# File lib/rufus/treechecker.rb, line 283
      def to_s

        s = "#{self.class} (#{self.object_id})\n"
        s << "  excluded symbols :\n"
        @excluded_symbols.each do |k, v|
          s << "    - #{k.inspect}, #{v}\n"
        end
        s << "  accepted patterns :\n"
        @accepted_patterns.each do |k, v|
          v.each do |p|
            s << "    - #{k.inspect}, #{p.inspect}\n"
          end
        end
        s << "  excluded patterns :\n"
        @excluded_patterns.each do |k, v|
          v.each do |p|
            s << "    - #{k.inspect}, #{p.inspect}\n"
          end
        end
        s
      end