    # File lib/ramaze/helper/formatting.rb, line 127
        def auto_link(text, opts = {})
          html_options = ' ' + opts.map{|k,v| "#{k}='#{v}'"}.join(' ') if opts.any?
          text.gsub(AUTO_LINK_RE) do
            all, a, b, c, d = $&, $1, $2, $3, $4
            if a =~ /<a\s/i # don't replace URL's that are already linked
              all
            else
              text = b + c
              text = yield(text) if block_given?
              %(#{a}<a href="#{b=="www."?"http://www.":b}#{c}"#{html_options}>#{text}</a>#{d})
            end
          end
        end