--- jsr166/src/main/java/util/TreeSet.java 2004/12/28 12:14:07 1.1
+++ jsr166/src/main/java/util/TreeSet.java 2005/05/16 08:13:36 1.11
@@ -1,35 +1,34 @@
/*
* %W% %E%
*
- * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
+ * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
-package java.util;
+package java.util;
/**
- * This class implements the Set interface, backed by a
- * TreeMap instance. This class guarantees that the sorted set will
- * be in ascending element order, sorted according to the natural order
- * of the elements (see Comparable), or by the comparator provided at
- * set creation time, depending on which constructor is used.
+ * A {@link NavigableSet} implementation based on a {@link TreeMap}.
+ * The elements are ordered using their {@linkplain Comparable natural
+ * ordering}, or by a {@link Comparator} provided at set creation
+ * time, depending on which constructor is used.
*
- * This implementation provides guaranteed log(n) time cost for the basic
- * operations (add, remove and contains).
+ *
This implementation provides guaranteed log(n) time cost for the basic
+ * operations (add, remove and contains).
*
- * Note that the ordering maintained by a set (whether or not an explicit
+ *
Note that the ordering maintained by a set (whether or not an explicit
* comparator is provided) must be consistent with equals if it is to
* correctly implement the Set interface. (See Comparable
* or Comparator for a precise definition of consistent with
* equals.) This is so because the Set interface is defined in
* terms of the equals operation, but a TreeSet instance
- * performs all key comparisons using its compareTo (or
- * compare) method, so two keys that are deemed equal by this method
+ * performs all element comparisons using its compareTo (or
+ * compare) method, so two elements that are deemed equal by this method
* are, from the standpoint of the set, equal. The behavior of a set
* is well-defined even if its ordering is inconsistent with equals; it
- * just fails to obey the general contract of the Set interface.
+ * just fails to obey the general contract of the Set interface.
*
- * Note that this implementation is not synchronized. If multiple
+ *
Note that this implementation is not synchronized. If multiple
* threads access a set concurrently, and at least one of the threads modifies
* the set, it must be synchronized externally. This is typically
* accomplished by synchronizing on some object that naturally encapsulates
@@ -37,12 +36,12 @@ package java.util;
* Collections.synchronizedSet method. This is best done at creation
* time, to prevent accidental unsynchronized access to the set:
* SortedSet s = Collections.synchronizedSortedSet(new TreeSet(...));
- *
+ *
*
- * The Iterators returned by this class's iterator method are
+ *
The iterators returned by this class's iterator method are
* fail-fast: if the set is modified at any time after the iterator is
* created, in any way except through the iterator's own remove
- * method, the iterator will throw a ConcurrentModificationException.
+ * method, the iterator will throw a {@link ConcurrentModificationException}.
* Thus, in the face of concurrent modification, the iterator fails quickly
* and cleanly, rather than risking arbitrary, non-deterministic behavior at
* an undetermined time in the future.
@@ -53,12 +52,14 @@ package java.util;
* throw ConcurrentModificationException on a best-effort basis.
* Therefore, it would be wrong to write a program that depended on this
* exception for its correctness: the fail-fast behavior of iterators
- * should be used only to detect bugs.
+ * should be used only to detect bugs.
*
- * This class is a member of the
+ *
This class is a member of the
*
* Java Collections Framework.
*
+ * @param the type of elements maintained by this set
+ *
* @author Josh Bloch
* @version %I%, %G%
* @see Collection
@@ -81,60 +82,62 @@ public class TreeSet
private static final Object PRESENT = new Object();
/**
- * Constructs a set backed by the specified sorted map.
+ * Constructs a set backed by the specified navigable map.
*/
private TreeSet(NavigableMap m) {
this.m = m;
}
/**
- * Constructs a new, empty set, sorted according to the elements' natural
- * order. All elements inserted into the set must implement the
- * Comparable interface. Furthermore, all such elements must be
- * mutually comparable: e1.compareTo(e2) must not throw a
+ * Constructs a new, empty tree set, sorted according to the
+ * natural ordering of its elements. All elements inserted into
+ * the set must implement the {@link Comparable} interface.
+ * Furthermore, all such elements must be mutually
+ * comparable: e1.compareTo(e2) must not throw a
* ClassCastException for any elements e1 and
- * e2 in the set. If the user attempts to add an element to the
- * set that violates this constraint (for example, the user attempts to
- * add a string element to a set whose elements are integers), the
- * add(Object) call will throw a ClassCastException.
- *
- * @see Comparable
+ * e2 in the set. If the user attempts to add an element
+ * to the set that violates this constraint (for example, the user
+ * attempts to add a string element to a set whose elements are
+ * integers), the add(Object) call will throw a
+ * ClassCastException.
*/
public TreeSet() {
this(new TreeMap());
}
/**
- * Constructs a new, empty set, sorted according to the specified
- * comparator. All elements inserted into the set must be mutually
- * comparable by the specified comparator: comparator.compare(e1,
- * e2) must not throw a ClassCastException for any elements
- * e1 and e2 in the set. If the user attempts to add
- * an element to the set that violates this constraint, the
- * add(Object) call will throw a ClassCastException.
- *
- * @param c the comparator that will be used to sort this set. A
- * null value indicates that the elements' natural
- * ordering should be used.
- */
- public TreeSet(Comparator super E> c) {
- this(new TreeMap(c));
+ * Constructs a new, empty tree set, sorted according to the
+ * specified comparator. All elements inserted into the set must
+ * be mutually comparable by the specified comparator:
+ * comparator.compare(e1, e2) must not throw a
+ * ClassCastException for any elements e1 and
+ * e2 in the set. If the user attempts to add an element
+ * to the set that violates this constraint, the
+ * add(Object) call will throw a
+ * ClassCastException.
+ *
+ * @param comparator the comparator that will be used to order this set.
+ * If null, the {@linkplain Comparable natural
+ * ordering} of the elements will be used.
+ */
+ public TreeSet(Comparator super E> comparator) {
+ this(new TreeMap(comparator));
}
/**
- * Constructs a new set containing the elements in the specified
- * collection, sorted according to the elements' natural order.
- * All keys inserted into the set must implement the Comparable
- * interface. Furthermore, all such keys must be mutually
- * comparable: k1.compareTo(k2) must not throw a
- * ClassCastException for any elements k1 and
- * k2 in the set.
- *
- * @param c The elements that will comprise the new set.
- *
- * @throws ClassCastException if the keys in the specified collection are
- * not comparable, or are not mutually comparable.
- * @throws NullPointerException if the specified collection is null.
+ * Constructs a new tree set containing the elements in the
+ * specified collection, sorted according to the natural
+ * ordering of its elements. All elements inserted into the
+ * set must implement the {@link Comparable} interface.
+ * Furthermore, all such elements must be mutually
+ * comparable: e1.compareTo(e2) must not throw a
+ * ClassCastException for any elements e1 and
+ * e2 in the set.
+ *
+ * @param c collection whose elements will comprise the new set
+ * @throws ClassCastException if the elements in c are
+ * not {@link Comparable}, or are not mutually comparable
+ * @throws NullPointerException if the specified collection is null
*/
public TreeSet(Collection extends E> c) {
this();
@@ -142,11 +145,11 @@ public class TreeSet
}
/**
- * Constructs a new set containing the same elements as the specified
- * sorted set, sorted according to the same ordering.
+ * Constructs a new tree set containing the same elements and
+ * using the same ordering as the specified sorted set.
*
- * @param s sorted set whose elements will comprise the new set.
- * @throws NullPointerException if the specified sorted set is null.
+ * @param s sorted set whose elements will comprise the new set
+ * @throws NullPointerException if the specified sorted set is null
*/
public TreeSet(SortedSet s) {
this(s.comparator());
@@ -157,17 +160,17 @@ public class TreeSet
* Returns an iterator over the elements in this set. The elements
* are returned in ascending order.
*
- * @return an iterator over the elements in this set.
+ * @return an iterator over the elements in this set
*/
public Iterator iterator() {
- return m.keySet().iterator();
+ return m.keySet().iterator();
}
/**
* Returns an iterator over the elements in this set. The elements
* are returned in descending order.
*
- * @return an iterator over the elements in this set.
+ * @return an iterator over the elements in this set
*/
public Iterator descendingIterator() {
return m.descendingKeySet().iterator();
@@ -176,7 +179,7 @@ public class TreeSet
/**
* Returns the number of elements in this set (its cardinality).
*
- * @return the number of elements in this set (its cardinality).
+ * @return the number of elements in this set (its cardinality)
*/
public int size() {
return m.size();
@@ -185,7 +188,7 @@ public class TreeSet
/**
* Returns true if this set contains no elements.
*
- * @return true if this set contains no elements.
+ * @return true if this set contains no elements
*/
public boolean isEmpty() {
return m.isEmpty();
@@ -194,14 +197,13 @@ public class TreeSet
/**
* Returns true if this set contains the specified element.
*
- * @param o the object to be checked for containment in this set.
- * @return true if this set contains the specified element.
- *
+ * @param o the object to be checked for containment in this set
+ * @return true if this set contains the specified element
* @throws ClassCastException if the specified object cannot be compared
- * with the elements currently in the set.
- * @throws NullPointerException o is null and this map
- * uses natural ordering and is non-empty, or its comparator does
- * not tolerate null keys.
+ * with the elements currently in the set
+ * @throws NullPointerException if the specified element is null and
+ * this set uses natural ordering and is non-empty, or its
+ * comparator does not permit null elements
*/
public boolean contains(Object o) {
return m.containsKey(o);
@@ -210,31 +212,29 @@ public class TreeSet
/**
* Adds the specified element to this set if it is not already present.
*
- * @param o element to be added to this set.
+ * @param e element to be added to this set
* @return true if the set did not already contain the specified
- * element.
- *
+ * element
* @throws ClassCastException if the specified object cannot be compared
- * with the elements currently in the set.
- * @throws NullPointerException o is null and this map
- * uses natural ordering and is non-empty, or its comparator does
- * not tolerate null keys.
+ * with the elements currently in the set
+ * @throws NullPointerException if the specified element is null and
+ * this set uses natural ordering and is non-empty, or its
+ * comparator does not permit null elements
*/
- public boolean add(E o) {
- return m.put(o, PRESENT)==null;
+ public boolean add(E e) {
+ return m.put(e, PRESENT)==null;
}
/**
* Removes the specified element from this set if it is present.
*
- * @param o object to be removed from this set, if present.
- * @return true if the set contained the specified element.
- *
+ * @param o object to be removed from this set, if present
+ * @return true if the set contained the specified element
* @throws ClassCastException if the specified object cannot be compared
- * with the elements currently in the set.
- * @throws NullPointerException o is null and this map
- * uses natural ordering and is non-empty, or its comparator does
- * not tolerate null keys.
+ * with the elements currently in the set
+ * @throws NullPointerException if the specified element is null and
+ * this set uses natural ordering and is non-empty, or its
+ * comparator does not permit null elements
*/
public boolean remove(Object o) {
return m.remove(o)==PRESENT;
@@ -242,6 +242,7 @@ public class TreeSet
/**
* Removes all of the elements from this set.
+ * The set will be empty after this call returns.
*/
public void clear() {
m.clear();
@@ -251,23 +252,21 @@ public class TreeSet
* Adds all of the elements in the specified collection to this set.
*
* @param c elements to be added
- * @return true if this set changed as a result of the call.
- *
+ * @return true if this set changed as a result of the call
* @throws ClassCastException if the elements provided cannot be compared
- * with the elements currently in the set.
- * @throws NullPointerException of the specified collection is
- * null or if any element is null and this map
- * uses natural ordering, or its comparator does not tolerate
- * null keys.
+ * with the elements currently in the set
+ * @throws NullPointerException if the specified collection is null or
+ * if any element is null and this set uses natural ordering, or
+ * its comparator does not permit null elements
*/
public boolean addAll(Collection extends E> c) {
// Use linear-time version if applicable
if (m.size()==0 && c.size() > 0 &&
c instanceof SortedSet &&
m instanceof TreeMap) {
- SortedSet> set = (SortedSet>) (SortedSet) c;
+ SortedSet extends E> set = (SortedSet extends E>) c;
TreeMap map = (TreeMap) m;
- Comparator super E> cc = (Comparator) set.comparator();
+ Comparator super E> cc = (Comparator super E>) set.comparator();
Comparator super E> mc = map.comparator();
if (cc==mc || (cc != null && cc.equals(mc))) {
map.addAllForTreeSet(set, PRESENT);
@@ -278,159 +277,99 @@ public class TreeSet
}
/**
- * Returns a view of the portion of this set whose elements range from
- * fromElement, inclusive, to toElement, exclusive. (If
- * fromElement and toElement are equal, the returned
- * sorted set is empty.) The returned sorted set is backed by this set,
- * so changes in the returned sorted set are reflected in this set, and
- * vice-versa. The returned sorted set supports all optional Set
- * operations.
- *
- * The sorted set returned by this method will throw an
- * IllegalArgumentException if the user attempts to insert an
- * element outside the specified range.
- *
- * Note: this method always returns a half-open range (which
- * includes its low endpoint but not its high endpoint). If you need a
- * closed range (which includes both endpoints), and the element
- * type allows for calculation of the successor of a specified value,
- * merely request the subrange from lowEndpoint to
- * successor(highEndpoint). For example, suppose that s
- * is a sorted set of strings. The following idiom obtains a view
- * containing all of the strings in s from low to
- * high, inclusive:
- * NavigableSet sub = s.subSet(low, high+"\0");
- *
- *
- * A similar technique can be used to generate an open range (which
- * contains neither endpoint). The following idiom obtains a view
- * containing all of the strings in s from low to
- * high, exclusive:
- * NavigableSet sub = s.subSet(low+"\0", high);
- *
- *
- * @param fromElement low endpoint (inclusive) of the subSet.
- * @param toElement high endpoint (exclusive) of the subSet.
- * @return a view of the portion of this set whose elements range from
- * fromElement, inclusive, to toElement,
- * exclusive.
- * @throws ClassCastException if fromElement and
- * toElement cannot be compared to one another using
- * this set's comparator (or, if the set has no comparator,
- * using natural ordering).
- * @throws IllegalArgumentException if fromElement is greater than
- * toElement.
+ * @throws ClassCastException {@inheritDoc}
* @throws NullPointerException if fromElement or
- * toElement is null and this set uses natural
- * order, or its comparator does not tolerate null
- * elements.
- */
- public NavigableSet subSet(E fromElement, E toElement) {
- return new TreeSet(m.subMap(fromElement, toElement));
- }
-
- /**
- * Returns a view of the portion of this set whose elements are strictly
- * less than toElement. The returned sorted set is backed by
- * this set, so changes in the returned sorted set are reflected in this
- * set, and vice-versa. The returned sorted set supports all optional set
- * operations.
- *
- * The sorted set returned by this method will throw an
- * IllegalArgumentException if the user attempts to insert an
- * element greater than or equal to toElement.
- *
- * Note: this method always returns a view that does not contain its
- * (high) endpoint. If you need a view that does contain this endpoint,
- * and the element type allows for calculation of the successor of a
- * specified value, merely request a headSet bounded by
- * successor(highEndpoint). For example, suppose that s
- * is a sorted set of strings. The following idiom obtains a view
- * containing all of the strings in s that are less than or equal
- * to high:
NavigableSet head = s.headSet(high+"\0");
- *
- * @param toElement high endpoint (exclusive) of the headSet.
- * @return a view of the portion of this set whose elements are strictly
- * less than toElement.
- * @throws ClassCastException if toElement is not compatible
- * with this set's comparator (or, if the set has no comparator,
- * if toElement does not implement Comparable).
- * @throws IllegalArgumentException if this set is itself a subSet,
- * headSet, or tailSet, and toElement is not within the
- * specified range of the subSet, headSet, or tailSet.
- * @throws NullPointerException if toElement is null and
- * this set uses natural ordering, or its comparator does
- * not tolerate null elements.
- */
- public NavigableSet headSet(E toElement) {
- return new TreeSet(m.headMap(toElement));
- }
-
- /**
- * Returns a view of the portion of this set whose elements are
- * greater than or equal to fromElement. The returned sorted set
- * is backed by this set, so changes in the returned sorted set are
- * reflected in this set, and vice-versa. The returned sorted set
- * supports all optional set operations.
- *
- * The sorted set returned by this method will throw an
- * IllegalArgumentException if the user attempts to insert an
- * element less than fromElement.
- *
- * Note: this method always returns a view that contains its (low)
- * endpoint. If you need a view that does not contain this endpoint, and
- * the element type allows for calculation of the successor of a specified
- * value, merely request a tailSet bounded by
- * successor(lowEndpoint). For example, suppose that s
- * is a sorted set of strings. The following idiom obtains a view
- * containing all of the strings in s that are strictly greater
- * than low:
- * NavigableSet tail = s.tailSet(low+"\0");
- *
- *
- * @param fromElement low endpoint (inclusive) of the tailSet.
- * @return a view of the portion of this set whose elements are
- * greater than or equal to fromElement.
- * @throws ClassCastException if fromElement is not compatible
- * with this set's comparator (or, if the set has no comparator,
- * if fromElement does not implement Comparable).
- * @throws IllegalArgumentException if this set is itself a subSet,
- * headSet, or tailSet, and fromElement is not within the
- * specified range of the subSet, headSet, or tailSet.
- * @throws NullPointerException if fromElement is null
- * and this set uses natural ordering, or its comparator does
- * not tolerate null elements.
- */
- public NavigableSet tailSet(E fromElement) {
- return new TreeSet(m.tailMap(fromElement));
+ * toElement is null and this set uses natural ordering,
+ * or its comparator does not permit null elements
+ * @throws IllegalArgumentException {@inheritDoc}
+ */
+ public NavigableSet navigableSubSet(E fromElement, E toElement) {
+ return new TreeSet(m.navigableSubMap(fromElement, toElement));
}
/**
- * Returns the comparator used to order this sorted set, or null
- * if this tree set uses its elements natural ordering.
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if toElement is null and
+ * this set uses natural ordering, or its comparator does
+ * not permit null elements
+ * @throws IllegalArgumentException {@inheritDoc}
+ */
+ public NavigableSet navigableHeadSet(E toElement) {
+ return new TreeSet(m.navigableHeadMap(toElement));
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if fromElement is null and
+ * this set uses natural ordering, or its comparator does
+ * not permit null elements
+ * @throws IllegalArgumentException {@inheritDoc}
+ */
+ public NavigableSet navigableTailSet(E fromElement) {
+ return new TreeSet(m.navigableTailMap(fromElement));
+ }
+
+ /**
+ * Equivalent to {@link #navigableSubSet} but with a return type
+ * conforming to the SortedSet interface.
+ *
+ * {@inheritDoc}
*
- * @return the comparator used to order this sorted set, or null
- * if this tree set uses its elements natural ordering.
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if fromElement or
+ * toElement is null and this set uses natural ordering,
+ * or its comparator does not permit null elements
+ * @throws IllegalArgumentException {@inheritDoc}
*/
+ public SortedSet subSet(E fromElement, E toElement) {
+ return new TreeSet(m.navigableSubMap(fromElement, toElement));
+ }
+
+ /**
+ * Equivalent to {@link #navigableHeadSet} but with a return type
+ * conforming to the SortedSet interface.
+ *
+ * {@inheritDoc}
+ *
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if toElement is null
+ * and this set uses natural ordering, or its comparator does
+ * not permit null elements
+ * @throws IllegalArgumentException {@inheritDoc}
+ */
+ public SortedSet headSet(E toElement) {
+ return new TreeSet(m.navigableHeadMap(toElement));
+ }
+
+ /**
+ * Equivalent to {@link #navigableTailSet} but with a return type
+ * conforming to the SortedSet interface.
+ *
+ * {@inheritDoc}
+ *
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if fromElement is null
+ * and this set uses natural ordering, or its comparator does
+ * not permit null elements
+ * @throws IllegalArgumentException {@inheritDoc}
+ */
+ public SortedSet tailSet(E fromElement) {
+ return new TreeSet(m.navigableTailMap(fromElement));
+ }
+
public Comparator super E> comparator() {
return m.comparator();
}
/**
- * Returns the first (lowest) element currently in this sorted set.
- *
- * @return the first (lowest) element currently in this sorted set.
- * @throws NoSuchElementException sorted set is empty.
+ * @throws NoSuchElementException {@inheritDoc}
*/
public E first() {
return m.firstKey();
}
/**
- * Returns the last (highest) element currently in this sorted set.
- *
- * @return the last (highest) element currently in this sorted set.
- * @throws NoSuchElementException sorted set is empty.
+ * @throws NoSuchElementException {@inheritDoc}
*/
public E last() {
return m.lastKey();
@@ -438,90 +377,51 @@ public class TreeSet
// NavigableSet API methods
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if the specified element is null and
+ * this set uses natural ordering and is non-empty,
+ * or its comparator does not permit null elements
+ */
+ public E lower(E e) {
+ return m.lowerKey(e);
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if the specified element is null and
+ * this set uses natural ordering and is non-empty,
+ * or its comparator does not permit null elements
+ */
+ public E floor(E e) {
+ return m.floorKey(e);
+ }
/**
- * Returns an element greater than or equal to the given element, or
- * null if there is no such element.
- *
- * @param o the value to match
- * @return an element greater than or equal to given element, or
- * null if there is no such element.
- * @throws ClassCastException if o cannot be compared with the elements
- * currently in the set.
- * @throws NullPointerException o is null and this map
- * uses natural ordering and is non-empty, or its comparator does
- * not tolerate null keys.
- */
- public E ceiling(E o) {
- return m.ceilingKey(o);
- }
-
- /**
- * Returns an element strictly less than the given element, or
- * null if there is no such element.
- *
- * @param o the value to match
- * @return the greatest element less than the given element, or
- * null if there is no such element.
- * @throws ClassCastException if o cannot be compared with the elements
- * currently in the set.
- * @throws NullPointerException o is null and this map
- * uses natural ordering and is non-empty, or its comparator does
- * not tolerate null keys.
- */
- public E lower(E o) {
- return m.lowerKey(o);
- }
-
- /**
- * Returns an element less than or equal to the given element, or
- * null if there is no such element.
- *
- * @param o the value to match
- * @return the greatest element less than or equal to given
- * element, or null if there is no such element.
- * @throws ClassCastException if o cannot be compared with the elements
- * currently in the set.
- * @throws NullPointerException o is null and this map
- * uses natural ordering and is non-empty, or its comparator does
- * not tolerate null keys.
- */
- public E floor(E o) {
- return m.floorKey(o);
- }
-
- /**
- * Returns an element strictly greater than the given element, or
- * null if there is no such element.
- *
- * @param o the value to match
- * @return the least element greater than the given element, or
- * null if there is no such element.
- * @throws ClassCastException if o cannot be compared with the elements
- * currently in the set.
- * @throws NullPointerException o is null and this map
- * uses natural ordering and is non-empty, or its comparator does
- * not tolerate null keys.
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if the specified element is null and
+ * this set uses natural ordering and is non-empty,
+ * or its comparator does not permit null elements
*/
- public E higher(E o) {
- return m.higherKey(o);
+ public E ceiling(E e) {
+ return m.ceilingKey(e);
}
/**
- * Retrieves and removes the first (lowest) element.
- *
- * @return the least element, or null if empty.
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if the specified element is null and
+ * this set uses natural ordering and is non-empty,
+ * or its comparator does not permit null elements
*/
+ public E higher(E e) {
+ return m.higherKey(e);
+ }
+
public E pollFirst() {
Map.Entry e = m.pollFirstEntry();
return (e == null)? null : e.getKey();
}
- /**
- * Retrieves and removes the last (highest) element.
- *
- * @return the last element, or null if empty.
- */
public E pollLast() {
Map.Entry e = m.pollLastEntry();
return (e == null)? null : e.getKey();
@@ -531,7 +431,7 @@ public class TreeSet
* Returns a shallow copy of this TreeSet instance. (The elements
* themselves are not cloned.)
*
- * @return a shallow copy of this set.
+ * @return a shallow copy of this set
*/
public Object clone() {
TreeSet clone = null;
@@ -551,11 +451,11 @@ public class TreeSet
* serialize it).
*
* @serialData Emits the comparator used to order this set, or
- * null if it obeys its elements' natural ordering
- * (Object), followed by the size of the set (the number of
- * elements it contains) (int), followed by all of its
- * elements (each an Object) in order (as determined by the
- * set's Comparator, or by the elements' natural ordering if
+ * null if it obeys its elements' natural ordering
+ * (Object), followed by the size of the set (the number of
+ * elements it contains) (int), followed by all of its
+ * elements (each an Object) in order (as determined by the
+ * set's Comparator, or by the elements' natural ordering if
* the set has no Comparator).
*/
private void writeObject(java.io.ObjectOutputStream s)
@@ -584,7 +484,7 @@ public class TreeSet
s.defaultReadObject();
// Read in Comparator
- Comparator c = (Comparator) s.readObject();
+ Comparator super E> c = (Comparator super E>) s.readObject();
// Create backing TreeMap
TreeMap tm;