| /******************************************************************************* |
| * Copyright (c) 2008 xored software, Inc. |
| * |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Public License v. 2.0 which is available at |
| * http://www.eclipse.org/legal/epl-2.0. |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * Contributors: |
| * xored software, Inc. - initial API and Implementation (Alex Panchenko) |
| *******************************************************************************/ |
| package org.eclipse.dltk.utils; |
| |
| import java.util.EmptyStackException; |
| |
| public class CharacterStack { |
| |
| private char[] buffer; |
| private int size; |
| |
| public CharacterStack() { |
| this(16); |
| } |
| |
| /** |
| * @param capacity |
| */ |
| public CharacterStack(int capacity) { |
| buffer = new char[capacity]; |
| size = 0; |
| } |
| |
| /** |
| * @return |
| */ |
| public int size() { |
| return size; |
| } |
| |
| /** |
| * @return |
| */ |
| public boolean isEmpty() { |
| return size == 0; |
| } |
| |
| /** |
| * @return |
| */ |
| public char peek() { |
| final int len = size; |
| if (size == 0) { |
| throw new EmptyStackException(); |
| } |
| return buffer[len - 1]; |
| } |
| |
| /** |
| * @return |
| */ |
| public char pop() { |
| int len = size; |
| if (len == 0) { |
| throw new EmptyStackException(); |
| } |
| --len; |
| final char result = buffer[len]; |
| size = len; |
| return result; |
| } |
| |
| /** |
| * @param c |
| */ |
| public void push(char c) { |
| if (size == buffer.length) { |
| char[] newBuffer = new char[buffer.length * 2 + 1]; |
| System.arraycopy(buffer, 0, newBuffer, 0, buffer.length); |
| buffer = newBuffer; |
| } |
| buffer[size++] = c; |
| } |
| |
| } |