[multiple changes]

2001-10-15  Bryce McKinlay  <bryce@waitaki.otago.ac.nz>

	* java/util/HashMap.java (HashEntry.clone): Removed.
	(HashMap(Map)): Use putAllInternal.
	(clone): Likewise.
	(putAllInternal): New method. Efficient counterpart to putAll which
	does not call put().
	* java/util/LinkedHashMap.java (rethread): Removed.
	(putAllInternal): New method. Clear "head" and "tail".
	(addEntry): New argument "callRemove". Don't call removeEldestEntry()
	if callRemove == false.

	* Makefile.am: Add new classes RandomAccess and LinkedHashMap.
	* Makefile.in: Rebuilt.

2001-10-15  Eric Blake  <ebb9@email.byu.edu>

	* java/util/Collection.java: Updated javadoc.
	* java/util/Comparator.java: Updated javadoc.
	* java/util/Enumeration.java: Updated javadoc.
	* java/util/Iterator.java: Updated javadoc.
	* java/util/List.java: Updated javadoc.
	* java/util/ListIterator.java: Updated javadoc.
	* java/util/Map.java: Updated javadoc.
	* java/util/RandomAccess.java: New file.
	* java/util/Set.java: Updated javadoc.
	* java/util/SortedMap.java: Updated javadoc.
	* java/util/SortedSet.java: Updated javadoc.

From-SVN: r46277

1 files changed, 53 insertions, 18 deletions

diff --git a/libjava/java/util/Comparator.java b/libjava/java/util/Comparator.java
index fc61fc30280..8522301eedf 100644
--- a/libjava/java/util/Comparator.java
+++ b/libjava/java/util/Comparator.java
@@ -29,36 +29,67 @@ package java.util;
 
 /**
  * Interface for objects that specify an ordering between objects. The ordering
- * can be <EM>total</EM>, such that two objects only compare equal if they are
- * equal by the equals method, or <EM>partial</EM> such that this is not
- * necessarily true. For example, a case-sensitive dictionary order comparison
- * of Strings is total, but if it is case-insensitive it is partial, because
- * "abc" and "ABC" compare as equal even though "abc".equals("ABC") returns
- * false.
+ * should be <em>total</em>, such that any two objects of the correct type
+ * can be compared, and the comparison is reflexive, anti-symmetric, and
+ * transitive.  It is also recommended that the comparator be <em>consistent
+ * with equals</em>, although this is not a strict requirement. A relation
+ * is consistent with equals if these two statements always have the same
+ * results (if no exceptions occur):<br>
+ * <code>compare((Object) e1, (Object) e2) == 0</code> and
+ * <code>e1.equals((Object) e2)</code><br>
+ * Comparators that violate consistency with equals may cause strange behavior
+ * in sorted lists and sets.  For example, a case-sensitive dictionary order
+ * comparison of Strings is consistent with equals, but if it is
+ * case-insensitive it is not, because "abc" and "ABC" compare as equal even
+ * though "abc".equals("ABC") returns false.
  * <P>
  * In general, Comparators should be Serializable, because when they are passed
  * to Serializable data structures such as SortedMap or SortedSet, the entire
  * data structure will only serialize correctly if the comparator is
  * Serializable.
+ *
+ * @author Original author unknown
+ * @author Eric Blake <ebb9@email.byu.edu>
+ * @see Comparable
+ * @see TreeMap
+ * @see TreeSet
+ * @see SortedMap
+ * @see SortedSet
+ * @see Arrays#sort(Object[], Comparator)
+ * @see java.io.Serializable
+ * @since 1.2
+ * @status updated to 1.4
  */
 public interface Comparator
 {
   /**
    * Return an integer that is negative, zero or positive depending on whether
    * the first argument is less than, equal to or greater than the second
-   * according to this ordering. This method should obey the following contract:
-   * <UL>
-   *   <LI>if compare(a, b) &lt; 0 then compare(b, a) &gt; 0</LI>
-   *   <LI>if compare(a, b) throws an exception, so does compare(b, a)</LI>
-   *   <LI>if compare(a, b) &lt; 0 and compare(b, c) &lt; 0 then compare(a, c)
-   *       &lt; 0</LI>
-   *   <LI>if a.equals(b) or both a and b are null, then compare(a, b) == 0.
-   *       The converse need not be true, but if it is, this Comparator
-   *       specifies a <EM>total</EM> ordering.</LI>
-   * </UL>
+   * according to this ordering. This method should obey the following
+   * contract:
+   * <ul>
+   *   <li>if compare(a, b) &lt; 0 then compare(b, a) &gt; 0</li>
+   *   <li>if compare(a, b) throws an exception, so does compare(b, a)</li>
+   *   <li>if compare(a, b) &lt; 0 and compare(b, c) &lt; 0 then compare(a, c)
+   *       &lt; 0</li>
+   *   <li>if compare(a, b) == 0 then compare(a, c) and compare(b, c) must
+   *       have the same sign</li
+   * </ul>
+   * To be consistent with equals, the following additional constraint is
+   * in place:
+   * <ul>
+   *   <li>if a.equals(b) or both a and b are null, then
+   *       compare(a, b) == 0.</li>
+   * </ul><p>
    *
+   * Although it is permissible for a comparator to provide an order
+   * inconsistent with equals, that should be documented.
+   *
+   * @param o1 the first object
+   * @param o2 the second object
+   * @return the comparison
    * @throws ClassCastException if the elements are not of types that can be
-   *   compared by this ordering.
+   *         compared by this ordering.
    */
   int compare(Object o1, Object o2);
 
@@ -66,8 +97,12 @@ public interface Comparator
    * Return true if the object is equal to this object.  To be
    * considered equal, the argument object must satisfy the constraints
    * of <code>Object.equals()</code>, be a Comparator, and impose the
-   * same ordering as this Comparator.
+   * same ordering as this Comparator. The default implementation
+   * inherited from Object is usually adequate.
+   *
    * @param obj The object
+   * @return true if it is a Comparator that imposes the same order
+   * @see Object#equals(Object)
    */
   boolean equals(Object obj);
 }