From 554fd8c5195424bdbcabf5de30fdc183aba391bd Mon Sep 17 00:00:00 2001 From: upstream source tree Date: Sun, 15 Mar 2015 20:14:05 -0400 Subject: obtained gcc-4.6.4.tar.bz2 from upstream website; verified gcc-4.6.4.tar.bz2.sig; imported gcc-4.6.4 source tree from verified upstream tarball. downloading a git-generated archive based on the 'upstream' tag should provide you with a source tree that is binary identical to the one extracted from the above tarball. if you have obtained the source via the command 'git clone', however, do note that line-endings of files in your working directory might differ from line-endings of the respective files in the upstream repository. --- .../classpath/java/util/AbstractCollection.java | 482 +++++++++++++++++++++ 1 file changed, 482 insertions(+) create mode 100644 libjava/classpath/java/util/AbstractCollection.java (limited to 'libjava/classpath/java/util/AbstractCollection.java') diff --git a/libjava/classpath/java/util/AbstractCollection.java b/libjava/classpath/java/util/AbstractCollection.java new file mode 100644 index 000000000..d3406c230 --- /dev/null +++ b/libjava/classpath/java/util/AbstractCollection.java @@ -0,0 +1,482 @@ +/* AbstractCollection.java -- Abstract implementation of most of Collection + Copyright (C) 1998, 2000, 2001, 2004, 2005 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package java.util; + +import gnu.java.lang.CPStringBuilder; + +import java.lang.reflect.Array; + +/** + * A basic implementation of most of the methods in the Collection interface to + * make it easier to create a collection. To create an unmodifiable Collection, + * just subclass AbstractCollection and provide implementations of the + * iterator() and size() methods. The Iterator returned by iterator() need only + * provide implementations of hasNext() and next() (that is, it may throw an + * UnsupportedOperationException if remove() is called). To create a modifiable + * Collection, you must in addition provide an implementation of the + * add(Object) method and the Iterator returned by iterator() must provide an + * implementation of remove(). Other methods should be overridden if the + * backing data structure allows for a more efficient implementation. The + * precise implementation used by AbstractCollection is documented, so that + * subclasses can tell which methods could be implemented more efficiently. + *

+ * + * The programmer should provide a no-argument constructor, and one that + * accepts another Collection, as recommended by the Collection interface. + * Unfortunately, there is no way to enforce this in Java. + * + * @author Original author unknown + * @author Bryce McKinlay + * @author Eric Blake (ebb9@email.byu.edu) + * @author Tom Tromey (tromey@redhat.com) + * @author Andrew John Hughes (gnu_andrew@member.fsf.org) + * @see Collection + * @see AbstractSet + * @see AbstractList + * @since 1.2 + * @status updated to 1.4 + */ +public abstract class AbstractCollection + implements Collection, Iterable +{ + /** + * The main constructor, for use by subclasses. + */ + protected AbstractCollection() + { + } + + /** + * Return an Iterator over this collection. The iterator must provide the + * hasNext and next methods and should in addition provide remove if the + * collection is modifiable. + * + * @return an iterator + */ + public abstract Iterator iterator(); + + /** + * Return the number of elements in this collection. If there are more than + * Integer.MAX_VALUE elements, return Integer.MAX_VALUE. + * + * @return the size + */ + public abstract int size(); + + /** + * Add an object to the collection (optional operation). This implementation + * always throws an UnsupportedOperationException - it should be + * overridden if the collection is to be modifiable. If the collection + * does not accept duplicates, simply return false. Collections may specify + * limitations on what may be added. + * + * @param o the object to add + * @return true if the add operation caused the Collection to change + * @throws UnsupportedOperationException if the add operation is not + * supported on this collection + * @throws NullPointerException if the collection does not support null + * @throws ClassCastException if the object is of the wrong type + * @throws IllegalArgumentException if some aspect of the object prevents + * it from being added + */ + public boolean add(E o) + { + throw new UnsupportedOperationException(); + } + + /** + * Add all the elements of a given collection to this collection (optional + * operation). This implementation obtains an Iterator over the given + * collection and iterates over it, adding each element with the + * add(Object) method (thus this method will fail with an + * UnsupportedOperationException if the add method does). The behavior is + * unspecified if the specified collection is modified during the iteration, + * including the special case of trying addAll(this) on a non-empty + * collection. + * + * @param c the collection to add the elements of to this collection + * @return true if the add operation caused the Collection to change + * @throws UnsupportedOperationException if the add operation is not + * supported on this collection + * @throws NullPointerException if the specified collection is null + * @throws ClassCastException if the type of any element in c is + * not a valid type for addition. + * @throws IllegalArgumentException if some aspect of any element + * in c prevents it being added. + * @throws NullPointerException if any element in c is null and this + * collection doesn't allow null values. + * @see #add(Object) + */ + public boolean addAll(Collection c) + { + Iterator itr = c.iterator(); + boolean modified = false; + int pos = c.size(); + while (--pos >= 0) + modified |= add(itr.next()); + return modified; + } + + /** + * Remove all elements from the collection (optional operation). This + * implementation obtains an iterator over the collection and calls next + * and remove on it repeatedly (thus this method will fail with an + * UnsupportedOperationException if the Iterator's remove method does) + * until there are no more elements to remove. + * Many implementations will have a faster way of doing this. + * + * @throws UnsupportedOperationException if the Iterator returned by + * iterator does not provide an implementation of remove + * @see Iterator#remove() + */ + public void clear() + { + Iterator itr = iterator(); + int pos = size(); + while (--pos >= 0) + { + itr.next(); + itr.remove(); + } + } + + /** + * Test whether this collection contains a given object. That is, if the + * collection has an element e such that (o == null ? e == null : + * o.equals(e)). This implementation obtains an iterator over the collection + * and iterates over it, testing each element for equality with the given + * object. If it is equal, true is returned. Otherwise false is returned when + * the end of the collection is reached. + * + * @param o the object to remove from this collection + * @return true if this collection contains an object equal to o + */ + public boolean contains(Object o) + { + Iterator itr = iterator(); + int pos = size(); + while (--pos >= 0) + if (equals(o, itr.next())) + return true; + return false; + } + + /** + * Tests whether this collection contains all the elements in a given + * collection. This implementation iterates over the given collection, + * testing whether each element is contained in this collection. If any one + * is not, false is returned. Otherwise true is returned. + * + * @param c the collection to test against + * @return true if this collection contains all the elements in the given + * collection + * @throws NullPointerException if the given collection is null + * @see #contains(Object) + */ + public boolean containsAll(Collection c) + { + Iterator itr = c.iterator(); + int pos = c.size(); + while (--pos >= 0) + if (!contains(itr.next())) + return false; + return true; + } + + /** + * Test whether this collection is empty. This implementation returns + * size() == 0. + * + * @return true if this collection is empty. + * @see #size() + */ + public boolean isEmpty() + { + return size() == 0; + } + + /** + * Remove a single instance of an object from this collection (optional + * operation). That is, remove one element e such that + * (o == null ? e == null : o.equals(e)), if such an element + * exists. This implementation obtains an iterator over the collection + * and iterates over it, testing each element for equality with the given + * object. If it is equal, it is removed by the iterator's remove method + * (thus this method will fail with an UnsupportedOperationException if + * the Iterator's remove method does). After the first element has been + * removed, true is returned; if the end of the collection is reached, false + * is returned. + * + * @param o the object to remove from this collection + * @return true if the remove operation caused the Collection to change, or + * equivalently if the collection did contain o. + * @throws UnsupportedOperationException if this collection's Iterator + * does not support the remove method + * @see Iterator#remove() + */ + public boolean remove(Object o) + { + Iterator itr = iterator(); + int pos = size(); + while (--pos >= 0) + if (equals(o, itr.next())) + { + itr.remove(); + return true; + } + return false; + } + + /** + * Remove from this collection all its elements that are contained in a given + * collection (optional operation). This implementation iterates over this + * collection, and for each element tests if it is contained in the given + * collection. If so, it is removed by the Iterator's remove method (thus + * this method will fail with an UnsupportedOperationException if the + * Iterator's remove method does). + * + * @param c the collection to remove the elements of + * @return true if the remove operation caused the Collection to change + * @throws UnsupportedOperationException if this collection's Iterator + * does not support the remove method + * @throws NullPointerException if the collection, c, is null. + * @see Iterator#remove() + */ + public boolean removeAll(Collection c) + { + return removeAllInternal(c); + } + + /** + * Remove from this collection all its elements that are contained in a given + * collection (optional operation). This implementation iterates over this + * collection, and for each element tests if it is contained in the given + * collection. If so, it is removed by the Iterator's remove method (thus + * this method will fail with an UnsupportedOperationException if the + * Iterator's remove method does). This method is necessary for ArrayList, + * which cannot publicly override removeAll but can optimize this call. + * + * @param c the collection to remove the elements of + * @return true if the remove operation caused the Collection to change + * @throws UnsupportedOperationException if this collection's Iterator + * does not support the remove method + * @throws NullPointerException if the collection, c, is null. + * @see Iterator#remove() + */ + // Package visible for use throughout java.util. + boolean removeAllInternal(Collection c) + { + Iterator itr = iterator(); + boolean modified = false; + int pos = size(); + while (--pos >= 0) + if (c.contains(itr.next())) + { + itr.remove(); + modified = true; + } + return modified; + } + + /** + * Remove from this collection all its elements that are not contained in a + * given collection (optional operation). This implementation iterates over + * this collection, and for each element tests if it is contained in the + * given collection. If not, it is removed by the Iterator's remove method + * (thus this method will fail with an UnsupportedOperationException if + * the Iterator's remove method does). + * + * @param c the collection to retain the elements of + * @return true if the remove operation caused the Collection to change + * @throws UnsupportedOperationException if this collection's Iterator + * does not support the remove method + * @throws NullPointerException if the collection, c, is null. + * @see Iterator#remove() + */ + public boolean retainAll(Collection c) + { + return retainAllInternal(c); + } + + /** + * Remove from this collection all its elements that are not contained in a + * given collection (optional operation). This implementation iterates over + * this collection, and for each element tests if it is contained in the + * given collection. If not, it is removed by the Iterator's remove method + * (thus this method will fail with an UnsupportedOperationException if + * the Iterator's remove method does). This method is necessary for + * ArrayList, which cannot publicly override retainAll but can optimize + * this call. + * + * @param c the collection to retain the elements of + * @return true if the remove operation caused the Collection to change + * @throws UnsupportedOperationException if this collection's Iterator + * does not support the remove method + * @throws NullPointerException if the collection, c, is null. + * @see Iterator#remove() + */ + // Package visible for use throughout java.util. + boolean retainAllInternal(Collection c) + { + Iterator itr = iterator(); + boolean modified = false; + int pos = size(); + while (--pos >= 0) + if (!c.contains(itr.next())) + { + itr.remove(); + modified = true; + } + return modified; + } + + /** + * Return an array containing the elements of this collection. This + * implementation creates an Object array of size size() and then iterates + * over the collection, setting each element of the array from the value + * returned by the iterator. The returned array is safe, and is not backed + * by the collection. + * + * @return an array containing the elements of this collection + */ + public Object[] toArray() + { + Iterator itr = iterator(); + int size = size(); + Object[] a = new Object[size]; + for (int pos = 0; pos < size; pos++) + a[pos] = itr.next(); + return a; + } + + /** + * Copy the collection into a given array if it will fit, or into a + * dynamically created array of the same run-time type as the given array if + * not. If there is space remaining in the array, the first element after the + * end of the collection is set to null (this is only useful if the + * collection is known to contain no null elements, however). This + * implementation first tests whether the given array is large enough to hold + * all the elements of the collection. If not, the reflection API is used to + * allocate a new array of the same run-time type. Next an iterator is + * obtained over the collection and the elements are placed in the array as + * they are returned by the iterator. Finally the first spare element, if + * any, of the array is set to null, and the created array is returned. + * The returned array is safe; it is not backed by the collection. Note that + * null may not mark the last element, if the collection allows null + * elements. + * + * @param a the array to copy into, or of the correct run-time type + * @return the array that was produced + * @throws NullPointerException if the given array is null + * @throws ArrayStoreException if the type of the array precludes holding + * one of the elements of the Collection + */ + public T[] toArray(T[] a) + { + int size = size(); + if (a.length < size) + a = (T[]) Array.newInstance(a.getClass().getComponentType(), + size); + else if (a.length > size) + a[size] = null; + + Iterator itr = iterator(); + for (int pos = 0; pos < size; pos++) + a[pos] = (T) (itr.next()); + return a; + } + + /** + * Creates a String representation of the Collection. The string returned is + * of the form "[a, b, ...]" where a and b etc are the results of calling + * toString on the elements of the collection. This implementation obtains an + * Iterator over the Collection and adds each element to a StringBuffer as it + * is returned by the iterator. "" is inserted when the collection + * contains itself (only works for direct containment, not for collections + * inside collections). + * + * @return a String representation of the Collection + */ + public String toString() + { + Iterator itr = iterator(); + CPStringBuilder r = new CPStringBuilder("["); + boolean hasNext = itr.hasNext(); + while (hasNext) + { + Object o = itr.next(); + if (o == this) + r.append(""); + else + r.append(o); + hasNext = itr.hasNext(); + if (hasNext) + r.append(", "); + } + r.append("]"); + return r.toString(); + } + + /** + * Compare two objects according to Collection semantics. + * + * @param o1 the first object + * @param o2 the second object + * @return o1 == null ? o2 == null : o1.equals(o2) + */ + // Package visible for use throughout java.util. + // It may be inlined since it is final. + static final boolean equals(Object o1, Object o2) + { + return o1 == null ? o2 == null : o1.equals(o2); + } + + /** + * Hash an object according to Collection semantics. + * + * @param o the object to hash + * @return o1 == null ? 0 : o1.hashCode() + */ + // Package visible for use throughout java.util. + // It may be inlined since it is final. + static final int hashCode(Object o) + { + return o == null ? 0 : o.hashCode(); + } +} -- cgit v1.2.3