anchor.diff:        colon:COLON                           {pattern = pattern + colon.getText();}
         sortStr=sort                          {pattern = pattern + sortStr;}
       ;
  +*/
   
   private basicPattern returns[String pattern]
   {
  
positive.code: private expression returns[String expr]
  {
      expr = "";
      String item = null;
  }
      : (    item=qualifiableRef    {expr = expr + item + " ";}
           | item=literal           {expr = expr + item + " ";}
           | item=specialSymbol     {expr = expr + item + " ";}
           | item=expressionKeyword {expr = expr + item + " ";}
        )+
      ;
  
  //---------------------------------------------------------------------------
  private specialSymbol returns[String text]
  {
      text = null;
  }
  
negative.code: }
      : text=qualifier             {sortName = text;}
        dot:DOT                    {sortName = sortName + ".";}
        text=nonKeywordName        {sortName = sortName + text;}
      ;
  */
  private idName returns[String name]
  {
      name = null;
  