| /* |
| [The "BSD licence"] |
| Copyright (c) 2005-2008 Terence Parr |
| All rights reserved. |
| |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions |
| are met: |
| 1. Redistributions of source code must retain the above copyright |
| notice, this list of conditions and the following disclaimer. |
| 2. Redistributions in binary form must reproduce the above copyright |
| notice, this list of conditions and the following disclaimer in the |
| documentation and/or other materials provided with the distribution. |
| 3. The name of the author may not be used to endorse or promote products |
| derived from this software without specific prior written permission. |
| |
| THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| package org.antlr.runtime.misc; |
| |
| /** A dynamic array that uses int not Integer objects. In principle this |
| * is more efficient in time, but certainly in space. |
| * |
| * This is simple enough that you can access the data array directly, |
| * but make sure that you append elements only with add() so that you |
| * get dynamic sizing. Make sure to call ensureCapacity() when you are |
| * manually adding new elements. |
| * |
| * Doesn't impl List because it doesn't return objects and I mean this |
| * really as just an array not a List per se. Manipulate the elements |
| * at will. This has stack methods too. |
| * |
| * When runtime can be 1.5, I'll make this generic. |
| */ |
| public class IntArray { |
| public static final int INITIAL_SIZE = 10; |
| public int[] data; |
| protected int p = -1; |
| |
| public void add(int v) { |
| ensureCapacity(p+1); |
| data[++p] = v; |
| } |
| |
| public void push(int v) { |
| add(v); |
| } |
| |
| public int pop() { |
| int v = data[p]; |
| p--; |
| return v; |
| } |
| |
| /** This only tracks elements added via push/add. */ |
| public int size() { |
| return p; |
| } |
| |
| public void clear() { |
| p = -1; |
| } |
| |
| public void ensureCapacity(int index) { |
| if ( data==null ) { |
| data = new int[INITIAL_SIZE]; |
| } |
| else if ( (index+1)>=data.length ) { |
| int newSize = data.length*2; |
| if ( index>newSize ) { |
| newSize = index+1; |
| } |
| int[] newData = new int[newSize]; |
| System.arraycopy(data, 0, newData, 0, data.length); |
| data = newData; |
| } |
| } |
| } |