Extended Interpreter class

package ru.dizpers.core;

import org.apache.commons.jexl2.JexlContext;

import org.apache.commons.jexl2.JexlContext;
import org.apache.commons.jexl2.JexlEngine;
import org.apache.commons.jexl2.JexlException;
import org.apache.commons.jexl2.parser.ASTBitwiseXorNode;

public class Interpreter extends org.apache.commons.jexl2.Interpreter {
    public Interpreter(JexlEngine jexl, JexlContext aContext) {
        super(jexl, aContext);
    }

    @Override
    public Object visit(ASTBitwiseXorNode node, Object data) {
        Object left = node.jjtGetChild(0).jjtAccept(this, data);
        Object right = node.jjtGetChild(1).jjtAccept(this, data);
        int n = 0;
        // coerce these two values longs and 'xor'.
        try {
            long l = arithmetic.toLong(left);
            n = 1;
            long r = arithmetic.toLong(right);
            return Double.valueOf(Math.pow(l, r));
        } catch (RuntimeException xrt) {
            throw new JexlException(node.jjtGetChild(n), "long coercion error", xrt);
        }
    }
}