XPath中如何比较不同类型的对象[5]

    boolean comparebasic(object operand1, object operand2, string operator) throws exception{

        if (operator is "<=" or "<" or ">=" or ">"){

            convert operand1 and operand2 to number

            compare the two numbers with the operator;

        }else if("=".equals(operator)||"!=".equals(operator)){

            if(at least one object is boolean){convert the other object to boolean}

            if(at least one object is number){convert the other object to number}