tool/src/main/java/org/antlr/misc/IntArrayList.java

/*
 * [The "BSD license"]
 *  Copyright (c) 2010 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.misc;

import java.util.AbstractList;

/** An ArrayList based upon int members.  Not quite a real implementation of a
 *  modifiable list as I don't do, for example, add(index,element).
 *  TODO: unused?
 */
public class IntArrayList extends AbstractList<Integer> implements Cloneable {
	private static final int DEFAULT_CAPACITY = 10;
	protected int n = 0;
	protected int[] elements = null;

	public IntArrayList() {
		this(DEFAULT_CAPACITY);
	}

	public IntArrayList(int initialCapacity) {
		elements = new int[initialCapacity];
	}

	/** Set the ith element.  Like ArrayList, this does NOT affect size. */
	public int set(int i, int newValue) {
		if ( i>=n ) {
			setSize(i); // unlike definition of set in ArrayList, set size
		}
		int v = elements[i];
		elements[i] = newValue;
		return v;
	}

	public boolean add(int o) {
		if ( n>=elements.length ) {
			grow();
		}
		elements[n] = o;
		n++;
		return true;
	}

	public void setSize(int newSize) {
		if ( newSize>=elements.length ) {
            ensureCapacity(newSize);
		}
		n = newSize;
	}

	protected void grow() {
		ensureCapacity((elements.length * 3)/2 + 1);
	}

	public boolean contains(int v) {
		for (int i = 0; i < n; i++) {
			int element = elements[i];
			if ( element == v ) {
				return true;
			}
		}
		return false;
	}

	public void ensureCapacity(int newCapacity) {
		int oldCapacity = elements.length;
		if (n>=oldCapacity) {
			int oldData[] = elements;
			elements = new int[newCapacity];
			System.arraycopy(oldData, 0, elements, 0, n);
		}
	}

	@Override
	public Integer get(int i) {
		return Utils.integer(element(i));
	}

	public int element(int i) {
		return elements[i];
	}

	public int[] elements() {
		int[] a = new int[n];
		System.arraycopy(elements, 0, a, 0, n);
		return a;
	}

	@Override
	public int size() {
		return n;
	}

    public int capacity() {
        return elements.length;
    }

	@Override
	public boolean equals(Object o) {
        if ( o==null ) {
            return false;
        }
        IntArrayList other = (IntArrayList)o;
        if ( this.size()!=other.size() ) {
            return false;
        }
		for (int i = 0; i < n; i++) {
			if ( elements[i] != other.elements[i] ) {
				return false;
			}
		}
		return true;
	}

	@Override
    public Object clone() throws CloneNotSupportedException {
		IntArrayList a = (IntArrayList)super.clone();
        a.n = this.n;
        System.arraycopy(this.elements, 0, a.elements, 0, this.elements.length);
        return a;
    }

	@Override
	public String toString() {
		StringBuilder buf = new StringBuilder();
		for (int i = 0; i < n; i++) {
			if ( i>0 ) {
				buf.append(", ");
			}
			buf.append(elements[i]);
		}
		return buf.toString();
	}
}