# File lib/facet/lisp-format.rb, line 119
      def <<(str)
        if str.is_a? Fixnum
          @output << str.chr
          # How should tabs be handled here?  They should perhaps be
          # interpreted as eight (8) characters wide?  This of course depends
          # on where @col is already at (8 - @col % 8).
          @col = str == ?\n ? 0 : @col + 1
        else
          @output << str
          @col += str.length - (str.rindex(?\n) or 0)
        end
      end