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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.
/** 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. /** 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;
		}
	}
}