1 files changed, 187 insertions, 4 deletions
diff --git a/libjava/java/util/Set.java b/libjava/java/util/Set.java
index 3c8c09b..c22228c 100644
--- a/libjava/java/util/Set.java
+++ b/libjava/java/util/Set.java
@@ -1,5 +1,5 @@
 /* Set.java -- A collection that prohibits duplicates
-   Copyright (C) 1998 Free Software Foundation, Inc.
+   Copyright (C) 1998, 2001 Free Software Foundation, Inc.
 
 This file is part of GNU Classpath.
 
@@ -25,25 +25,208 @@ This exception does not however invalidate any other reasons why the
 executable file might be covered by the GNU General Public License. */
 
 
-// TO DO:
-// ~ Doc comments for everything.
-
 package java.util;
 
+/**
+ * A collection that contains no duplicates. In other words, for two set
+ * elements e1 and e2, <code>e1.equals(e2)</code> returns false. There
+ * are additional stipulations on <code>add</code>, <code>equals</code>
+ * and <code>hashCode</code>, as well as the requirements that constructors
+ * do not permit duplicate elements. The Set interface is incompatible with
+ * List; you cannot implement both simultaneously.
+ * <p>
+ *
+ * Note: Be careful about using mutable objects in sets.  In particular,
+ * if a mutable object changes to become equal to another set element, you
+ * have violated the contract.  As a special case of this, a Set is not
+ * allowed to be an element of itself, without risking undefined behavior.
+ *
+ * @author Original author unknown
+ * @author Eric Blake <ebb9@email.byu.edu>
+ * @see Collection
+ * @see List
+ * @see SortedSet
+ * @see HashSet
+ * @see TreeSet
+ * @see LinkedHashSet
+ * @see AbstractSet
+ * @see Collections#singleton(Object)
+ * @see Collections#EMPTY_SET
+ * @since 1.2
+ * @status updated to 1.4
+ */
 public interface Set extends Collection
 {
+  /**
+   * Adds the specified element to the set if it is not already present
+   * (optional operation). In particular, the comparison algorithm is
+   * <code>o == null ? e == null : o.equals(e)</code>. Sets need not permit
+   * all values, and may document what exceptions will be thrown if
+   * a value is not permitted.
+   *
+   * @param o the object to add
+   * @return true if the object was not previously in the set
+   * @throws UnsupportedOperationException if this operation is not allowed
+   * @throws ClassCastException if the class of o prevents it from being added
+   * @throws IllegalArgumentException if some aspect of o prevents it from
+   *         being added
+   * @throws NullPointerException if null is not permitted in this set
+   */
   boolean add(Object o);
+
+  /**
+   * Adds all of the elements of the given collection to this set (optional
+   * operation). If the argument is also a Set, this returns the mathematical
+   * <i>union</i> of the two. The behavior is unspecified if the set is
+   * modified while this is taking place.
+   *
+   * @param c the collection to add
+   * @return true if the set changed as a result
+   * @throws UnsupportedOperationException if this operation is not allowed
+   * @throws ClassCastException if the class of an element prevents it from
+   *         being added
+   * @throws IllegalArgumentException if something about an element prevents
+   *         it from being added
+   * @throws NullPointerException if null is not permitted in this set, or
+   *         if the argument c is null
+   * @see #add(Object)
+   */
   boolean addAll(Collection c);
+
+  /**
+   * Removes all elements from this set (optional operation). This set will
+   * be empty afterwords, unless an exception occurs.
+   *
+   * @throws UnsupportedOperationException if this operation is not allowed
+   */
   void clear();
+
+  /**
+   * Returns true if the set contains the specified element. In other words,
+   * this looks for <code>o == null ? e == null : o.equals(e)</code>.
+   *
+   * @param o the object to look for
+   * @return true if it is found in the set
+   */
   boolean contains(Object o);
+
+  /**
+   * Returns true if this set contains all elements in the specified
+   * collection. If the argument is also a set, this is the <i>subset</i>
+   * relationship.
+   *
+   * @param c the collection to check membership in
+   * @return true if all elements in this set are in c
+   * @throws NullPointerException if c is null
+   * @see #contains(Object)
+   */
   boolean containsAll(Collection c);
+
+  /**
+   * Compares the specified object to this for equality. For sets, the object
+   * must be a set, the two must have the same size, and every element in
+   * one must be in the other.
+   *
+   * @param o the object to compare to
+   * @return true if it is an equal set
+   */
   boolean equals(Object o);
+
+  /**
+   * Returns the hash code for this set. In order to satisfy the contract of
+   * equals, this is the sum of the hashcode of all elements in the set.
+   *
+   * @return the sum of the hashcodes of all set elements
+   */
   int hashCode();
+
+  /**
+   * Returns true if the set contains no elements.
+   *
+   * @return true if the set is empty
+   */
   boolean isEmpty();
+
+  /**
+   * Returns an iterator over the set.  The iterator has no specific order,
+   * unless further specified.
+   *
+   * @return a set iterator
+   */
   Iterator iterator();
+
+  /**
+   * Removes the specified element from this set (optional operation). If
+   * an element e exists, <code>o == null ? e == null : o.equals(e)</code>,
+   * it is removed from the set.
+   *
+   * @param o the object to remove
+   * @return true if the set changed (an object was removed)
+   * @throws UnsupportedOperationException if this operation is not allowed
+   */
   boolean remove(Object o);
+
+  /**
+   * Removes from this set all elements contained in the specified collection
+   * (optional operation). If the argument is a set, this returns the
+   * <i>asymmetric set difference</i> of the two sets.
+   *
+   * @param c the collection to remove from this set
+   * @return true if this set changed as a result
+   * @throws UnsupportedOperationException if this operation is not allowed
+   * @throws NullPointerException if c is null
+   * @see #remove(Object)
+   */
   boolean removeAll(Collection c);
+
+  /**
+   * Retains only the elements in this set that are also in the specified
+   * collection (optional operation). If the argument is also a set, this
+   * performs the <i>intersection</i> of the two sets.
+   *
+   * @param c the collection to keep
+   * @return true if this set was modified
+   * @throws UnsupportedOperationException if this operation is not allowed
+   * @throws NullPointerException if c is null
+   * @see #remove(Object)
+   */
   boolean retainAll(Collection c);
+
+  /**
+   * Returns the number of elements in the set. If there are more
+   * than Integer.MAX_VALUE mappings, return Integer.MAX_VALUE. This is
+   * the <i>cardinality</i> of the set.
+   *
+   * @return the number of elements
+   */
   int size();
+
+  /**
+   * Returns an array containing the elements of this set. If the set
+   * makes a guarantee about iteration order, the array has the same
+   * order. The array is distinct from the set; modifying one does not
+   * affect the other.
+   *
+   * @return an array of this set's elements
+   * @see #toArray(Object[])
+   */
   Object[] toArray();
+
+  /**
+   * Returns an array containing the elements of this set, of the same runtime
+   * type of the argument. If the given set is large enough, it is reused,
+   * and null is inserted in the first unused slot. Otherwise, reflection
+   * is used to build a new array. If the set makes a guarantee about iteration
+   * order, the array has the same order. The array is distinct from the set;
+   * modifying one does not affect the other.
+   *
+   * @param a the array to determine the return type; if it is big enough
+   *        it is used and returned
+   * @return an array holding the elements of the set
+   * @throws ArrayStoreException if the runtime type of a is not a supertype
+   *         of all elements in the set
+   * @throws NullPointerException if a is null
+   * @see #toArray()
+   */
+  Object[] toArray(Object[] a);
 }