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1 /*
2  * The Apache Software License, Version 1.1
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4  *
5  * Copyright (c) 2000-2002 The Apache Software Foundation.
6  * All rights reserved.
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8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
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13  * notice, this list of conditions and the following disclaimer.
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16  * notice, this list of conditions and the following disclaimer in
17  * the documentation and/or other materials provided with the
18  * distribution.
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20  * 3. The end-user documentation included with the redistribution,
21  * if any, must include the following acknowledgment:
22  * "This product includes software developed by the
23  * Apache Software Foundation (http://www.apache.org/)."
24  * Alternately, this acknowledgment may appear in the software itself,
25  * if and wherever such third-party acknowledgments normally appear.
26  *
27  * 4. The names "Xerces" and "Apache Software Foundation" must
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29  * software without prior written permission. For written
30  * permission, please contact apache@apache.org.
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47  * SUCH DAMAGE.
48  * ====================================================================
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50  * This software consists of voluntary contributions made by many
51  * individuals on behalf of the Apache Software Foundation and was
52  * originally based on software copyright (c) 1999, International
53  * Business Machines, Inc., http://www.apache.org. For more
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55  * <http://www.apache.org/>.
56  */
57
58 package com.sun.org.apache.xerces.internal.util;
59
60 /**
61  * A simple integer based stack.
62  *
63  * moved to com.sun.org.apache.xerces.internal.util by neilg to support the
64  * XPathMatcher.
65  * @author Andy Clark, IBM
66  *
67  * @version $Id: IntStack.java,v 1.4 2003/10/17 18:14:30 mrglavas Exp $
68  */
69 public final class IntStack {
70
71     //
72 // Data
73 //
74
75     /** Stack depth. */
76     private int fDepth;
77
78     /** Stack data. */
79     private int[] fData;
80
81     //
82 // Public methods
83 //
84
85     /** Returns the size of the stack. */
86     public int size() {
87         return fDepth;
88     }
89
90     /** Pushes a value onto the stack. */
91     public void push(int value) {
92         ensureCapacity(fDepth + 1);
93         fData[fDepth++] = value;
94     }
95
96     /** Peeks at the top of the stack. */
97     public int peek() {
98         return fData[fDepth - 1];
99     }
100
101     /** Returns the element at the specified depth in the stack. */
102     public int elementAt(int depth) {
103         return fData[depth];
104     }
105
106     /** Pops a value off of the stack. */
107     public int pop() {
108         return fData[--fDepth];
109     }
110
111     /** Clears the stack. */
112     public void clear() {
113         fDepth = 0;
114     }
115
116     // debugging
117
118     /** Prints the stack. */
119     public void print() {
120         System.out.print('(');
121         System.out.print(fDepth);
122         System.out.print(") {");
123         for (int i = 0; i < fDepth; i++) {
124             if (i == 3) {
125                 System.out.print(" ...");
126                 break;
127             }
128             System.out.print(' ');
129             System.out.print(fData[i]);
130             if (i < fDepth - 1) {
131                 System.out.print(',');
132             }
133         }
134         System.out.print(" }");
135         System.out.println();
136     }
137
138     //
139 // Private methods
140 //
141
142     /** Ensures capacity. */
143     private void ensureCapacity(int size) {
144         if (fData == null) {
145             fData = new int[32];
146         }
147         else if (fData.length <= size) {
148             int[] newdata = new int[fData.length * 2];
149             System.arraycopy(fData, 0, newdata, 0, fData.length);
150             fData = newdata;
151         }
152     }
153
154 } // class IntStack
155
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