anchor.diff:      | HexEscape
       | UtfEscape
       ;
  -    
  +
   fragment
   DecimalEscape
       : '\\' Digit
       | '\\' Digit Digit
       | '\\' [0-2] Digit Digit
       ;
  -    
  +
   fragment
   HexEscape
       : '\\' 'x' HexDigit HexDigit
  
positive.code:     ;
  
  NORMALSTRING
      : '"' ( EscapeSequence | ~('\\'|'"') )* '"' 
      ;
  
  CHARSTRING
  
negative.code:     ;
  
  functioncall
      : prefixexp args | prefixexp ':' NAME args
      ;
  */
  
  