techbook_directive_columns (PDF::TechBook)

         # File lib/pdf/techbook.rb, line 719
    719:   def techbook_directive_columns(args)
    720:     av = /^(\d+|off)(?: (\d+))?(?: .*)?$/o.match(args)
    721:     unless av
    722:       $stderr.puts PDF::Writer::Lang[:techbook_bad_columns_directive] % args
    723:       raise ArgumentError
    724:     end
    725:     cols = av.captures[0]
    726:
    727:       # Flush the paragraph cache.
    728:     __render_paragraph
    729:
    730:     if cols == "off" or cols.to_i < 2
    731:       stop_columns
    732:     else
    733:       if av.captures[1]
    734:         start_columns(cols.to_i, av.captures[1].to_i)
    735:       else
    736:         start_columns(cols.to_i)
    737:       end
    738:     end
    739:   end