A simple integer based stack.
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* A simple integer based stack.
*
* moved to org.apache.xerces.util by neilg to support the
* XPathMatcher.
* @author Andy Clark, IBM
*
* @version $Id: IntStack.java 447241 2006-09-18 05:12:57Z mrglavas $
*/
public final class IntStack {
//
// Data
//
/** Stack depth. */
private int fDepth;
/** Stack data. */
private int[] fData;
//
// Public methods
//
/** Returns the size of the stack. */
public int size() {
return fDepth;
}
/** Pushes a value onto the stack. */
public void push(int value) {
ensureCapacity(fDepth + 1);
fData[fDepth++] = value;
}
/** Peeks at the top of the stack. */
public int peek() {
return fData[fDepth - 1];
}
/** Returns the element at the specified depth in the stack. */
public int elementAt(int depth) {
return fData[depth];
}
/** Pops a value off of the stack. */
public int pop() {
return fData[--fDepth];
}
/** Clears the stack. */
public void clear() {
fDepth = 0;
}
// debugging
/** Prints the stack. */
public void print() {
System.out.print('(');
System.out.print(fDepth);
System.out.print(") {");
for (int i = 0; i < fDepth; i++) {
if (i == 3) {
System.out.print(" ...");
break;
}
System.out.print(' ');
System.out.print(fData[i]);
if (i < fDepth - 1) {
System.out.print(',');
}
}
System.out.print(" }");
System.out.println();
}
//
// Private methods
//
/** Ensures capacity. */
private void ensureCapacity(int size) {
if (fData == null) {
fData = new int[32];
}
else if (fData.length <= size) {
int[] newdata = new int[fData.length * 2];
System.arraycopy(fData, 0, newdata, 0, fData.length);
fData = newdata;
}
}
} // class IntStack
Related examples in the same category
