--- /dev/null
+/*
+ * @(#)AbstractSet.java 1.19 03/01/23
+ *
+ * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
+ * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
+ */
+
+package instrumented.java.util;
+
+/**
+ * This class provides a skeletal implementation of the <tt>Set</tt>
+ * interface to minimize the effort required to implement this
+ * interface. <p>
+ *
+ * The process of implementing a set by extending this class is identical
+ * to that of implementing a Collection by extending AbstractCollection,
+ * except that all of the methods and constructors in subclasses of this
+ * class must obey the additional constraints imposed by the <tt>Set</tt>
+ * interface (for instance, the add method must not permit addition of
+ * multiple intances of an object to a set).<p>
+ *
+ * Note that this class does not override any of the implementations from
+ * the <tt>AbstractCollection</tt> class. It merely adds implementations
+ * for <tt>equals</tt> and <tt>hashCode</tt>.<p>
+ *
+ * This class is a member of the
+ * <a href="{@docRoot}/../guide/collections/index.html">
+ * Java Collections Framework</a>.
+ *
+ * @author Josh Bloch
+ * @version 1.19, 01/23/03
+ * @see Collection
+ * @see AbstractCollection
+ * @see Set
+ * @since 1.2
+ */
+
+public abstract class AbstractSet extends AbstractCollection implements Set {
+ /**
+ * Sole constructor. (For invocation by subclass constructors, typically
+ * implicit.)
+ */
+ protected AbstractSet() {
+ }
+
+ // Comparison and hashing
+
+ /**
+ * Compares the specified object with this set for equality. Returns
+ * <tt>true</tt> if the given object is also a set, the two sets have
+ * the same size, and every member of the given set is contained in
+ * this set. This ensures that the <tt>equals</tt> method works
+ * properly across different implementations of the <tt>Set</tt>
+ * interface.<p>
+ *
+ * This implementation first checks if the specified object is this
+ * set; if so it returns <tt>true</tt>. Then, it checks if the
+ * specified object is a set whose size is identical to the size of
+ * this set; if not, it it returns false. If so, it returns
+ * <tt>containsAll((Collection) o)</tt>.
+ *
+ * @param o Object to be compared for equality with this set.
+ * @return <tt>true</tt> if the specified object is equal to this set.
+ */
+ public boolean equals(Object o) {
+ if (o == this)
+ return true;
+
+ if (!(o instanceof Set))
+ return false;
+ Collection c = (Collection) o;
+ if (c.size() != size())
+ return false;
+ try {
+ return containsAll(c);
+ } catch(ClassCastException unused) {
+ return false;
+ } catch(NullPointerException unused) {
+ return false;
+ }
+ }
+
+ /**
+ * Returns the hash code value for this set. The hash code of a set is
+ * defined to be the sum of the hash codes of the elements in the set.
+ * This ensures that <tt>s1.equals(s2)</tt> implies that
+ * <tt>s1.hashCode()==s2.hashCode()</tt> for any two sets <tt>s1</tt>
+ * and <tt>s2</tt>, as required by the general contract of
+ * Object.hashCode.<p>
+ *
+ * This implementation enumerates over the set, calling the
+ * <tt>hashCode</tt> method on each element in the collection, and
+ * adding up the results.
+ *
+ * @return the hash code value for this set.
+ */
+ public int hashCode() {
+ int h = 0;
+ Iterator i = iterator();
+ while (i.hasNext()) {
+ Object obj = i.next();
+ if (obj != null)
+ h += obj.hashCode();
+ }
+ return h;
+ }
+
+ /**
+ * Removes from this set all of its elements that are contained in
+ * the specified collection (optional operation).<p>
+ *
+ * This implementation determines which is the smaller of this set
+ * and the specified collection, by invoking the <tt>size</tt>
+ * method on each. If this set has fewer elements, then the
+ * implementation iterates over this set, checking each element
+ * returned by the iterator in turn to see if it is contained in
+ * the specified collection. If it is so contained, it is removed
+ * from this set with the iterator's <tt>remove</tt> method. If
+ * the specified collection has fewer elements, then the
+ * implementation iterates over the specified collection, removing
+ * from this set each element returned by the iterator, using this
+ * set's <tt>remove</tt> method.<p>
+ *
+ * Note that this implementation will throw an
+ * <tt>UnsupportedOperationException</tt> if the iterator returned by the
+ * <tt>iterator</tt> method does not implement the <tt>remove</tt> method.
+ *
+ * @param c elements to be removed from this set.
+ * @return <tt>true</tt> if this set changed as a result of the call.
+ *
+ * @throws UnsupportedOperationException removeAll is not supported
+ * by this set.
+ * @throws NullPointerException if the specified collection is null.
+ * @see #remove(Object)
+ * @see #contains(Object)
+ */
+ public boolean removeAll(Collection c) {
+ boolean modified = false;
+
+ if (size() > c.size()) {
+ for (Iterator i = c.iterator(); i.hasNext(); ) {
+ modified |= remove(i.next());
+ }
+ } else {
+ for (Iterator i = iterator(); i.hasNext(); ) {
+ if(c.contains(i.next())) {
+ i.remove();
+ modified = true;
+ }
+ }
+ }
+ return modified;
+ }
+
+}
+
projects / Benchmarks_CSolver.git / blobdiff