jaroslav@557: /*
jaroslav@557:  * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
jaroslav@557:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
jaroslav@557:  *
jaroslav@557:  * This code is free software; you can redistribute it and/or modify it
jaroslav@557:  * under the terms of the GNU General Public License version 2 only, as
jaroslav@557:  * published by the Free Software Foundation.  Oracle designates this
jaroslav@557:  * particular file as subject to the "Classpath" exception as provided
jaroslav@557:  * by Oracle in the LICENSE file that accompanied this code.
jaroslav@557:  *
jaroslav@557:  * This code is distributed in the hope that it will be useful, but WITHOUT
jaroslav@557:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
jaroslav@557:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
jaroslav@557:  * version 2 for more details (a copy is included in the LICENSE file that
jaroslav@557:  * accompanied this code).
jaroslav@557:  *
jaroslav@557:  * You should have received a copy of the GNU General Public License version
jaroslav@557:  * 2 along with this work; if not, write to the Free Software Foundation,
jaroslav@557:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
jaroslav@557:  *
jaroslav@557:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
jaroslav@557:  * or visit www.oracle.com if you need additional information or have any
jaroslav@557:  * questions.
jaroslav@557:  */
jaroslav@557: 
jaroslav@557: package java.util;
jaroslav@557: 
jaroslav@560: 
jaroslav@557: /**
jaroslav@557:  * Resizable-array implementation of the <tt>List</tt> interface.  Implements
jaroslav@557:  * all optional list operations, and permits all elements, including
jaroslav@557:  * <tt>null</tt>.  In addition to implementing the <tt>List</tt> interface,
jaroslav@557:  * this class provides methods to manipulate the size of the array that is
jaroslav@557:  * used internally to store the list.  (This class is roughly equivalent to
jaroslav@557:  * <tt>Vector</tt>, except that it is unsynchronized.)
jaroslav@557:  *
jaroslav@557:  * <p>The <tt>size</tt>, <tt>isEmpty</tt>, <tt>get</tt>, <tt>set</tt>,
jaroslav@557:  * <tt>iterator</tt>, and <tt>listIterator</tt> operations run in constant
jaroslav@557:  * time.  The <tt>add</tt> operation runs in <i>amortized constant time</i>,
jaroslav@557:  * that is, adding n elements requires O(n) time.  All of the other operations
jaroslav@557:  * run in linear time (roughly speaking).  The constant factor is low compared
jaroslav@557:  * to that for the <tt>LinkedList</tt> implementation.
jaroslav@557:  *
jaroslav@557:  * <p>Each <tt>ArrayList</tt> instance has a <i>capacity</i>.  The capacity is
jaroslav@557:  * the size of the array used to store the elements in the list.  It is always
jaroslav@557:  * at least as large as the list size.  As elements are added to an ArrayList,
jaroslav@557:  * its capacity grows automatically.  The details of the growth policy are not
jaroslav@557:  * specified beyond the fact that adding an element has constant amortized
jaroslav@557:  * time cost.
jaroslav@557:  *
jaroslav@557:  * <p>An application can increase the capacity of an <tt>ArrayList</tt> instance
jaroslav@557:  * before adding a large number of elements using the <tt>ensureCapacity</tt>
jaroslav@557:  * operation.  This may reduce the amount of incremental reallocation.
jaroslav@557:  *
jaroslav@557:  * <p><strong>Note that this implementation is not synchronized.</strong>
jaroslav@557:  * If multiple threads access an <tt>ArrayList</tt> instance concurrently,
jaroslav@557:  * and at least one of the threads modifies the list structurally, it
jaroslav@557:  * <i>must</i> be synchronized externally.  (A structural modification is
jaroslav@557:  * any operation that adds or deletes one or more elements, or explicitly
jaroslav@557:  * resizes the backing array; merely setting the value of an element is not
jaroslav@557:  * a structural modification.)  This is typically accomplished by
jaroslav@557:  * synchronizing on some object that naturally encapsulates the list.
jaroslav@557:  *
jaroslav@557:  * If no such object exists, the list should be "wrapped" using the
jaroslav@557:  * {@link Collections#synchronizedList Collections.synchronizedList}
jaroslav@557:  * method.  This is best done at creation time, to prevent accidental
jaroslav@557:  * unsynchronized access to the list:<pre>
jaroslav@557:  *   List list = Collections.synchronizedList(new ArrayList(...));</pre>
jaroslav@557:  *
jaroslav@557:  * <p><a name="fail-fast"/>
jaroslav@557:  * The iterators returned by this class's {@link #iterator() iterator} and
jaroslav@557:  * {@link #listIterator(int) listIterator} methods are <em>fail-fast</em>:
jaroslav@557:  * if the list is structurally modified at any time after the iterator is
jaroslav@557:  * created, in any way except through the iterator's own
jaroslav@557:  * {@link ListIterator#remove() remove} or
jaroslav@557:  * {@link ListIterator#add(Object) add} methods, the iterator will throw a
jaroslav@557:  * {@link ConcurrentModificationException}.  Thus, in the face of
jaroslav@557:  * concurrent modification, the iterator fails quickly and cleanly, rather
jaroslav@557:  * than risking arbitrary, non-deterministic behavior at an undetermined
jaroslav@557:  * time in the future.
jaroslav@557:  *
jaroslav@557:  * <p>Note that the fail-fast behavior of an iterator cannot be guaranteed
jaroslav@557:  * as it is, generally speaking, impossible to make any hard guarantees in the
jaroslav@557:  * presence of unsynchronized concurrent modification.  Fail-fast iterators
jaroslav@557:  * throw {@code ConcurrentModificationException} on a best-effort basis.
jaroslav@557:  * Therefore, it would be wrong to write a program that depended on this
jaroslav@557:  * exception for its correctness:  <i>the fail-fast behavior of iterators
jaroslav@557:  * should be used only to detect bugs.</i>
jaroslav@557:  *
jaroslav@557:  * <p>This class is a member of the
jaroslav@557:  * <a href="{@docRoot}/../technotes/guides/collections/index.html">
jaroslav@557:  * Java Collections Framework</a>.
jaroslav@557:  *
jaroslav@557:  * @author  Josh Bloch
jaroslav@557:  * @author  Neal Gafter
jaroslav@557:  * @see     Collection
jaroslav@557:  * @see     List
jaroslav@557:  * @see     LinkedList
jaroslav@557:  * @see     Vector
jaroslav@557:  * @since   1.2
jaroslav@557:  */
jaroslav@557: 
jaroslav@557: public class ArrayList<E> extends AbstractList<E>
jaroslav@557:         implements List<E>, RandomAccess, Cloneable, java.io.Serializable
jaroslav@557: {
jaroslav@557:     private static final long serialVersionUID = 8683452581122892189L;
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * The array buffer into which the elements of the ArrayList are stored.
jaroslav@557:      * The capacity of the ArrayList is the length of this array buffer.
jaroslav@557:      */
jaroslav@557:     private transient Object[] elementData;
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * The size of the ArrayList (the number of elements it contains).
jaroslav@557:      *
jaroslav@557:      * @serial
jaroslav@557:      */
jaroslav@557:     private int size;
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Constructs an empty list with the specified initial capacity.
jaroslav@557:      *
jaroslav@557:      * @param  initialCapacity  the initial capacity of the list
jaroslav@557:      * @throws IllegalArgumentException if the specified initial capacity
jaroslav@557:      *         is negative
jaroslav@557:      */
jaroslav@557:     public ArrayList(int initialCapacity) {
jaroslav@557:         super();
jaroslav@557:         if (initialCapacity < 0)
jaroslav@557:             throw new IllegalArgumentException("Illegal Capacity: "+
jaroslav@557:                                                initialCapacity);
jaroslav@557:         this.elementData = new Object[initialCapacity];
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Constructs an empty list with an initial capacity of ten.
jaroslav@557:      */
jaroslav@557:     public ArrayList() {
jaroslav@557:         this(10);
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Constructs a list containing the elements of the specified
jaroslav@557:      * collection, in the order they are returned by the collection's
jaroslav@557:      * iterator.
jaroslav@557:      *
jaroslav@557:      * @param c the collection whose elements are to be placed into this list
jaroslav@557:      * @throws NullPointerException if the specified collection is null
jaroslav@557:      */
jaroslav@557:     public ArrayList(Collection<? extends E> c) {
jaroslav@557:         elementData = c.toArray();
jaroslav@557:         size = elementData.length;
jaroslav@557:         // c.toArray might (incorrectly) not return Object[] (see 6260652)
jaroslav@557:         if (elementData.getClass() != Object[].class)
jaroslav@557:             elementData = Arrays.copyOf(elementData, size, Object[].class);
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Trims the capacity of this <tt>ArrayList</tt> instance to be the
jaroslav@557:      * list's current size.  An application can use this operation to minimize
jaroslav@557:      * the storage of an <tt>ArrayList</tt> instance.
jaroslav@557:      */
jaroslav@557:     public void trimToSize() {
jaroslav@557:         modCount++;
jaroslav@557:         int oldCapacity = elementData.length;
jaroslav@557:         if (size < oldCapacity) {
jaroslav@557:             elementData = Arrays.copyOf(elementData, size);
jaroslav@557:         }
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Increases the capacity of this <tt>ArrayList</tt> instance, if
jaroslav@557:      * necessary, to ensure that it can hold at least the number of elements
jaroslav@557:      * specified by the minimum capacity argument.
jaroslav@557:      *
jaroslav@557:      * @param   minCapacity   the desired minimum capacity
jaroslav@557:      */
jaroslav@557:     public void ensureCapacity(int minCapacity) {
jaroslav@557:         if (minCapacity > 0)
jaroslav@557:             ensureCapacityInternal(minCapacity);
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     private void ensureCapacityInternal(int minCapacity) {
jaroslav@557:         modCount++;
jaroslav@557:         // overflow-conscious code
jaroslav@557:         if (minCapacity - elementData.length > 0)
jaroslav@557:             grow(minCapacity);
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * The maximum size of array to allocate.
jaroslav@557:      * Some VMs reserve some header words in an array.
jaroslav@557:      * Attempts to allocate larger arrays may result in
jaroslav@557:      * OutOfMemoryError: Requested array size exceeds VM limit
jaroslav@557:      */
jaroslav@557:     private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Increases the capacity to ensure that it can hold at least the
jaroslav@557:      * number of elements specified by the minimum capacity argument.
jaroslav@557:      *
jaroslav@557:      * @param minCapacity the desired minimum capacity
jaroslav@557:      */
jaroslav@557:     private void grow(int minCapacity) {
jaroslav@557:         // overflow-conscious code
jaroslav@557:         int oldCapacity = elementData.length;
jaroslav@557:         int newCapacity = oldCapacity + (oldCapacity >> 1);
jaroslav@557:         if (newCapacity - minCapacity < 0)
jaroslav@557:             newCapacity = minCapacity;
jaroslav@557:         if (newCapacity - MAX_ARRAY_SIZE > 0)
jaroslav@557:             newCapacity = hugeCapacity(minCapacity);
jaroslav@557:         // minCapacity is usually close to size, so this is a win:
jaroslav@557:         elementData = Arrays.copyOf(elementData, newCapacity);
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     private static int hugeCapacity(int minCapacity) {
jaroslav@557:         if (minCapacity < 0) // overflow
jaroslav@557:             throw new OutOfMemoryError();
jaroslav@557:         return (minCapacity > MAX_ARRAY_SIZE) ?
jaroslav@557:             Integer.MAX_VALUE :
jaroslav@557:             MAX_ARRAY_SIZE;
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Returns the number of elements in this list.
jaroslav@557:      *
jaroslav@557:      * @return the number of elements in this list
jaroslav@557:      */
jaroslav@557:     public int size() {
jaroslav@557:         return size;
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Returns <tt>true</tt> if this list contains no elements.
jaroslav@557:      *
jaroslav@557:      * @return <tt>true</tt> if this list contains no elements
jaroslav@557:      */
jaroslav@557:     public boolean isEmpty() {
jaroslav@557:         return size == 0;
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Returns <tt>true</tt> if this list contains the specified element.
jaroslav@557:      * More formally, returns <tt>true</tt> if and only if this list contains
jaroslav@557:      * at least one element <tt>e</tt> such that
jaroslav@557:      * <tt>(o==null&nbsp;?&nbsp;e==null&nbsp;:&nbsp;o.equals(e))</tt>.
jaroslav@557:      *
jaroslav@557:      * @param o element whose presence in this list is to be tested
jaroslav@557:      * @return <tt>true</tt> if this list contains the specified element
jaroslav@557:      */
jaroslav@557:     public boolean contains(Object o) {
jaroslav@557:         return indexOf(o) >= 0;
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Returns the index of the first occurrence of the specified element
jaroslav@557:      * in this list, or -1 if this list does not contain the element.
jaroslav@557:      * More formally, returns the lowest index <tt>i</tt> such that
jaroslav@557:      * <tt>(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i)))</tt>,
jaroslav@557:      * or -1 if there is no such index.
jaroslav@557:      */
jaroslav@557:     public int indexOf(Object o) {
jaroslav@557:         if (o == null) {
jaroslav@557:             for (int i = 0; i < size; i++)
jaroslav@557:                 if (elementData[i]==null)
jaroslav@557:                     return i;
jaroslav@557:         } else {
jaroslav@557:             for (int i = 0; i < size; i++)
jaroslav@557:                 if (o.equals(elementData[i]))
jaroslav@557:                     return i;
jaroslav@557:         }
jaroslav@557:         return -1;
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Returns the index of the last occurrence of the specified element
jaroslav@557:      * in this list, or -1 if this list does not contain the element.
jaroslav@557:      * More formally, returns the highest index <tt>i</tt> such that
jaroslav@557:      * <tt>(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i)))</tt>,
jaroslav@557:      * or -1 if there is no such index.
jaroslav@557:      */
jaroslav@557:     public int lastIndexOf(Object o) {
jaroslav@557:         if (o == null) {
jaroslav@557:             for (int i = size-1; i >= 0; i--)
jaroslav@557:                 if (elementData[i]==null)
jaroslav@557:                     return i;
jaroslav@557:         } else {
jaroslav@557:             for (int i = size-1; i >= 0; i--)
jaroslav@557:                 if (o.equals(elementData[i]))
jaroslav@557:                     return i;
jaroslav@557:         }
jaroslav@557:         return -1;
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Returns a shallow copy of this <tt>ArrayList</tt> instance.  (The
jaroslav@557:      * elements themselves are not copied.)
jaroslav@557:      *
jaroslav@557:      * @return a clone of this <tt>ArrayList</tt> instance
jaroslav@557:      */
jaroslav@557:     public Object clone() {
jaroslav@557:         try {
jaroslav@557:             @SuppressWarnings("unchecked")
jaroslav@557:                 ArrayList<E> v = (ArrayList<E>) super.clone();
jaroslav@557:             v.elementData = Arrays.copyOf(elementData, size);
jaroslav@557:             v.modCount = 0;
jaroslav@557:             return v;
jaroslav@557:         } catch (CloneNotSupportedException e) {
jaroslav@557:             // this shouldn't happen, since we are Cloneable
jaroslav@557:             throw new InternalError();
jaroslav@557:         }
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Returns an array containing all of the elements in this list
jaroslav@557:      * in proper sequence (from first to last element).
jaroslav@557:      *
jaroslav@557:      * <p>The returned array will be "safe" in that no references to it are
jaroslav@557:      * maintained by this list.  (In other words, this method must allocate
jaroslav@557:      * a new array).  The caller is thus free to modify the returned array.
jaroslav@557:      *
jaroslav@557:      * <p>This method acts as bridge between array-based and collection-based
jaroslav@557:      * APIs.
jaroslav@557:      *
jaroslav@557:      * @return an array containing all of the elements in this list in
jaroslav@557:      *         proper sequence
jaroslav@557:      */
jaroslav@557:     public Object[] toArray() {
jaroslav@557:         return Arrays.copyOf(elementData, size);
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Returns an array containing all of the elements in this list in proper
jaroslav@557:      * sequence (from first to last element); the runtime type of the returned
jaroslav@557:      * array is that of the specified array.  If the list fits in the
jaroslav@557:      * specified array, it is returned therein.  Otherwise, a new array is
jaroslav@557:      * allocated with the runtime type of the specified array and the size of
jaroslav@557:      * this list.
jaroslav@557:      *
jaroslav@557:      * <p>If the list fits in the specified array with room to spare
jaroslav@557:      * (i.e., the array has more elements than the list), the element in
jaroslav@557:      * the array immediately following the end of the collection is set to
jaroslav@557:      * <tt>null</tt>.  (This is useful in determining the length of the
jaroslav@557:      * list <i>only</i> if the caller knows that the list does not contain
jaroslav@557:      * any null elements.)
jaroslav@557:      *
jaroslav@557:      * @param a the array into which the elements of the list are to
jaroslav@557:      *          be stored, if it is big enough; otherwise, a new array of the
jaroslav@557:      *          same runtime type is allocated for this purpose.
jaroslav@557:      * @return an array containing the elements of the list
jaroslav@557:      * @throws ArrayStoreException if the runtime type of the specified array
jaroslav@557:      *         is not a supertype of the runtime type of every element in
jaroslav@557:      *         this list
jaroslav@557:      * @throws NullPointerException if the specified array is null
jaroslav@557:      */
jaroslav@557:     @SuppressWarnings("unchecked")
jaroslav@557:     public <T> T[] toArray(T[] a) {
jaroslav@557:         if (a.length < size)
jaroslav@557:             // Make a new array of a's runtime type, but my contents:
jaroslav@557:             return (T[]) Arrays.copyOf(elementData, size, a.getClass());
jaroslav@557:         System.arraycopy(elementData, 0, a, 0, size);
jaroslav@557:         if (a.length > size)
jaroslav@557:             a[size] = null;
jaroslav@557:         return a;
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     // Positional Access Operations
jaroslav@557: 
jaroslav@557:     @SuppressWarnings("unchecked")
jaroslav@557:     E elementData(int index) {
jaroslav@557:         return (E) elementData[index];
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Returns the element at the specified position in this list.
jaroslav@557:      *
jaroslav@557:      * @param  index index of the element to return
jaroslav@557:      * @return the element at the specified position in this list
jaroslav@557:      * @throws IndexOutOfBoundsException {@inheritDoc}
jaroslav@557:      */
jaroslav@557:     public E get(int index) {
jaroslav@557:         rangeCheck(index);
jaroslav@557: 
jaroslav@557:         return elementData(index);
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Replaces the element at the specified position in this list with
jaroslav@557:      * the specified element.
jaroslav@557:      *
jaroslav@557:      * @param index index of the element to replace
jaroslav@557:      * @param element element to be stored at the specified position
jaroslav@557:      * @return the element previously at the specified position
jaroslav@557:      * @throws IndexOutOfBoundsException {@inheritDoc}
jaroslav@557:      */
jaroslav@557:     public E set(int index, E element) {
jaroslav@557:         rangeCheck(index);
jaroslav@557: 
jaroslav@557:         E oldValue = elementData(index);
jaroslav@557:         elementData[index] = element;
jaroslav@557:         return oldValue;
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Appends the specified element to the end of this list.
jaroslav@557:      *
jaroslav@557:      * @param e element to be appended to this list
jaroslav@557:      * @return <tt>true</tt> (as specified by {@link Collection#add})
jaroslav@557:      */
jaroslav@557:     public boolean add(E e) {
jaroslav@557:         ensureCapacityInternal(size + 1);  // Increments modCount!!
jaroslav@557:         elementData[size++] = e;
jaroslav@557:         return true;
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Inserts the specified element at the specified position in this
jaroslav@557:      * list. Shifts the element currently at that position (if any) and
jaroslav@557:      * any subsequent elements to the right (adds one to their indices).
jaroslav@557:      *
jaroslav@557:      * @param index index at which the specified element is to be inserted
jaroslav@557:      * @param element element to be inserted
jaroslav@557:      * @throws IndexOutOfBoundsException {@inheritDoc}
jaroslav@557:      */
jaroslav@557:     public void add(int index, E element) {
jaroslav@557:         rangeCheckForAdd(index);
jaroslav@557: 
jaroslav@557:         ensureCapacityInternal(size + 1);  // Increments modCount!!
jaroslav@557:         System.arraycopy(elementData, index, elementData, index + 1,
jaroslav@557:                          size - index);
jaroslav@557:         elementData[index] = element;
jaroslav@557:         size++;
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Removes the element at the specified position in this list.
jaroslav@557:      * Shifts any subsequent elements to the left (subtracts one from their
jaroslav@557:      * indices).
jaroslav@557:      *
jaroslav@557:      * @param index the index of the element to be removed
jaroslav@557:      * @return the element that was removed from the list
jaroslav@557:      * @throws IndexOutOfBoundsException {@inheritDoc}
jaroslav@557:      */
jaroslav@557:     public E remove(int index) {
jaroslav@557:         rangeCheck(index);
jaroslav@557: 
jaroslav@557:         modCount++;
jaroslav@557:         E oldValue = elementData(index);
jaroslav@557: 
jaroslav@557:         int numMoved = size - index - 1;
jaroslav@557:         if (numMoved > 0)
jaroslav@557:             System.arraycopy(elementData, index+1, elementData, index,
jaroslav@557:                              numMoved);
jaroslav@557:         elementData[--size] = null; // Let gc do its work
jaroslav@557: 
jaroslav@557:         return oldValue;
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Removes the first occurrence of the specified element from this list,
jaroslav@557:      * if it is present.  If the list does not contain the element, it is
jaroslav@557:      * unchanged.  More formally, removes the element with the lowest index
jaroslav@557:      * <tt>i</tt> such that
jaroslav@557:      * <tt>(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i)))</tt>
jaroslav@557:      * (if such an element exists).  Returns <tt>true</tt> if this list
jaroslav@557:      * contained the specified element (or equivalently, if this list
jaroslav@557:      * changed as a result of the call).
jaroslav@557:      *
jaroslav@557:      * @param o element to be removed from this list, if present
jaroslav@557:      * @return <tt>true</tt> if this list contained the specified element
jaroslav@557:      */
jaroslav@557:     public boolean remove(Object o) {
jaroslav@557:         if (o == null) {
jaroslav@557:             for (int index = 0; index < size; index++)
jaroslav@557:                 if (elementData[index] == null) {
jaroslav@557:                     fastRemove(index);
jaroslav@557:                     return true;
jaroslav@557:                 }
jaroslav@557:         } else {
jaroslav@557:             for (int index = 0; index < size; index++)
jaroslav@557:                 if (o.equals(elementData[index])) {
jaroslav@557:                     fastRemove(index);
jaroslav@557:                     return true;
jaroslav@557:                 }
jaroslav@557:         }
jaroslav@557:         return false;
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /*
jaroslav@557:      * Private remove method that skips bounds checking and does not
jaroslav@557:      * return the value removed.
jaroslav@557:      */
jaroslav@557:     private void fastRemove(int index) {
jaroslav@557:         modCount++;
jaroslav@557:         int numMoved = size - index - 1;
jaroslav@557:         if (numMoved > 0)
jaroslav@557:             System.arraycopy(elementData, index+1, elementData, index,
jaroslav@557:                              numMoved);
jaroslav@557:         elementData[--size] = null; // Let gc do its work
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Removes all of the elements from this list.  The list will
jaroslav@557:      * be empty after this call returns.
jaroslav@557:      */
jaroslav@557:     public void clear() {
jaroslav@557:         modCount++;
jaroslav@557: 
jaroslav@557:         // Let gc do its work
jaroslav@557:         for (int i = 0; i < size; i++)
jaroslav@557:             elementData[i] = null;
jaroslav@557: 
jaroslav@557:         size = 0;
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Appends all of the elements in the specified collection to the end of
jaroslav@557:      * this list, in the order that they are returned by the
jaroslav@557:      * specified collection's Iterator.  The behavior of this operation is
jaroslav@557:      * undefined if the specified collection is modified while the operation
jaroslav@557:      * is in progress.  (This implies that the behavior of this call is
jaroslav@557:      * undefined if the specified collection is this list, and this
jaroslav@557:      * list is nonempty.)
jaroslav@557:      *
jaroslav@557:      * @param c collection containing elements to be added to this list
jaroslav@557:      * @return <tt>true</tt> if this list changed as a result of the call
jaroslav@557:      * @throws NullPointerException if the specified collection is null
jaroslav@557:      */
jaroslav@557:     public boolean addAll(Collection<? extends E> c) {
jaroslav@557:         Object[] a = c.toArray();
jaroslav@557:         int numNew = a.length;
jaroslav@557:         ensureCapacityInternal(size + numNew);  // Increments modCount
jaroslav@557:         System.arraycopy(a, 0, elementData, size, numNew);
jaroslav@557:         size += numNew;
jaroslav@557:         return numNew != 0;
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Inserts all of the elements in the specified collection into this
jaroslav@557:      * list, starting at the specified position.  Shifts the element
jaroslav@557:      * currently at that position (if any) and any subsequent elements to
jaroslav@557:      * the right (increases their indices).  The new elements will appear
jaroslav@557:      * in the list in the order that they are returned by the
jaroslav@557:      * specified collection's iterator.
jaroslav@557:      *
jaroslav@557:      * @param index index at which to insert the first element from the
jaroslav@557:      *              specified collection
jaroslav@557:      * @param c collection containing elements to be added to this list
jaroslav@557:      * @return <tt>true</tt> if this list changed as a result of the call
jaroslav@557:      * @throws IndexOutOfBoundsException {@inheritDoc}
jaroslav@557:      * @throws NullPointerException if the specified collection is null
jaroslav@557:      */
jaroslav@557:     public boolean addAll(int index, Collection<? extends E> c) {
jaroslav@557:         rangeCheckForAdd(index);
jaroslav@557: 
jaroslav@557:         Object[] a = c.toArray();
jaroslav@557:         int numNew = a.length;
jaroslav@557:         ensureCapacityInternal(size + numNew);  // Increments modCount
jaroslav@557: 
jaroslav@557:         int numMoved = size - index;
jaroslav@557:         if (numMoved > 0)
jaroslav@557:             System.arraycopy(elementData, index, elementData, index + numNew,
jaroslav@557:                              numMoved);
jaroslav@557: 
jaroslav@557:         System.arraycopy(a, 0, elementData, index, numNew);
jaroslav@557:         size += numNew;
jaroslav@557:         return numNew != 0;
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Removes from this list all of the elements whose index is between
jaroslav@557:      * {@code fromIndex}, inclusive, and {@code toIndex}, exclusive.
jaroslav@557:      * Shifts any succeeding elements to the left (reduces their index).
jaroslav@557:      * This call shortens the list by {@code (toIndex - fromIndex)} elements.
jaroslav@557:      * (If {@code toIndex==fromIndex}, this operation has no effect.)
jaroslav@557:      *
jaroslav@557:      * @throws IndexOutOfBoundsException if {@code fromIndex} or
jaroslav@557:      *         {@code toIndex} is out of range
jaroslav@557:      *         ({@code fromIndex < 0 ||
jaroslav@557:      *          fromIndex >= size() ||
jaroslav@557:      *          toIndex > size() ||
jaroslav@557:      *          toIndex < fromIndex})
jaroslav@557:      */
jaroslav@557:     protected void removeRange(int fromIndex, int toIndex) {
jaroslav@557:         modCount++;
jaroslav@557:         int numMoved = size - toIndex;
jaroslav@557:         System.arraycopy(elementData, toIndex, elementData, fromIndex,
jaroslav@557:                          numMoved);
jaroslav@557: 
jaroslav@557:         // Let gc do its work
jaroslav@557:         int newSize = size - (toIndex-fromIndex);
jaroslav@557:         while (size != newSize)
jaroslav@557:             elementData[--size] = null;
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Checks if the given index is in range.  If not, throws an appropriate
jaroslav@557:      * runtime exception.  This method does *not* check if the index is
jaroslav@557:      * negative: It is always used immediately prior to an array access,
jaroslav@557:      * which throws an ArrayIndexOutOfBoundsException if index is negative.
jaroslav@557:      */
jaroslav@557:     private void rangeCheck(int index) {
jaroslav@557:         if (index >= size)
jaroslav@557:             throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * A version of rangeCheck used by add and addAll.
jaroslav@557:      */
jaroslav@557:     private void rangeCheckForAdd(int index) {
jaroslav@557:         if (index > size || index < 0)
jaroslav@557:             throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Constructs an IndexOutOfBoundsException detail message.
jaroslav@557:      * Of the many possible refactorings of the error handling code,
jaroslav@557:      * this "outlining" performs best with both server and client VMs.
jaroslav@557:      */
jaroslav@557:     private String outOfBoundsMsg(int index) {
jaroslav@557:         return "Index: "+index+", Size: "+size;
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Removes from this list all of its elements that are contained in the
jaroslav@557:      * specified collection.
jaroslav@557:      *
jaroslav@557:      * @param c collection containing elements to be removed from this list
jaroslav@557:      * @return {@code true} if this list changed as a result of the call
jaroslav@557:      * @throws ClassCastException if the class of an element of this list
jaroslav@557:      *         is incompatible with the specified collection
jaroslav@557:      * (<a href="Collection.html#optional-restrictions">optional</a>)
jaroslav@557:      * @throws NullPointerException if this list contains a null element and the
jaroslav@557:      *         specified collection does not permit null elements
jaroslav@557:      * (<a href="Collection.html#optional-restrictions">optional</a>),
jaroslav@557:      *         or if the specified collection is null
jaroslav@557:      * @see Collection#contains(Object)
jaroslav@557:      */
jaroslav@557:     public boolean removeAll(Collection<?> c) {
jaroslav@557:         return batchRemove(c, false);
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Retains only the elements in this list that are contained in the
jaroslav@557:      * specified collection.  In other words, removes from this list all
jaroslav@557:      * of its elements that are not contained in the specified collection.
jaroslav@557:      *
jaroslav@557:      * @param c collection containing elements to be retained in this list
jaroslav@557:      * @return {@code true} if this list changed as a result of the call
jaroslav@557:      * @throws ClassCastException if the class of an element of this list
jaroslav@557:      *         is incompatible with the specified collection
jaroslav@557:      * (<a href="Collection.html#optional-restrictions">optional</a>)
jaroslav@557:      * @throws NullPointerException if this list contains a null element and the
jaroslav@557:      *         specified collection does not permit null elements
jaroslav@557:      * (<a href="Collection.html#optional-restrictions">optional</a>),
jaroslav@557:      *         or if the specified collection is null
jaroslav@557:      * @see Collection#contains(Object)
jaroslav@557:      */
jaroslav@557:     public boolean retainAll(Collection<?> c) {
jaroslav@557:         return batchRemove(c, true);
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     private boolean batchRemove(Collection<?> c, boolean complement) {
jaroslav@557:         final Object[] elementData = this.elementData;
jaroslav@557:         int r = 0, w = 0;
jaroslav@557:         boolean modified = false;
jaroslav@557:         try {
jaroslav@557:             for (; r < size; r++)
jaroslav@557:                 if (c.contains(elementData[r]) == complement)
jaroslav@557:                     elementData[w++] = elementData[r];
jaroslav@557:         } finally {
jaroslav@557:             // Preserve behavioral compatibility with AbstractCollection,
jaroslav@557:             // even if c.contains() throws.
jaroslav@557:             if (r != size) {
jaroslav@557:                 System.arraycopy(elementData, r,
jaroslav@557:                                  elementData, w,
jaroslav@557:                                  size - r);
jaroslav@557:                 w += size - r;
jaroslav@557:             }
jaroslav@557:             if (w != size) {
jaroslav@557:                 for (int i = w; i < size; i++)
jaroslav@557:                     elementData[i] = null;
jaroslav@557:                 modCount += size - w;
jaroslav@557:                 size = w;
jaroslav@557:                 modified = true;
jaroslav@557:             }
jaroslav@557:         }
jaroslav@557:         return modified;
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Returns a list iterator over the elements in this list (in proper
jaroslav@557:      * sequence), starting at the specified position in the list.
jaroslav@557:      * The specified index indicates the first element that would be
jaroslav@557:      * returned by an initial call to {@link ListIterator#next next}.
jaroslav@557:      * An initial call to {@link ListIterator#previous previous} would
jaroslav@557:      * return the element with the specified index minus one.
jaroslav@557:      *
jaroslav@557:      * <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
jaroslav@557:      *
jaroslav@557:      * @throws IndexOutOfBoundsException {@inheritDoc}
jaroslav@557:      */
jaroslav@557:     public ListIterator<E> listIterator(int index) {
jaroslav@557:         if (index < 0 || index > size)
jaroslav@557:             throw new IndexOutOfBoundsException("Index: "+index);
jaroslav@557:         return new ListItr(index);
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Returns a list iterator over the elements in this list (in proper
jaroslav@557:      * sequence).
jaroslav@557:      *
jaroslav@557:      * <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
jaroslav@557:      *
jaroslav@557:      * @see #listIterator(int)
jaroslav@557:      */
jaroslav@557:     public ListIterator<E> listIterator() {
jaroslav@557:         return new ListItr(0);
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Returns an iterator over the elements in this list in proper sequence.
jaroslav@557:      *
jaroslav@557:      * <p>The returned iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
jaroslav@557:      *
jaroslav@557:      * @return an iterator over the elements in this list in proper sequence
jaroslav@557:      */
jaroslav@557:     public Iterator<E> iterator() {
jaroslav@557:         return new Itr();
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * An optimized version of AbstractList.Itr
jaroslav@557:      */
jaroslav@557:     private class Itr implements Iterator<E> {
jaroslav@557:         int cursor;       // index of next element to return
jaroslav@557:         int lastRet = -1; // index of last element returned; -1 if no such
jaroslav@557:         int expectedModCount = modCount;
jaroslav@557: 
jaroslav@557:         public boolean hasNext() {
jaroslav@557:             return cursor != size;
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         @SuppressWarnings("unchecked")
jaroslav@557:         public E next() {
jaroslav@557:             checkForComodification();
jaroslav@557:             int i = cursor;
jaroslav@557:             if (i >= size)
jaroslav@557:                 throw new NoSuchElementException();
jaroslav@557:             Object[] elementData = ArrayList.this.elementData;
jaroslav@557:             if (i >= elementData.length)
jaroslav@557:                 throw new ConcurrentModificationException();
jaroslav@557:             cursor = i + 1;
jaroslav@557:             return (E) elementData[lastRet = i];
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         public void remove() {
jaroslav@557:             if (lastRet < 0)
jaroslav@557:                 throw new IllegalStateException();
jaroslav@557:             checkForComodification();
jaroslav@557: 
jaroslav@557:             try {
jaroslav@557:                 ArrayList.this.remove(lastRet);
jaroslav@557:                 cursor = lastRet;
jaroslav@557:                 lastRet = -1;
jaroslav@557:                 expectedModCount = modCount;
jaroslav@557:             } catch (IndexOutOfBoundsException ex) {
jaroslav@557:                 throw new ConcurrentModificationException();
jaroslav@557:             }
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         final void checkForComodification() {
jaroslav@557:             if (modCount != expectedModCount)
jaroslav@557:                 throw new ConcurrentModificationException();
jaroslav@557:         }
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * An optimized version of AbstractList.ListItr
jaroslav@557:      */
jaroslav@557:     private class ListItr extends Itr implements ListIterator<E> {
jaroslav@557:         ListItr(int index) {
jaroslav@557:             super();
jaroslav@557:             cursor = index;
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         public boolean hasPrevious() {
jaroslav@557:             return cursor != 0;
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         public int nextIndex() {
jaroslav@557:             return cursor;
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         public int previousIndex() {
jaroslav@557:             return cursor - 1;
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         @SuppressWarnings("unchecked")
jaroslav@557:         public E previous() {
jaroslav@557:             checkForComodification();
jaroslav@557:             int i = cursor - 1;
jaroslav@557:             if (i < 0)
jaroslav@557:                 throw new NoSuchElementException();
jaroslav@557:             Object[] elementData = ArrayList.this.elementData;
jaroslav@557:             if (i >= elementData.length)
jaroslav@557:                 throw new ConcurrentModificationException();
jaroslav@557:             cursor = i;
jaroslav@557:             return (E) elementData[lastRet = i];
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         public void set(E e) {
jaroslav@557:             if (lastRet < 0)
jaroslav@557:                 throw new IllegalStateException();
jaroslav@557:             checkForComodification();
jaroslav@557: 
jaroslav@557:             try {
jaroslav@557:                 ArrayList.this.set(lastRet, e);
jaroslav@557:             } catch (IndexOutOfBoundsException ex) {
jaroslav@557:                 throw new ConcurrentModificationException();
jaroslav@557:             }
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         public void add(E e) {
jaroslav@557:             checkForComodification();
jaroslav@557: 
jaroslav@557:             try {
jaroslav@557:                 int i = cursor;
jaroslav@557:                 ArrayList.this.add(i, e);
jaroslav@557:                 cursor = i + 1;
jaroslav@557:                 lastRet = -1;
jaroslav@557:                 expectedModCount = modCount;
jaroslav@557:             } catch (IndexOutOfBoundsException ex) {
jaroslav@557:                 throw new ConcurrentModificationException();
jaroslav@557:             }
jaroslav@557:         }
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     /**
jaroslav@557:      * Returns a view of the portion of this list between the specified
jaroslav@557:      * {@code fromIndex}, inclusive, and {@code toIndex}, exclusive.  (If
jaroslav@557:      * {@code fromIndex} and {@code toIndex} are equal, the returned list is
jaroslav@557:      * empty.)  The returned list is backed by this list, so non-structural
jaroslav@557:      * changes in the returned list are reflected in this list, and vice-versa.
jaroslav@557:      * The returned list supports all of the optional list operations.
jaroslav@557:      *
jaroslav@557:      * <p>This method eliminates the need for explicit range operations (of
jaroslav@557:      * the sort that commonly exist for arrays).  Any operation that expects
jaroslav@557:      * a list can be used as a range operation by passing a subList view
jaroslav@557:      * instead of a whole list.  For example, the following idiom
jaroslav@557:      * removes a range of elements from a list:
jaroslav@557:      * <pre>
jaroslav@557:      *      list.subList(from, to).clear();
jaroslav@557:      * </pre>
jaroslav@557:      * Similar idioms may be constructed for {@link #indexOf(Object)} and
jaroslav@557:      * {@link #lastIndexOf(Object)}, and all of the algorithms in the
jaroslav@557:      * {@link Collections} class can be applied to a subList.
jaroslav@557:      *
jaroslav@557:      * <p>The semantics of the list returned by this method become undefined if
jaroslav@557:      * the backing list (i.e., this list) is <i>structurally modified</i> in
jaroslav@557:      * any way other than via the returned list.  (Structural modifications are
jaroslav@557:      * those that change the size of this list, or otherwise perturb it in such
jaroslav@557:      * a fashion that iterations in progress may yield incorrect results.)
jaroslav@557:      *
jaroslav@557:      * @throws IndexOutOfBoundsException {@inheritDoc}
jaroslav@557:      * @throws IllegalArgumentException {@inheritDoc}
jaroslav@557:      */
jaroslav@557:     public List<E> subList(int fromIndex, int toIndex) {
jaroslav@557:         subListRangeCheck(fromIndex, toIndex, size);
jaroslav@557:         return new SubList(this, 0, fromIndex, toIndex);
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     static void subListRangeCheck(int fromIndex, int toIndex, int size) {
jaroslav@557:         if (fromIndex < 0)
jaroslav@557:             throw new IndexOutOfBoundsException("fromIndex = " + fromIndex);
jaroslav@557:         if (toIndex > size)
jaroslav@557:             throw new IndexOutOfBoundsException("toIndex = " + toIndex);
jaroslav@557:         if (fromIndex > toIndex)
jaroslav@557:             throw new IllegalArgumentException("fromIndex(" + fromIndex +
jaroslav@557:                                                ") > toIndex(" + toIndex + ")");
jaroslav@557:     }
jaroslav@557: 
jaroslav@557:     private class SubList extends AbstractList<E> implements RandomAccess {
jaroslav@557:         private final AbstractList<E> parent;
jaroslav@557:         private final int parentOffset;
jaroslav@557:         private final int offset;
jaroslav@557:         int size;
jaroslav@557: 
jaroslav@557:         SubList(AbstractList<E> parent,
jaroslav@557:                 int offset, int fromIndex, int toIndex) {
jaroslav@557:             this.parent = parent;
jaroslav@557:             this.parentOffset = fromIndex;
jaroslav@557:             this.offset = offset + fromIndex;
jaroslav@557:             this.size = toIndex - fromIndex;
jaroslav@557:             this.modCount = ArrayList.this.modCount;
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         public E set(int index, E e) {
jaroslav@557:             rangeCheck(index);
jaroslav@557:             checkForComodification();
jaroslav@557:             E oldValue = ArrayList.this.elementData(offset + index);
jaroslav@557:             ArrayList.this.elementData[offset + index] = e;
jaroslav@557:             return oldValue;
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         public E get(int index) {
jaroslav@557:             rangeCheck(index);
jaroslav@557:             checkForComodification();
jaroslav@557:             return ArrayList.this.elementData(offset + index);
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         public int size() {
jaroslav@557:             checkForComodification();
jaroslav@557:             return this.size;
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         public void add(int index, E e) {
jaroslav@557:             rangeCheckForAdd(index);
jaroslav@557:             checkForComodification();
jaroslav@557:             parent.add(parentOffset + index, e);
jaroslav@557:             this.modCount = parent.modCount;
jaroslav@557:             this.size++;
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         public E remove(int index) {
jaroslav@557:             rangeCheck(index);
jaroslav@557:             checkForComodification();
jaroslav@557:             E result = parent.remove(parentOffset + index);
jaroslav@557:             this.modCount = parent.modCount;
jaroslav@557:             this.size--;
jaroslav@557:             return result;
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         protected void removeRange(int fromIndex, int toIndex) {
jaroslav@557:             checkForComodification();
jaroslav@557:             parent.removeRange(parentOffset + fromIndex,
jaroslav@557:                                parentOffset + toIndex);
jaroslav@557:             this.modCount = parent.modCount;
jaroslav@557:             this.size -= toIndex - fromIndex;
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         public boolean addAll(Collection<? extends E> c) {
jaroslav@557:             return addAll(this.size, c);
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         public boolean addAll(int index, Collection<? extends E> c) {
jaroslav@557:             rangeCheckForAdd(index);
jaroslav@557:             int cSize = c.size();
jaroslav@557:             if (cSize==0)
jaroslav@557:                 return false;
jaroslav@557: 
jaroslav@557:             checkForComodification();
jaroslav@557:             parent.addAll(parentOffset + index, c);
jaroslav@557:             this.modCount = parent.modCount;
jaroslav@557:             this.size += cSize;
jaroslav@557:             return true;
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         public Iterator<E> iterator() {
jaroslav@557:             return listIterator();
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         public ListIterator<E> listIterator(final int index) {
jaroslav@557:             checkForComodification();
jaroslav@557:             rangeCheckForAdd(index);
jaroslav@557:             final int offset = this.offset;
jaroslav@557: 
jaroslav@557:             return new ListIterator<E>() {
jaroslav@557:                 int cursor = index;
jaroslav@557:                 int lastRet = -1;
jaroslav@557:                 int expectedModCount = ArrayList.this.modCount;
jaroslav@557: 
jaroslav@557:                 public boolean hasNext() {
jaroslav@557:                     return cursor != SubList.this.size;
jaroslav@557:                 }
jaroslav@557: 
jaroslav@557:                 @SuppressWarnings("unchecked")
jaroslav@557:                 public E next() {
jaroslav@557:                     checkForComodification();
jaroslav@557:                     int i = cursor;
jaroslav@557:                     if (i >= SubList.this.size)
jaroslav@557:                         throw new NoSuchElementException();
jaroslav@557:                     Object[] elementData = ArrayList.this.elementData;
jaroslav@557:                     if (offset + i >= elementData.length)
jaroslav@557:                         throw new ConcurrentModificationException();
jaroslav@557:                     cursor = i + 1;
jaroslav@557:                     return (E) elementData[offset + (lastRet = i)];
jaroslav@557:                 }
jaroslav@557: 
jaroslav@557:                 public boolean hasPrevious() {
jaroslav@557:                     return cursor != 0;
jaroslav@557:                 }
jaroslav@557: 
jaroslav@557:                 @SuppressWarnings("unchecked")
jaroslav@557:                 public E previous() {
jaroslav@557:                     checkForComodification();
jaroslav@557:                     int i = cursor - 1;
jaroslav@557:                     if (i < 0)
jaroslav@557:                         throw new NoSuchElementException();
jaroslav@557:                     Object[] elementData = ArrayList.this.elementData;
jaroslav@557:                     if (offset + i >= elementData.length)
jaroslav@557:                         throw new ConcurrentModificationException();
jaroslav@557:                     cursor = i;
jaroslav@557:                     return (E) elementData[offset + (lastRet = i)];
jaroslav@557:                 }
jaroslav@557: 
jaroslav@557:                 public int nextIndex() {
jaroslav@557:                     return cursor;
jaroslav@557:                 }
jaroslav@557: 
jaroslav@557:                 public int previousIndex() {
jaroslav@557:                     return cursor - 1;
jaroslav@557:                 }
jaroslav@557: 
jaroslav@557:                 public void remove() {
jaroslav@557:                     if (lastRet < 0)
jaroslav@557:                         throw new IllegalStateException();
jaroslav@557:                     checkForComodification();
jaroslav@557: 
jaroslav@557:                     try {
jaroslav@557:                         SubList.this.remove(lastRet);
jaroslav@557:                         cursor = lastRet;
jaroslav@557:                         lastRet = -1;
jaroslav@557:                         expectedModCount = ArrayList.this.modCount;
jaroslav@557:                     } catch (IndexOutOfBoundsException ex) {
jaroslav@557:                         throw new ConcurrentModificationException();
jaroslav@557:                     }
jaroslav@557:                 }
jaroslav@557: 
jaroslav@557:                 public void set(E e) {
jaroslav@557:                     if (lastRet < 0)
jaroslav@557:                         throw new IllegalStateException();
jaroslav@557:                     checkForComodification();
jaroslav@557: 
jaroslav@557:                     try {
jaroslav@557:                         ArrayList.this.set(offset + lastRet, e);
jaroslav@557:                     } catch (IndexOutOfBoundsException ex) {
jaroslav@557:                         throw new ConcurrentModificationException();
jaroslav@557:                     }
jaroslav@557:                 }
jaroslav@557: 
jaroslav@557:                 public void add(E e) {
jaroslav@557:                     checkForComodification();
jaroslav@557: 
jaroslav@557:                     try {
jaroslav@557:                         int i = cursor;
jaroslav@557:                         SubList.this.add(i, e);
jaroslav@557:                         cursor = i + 1;
jaroslav@557:                         lastRet = -1;
jaroslav@557:                         expectedModCount = ArrayList.this.modCount;
jaroslav@557:                     } catch (IndexOutOfBoundsException ex) {
jaroslav@557:                         throw new ConcurrentModificationException();
jaroslav@557:                     }
jaroslav@557:                 }
jaroslav@557: 
jaroslav@557:                 final void checkForComodification() {
jaroslav@557:                     if (expectedModCount != ArrayList.this.modCount)
jaroslav@557:                         throw new ConcurrentModificationException();
jaroslav@557:                 }
jaroslav@557:             };
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         public List<E> subList(int fromIndex, int toIndex) {
jaroslav@557:             subListRangeCheck(fromIndex, toIndex, size);
jaroslav@557:             return new SubList(this, offset, fromIndex, toIndex);
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         private void rangeCheck(int index) {
jaroslav@557:             if (index < 0 || index >= this.size)
jaroslav@557:                 throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         private void rangeCheckForAdd(int index) {
jaroslav@557:             if (index < 0 || index > this.size)
jaroslav@557:                 throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         private String outOfBoundsMsg(int index) {
jaroslav@557:             return "Index: "+index+", Size: "+this.size;
jaroslav@557:         }
jaroslav@557: 
jaroslav@557:         private void checkForComodification() {
jaroslav@557:             if (ArrayList.this.modCount != this.modCount)
jaroslav@557:                 throw new ConcurrentModificationException();
jaroslav@557:         }
jaroslav@557:     }
jaroslav@557: }