, False, False])
    (1, 2)
    """
    start = i
    end = i + 1
    while start > 0 and is_puncts[start - 1]:
        start -= 1
    while end < len(is_puncts) and is_puncts[end]:
        end += 1
    return start, end
