anchor.diff:  
   constant
   	:	NUM_INT
  +	|	CHAR_LITERAL
   	|	STRING_LITERAL
   	|	NUM_FLOAT
   	|	NUM_LONG
  
positive.code: 	;
  
  
  // string literals
  STRING_LITERAL
  	:	'"' (ESC|~('"'|'\\'|'\n'|'\r'))* '"'
  	// no CHAR_LITERALs in groovy...
  	|	'\'' ( ESC | ~('\''|'\n'|'\r'|'\\') ) '\''
  	;
  
  
  // escape sequence -- note that this is protected; it can only be called
  
negative.code: 			//   a) [ expr ] and [ ] are not mixed
  			//   b) [ expr ] and an init are not used together
  
  		|	newArrayDeclarator (arrayInitializer)?
  		)
  	;
  
  