KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > apache > commons > jexl > parser > ASTDivNode


1 /*
2  * Copyright 2003-2006 The Apache Software Foundation.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package org.apache.commons.jexl.parser;
17
18 import org.apache.commons.jexl.util.Coercion;
19 import org.apache.commons.jexl.JexlContext;
20
21 /**
22  * a / b, mathematical divide.
23  *
24  * @author <a HREF="mailto:geirm@apache.org">Geir Magnusson Jr.</a>
25  * @version $Id: ASTDivNode.java 398187 2006-04-29 15:58:45Z dion $
26  */
27 public class ASTDivNode extends SimpleNode {
28     /**
29      * Create the node given an id.
30      *
31      * @param id node id.
32      */
33     public ASTDivNode(int id) {
34         super(id);
35     }
36
37     /**
38      * Create a node with the given parser and id.
39      *
40      * @param p a parser.
41      * @param id node id.
42      */
43     public ASTDivNode(Parser p, int id) {
44         super(p, id);
45     }
46
47     /** {@inheritDoc} */
48     public Object JavaDoc jjtAccept(ParserVisitor visitor, Object JavaDoc data) {
49         return visitor.visit(this, data);
50     }
51
52     /** {@inheritDoc} */
53     public Object JavaDoc value(JexlContext jc) throws Exception JavaDoc {
54         Object JavaDoc left = ((SimpleNode) jjtGetChild(0)).value(jc);
55         Object JavaDoc right = ((SimpleNode) jjtGetChild(1)).value(jc);
56
57         /*
58          * the spec says 'and', I think 'or'
59          */
60         if (left == null && right == null) {
61             return new Byte JavaDoc((byte) 0);
62         }
63
64         Double JavaDoc l = Coercion.coerceDouble(left);
65         Double JavaDoc r = Coercion.coerceDouble(right);
66
67         /*
68          * catch div/0
69          */
70         if (r.doubleValue() == 0.0) {
71             return new Double JavaDoc(0.0);
72         }
73
74         return new Double JavaDoc(l.doubleValue() / r.doubleValue());
75
76     }
77 }
78
Popular Tags