Natools

                     end loop;
                  else
                     Append
                       (Event_List (Previous.Update.Data.all),
                        Callback);
                  end if;
               elsif Callback.Query.Data.all in Event_List then
                  Prepend (Event_List (Callback.Update.Data.all), Previous);
                  Map.Replace_Element (Position, Callback);
               else
                  Map.Replace_Element
                    (Position,
                     Create_Event_List (Previous, Callback));
               end if;
            end if;

   procedure Append
     (Self : in out Event_List;
      Ref : in Callback_Refs.Reference) is
   begin
      Self.List.Append (Ref);
   end Append;


   procedure Prepend
     (Self : in out Event_List;
      Ref : in Callback_Refs.Reference) is
   begin
      Self.List.Prepend (Ref);
   end Prepend;


   procedure Remove
     (Self : in out Event_List;
      Ref : in Callback_Refs.Reference;
      Removed : out Boolean)
   is
      use type Callback_Refs.Reference;