ExpressionNode.java revision 9f8118474e9513f7a5b7d2a05e4a0fb15d1a6569 
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 */
21package org.apache.xpath;
22
23import 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 */
34public interface ExpressionNode extends SourceLocator
35{
36  /** This pair of methods are used to inform the node of its
37    parent. */
38  public void exprSetParent(ExpressionNode n);
39  public ExpressionNode exprGetParent();
40
41  /** This method tells the node to add its argument to the node's
42    list of children.  */
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. */
47  public ExpressionNode exprGetChild(int i);
48
49  /** Return the number of children the node has. */
50  public int exprGetNumChildren();
51}
52
53