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/* |
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* Written by Doug Lea with assistance from members of JCP JSR-166 |
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* Expert Group and released to the public domain, as explained at |
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* http://creativecommons.org/licenses/publicdomain |
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* Written by Doug Lea and Josh Bloch with assistance from members of JCP |
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* JSR-166 Expert Group and released to the public domain, as explained at |
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* http://creativecommons.org/publicdomain/zero/1.0/ |
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*/ |
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package java.util; |
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import java.util.*; // for javadoc (till 6280605 is fixed) |
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/** |
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* A {@link SortedSet} extended with navigation methods reporting |
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* closest matches for given search targets. Methods <tt>lower</tt>, |
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* <tt>floor</tt>, <tt>ceiling</tt>, and <tt>higher</tt> return elements |
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* closest matches for given search targets. Methods {@link #lower}, |
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* {@link #floor}, {@link #ceiling}, and {@link #higher} return elements |
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* respectively less than, less than or equal, greater than or equal, |
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* and greater than a given element, returning <tt>null</tt> if there is |
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* no such element. A <tt>NavigableSet</tt> may be viewed and traversed |
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* in either ascending or descending order. The <tt>Collection</tt> |
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* <tt>iterator</tt> method returns an ascending <tt>Iterator</tt> and |
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* the additional method <tt>descendingIterator</tt> returns a |
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* descending iterator. The performance of ascending traversals is |
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* likely to be faster than descending traversals. This interface |
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* additionally defines methods <tt>pollFirst</tt> and |
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* <tt>pollLast</tt> that return and remove the lowest and highest |
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* element, if one exists, else returning <tt>null</tt>. |
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* Methods <tt>navigableSubSet</tt>, <tt>navigableHeadSet</tt>, and |
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* <tt>navigableTailSet</tt> differ from the similarly named |
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* <tt>SortedSet</tt> methods only in their declared return types. |
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* Subsets of any <tt>NavigableSet</tt> must implement the |
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* <tt>NavigableSet</tt> interface. |
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* and greater than a given element, returning {@code null} if there |
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* is no such element. |
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* |
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* <p> The return values of navigation methods may be ambiguous in |
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* implementations that permit <tt>null</tt> elements. However, even |
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* <p>A {@code NavigableSet} may be accessed and traversed in either |
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* ascending or descending order. The {@link #descendingSet} method |
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* returns a view of the set with the senses of all relational and |
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* directional methods inverted. The performance of ascending |
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* operations and views is likely to be faster than that of descending |
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* ones. This interface additionally defines methods {@link |
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* #pollFirst} and {@link #pollLast} that return and remove the lowest |
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* and highest element, if one exists, else returning {@code null}. |
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* Methods |
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* {@link #subSet(Object, boolean, Object, boolean) subSet(E, boolean, E, boolean)}, |
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* {@link #headSet(Object, boolean) headSet(E, boolean)}, and |
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* {@link #tailSet(Object, boolean) tailSet(E, boolean)} |
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* differ from the like-named {@code SortedSet} methods in accepting |
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* additional arguments describing whether lower and upper bounds are |
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* inclusive versus exclusive. Subsets of any {@code NavigableSet} |
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* must implement the {@code NavigableSet} interface. |
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* |
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* <p>The return values of navigation methods may be ambiguous in |
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* implementations that permit {@code null} elements. However, even |
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* in this case the result can be disambiguated by checking |
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* <tt>contains(null)</tt>. To avoid such issues, implementations of |
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* {@code contains(null)}. To avoid such issues, implementations of |
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* this interface are encouraged to <em>not</em> permit insertion of |
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* <tt>null</tt> elements. (Note that sorted sets of {@link |
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* Comparable} elements intrinsically do not permit <tt>null</tt>.) |
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* {@code null} elements. (Note that sorted sets of {@link |
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* Comparable} elements intrinsically do not permit {@code null}.) |
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* |
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* <p>Methods |
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* {@link #subSet(Object, Object) subSet(E, E)}, |
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* {@link #headSet(Object) headSet(E)}, and |
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* {@link #tailSet(Object) tailSet(E)} |
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* are specified to return {@code SortedSet} to allow existing |
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* implementations of {@code SortedSet} to be compatibly retrofitted to |
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* implement {@code NavigableSet}, but extensions and implementations |
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* of this interface are encouraged to override these methods to return |
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* {@code NavigableSet}. |
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* |
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* <p>This interface is a member of the |
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* <a href="{@docRoot}/../guide/collections/index.html"> |
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* <a href="{@docRoot}/../technotes/guides/collections/index.html"> |
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* Java Collections Framework</a>. |
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* |
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* @author Doug Lea |
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* @author Josh Bloch |
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* @param <E> the type of elements maintained by this set |
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* @since 1.6 |
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*/ |
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public interface NavigableSet<E> extends SortedSet<E> { |
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/** |
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* Returns the greatest element in this set strictly less than the |
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* given element, or <tt>null</tt> if there is no such element. |
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* given element, or {@code null} if there is no such element. |
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* |
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* @param e the value to match |
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* @return the greatest element less than <tt>e</tt>, |
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* or <tt>null</tt> if there is no such element |
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* @return the greatest element less than {@code e}, |
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* or {@code null} if there is no such element |
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* @throws ClassCastException if the specified element cannot be |
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* compared with the elements currently in the set |
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* @throws NullPointerException if the specified element is null |
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/** |
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* Returns the greatest element in this set less than or equal to |
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* the given element, or <tt>null</tt> if there is no such element. |
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* the given element, or {@code null} if there is no such element. |
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* |
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* @param e the value to match |
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* @return the greatest element less than or equal to <tt>e</tt>, |
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* or <tt>null</tt> if there is no such element |
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* @return the greatest element less than or equal to {@code e}, |
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* or {@code null} if there is no such element |
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* @throws ClassCastException if the specified element cannot be |
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* compared with the elements currently in the set |
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* @throws NullPointerException if the specified element is null |
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/** |
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* Returns the least element in this set greater than or equal to |
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* the given element, or <tt>null</tt> if there is no such element. |
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* the given element, or {@code null} if there is no such element. |
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* |
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* @param e the value to match |
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* @return the least element greater than or equal to <tt>e</tt>, |
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* or <tt>null</tt> if there is no such element |
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* @return the least element greater than or equal to {@code e}, |
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* or {@code null} if there is no such element |
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* @throws ClassCastException if the specified element cannot be |
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* compared with the elements currently in the set |
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* @throws NullPointerException if the specified element is null |
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/** |
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* Returns the least element in this set strictly greater than the |
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* given element, or <tt>null</tt> if there is no such element. |
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* given element, or {@code null} if there is no such element. |
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* |
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* @param e the value to match |
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* @return the least element greater than <tt>e</tt>, |
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* or <tt>null</tt> if there is no such element |
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> |
* @return the least element greater than {@code e}, |
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* or {@code null} if there is no such element |
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* @throws ClassCastException if the specified element cannot be |
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* compared with the elements currently in the set |
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* @throws NullPointerException if the specified element is null |
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|
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/** |
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* Retrieves and removes the first (lowest) element, |
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* or returns <tt>null</tt> if this set is empty. |
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* or returns {@code null} if this set is empty. |
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* |
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* @return the first element, or <tt>null</tt> if this set is empty |
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* @return the first element, or {@code null} if this set is empty |
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*/ |
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E pollFirst(); |
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/** |
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* Retrieves and removes the last (highest) element, |
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* or returns <tt>null</tt> if this set is empty. |
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* or returns {@code null} if this set is empty. |
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* |
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* @return the last element, or <tt>null</tt> if this set is empty |
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* @return the last element, or {@code null} if this set is empty |
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*/ |
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E pollLast(); |
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Iterator<E> iterator(); |
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/** |
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* Returns a reverse order view of the elements contained in this set. |
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* The descending set is backed by this set, so changes to the set are |
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* reflected in the descending set, and vice-versa. If either set is |
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* modified while an iteration over either set is in progress (except |
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* through the iterator's own {@code remove} operation), the results of |
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* the iteration are undefined. |
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* |
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* <p>The returned set has an ordering equivalent to |
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* {@link Collections#reverseOrder(Comparator) Collections.reverseOrder}{@code (comparator())}. |
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* The expression {@code s.descendingSet().descendingSet()} returns a |
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* view of {@code s} essentially equivalent to {@code s}. |
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* |
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* @return a reverse order view of this set |
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*/ |
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NavigableSet<E> descendingSet(); |
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|
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/** |
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* Returns an iterator over the elements in this set, in descending order. |
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* Equivalent in effect to {@code descendingSet().iterator()}. |
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* |
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* @return an iterator over the elements in this set, in descending order |
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*/ |
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Iterator<E> descendingIterator(); |
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/** |
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* Returns a view of the portion of this set whose elements range |
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* from <tt>fromElement</tt>, inclusive, to <tt>toElement</tt>, |
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* exclusive. (If <tt>fromElement</tt> and <tt>toElement</tt> are |
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* equal, the returned set is empty.) The returned set is backed |
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* by this set, so changes in the returned set are reflected in |
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* this set, and vice-versa. The returned set supports all |
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* optional set operations that this set supports. |
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> |
* Returns a view of the portion of this set whose elements range from |
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> |
* {@code fromElement} to {@code toElement}. If {@code fromElement} and |
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> |
* {@code toElement} are equal, the returned set is empty unless {@code |
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* fromInclusive} and {@code toInclusive} are both true. The returned set |
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> |
* is backed by this set, so changes in the returned set are reflected in |
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* this set, and vice-versa. The returned set supports all optional set |
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* operations that this set supports. |
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* |
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< |
* <p>The returned set will throw an <tt>IllegalArgumentException</tt> |
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> |
* <p>The returned set will throw an {@code IllegalArgumentException} |
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* on an attempt to insert an element outside its range. |
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* |
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< |
* @param fromElement low endpoint (inclusive) of the returned set |
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< |
* @param toElement high endpoint (exclusive) of the returned set |
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> |
* @param fromElement low endpoint of the returned set |
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> |
* @param fromInclusive {@code true} if the low endpoint |
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* is to be included in the returned view |
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> |
* @param toElement high endpoint of the returned set |
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> |
* @param toInclusive {@code true} if the high endpoint |
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> |
* is to be included in the returned view |
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* @return a view of the portion of this set whose elements range from |
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< |
* <tt>fromElement</tt>, inclusive, to <tt>toElement</tt>, exclusive |
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< |
* @throws ClassCastException if <tt>fromElement</tt> and |
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< |
* <tt>toElement</tt> cannot be compared to one another using this |
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> |
* {@code fromElement}, inclusive, to {@code toElement}, exclusive |
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> |
* @throws ClassCastException if {@code fromElement} and |
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> |
* {@code toElement} cannot be compared to one another using this |
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* set's comparator (or, if the set has no comparator, using |
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* natural ordering). Implementations may, but are not required |
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* to, throw this exception if <tt>fromElement</tt> or |
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< |
* <tt>toElement</tt> cannot be compared to elements currently in |
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> |
* to, throw this exception if {@code fromElement} or |
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> |
* {@code toElement} cannot be compared to elements currently in |
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* the set. |
| 193 |
< |
* @throws NullPointerException if <tt>fromElement</tt> or |
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< |
* <tt>toElement</tt> is null and this set does |
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> |
* @throws NullPointerException if {@code fromElement} or |
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> |
* {@code toElement} is null and this set does |
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* not permit null elements |
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< |
* @throws IllegalArgumentException if <tt>fromElement</tt> is |
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< |
* greater than <tt>toElement</tt>; or if this set itself |
| 198 |
< |
* has a restricted range, and <tt>fromElement</tt> or |
| 199 |
< |
* <tt>toElement</tt> lies outside the bounds of the range. |
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< |
*/ |
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< |
NavigableSet<E> navigableSubSet(E fromElement, E toElement); |
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> |
* @throws IllegalArgumentException if {@code fromElement} is |
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> |
* greater than {@code toElement}; or if this set itself |
| 198 |
> |
* has a restricted range, and {@code fromElement} or |
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> |
* {@code toElement} lies outside the bounds of the range. |
| 200 |
> |
*/ |
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> |
NavigableSet<E> subSet(E fromElement, boolean fromInclusive, |
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> |
E toElement, boolean toInclusive); |
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|
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/** |
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< |
* Returns a view of the portion of this set whose elements are |
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< |
* strictly less than <tt>toElement</tt>. The returned set is |
| 207 |
< |
* backed by this set, so changes in the returned set are |
| 208 |
< |
* reflected in this set, and vice-versa. The returned set |
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< |
* supports all optional set operations that this set supports. |
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> |
* Returns a view of the portion of this set whose elements are less than |
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> |
* (or equal to, if {@code inclusive} is true) {@code toElement}. The |
| 207 |
> |
* returned set is backed by this set, so changes in the returned set are |
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> |
* reflected in this set, and vice-versa. The returned set supports all |
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> |
* optional set operations that this set supports. |
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* |
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< |
* <p>The returned set will throw an <tt>IllegalArgumentException</tt> |
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> |
* <p>The returned set will throw an {@code IllegalArgumentException} |
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* on an attempt to insert an element outside its range. |
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* |
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< |
* @param toElement high endpoint (exclusive) of the returned set |
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< |
* @return a view of the portion of this set whose elements are strictly |
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< |
* less than <tt>toElement</tt> |
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< |
* @throws ClassCastException if <tt>toElement</tt> is not compatible |
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> |
* @param toElement high endpoint of the returned set |
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> |
* @param inclusive {@code true} if the high endpoint |
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> |
* is to be included in the returned view |
| 217 |
> |
* @return a view of the portion of this set whose elements are less than |
| 218 |
> |
* (or equal to, if {@code inclusive} is true) {@code toElement} |
| 219 |
> |
* @throws ClassCastException if {@code toElement} is not compatible |
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* with this set's comparator (or, if the set has no comparator, |
| 221 |
< |
* if <tt>toElement</tt> does not implement {@link Comparable}). |
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> |
* if {@code toElement} does not implement {@link Comparable}). |
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* Implementations may, but are not required to, throw this |
| 223 |
< |
* exception if <tt>toElement</tt> cannot be compared to elements |
| 223 |
> |
* exception if {@code toElement} cannot be compared to elements |
| 224 |
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* currently in the set. |
| 225 |
< |
* @throws NullPointerException if <tt>toElement</tt> is null and |
| 225 |
> |
* @throws NullPointerException if {@code toElement} is null and |
| 226 |
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* this set does not permit null elements |
| 227 |
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* @throws IllegalArgumentException if this set itself has a |
| 228 |
< |
* restricted range, and <tt>toElement</tt> lies outside the |
| 228 |
> |
* restricted range, and {@code toElement} lies outside the |
| 229 |
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* bounds of the range |
| 230 |
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*/ |
| 231 |
< |
NavigableSet<E> navigableHeadSet(E toElement); |
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> |
NavigableSet<E> headSet(E toElement, boolean inclusive); |
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|
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/** |
| 234 |
< |
* Returns a view of the portion of this set whose elements are |
| 235 |
< |
* greater than or equal to <tt>fromElement</tt>. The returned |
| 236 |
< |
* set is backed by this set, so changes in the returned set are |
| 237 |
< |
* reflected in this set, and vice-versa. The returned set |
| 238 |
< |
* supports all optional set operations that this set supports. |
| 234 |
> |
* Returns a view of the portion of this set whose elements are greater |
| 235 |
> |
* than (or equal to, if {@code inclusive} is true) {@code fromElement}. |
| 236 |
> |
* The returned set is backed by this set, so changes in the returned set |
| 237 |
> |
* are reflected in this set, and vice-versa. The returned set supports |
| 238 |
> |
* all optional set operations that this set supports. |
| 239 |
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* |
| 240 |
< |
* <p>The returned set will throw an <tt>IllegalArgumentException</tt> |
| 240 |
> |
* <p>The returned set will throw an {@code IllegalArgumentException} |
| 241 |
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* on an attempt to insert an element outside its range. |
| 242 |
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* |
| 243 |
< |
* @param fromElement low endpoint (inclusive) of the returned set |
| 243 |
> |
* @param fromElement low endpoint of the returned set |
| 244 |
> |
* @param inclusive {@code true} if the low endpoint |
| 245 |
> |
* is to be included in the returned view |
| 246 |
|
* @return a view of the portion of this set whose elements are greater |
| 247 |
< |
* than or equal to <tt>fromElement</tt> |
| 248 |
< |
* @throws ClassCastException if <tt>fromElement</tt> is not compatible |
| 247 |
> |
* than or equal to {@code fromElement} |
| 248 |
> |
* @throws ClassCastException if {@code fromElement} is not compatible |
| 249 |
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* with this set's comparator (or, if the set has no comparator, |
| 250 |
< |
* if <tt>fromElement</tt> does not implement {@link Comparable}). |
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> |
* if {@code fromElement} does not implement {@link Comparable}). |
| 251 |
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* Implementations may, but are not required to, throw this |
| 252 |
< |
* exception if <tt>fromElement</tt> cannot be compared to elements |
| 252 |
> |
* exception if {@code fromElement} cannot be compared to elements |
| 253 |
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* currently in the set. |
| 254 |
< |
* @throws NullPointerException if <tt>fromElement</tt> is null |
| 254 |
> |
* @throws NullPointerException if {@code fromElement} is null |
| 255 |
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* and this set does not permit null elements |
| 256 |
|
* @throws IllegalArgumentException if this set itself has a |
| 257 |
< |
* restricted range, and <tt>fromElement</tt> lies outside the |
| 257 |
> |
* restricted range, and {@code fromElement} lies outside the |
| 258 |
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* bounds of the range |
| 259 |
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*/ |
| 260 |
< |
NavigableSet<E> navigableTailSet(E fromElement); |
| 260 |
> |
NavigableSet<E> tailSet(E fromElement, boolean inclusive); |
| 261 |
> |
|
| 262 |
> |
/** |
| 263 |
> |
* {@inheritDoc} |
| 264 |
> |
* |
| 265 |
> |
* <p>Equivalent to {@code subSet(fromElement, true, toElement, false)}. |
| 266 |
> |
* |
| 267 |
> |
* @throws ClassCastException {@inheritDoc} |
| 268 |
> |
* @throws NullPointerException {@inheritDoc} |
| 269 |
> |
* @throws IllegalArgumentException {@inheritDoc} |
| 270 |
> |
*/ |
| 271 |
> |
SortedSet<E> subSet(E fromElement, E toElement); |
| 272 |
> |
|
| 273 |
> |
/** |
| 274 |
> |
* {@inheritDoc} |
| 275 |
> |
* |
| 276 |
> |
* <p>Equivalent to {@code headSet(toElement, false)}. |
| 277 |
> |
* |
| 278 |
> |
* @throws ClassCastException {@inheritDoc} |
| 279 |
> |
* @throws NullPointerException {@inheritDoc} |
| 280 |
> |
* @throws IllegalArgumentException {@inheritDoc} |
| 281 |
> |
*/ |
| 282 |
> |
SortedSet<E> headSet(E toElement); |
| 283 |
> |
|
| 284 |
> |
/** |
| 285 |
> |
* {@inheritDoc} |
| 286 |
> |
* |
| 287 |
> |
* <p>Equivalent to {@code tailSet(fromElement, true)}. |
| 288 |
> |
* |
| 289 |
> |
* @throws ClassCastException {@inheritDoc} |
| 290 |
> |
* @throws NullPointerException {@inheritDoc} |
| 291 |
> |
* @throws IllegalArgumentException {@inheritDoc} |
| 292 |
> |
*/ |
| 293 |
> |
SortedSet<E> tailSet(E fromElement); |
| 294 |
|
} |
