anchor.diff:  
   fragment DIGIT: [0-9];
   
  -IntegerLiteral:
  -	DecimalLiteral Integersuffix?
  -	| OctalLiteral Integersuffix?
  -	| HexadecimalLiteral Integersuffix?
  -	| BinaryLiteral Integersuffix?;
  -
   DecimalLiteral: NONZERODIGIT ('\''? DIGIT)*;
   
   OctalLiteral: '0' ('\''? OCTALDIGIT)*;
  
positive.code: 	| '\\f'
  	| '\\n'
  	| '\\r'
  	| '\\t'
  	| '\\v';
  
  
negative.code: 	| Escapesequence
  	| Universalcharactername;
  
  fragment Rawstring: '"' (~[\r\n])*? '(' (~[\r\n])*? ')' (~[\r\n])*? '"';
  
  UserDefinedIntegerLiteral:
  	DecimalLiteral Udsuffix
  