/**
* Adds all elements in {@code iterable} to {@code collection}.
*
* @return {@code true} if {@code collection} was modified as a result of this operation.
*/
public static <T> boolean addAll(Collection<T> addTo, Iterable<? extends T> elementsToAdd) {
if (elementsToAdd instanceof Collection) {
Collection<? extends T> c = Collections2.cast(elementsToAdd);
return addTo.addAll(c);
}
return Iterators.addAll(addTo, checkNotNull(elementsToAdd).iterator());
}
/**
* Creates an {@code ArrayDeque} containing the elements of the specified iterable, in the order
* they are returned by the iterable's iterator.
*
* @since 12.0
*/
public static <E> ArrayDeque<E> newArrayDeque(Iterable<? extends E> elements) {
if (elements instanceof Collection) {
return new ArrayDeque<E>(Collections2.cast(elements));
}
ArrayDeque<E> deque = new ArrayDeque<E>();
Iterables.addAll(deque, elements);
return deque;
}
/**
* Creates a {@code LinkedBlockingQueue} with a capacity of {@link Integer#MAX_VALUE}, containing
* the elements of the specified iterable, in the order they are returned by the iterable's
* iterator.
*
* @param elements the elements that the queue should contain, in order
* @return a new {@code LinkedBlockingQueue} containing those elements
*/
public static <E> LinkedBlockingQueue<E> newLinkedBlockingQueue(Iterable<? extends E> elements) {
if (elements instanceof Collection) {
return new LinkedBlockingQueue<E>(Collections2.cast(elements));
}
LinkedBlockingQueue<E> queue = new LinkedBlockingQueue<E>();
Iterables.addAll(queue, elements);
return queue;
}
/**
* Creates a <i>mutable</i> {@code ArrayList} instance containing the given elements; a very thin
* shortcut for creating an empty list then calling {@link Iterables#addAll}.
*
* <p><b>Note:</b> if mutability is not required and the elements are non-null, use {@link
* ImmutableList#copyOf(Iterable)} instead. (Or, change {@code elements} to be a {@link
* FluentIterable} and call {@code elements.toList()}.)
*
* <p><b>Note for Java 7 and later:</b> if {@code elements} is a {@link Collection}, you don't
* need this method. Use the {@code ArrayList} {@linkplain ArrayList#ArrayList(Collection)
* constructor} directly, taking advantage of the new <a href="http://goo.gl/iz2Wi">"diamond"
* syntax</a>.
*/
@GwtCompatible(serializable = true)
public static <E> ArrayList<E> newArrayList(Iterable<? extends E> elements) {
checkNotNull(elements); // for GWT
// Let ArrayList's sizing logic work, if possible
return (elements instanceof Collection)
? new ArrayList<E>(Collections2.cast(elements))
: newArrayList(elements.iterator());
}
/**
* Creates a {@code PriorityQueue} containing the given elements.
*
* <p><b>Note:</b> If the specified iterable is a {@code SortedSet} or a {@code PriorityQueue},
* this priority queue will be ordered according to the same ordering.
*
* @since 11.0 (requires that {@code E} be {@code Comparable} since 15.0).
*/
public static <E extends Comparable> PriorityQueue<E> newPriorityQueue(
Iterable<? extends E> elements) {
if (elements instanceof Collection) {
return new PriorityQueue<E>(Collections2.cast(elements));
}
PriorityQueue<E> queue = new PriorityQueue<E>();
Iterables.addAll(queue, elements);
return queue;
}
/**
* Creates a {@code CopyOnWriteArrayList} instance containing the given elements.
*
* @param elements the elements that the list should contain, in order
* @return a new {@code CopyOnWriteArrayList} containing those elements
* @since 12.0
*/
@GwtIncompatible("CopyOnWriteArrayList")
public static <E> CopyOnWriteArrayList<E> newCopyOnWriteArrayList(
Iterable<? extends E> elements) {
// We copy elements to an ArrayList first, rather than incurring the
// quadratic cost of adding them to the COWAL directly.
Collection<? extends E> elementsCollection =
(elements instanceof Collection) ? Collections2.cast(elements) : newArrayList(elements);
return new CopyOnWriteArrayList<E>(elementsCollection);
}
/**
* Returns the last element of {@code iterable} or {@code defaultValue} if the iterable is empty.
*
* @param defaultValue the value to return if {@code iterable} is empty
* @return the last element of {@code iterable} or the default value
* @since 3.0
*/
@Nullable
public static <T> T getLast(Iterable<? extends T> iterable, @Nullable T defaultValue) {
if (iterable instanceof Collection) {
Collection<? extends T> c = Collections2.cast(iterable);
if (c.isEmpty()) {
return defaultValue;
} else if (iterable instanceof List) {
return getLastInNonemptyList(Lists.cast(iterable));
}
}
return Iterators.getLast(iterable.iterator(), defaultValue);
}
/**
* Returns an immutable list containing the given elements, in order. If {@code elements} is a
* {@link java.util.Collection}, this method behaves exactly as {@link
* #copyOf(java.util.Collection)}; otherwise, it behaves exactly as {@code
* copyOf(elements.iterator()}.
*
* @throws NullPointerException if any of {@code elements} is null
*/
public static <E> ImmutableList<E> copyOf(Iterable<? extends E> elements) {
checkNotNull(elements); // TODO(kevinb): is this here only for GWT?
return (elements instanceof Collection)
? copyOf(Collections2.cast(elements))
: copyOf(elements.iterator());
}
