def build_class_list(level, from, section, infile=nil)
      res = ""
      prefix = "&nbsp;&nbsp;::" * level;

      from.modules.sort.each do |mod|
        next unless mod.section == section
        next if infile && !mod.defined_in?(infile)
        if mod.document_self
          res << 
            prefix <<
            "Module " <<
            href(url(mod.viewer.path), "link", mod.full_name) <<
            "<br />\n" <<
            build_class_list(level + 1, mod, section, infile)
        end
      end

      from.classes.sort.each do |cls|
        next unless cls.section == section
        next if infile && !cls.defined_in?(infile)
        if cls.document_self
          res      <<
            prefix << 
            "Class " <<
            href(url(cls.viewer.path), "link", cls.full_name) <<
            "<br />\n" <<
            build_class_list(level + 1, cls, section, infile)
        end
      end

      res
    end
def build_class_list(level, from, section, infile=nil)
      res = ""
      prefix = "&nbsp;&nbsp;::" * level;

      from.modules.sort.each do |mod|
        next unless mod.section == section
        next if infile && !mod.defined_in?(infile)
        if mod.document_self
          res << 
            prefix <<
            "Module " <<
            href(url(mod.viewer.path), "link", mod.full_name) <<
            "<br />\n" <<
            build_class_list(level + 1, mod, section, infile)
        end
      end

      from.classes.sort.each do |cls|
        next unless cls.section == section
        next if infile && !cls.defined_in?(infile)
        if cls.document_self
          res      <<
            prefix << 
            "Class " <<
            href(url(cls.viewer.path), "link", cls.full_name) <<
            "<br />\n" <<
            build_class_list(level + 1, cls, section, infile)
        end
      end

      res
    end
Build the structured list of classes and modules contained
 in this context.