def parse_num
      s0 = @current_pos
      s1 = match_regexp(/^[１２３４５６７８９]/)
      if s1 != :failed
        @reported_pos = s0
        s1 = zen2n(s1)
      end
      s1
    end
def parse_num
      s0 = @current_pos
      s1 = match_regexp(/^[１２３４５６７８９]/)
      if s1 != :failed
        @reported_pos = s0
        s1 = zen2n(s1)
      end
      s1
    end
num : [１２３４５６７８９]