| /* Copyright 2004 The Apache Software Foundation |
| * |
| * Licensed 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. |
| */ |
| |
| package org.apache.xmlbeans.impl.regex; |
| |
| /** |
| * A simple integer based stack. |
| * |
| * This is copied from https://raw.githubusercontent.com/apache/xerces2-j/trunk/src/org/apache/xerces/util/IntStack.java |
| * and is used by RegularExpression.java |
| */ |
| 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 |