1 /*
2  * Licensed to the Apache Software Foundation (ASF) under one
3  * or more contributor license agreements. See the NOTICE file
4  * distributed with this work for additional information
5  * regarding copyright ownership. The ASF licenses this file
6  * to you under the Apache License, Version 2.0 (the  "License");
7  * you may not use this file except in compliance with the License.
8  * You may obtain a copy of the License at
9  *
10  *     http://www.apache.org/licenses/LICENSE-2.0
11  *
12  * Unless required by applicable law or agreed to in writing, software
13  * distributed under the License is distributed on an "AS IS" BASIS,
14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15  * See the License for the specific language governing permissions and
16  * limitations under the License.
17  */
18 /*
19  * $Id: ExpressionNode.java 468655 2006-10-28 07:12:06Z minchau $
20  */
21 package org.apache.xpath;
22 
23 import javax.xml.transform.SourceLocator;
24 
25 /**
26  * A class that implements this interface can construct expressions,
27  * give information about child and parent expressions,
28  * and give the originating source information.  A class that implements
29  * this interface does not lay any claim to being directly executable.
30  *
31  * <p>Note: This interface should not be considered stable.  Only exprSetParent
32  * and exprGetParent can be counted on to work reliably.  Work in progress.</p>
33  */
34 public interface ExpressionNode extends SourceLocator
35 {
36   /** This pair of methods are used to inform the node of its
37     parent. */
exprSetParent(ExpressionNode n)38   public void exprSetParent(ExpressionNode n);
exprGetParent()39   public ExpressionNode exprGetParent();
40 
41   /** This method tells the node to add its argument to the node's
42     list of children.  */
exprAddChild(ExpressionNode n, int i)43   public void exprAddChild(ExpressionNode n, int i);
44 
45   /** This method returns a child node.  The children are numbered
46      from zero, left to right. */
exprGetChild(int i)47   public ExpressionNode exprGetChild(int i);
48 
49   /** Return the number of children the node has. */
exprGetNumChildren()50   public int exprGetNumChildren();
51 }
52 
53