anchor.diff:    ;
   
   quiet_element_separator_comma :
  -     t_COMMA {System.err.println("deleting comma " + retval.start);}-> template() "" //delete comma
  +     dt_COMMA {System.err.println("deleting comma " + retval.start);}-> template() "" //delete comma
     ;
   
   input_params :
  
positive.code: t_FILLER : FILLER { offsetTracker.advanceByTextSize($text); };
  
  t_LINE_TERMINATOR : LINE_TERMINATOR { offsetTracker.advanceToNewLine(1, 1); };
  
  //// LEXER /////////////////////////////////////////////////////////////////////
  
  
negative.code: //non-empty
  element_separator_list :
       t_FILLER? t_COMMA t_FILLER? //just echo
    |  {isElementSeparator()}? { offsetTracker.recordOffsetChange(0, -1); } t_FILLER {System.err.println("inserting comma before " + input.LT(1));}-> template(filler={$text}) ",<filler>" //insert comma
    ;
  
  //non-empty
  