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package java.util; |
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/** |
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* This class implements the <tt>Set</tt> interface, backed by a |
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* <tt>TreeMap</tt> instance. This class guarantees that the sorted set will |
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* be in ascending element order, sorted according to the <i>natural order</i> |
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* of the elements (see <tt>Comparable</tt>), or by the comparator provided at |
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* set creation time, depending on which constructor is used.<p> |
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* A {@link NavigableSet} implementation based on a {@link TreeMap}. |
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* The elements are ordered using their {@linkplain Comparable natural |
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* ordering}, or by a {@link Comparator} provided at set creation |
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* time, depending on which constructor is used. |
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* |
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* This implementation provides guaranteed log(n) time cost for the basic |
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* operations (<tt>add</tt>, <tt>remove</tt> and <tt>contains</tt>).<p> |
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* <p>This implementation provides guaranteed log(n) time cost for the basic |
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* operations (<tt>add</tt>, <tt>remove</tt> and <tt>contains</tt>). |
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* |
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* Note that the ordering maintained by a set (whether or not an explicit |
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* <p>Note that the ordering maintained by a set (whether or not an explicit |
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* comparator is provided) must be <i>consistent with equals</i> if it is to |
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* correctly implement the <tt>Set</tt> interface. (See <tt>Comparable</tt> |
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* or <tt>Comparator</tt> for a precise definition of <i>consistent with |
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* equals</i>.) This is so because the <tt>Set</tt> interface is defined in |
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* terms of the <tt>equals</tt> operation, but a <tt>TreeSet</tt> instance |
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* performs all key comparisons using its <tt>compareTo</tt> (or |
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* <tt>compare</tt>) method, so two keys that are deemed equal by this method |
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* performs all element comparisons using its <tt>compareTo</tt> (or |
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* <tt>compare</tt>) method, so two elements that are deemed equal by this method |
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* are, from the standpoint of the set, equal. The behavior of a set |
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* <i>is</i> well-defined even if its ordering is inconsistent with equals; it |
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* just fails to obey the general contract of the <tt>Set</tt> interface.<p> |
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* just fails to obey the general contract of the <tt>Set</tt> interface. |
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* |
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* <b>Note that this implementation is not synchronized.</b> If multiple |
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* <p><b>Note that this implementation is not synchronized.</b> If multiple |
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* threads access a set concurrently, and at least one of the threads modifies |
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* the set, it <i>must</i> be synchronized externally. This is typically |
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* accomplished by synchronizing on some object that naturally encapsulates |
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* <tt>Collections.synchronizedSet</tt> method. This is best done at creation |
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* time, to prevent accidental unsynchronized access to the set: <pre> |
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* SortedSet s = Collections.synchronizedSortedSet(new TreeSet(...)); |
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* </pre><p> |
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* </pre> |
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* |
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* The Iterators returned by this class's <tt>iterator</tt> method are |
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* <p>The iterators returned by this class's <tt>iterator</tt> method are |
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* <i>fail-fast</i>: if the set is modified at any time after the iterator is |
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* created, in any way except through the iterator's own <tt>remove</tt> |
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* method, the iterator will throw a <tt>ConcurrentModificationException</tt>. |
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* method, the iterator will throw a {@link ConcurrentModificationException}. |
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* Thus, in the face of concurrent modification, the iterator fails quickly |
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* and cleanly, rather than risking arbitrary, non-deterministic behavior at |
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* an undetermined time in the future. |
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* throw <tt>ConcurrentModificationException</tt> on a best-effort basis. |
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* Therefore, it would be wrong to write a program that depended on this |
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* exception for its correctness: <i>the fail-fast behavior of iterators |
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* should be used only to detect bugs.</i><p> |
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* should be used only to detect bugs.</i> |
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* |
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* This class is a member of the |
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* <p>This class is a member of the |
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* <a href="{@docRoot}/../guide/collections/index.html"> |
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* Java Collections Framework</a>. |
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* |
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* @param <E> the type of elements maintained by this set |
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* |
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* @author Josh Bloch |
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* @version %I%, %G% |
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* @see Collection |
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private static final Object PRESENT = new Object(); |
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/** |
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* Constructs a set backed by the specified sorted map. |
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* Constructs a set backed by the specified navigable map. |
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*/ |
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private TreeSet(NavigableMap<E,Object> m) { |
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this.m = m; |
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} |
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/** |
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* Constructs a new, empty set, sorted according to the elements' natural |
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* order. All elements inserted into the set must implement the |
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* <tt>Comparable</tt> interface. Furthermore, all such elements must be |
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* <i>mutually comparable</i>: <tt>e1.compareTo(e2)</tt> must not throw a |
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* Constructs a new, empty tree set, sorted according to the |
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* natural ordering of its elements. All elements inserted into |
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* the set must implement the {@link Comparable} interface. |
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* Furthermore, all such elements must be <i>mutually |
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* comparable</i>: <tt>e1.compareTo(e2)</tt> must not throw a |
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* <tt>ClassCastException</tt> for any elements <tt>e1</tt> and |
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* <tt>e2</tt> in the set. If the user attempts to add an element to the |
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* set that violates this constraint (for example, the user attempts to |
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* add a string element to a set whose elements are integers), the |
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* <tt>add(Object)</tt> call will throw a <tt>ClassCastException</tt>. |
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* |
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* @see Comparable |
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* <tt>e2</tt> in the set. If the user attempts to add an element |
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* to the set that violates this constraint (for example, the user |
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* attempts to add a string element to a set whose elements are |
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* integers), the <tt>add(Object)</tt> call will throw a |
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* <tt>ClassCastException</tt>. |
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*/ |
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public TreeSet() { |
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this(new TreeMap<E,Object>()); |
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} |
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/** |
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* Constructs a new, empty set, sorted according to the specified |
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* Constructs a new, empty tree set, sorted according to the specified |
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* comparator. All elements inserted into the set must be <i>mutually |
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* comparable</i> by the specified comparator: <tt>comparator.compare(e1, |
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* e2)</tt> must not throw a <tt>ClassCastException</tt> for any elements |
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* an element to the set that violates this constraint, the |
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* <tt>add(Object)</tt> call will throw a <tt>ClassCastException</tt>. |
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* |
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* @param c the comparator that will be used to sort this set. A |
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* <tt>null</tt> value indicates that the elements' <i>natural |
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* ordering</i> should be used. |
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* @param comparator the comparator that will be used to order this set. |
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* If <tt>null</tt>, the {@linkplain Comparable natural |
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* ordering} of the elements will be used. |
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*/ |
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public TreeSet(Comparator<? super E> c) { |
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this(new TreeMap<E,Object>(c)); |
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public TreeSet(Comparator<? super E> comparator) { |
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this(new TreeMap<E,Object>(comparator)); |
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} |
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/** |
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* Constructs a new set containing the elements in the specified |
127 |
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* collection, sorted according to the elements' <i>natural order</i>. |
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* All keys inserted into the set must implement the <tt>Comparable</tt> |
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* interface. Furthermore, all such keys must be <i>mutually |
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* comparable</i>: <tt>k1.compareTo(k2)</tt> must not throw a |
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* <tt>ClassCastException</tt> for any elements <tt>k1</tt> and |
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* <tt>k2</tt> in the set. |
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* |
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* @param c The elements that will comprise the new set. |
126 |
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* Constructs a new tree set containing the elements in the specified |
127 |
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* collection, sorted according to the <i>natural ordering</i> of its |
128 |
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* elements. All elements inserted into the set must implement the |
129 |
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* {@link Comparable} interface. Furthermore, all such elements must be |
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* <i>mutually comparable</i>: <tt>e1.compareTo(e2)</tt> must not throw a |
131 |
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* <tt>ClassCastException</tt> for any elements <tt>e1</tt> and |
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* <tt>e2</tt> in the set. |
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* |
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* @throws ClassCastException if the keys in the specified collection are |
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* not comparable, or are not mutually comparable. |
136 |
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* @throws NullPointerException if the specified collection is null. |
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* @param c collection whose elements will comprise the new set |
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* @throws ClassCastException if the elements in <tt>c</tt> are |
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* not {@link Comparable}, or are not mutually comparable |
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* @throws NullPointerException if the specified collection is null |
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*/ |
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public TreeSet(Collection<? extends E> c) { |
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this(); |
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} |
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/** |
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* Constructs a new set containing the same elements as the specified |
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* sorted set, sorted according to the same ordering. |
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* Constructs a new tree set containing the same elements and |
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* using the same ordering as the specified sorted set. |
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* |
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* @param s sorted set whose elements will comprise the new set. |
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* @throws NullPointerException if the specified sorted set is null. |
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* @param s sorted set whose elements will comprise the new set |
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* @throws NullPointerException if the specified sorted set is null |
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*/ |
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public TreeSet(SortedSet<E> s) { |
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this(s.comparator()); |
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* Returns an iterator over the elements in this set. The elements |
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* are returned in ascending order. |
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* |
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* @return an iterator over the elements in this set. |
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* @return an iterator over the elements in this set |
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*/ |
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public Iterator<E> iterator() { |
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return m.keySet().iterator(); |
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return m.keySet().iterator(); |
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} |
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/** |
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* Returns an iterator over the elements in this set. The elements |
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* are returned in descending order. |
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* |
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* @return an iterator over the elements in this set. |
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* @return an iterator over the elements in this set |
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*/ |
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public Iterator<E> descendingIterator() { |
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return m.descendingKeySet().iterator(); |
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/** |
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* Returns the number of elements in this set (its cardinality). |
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* |
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* @return the number of elements in this set (its cardinality). |
179 |
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* @return the number of elements in this set (its cardinality) |
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*/ |
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public int size() { |
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return m.size(); |
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/** |
186 |
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* Returns <tt>true</tt> if this set contains no elements. |
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* |
188 |
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* @return <tt>true</tt> if this set contains no elements. |
188 |
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* @return <tt>true</tt> if this set contains no elements |
189 |
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*/ |
190 |
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public boolean isEmpty() { |
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return m.isEmpty(); |
194 |
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/** |
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* Returns <tt>true</tt> if this set contains the specified element. |
196 |
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* |
197 |
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* @param o the object to be checked for containment in this set. |
198 |
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* @return <tt>true</tt> if this set contains the specified element. |
199 |
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* |
197 |
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* @param o the object to be checked for containment in this set |
198 |
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* @return <tt>true</tt> if this set contains the specified element |
199 |
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* @throws ClassCastException if the specified object cannot be compared |
200 |
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* with the elements currently in the set. |
201 |
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* @throws NullPointerException if o is <tt>null</tt> and this map |
202 |
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* uses natural ordering and is non-empty, or its comparator does |
203 |
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* not tolerate <tt>null</tt> keys. |
200 |
> |
* with the elements currently in the set |
201 |
> |
* @throws NullPointerException if the specified element is null and |
202 |
> |
* this set uses natural ordering and is non-empty, or its |
203 |
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* comparator does not permit null elements |
204 |
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*/ |
205 |
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public boolean contains(Object o) { |
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return m.containsKey(o); |
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/** |
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* Adds the specified element to this set if it is not already present. |
211 |
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* |
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* @param e element to be added to this set. |
212 |
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* @param e element to be added to this set |
213 |
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* @return <tt>true</tt> if the set did not already contain the specified |
214 |
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* element. |
216 |
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* |
214 |
> |
* element |
215 |
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* @throws ClassCastException if the specified object cannot be compared |
216 |
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* with the elements currently in the set. |
217 |
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* @throws NullPointerException if e is <tt>null</tt> and this map |
218 |
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* uses natural ordering and is non-empty, or its comparator does |
219 |
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* not tolerate <tt>null</tt> keys. |
216 |
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* with the elements currently in the set |
217 |
> |
* @throws NullPointerException if the specified element is null and |
218 |
> |
* this set uses natural ordering and is non-empty, or its |
219 |
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* comparator does not permit null elements |
220 |
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*/ |
221 |
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public boolean add(E e) { |
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return m.put(e, PRESENT)==null; |
225 |
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/** |
226 |
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* Removes the specified element from this set if it is present. |
227 |
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* |
228 |
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* @param o object to be removed from this set, if present. |
229 |
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* @return <tt>true</tt> if the set contained the specified element. |
232 |
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* |
228 |
> |
* @param o object to be removed from this set, if present |
229 |
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* @return <tt>true</tt> if the set contained the specified element |
230 |
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* @throws ClassCastException if the specified object cannot be compared |
231 |
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* with the elements currently in the set. |
232 |
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* @throws NullPointerException if o is <tt>null</tt> and this map |
233 |
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* uses natural ordering and is non-empty, or its comparator does |
234 |
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* not tolerate <tt>null</tt> keys. |
231 |
> |
* with the elements currently in the set |
232 |
> |
* @throws NullPointerException if the specified element is null and |
233 |
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* this set uses natural ordering and is non-empty, or its |
234 |
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* comparator does not permit null elements |
235 |
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*/ |
236 |
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public boolean remove(Object o) { |
237 |
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return m.remove(o)==PRESENT; |
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|
240 |
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/** |
241 |
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* Removes all of the elements from this set. |
242 |
+ |
* The set will be empty after this call returns. |
243 |
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*/ |
244 |
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public void clear() { |
245 |
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m.clear(); |
249 |
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* Adds all of the elements in the specified collection to this set. |
250 |
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* |
251 |
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* @param c elements to be added |
252 |
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* @return <tt>true</tt> if this set changed as a result of the call. |
255 |
< |
* |
252 |
> |
* @return <tt>true</tt> if this set changed as a result of the call |
253 |
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* @throws ClassCastException if the elements provided cannot be compared |
254 |
< |
* with the elements currently in the set. |
255 |
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* @throws NullPointerException if the specified collection is |
256 |
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* <tt>null</tt> or if any element is <tt>null</tt> and this map |
257 |
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* uses natural ordering, or its comparator does not tolerate |
261 |
< |
* <tt>null</tt> keys. |
254 |
> |
* with the elements currently in the set |
255 |
> |
* @throws NullPointerException if the specified collection is null or |
256 |
> |
* if any element is null and this set uses natural ordering, or |
257 |
> |
* its comparator does not permit null elements |
258 |
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*/ |
259 |
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public boolean addAll(Collection<? extends E> c) { |
260 |
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// Use linear-time version if applicable |
261 |
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if (m.size()==0 && c.size() > 0 && |
262 |
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c instanceof SortedSet && |
263 |
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m instanceof TreeMap) { |
264 |
< |
SortedSet<Map.Entry<E, Object>> set = (SortedSet<Map.Entry<E, Object>>) (SortedSet) c; |
264 |
> |
SortedSet<? extends E> set = (SortedSet<? extends E>) c; |
265 |
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TreeMap<E,Object> map = (TreeMap<E, Object>) m; |
266 |
< |
Comparator<? super E> cc = (Comparator<E>) set.comparator(); |
266 |
> |
Comparator<? super E> cc = (Comparator<? super E>) set.comparator(); |
267 |
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Comparator<? super E> mc = map.comparator(); |
268 |
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if (cc==mc || (cc != null && cc.equals(mc))) { |
269 |
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map.addAllForTreeSet(set, PRESENT); |
274 |
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} |
275 |
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|
276 |
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/** |
277 |
< |
* Returns a view of the portion of this set whose elements range |
282 |
< |
* from <tt>fromElement</tt>, inclusive, to <tt>toElement</tt>, |
283 |
< |
* exclusive. (If <tt>fromElement</tt> and <tt>toElement</tt> are |
284 |
< |
* equal, the returned navigable set is empty.) The returned |
285 |
< |
* navigable set is backed by this set, so changes in the returned |
286 |
< |
* navigable set are reflected in this set, and vice-versa. The |
287 |
< |
* returned navigable set supports all optional Set operations.<p> |
288 |
< |
* |
289 |
< |
* The navigable set returned by this method will throw an |
290 |
< |
* <tt>IllegalArgumentException</tt> if the user attempts to insert an |
291 |
< |
* element outside the specified range.<p> |
292 |
< |
* |
293 |
< |
* Note: this method always returns a <i>half-open range</i> |
294 |
< |
* (which includes its low endpoint but not its high endpoint). |
295 |
< |
* If you need a <i>closed range</i> (which includes both |
296 |
< |
* endpoints), and the element type allows for calculation of the |
297 |
< |
* successor of a specified value, merely request the subrange |
298 |
< |
* from <tt>lowEndpoint</tt> to <tt>successor(highEndpoint)</tt>. |
299 |
< |
* For example, suppose that <tt>s</tt> is a navigable set of |
300 |
< |
* strings. The following idiom obtains a view containing all of |
301 |
< |
* the strings in <tt>s</tt> from <tt>low</tt> to <tt>high</tt>, |
302 |
< |
* inclusive: |
303 |
< |
* <pre> NavigableSet sub = s.navigableSubSet(low, high+"\0"); |
304 |
< |
* </pre> |
305 |
< |
* |
306 |
< |
* A similar technique can be used to generate an <i>open range</i> (which |
307 |
< |
* contains neither endpoint). The following idiom obtains a view |
308 |
< |
* containing all of the strings in <tt>s</tt> from <tt>low</tt> to |
309 |
< |
* <tt>high</tt>, exclusive: <pre> |
310 |
< |
* NavigableSet sub = s.navigableSubSet(low+"\0", high); |
311 |
< |
* </pre> |
312 |
< |
* |
313 |
< |
* @param fromElement low endpoint (inclusive) of the range. |
314 |
< |
* @param toElement high endpoint (exclusive) of the range. |
315 |
< |
* @return a view of the portion of this set whose elements range from |
316 |
< |
* <tt>fromElement</tt>, inclusive, to <tt>toElement</tt>, |
317 |
< |
* exclusive. |
318 |
< |
* @throws ClassCastException if <tt>fromElement</tt> and |
319 |
< |
* <tt>toElement</tt> cannot be compared to one another using |
320 |
< |
* this set's comparator (or, if the set has no comparator, |
321 |
< |
* using natural ordering). |
322 |
< |
* @throws IllegalArgumentException if <tt>fromElement</tt> is greater than |
323 |
< |
* <tt>toElement</tt>. |
277 |
> |
* @throws ClassCastException {@inheritDoc} |
278 |
|
* @throws NullPointerException if <tt>fromElement</tt> or |
279 |
< |
* <tt>toElement</tt> is <tt>null</tt> and this set uses natural |
280 |
< |
* order, or its comparator does not tolerate <tt>null</tt> |
281 |
< |
* elements. |
279 |
> |
* <tt>toElement</tt> is null and this set uses natural ordering, |
280 |
> |
* or its comparator does not permit null elements |
281 |
> |
* @throws IllegalArgumentException {@inheritDoc} |
282 |
|
*/ |
283 |
|
public NavigableSet<E> navigableSubSet(E fromElement, E toElement) { |
284 |
|
return new TreeSet<E>(m.navigableSubMap(fromElement, toElement)); |
285 |
|
} |
286 |
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|
287 |
|
/** |
288 |
< |
* Returns a view of the portion of this set whose elements are |
289 |
< |
* strictly less than <tt>toElement</tt>. The returned navigable |
290 |
< |
* set is backed by this set, so changes in the returned navigable |
291 |
< |
* set are reflected in this set, and vice-versa. The returned |
292 |
< |
* navigable set supports all optional set operations.<p> |
339 |
< |
* |
340 |
< |
* The navigable set returned by this method will throw an |
341 |
< |
* <tt>IllegalArgumentException</tt> if the user attempts to |
342 |
< |
* insert an element greater than or equal to |
343 |
< |
* <tt>toElement</tt>.<p> |
344 |
< |
* |
345 |
< |
* Note: this method always returns a view that does not contain |
346 |
< |
* its (high) endpoint. If you need a view that does contain this |
347 |
< |
* endpoint, and the element type allows for calculation of the |
348 |
< |
* successor of a specified value, merely request a headSet |
349 |
< |
* bounded by <tt>successor(highEndpoint)</tt>. For example, |
350 |
< |
* suppose that <tt>s</tt> is a navigable set of strings. The |
351 |
< |
* following idiom obtains a view containing all of the strings in |
352 |
< |
* <tt>s</tt> that are less than or equal to <tt>high</tt>: |
353 |
< |
* <pre> NavigableSet head = s.navigableHeadSet(high+"\0");</pre> |
354 |
< |
* |
355 |
< |
* @param toElement high endpoint (exclusive) of the headSet. |
356 |
< |
* @return a view of the portion of this set whose elements are strictly |
357 |
< |
* less than <tt>toElement</tt>. |
358 |
< |
* @throws ClassCastException if <tt>toElement</tt> is not compatible |
359 |
< |
* with this set's comparator (or, if the set has no comparator, |
360 |
< |
* if <tt>toElement</tt> does not implement <tt>Comparable</tt>). |
361 |
< |
* @throws IllegalArgumentException if this set is itself a subset, |
362 |
< |
* and <tt>toElement</tt> is not within the |
363 |
< |
* specified range of the subset. |
364 |
< |
* @throws NullPointerException if <tt>toElement</tt> is <tt>null</tt> and |
365 |
< |
* this set uses natural ordering, or its comparator does |
366 |
< |
* not tolerate <tt>null</tt> elements. |
288 |
> |
* @throws ClassCastException {@inheritDoc} |
289 |
> |
* @throws NullPointerException if <tt>toElement</tt> is null and |
290 |
> |
* this set uses natural ordering, or its comparator does |
291 |
> |
* not permit null elements |
292 |
> |
* @throws IllegalArgumentException {@inheritDoc} |
293 |
|
*/ |
294 |
|
public NavigableSet<E> navigableHeadSet(E toElement) { |
295 |
|
return new TreeSet<E>(m.navigableHeadMap(toElement)); |
296 |
|
} |
297 |
|
|
298 |
|
/** |
299 |
< |
* Returns a view of the portion of this set whose elements are |
300 |
< |
* greater than or equal to <tt>fromElement</tt>. The returned |
301 |
< |
* navigable set is backed by this set, so changes in the returned |
302 |
< |
* navigable set are reflected in this set, and vice-versa. The |
303 |
< |
* returned navigable set supports all optional set operations.<p> |
378 |
< |
* |
379 |
< |
* The navigable set returned by this method will throw an |
380 |
< |
* <tt>IllegalArgumentException</tt> if the user attempts to insert an |
381 |
< |
* element less than <tt>fromElement</tt>. |
382 |
< |
* |
383 |
< |
* Note: this method always returns a view that contains its (low) |
384 |
< |
* endpoint. If you need a view that does not contain this |
385 |
< |
* endpoint, and the element type allows for calculation of the |
386 |
< |
* successor of a specified value, merely request a tailSet |
387 |
< |
* bounded by <tt>successor(lowEndpoint)</tt>. For example, |
388 |
< |
* suppose that <tt>s</tt> is a navigable set of strings. The |
389 |
< |
* following idiom obtains a view containing all of the strings in |
390 |
< |
* <tt>s</tt> that are strictly greater than <tt>low</tt>: |
391 |
< |
* <pre> NavigableSet tail = s.navigableTailSet(low+"\0"); |
392 |
< |
* </pre> |
393 |
< |
* |
394 |
< |
* @param fromElement low endpoint (inclusive) of the tailSet. |
395 |
< |
* @return a view of the portion of this set whose elements are |
396 |
< |
* greater than or equal to <tt>fromElement</tt>. |
397 |
< |
* @throws ClassCastException if <tt>fromElement</tt> is not compatible |
398 |
< |
* with this set's comparator (or, if the set has no comparator, |
399 |
< |
* if <tt>fromElement</tt> does not implement <tt>Comparable</tt>). |
400 |
< |
* @throws IllegalArgumentException if this set is itself a subset, |
401 |
< |
* and <tt>fromElement</tt> is not within the |
402 |
< |
* specified range of the subset. |
403 |
< |
* @throws NullPointerException if <tt>fromElement</tt> is <tt>null</tt> |
404 |
< |
* and this set uses natural ordering, or its comparator does |
405 |
< |
* not tolerate <tt>null</tt> elements. |
299 |
> |
* @throws ClassCastException {@inheritDoc} |
300 |
> |
* @throws NullPointerException if <tt>fromElement</tt> is null and |
301 |
> |
* this set uses natural ordering, or its comparator does |
302 |
> |
* not permit null elements |
303 |
> |
* @throws IllegalArgumentException {@inheritDoc} |
304 |
|
*/ |
305 |
|
public NavigableSet<E> navigableTailSet(E fromElement) { |
306 |
|
return new TreeSet<E>(m.navigableTailMap(fromElement)); |
307 |
|
} |
308 |
|
|
411 |
– |
|
309 |
|
/** |
310 |
< |
* Equivalent to <tt>navigableSubSet</tt> but with a return |
311 |
< |
* type conforming to the <tt>SortedSet</tt> interface. |
312 |
< |
* @param fromElement low endpoint (inclusive) of the range. |
313 |
< |
* @param toElement high endpoint (exclusive) of the range. |
314 |
< |
* @return a view of the portion of this set whose elements range from |
315 |
< |
* <tt>fromElement</tt>, inclusive, to <tt>toElement</tt>, |
419 |
< |
* exclusive. |
420 |
< |
* @throws ClassCastException if <tt>fromElement</tt> and |
421 |
< |
* <tt>toElement</tt> cannot be compared to one another using |
422 |
< |
* this set's comparator (or, if the set has no comparator, |
423 |
< |
* using natural ordering). |
424 |
< |
* @throws IllegalArgumentException if <tt>fromElement</tt> is greater than |
425 |
< |
* <tt>toElement</tt>. |
310 |
> |
* Equivalent to {@link #navigableSubSet} but with a return type |
311 |
> |
* conforming to the <tt>SortedSet</tt> interface. |
312 |
> |
* |
313 |
> |
* <p>{@inheritDoc} |
314 |
> |
* |
315 |
> |
* @throws ClassCastException {@inheritDoc} |
316 |
|
* @throws NullPointerException if <tt>fromElement</tt> or |
317 |
< |
* <tt>toElement</tt> is <tt>null</tt> and this set uses natural |
318 |
< |
* order, or its comparator does not tolerate <tt>null</tt> |
319 |
< |
* elements. |
317 |
> |
* <tt>toElement</tt> is null and this set uses natural ordering, |
318 |
> |
* or its comparator does not permit null elements |
319 |
> |
* @throws IllegalArgumentException {@inheritDoc} |
320 |
|
*/ |
321 |
|
public SortedSet<E> subSet(E fromElement, E toElement) { |
322 |
|
return new TreeSet<E>(m.navigableSubMap(fromElement, toElement)); |
323 |
|
} |
324 |
|
|
325 |
|
/** |
326 |
< |
* Equivalent to <tt>navigableHeadSet</tt> but with a return |
327 |
< |
* type conforming to the <tt>SortedSet</tt> interface. |
326 |
> |
* Equivalent to {@link #navigableHeadSet} but with a return type |
327 |
> |
* conforming to the <tt>SortedSet</tt> interface. |
328 |
> |
* |
329 |
> |
* <p>{@inheritDoc} |
330 |
|
* |
331 |
< |
* @param toElement high endpoint (exclusive) of the headSet. |
332 |
< |
* @return a view of the portion of this set whose elements are strictly |
333 |
< |
* less than <tt>toElement</tt>. |
334 |
< |
* @throws ClassCastException if <tt>toElement</tt> is not compatible |
335 |
< |
* with this set's comparator (or, if the set has no comparator, |
444 |
< |
* if <tt>toElement</tt> does not implement <tt>Comparable</tt>). |
445 |
< |
* @throws IllegalArgumentException if this set is itself a subset, |
446 |
< |
* and <tt>toElement</tt> is not within the |
447 |
< |
* specified range of the subset. |
448 |
< |
* @throws NullPointerException if <tt>toElement</tt> is <tt>null</tt> and |
449 |
< |
* this set uses natural ordering, or its comparator does |
450 |
< |
* not tolerate <tt>null</tt> elements. |
331 |
> |
* @throws ClassCastException {@inheritDoc} |
332 |
> |
* @throws NullPointerException if <tt>toElement</tt> is null |
333 |
> |
* and this set uses natural ordering, or its comparator does |
334 |
> |
* not permit null elements |
335 |
> |
* @throws IllegalArgumentException {@inheritDoc} |
336 |
|
*/ |
337 |
|
public SortedSet<E> headSet(E toElement) { |
338 |
|
return new TreeSet<E>(m.navigableHeadMap(toElement)); |
339 |
|
} |
340 |
|
|
341 |
|
/** |
342 |
< |
* Equivalent to <tt>navigableTailSet</tt> but with a return |
343 |
< |
* type conforming to the <tt>SortedSet</tt> interface. |
344 |
< |
* @param fromElement low endpoint (inclusive) of the tailSet. |
345 |
< |
* @return a view of the portion of this set whose elements are |
346 |
< |
* greater than or equal to <tt>fromElement</tt>. |
347 |
< |
* @throws ClassCastException if <tt>fromElement</tt> is not compatible |
348 |
< |
* with this set's comparator (or, if the set has no comparator, |
349 |
< |
* if <tt>fromElement</tt> does not implement <tt>Comparable</tt>). |
350 |
< |
* @throws IllegalArgumentException if this set is itself a subset, |
351 |
< |
* and <tt>fromElement</tt> is not within the |
467 |
< |
* specified range of the subset. |
468 |
< |
* @throws NullPointerException if <tt>fromElement</tt> is <tt>null</tt> |
469 |
< |
* and this set uses natural ordering, or its comparator does |
470 |
< |
* not tolerate <tt>null</tt> elements. |
342 |
> |
* Equivalent to {@link #navigableTailSet} but with a return type |
343 |
> |
* conforming to the <tt>SortedSet</tt> interface. |
344 |
> |
* |
345 |
> |
* <p>{@inheritDoc} |
346 |
> |
* |
347 |
> |
* @throws ClassCastException {@inheritDoc} |
348 |
> |
* @throws NullPointerException if <tt>fromElement</tt> is null |
349 |
> |
* and this set uses natural ordering, or its comparator does |
350 |
> |
* not permit null elements |
351 |
> |
* @throws IllegalArgumentException {@inheritDoc} |
352 |
|
*/ |
353 |
|
public SortedSet<E> tailSet(E fromElement) { |
354 |
|
return new TreeSet<E>(m.navigableTailMap(fromElement)); |
355 |
|
} |
356 |
|
|
476 |
– |
/** |
477 |
– |
* Returns the comparator used to order this sorted set, or <tt>null</tt> |
478 |
– |
* if this tree set uses its elements natural ordering. |
479 |
– |
* |
480 |
– |
* @return the comparator used to order this sorted set, or <tt>null</tt> |
481 |
– |
* if this tree set uses its elements natural ordering. |
482 |
– |
*/ |
357 |
|
public Comparator<? super E> comparator() { |
358 |
|
return m.comparator(); |
359 |
|
} |
360 |
|
|
361 |
|
/** |
362 |
< |
* Returns the first (lowest) element currently in this sorted set. |
489 |
< |
* |
490 |
< |
* @return the first (lowest) element currently in this sorted set. |
491 |
< |
* @throws NoSuchElementException sorted set is empty. |
362 |
> |
* @throws NoSuchElementException {@inheritDoc} |
363 |
|
*/ |
364 |
|
public E first() { |
365 |
|
return m.firstKey(); |
366 |
|
} |
367 |
|
|
368 |
|
/** |
369 |
< |
* Returns the last (highest) element currently in this sorted set. |
499 |
< |
* |
500 |
< |
* @return the last (highest) element currently in this sorted set. |
501 |
< |
* @throws NoSuchElementException sorted set is empty. |
369 |
> |
* @throws NoSuchElementException {@inheritDoc} |
370 |
|
*/ |
371 |
|
public E last() { |
372 |
|
return m.lastKey(); |
374 |
|
|
375 |
|
// NavigableSet API methods |
376 |
|
|
509 |
– |
|
377 |
|
/** |
378 |
< |
* Returns an element greater than or equal to the given element, or |
379 |
< |
* <tt>null</tt> if there is no such element. |
380 |
< |
* |
381 |
< |
* @param e the value to match |
515 |
< |
* @return an element greater than or equal to given element, or |
516 |
< |
* <tt>null</tt> if there is no such element. |
517 |
< |
* @throws ClassCastException if e cannot be compared with the elements |
518 |
< |
* currently in the set. |
519 |
< |
* @throws NullPointerException if e is <tt>null</tt> and this map |
520 |
< |
* uses natural ordering and is non-empty, or its comparator does |
521 |
< |
* not tolerate <tt>null</tt> keys. |
522 |
< |
*/ |
523 |
< |
public E ceiling(E e) { |
524 |
< |
return m.ceilingKey(e); |
525 |
< |
} |
526 |
< |
|
527 |
< |
/** |
528 |
< |
* Returns an element strictly less than the given element, or |
529 |
< |
* <tt>null</tt> if there is no such element. |
530 |
< |
* |
531 |
< |
* @param e the value to match |
532 |
< |
* @return the greatest element less than the given element, or |
533 |
< |
* <tt>null</tt> if there is no such element. |
534 |
< |
* @throws ClassCastException if e cannot be compared with the elements |
535 |
< |
* currently in the set. |
536 |
< |
* @throws NullPointerException if e is <tt>null</tt> and this map |
537 |
< |
* uses natural ordering and is non-empty, or its comparator does |
538 |
< |
* not tolerate <tt>null</tt> keys. |
378 |
> |
* @throws ClassCastException {@inheritDoc} |
379 |
> |
* @throws NullPointerException if the specified element is null and |
380 |
> |
* this set uses natural ordering and is non-empty, |
381 |
> |
* or its comparator does not permit null elements |
382 |
|
*/ |
383 |
|
public E lower(E e) { |
384 |
|
return m.lowerKey(e); |
385 |
|
} |
386 |
|
|
387 |
|
/** |
388 |
< |
* Returns an element less than or equal to the given element, or |
389 |
< |
* <tt>null</tt> if there is no such element. |
390 |
< |
* |
391 |
< |
* @param e the value to match |
549 |
< |
* @return the greatest element less than or equal to given |
550 |
< |
* element, or <tt>null</tt> if there is no such element. |
551 |
< |
* @throws ClassCastException if e cannot be compared with the elements |
552 |
< |
* currently in the set. |
553 |
< |
* @throws NullPointerException if e is <tt>null</tt> and this map |
554 |
< |
* uses natural ordering and is non-empty, or its comparator does |
555 |
< |
* not tolerate <tt>null</tt> keys. |
388 |
> |
* @throws ClassCastException {@inheritDoc} |
389 |
> |
* @throws NullPointerException if the specified element is null and |
390 |
> |
* this set uses natural ordering and is non-empty, |
391 |
> |
* or its comparator does not permit null elements |
392 |
|
*/ |
393 |
|
public E floor(E e) { |
394 |
|
return m.floorKey(e); |
395 |
|
} |
396 |
|
|
397 |
|
/** |
398 |
< |
* Returns an element strictly greater than the given element, or |
399 |
< |
* <tt>null</tt> if there is no such element. |
400 |
< |
* |
401 |
< |
* @param e the value to match |
566 |
< |
* @return the least element greater than the given element, or |
567 |
< |
* <tt>null</tt> if there is no such element. |
568 |
< |
* @throws ClassCastException if e cannot be compared with the elements |
569 |
< |
* currently in the set. |
570 |
< |
* @throws NullPointerException if e is <tt>null</tt> and this map |
571 |
< |
* uses natural ordering and is non-empty, or its comparator does |
572 |
< |
* not tolerate <tt>null</tt> keys. |
398 |
> |
* @throws ClassCastException {@inheritDoc} |
399 |
> |
* @throws NullPointerException if the specified element is null and |
400 |
> |
* this set uses natural ordering and is non-empty, |
401 |
> |
* or its comparator does not permit null elements |
402 |
|
*/ |
403 |
< |
public E higher(E e) { |
404 |
< |
return m.higherKey(e); |
403 |
> |
public E ceiling(E e) { |
404 |
> |
return m.ceilingKey(e); |
405 |
|
} |
406 |
|
|
407 |
|
/** |
408 |
< |
* Retrieves and removes the first (lowest) element. |
409 |
< |
* |
410 |
< |
* @return the least element, or <tt>null</tt> if empty. |
408 |
> |
* @throws ClassCastException {@inheritDoc} |
409 |
> |
* @throws NullPointerException if the specified element is null and |
410 |
> |
* this set uses natural ordering and is non-empty, |
411 |
> |
* or its comparator does not permit null elements |
412 |
|
*/ |
413 |
+ |
public E higher(E e) { |
414 |
+ |
return m.higherKey(e); |
415 |
+ |
} |
416 |
+ |
|
417 |
|
public E pollFirst() { |
418 |
|
Map.Entry<E,?> e = m.pollFirstEntry(); |
419 |
|
return (e == null)? null : e.getKey(); |
420 |
|
} |
421 |
|
|
588 |
– |
/** |
589 |
– |
* Retrieves and removes the last (highest) element. |
590 |
– |
* |
591 |
– |
* @return the last element, or <tt>null</tt> if empty. |
592 |
– |
*/ |
422 |
|
public E pollLast() { |
423 |
|
Map.Entry<E,?> e = m.pollLastEntry(); |
424 |
|
return (e == null)? null : e.getKey(); |
428 |
|
* Returns a shallow copy of this <tt>TreeSet</tt> instance. (The elements |
429 |
|
* themselves are not cloned.) |
430 |
|
* |
431 |
< |
* @return a shallow copy of this set. |
431 |
> |
* @return a shallow copy of this set |
432 |
|
*/ |
433 |
|
public Object clone() { |
434 |
|
TreeSet<E> clone = null; |
448 |
|
* serialize it). |
449 |
|
* |
450 |
|
* @serialData Emits the comparator used to order this set, or |
451 |
< |
* <tt>null</tt> if it obeys its elements' natural ordering |
452 |
< |
* (Object), followed by the size of the set (the number of |
453 |
< |
* elements it contains) (int), followed by all of its |
454 |
< |
* elements (each an Object) in order (as determined by the |
455 |
< |
* set's Comparator, or by the elements' natural ordering if |
451 |
> |
* <tt>null</tt> if it obeys its elements' natural ordering |
452 |
> |
* (Object), followed by the size of the set (the number of |
453 |
> |
* elements it contains) (int), followed by all of its |
454 |
> |
* elements (each an Object) in order (as determined by the |
455 |
> |
* set's Comparator, or by the elements' natural ordering if |
456 |
|
* the set has no Comparator). |
457 |
|
*/ |
458 |
|
private void writeObject(java.io.ObjectOutputStream s) |
481 |
|
s.defaultReadObject(); |
482 |
|
|
483 |
|
// Read in Comparator |
484 |
< |
Comparator<E> c = (Comparator<E>) s.readObject(); |
484 |
> |
Comparator<? super E> c = (Comparator<? super E>) s.readObject(); |
485 |
|
|
486 |
|
// Create backing TreeMap |
487 |
|
TreeMap<E,Object> tm; |