NotOpt.java

package org.nutz.el.opt.logic;

import java.util.Queue;

import org.nutz.el.ElException;
import org.nutz.el.opt.AbstractOpt;

/**
 * Not(!)
 * @author juqkai(juqkai@gmail.com)
 *
 */
public class NotOpt extends AbstractOpt{
    private Object right;
    
    public int fetchPriority() {
        return 7;
    }
    public void wrap(Queue<Object> rpn){
        right = rpn.poll();
    }
    
    public Object calculate() {
        Object rval = calculateItem(this.right);
        if(rval instanceof Boolean){
            return !(Boolean) rval;
        }
        throw new ElException("'!'操作符操作失败!");
    }
    
    public String fetchSelf() {
        return "!";
    }
}