anchor.diff:  	)*
   
   	<<   
  +	  //d_printf2("XQParser: constr_val=%s\n", val.c_str());
  +
   	  if ( !(val.empty()) )
   	  {
   	     bool isBoundWhiteSpace = true;
  
positive.code: 	  ASTBase *cnt = NULL;
  	>>
  
  	( ca:CHAR_ATTR <<val +=$ca->getText();>>
  	| APOS << val += "\'"; >>
  	| DOUBLEQUOT <<val += "\"";>>
  	| DOUBLELBRACE <<val += "{";>>
  	| DOUBLERBRACE <<val += "}";>>
  	| per:predefinedEntityRef <<val += #per->getText();>>
  
negative.code: 	( AMPLT <<#0 = #["<", AST_CHAR_SEQ];>>
  	| AMPGT <<#0 = #[">", AST_CHAR_SEQ];>>
  	| AMPAMP <<#0 = #["&", AST_CHAR_SEQ];>>
  	| AMPEQUOT <<#0 = #["\\\"", AST_CHAR_SEQ];>>
  	| AMPEAPOS <<#0 = #["\'", AST_CHAR_SEQ];>>
  	)
  ;	
  