ViewVC Help
View File | Revision Log | Show Annotations | Download File | Root Listing
root/jsr166/jsr166/src/main/java/util/Deque.java
(Generate patch)

Comparing jsr166/src/main/java/util/Deque.java (file contents):
Revision 1.21 by jsr166, Sun Oct 21 06:40:20 2012 UTC vs.
Revision 1.22 by jsr166, Wed Jan 16 01:59:47 2013 UTC

# Line 9 | Line 9 | package java.util;
9   /**
10   * A linear collection that supports element insertion and removal at
11   * both ends.  The name <i>deque</i> is short for "double ended queue"
12 < * and is usually pronounced "deck".  Most <tt>Deque</tt>
12 > * and is usually pronounced "deck".  Most {@code Deque}
13   * implementations place no fixed limits on the number of elements
14   * they may contain, but this interface supports capacity-restricted
15   * deques as well as those with no fixed size limit.
# Line 18 | Line 18 | package java.util;
18   * ends of the deque.  Methods are provided to insert, remove, and
19   * examine the element.  Each of these methods exists in two forms:
20   * one throws an exception if the operation fails, the other returns a
21 < * special value (either <tt>null</tt> or <tt>false</tt>, depending on
21 > * special value (either {@code null} or {@code false}, depending on
22   * the operation).  The latter form of the insert operation is
23   * designed specifically for use with capacity-restricted
24 < * <tt>Deque</tt> implementations; in most implementations, insert
24 > * {@code Deque} implementations; in most implementations, insert
25   * operations cannot fail.
26   *
27   * <p>The twelve methods described above are summarized in the
# Line 67 | Line 67 | package java.util;
67   * <p>This interface extends the {@link Queue} interface.  When a deque is
68   * used as a queue, FIFO (First-In-First-Out) behavior results.  Elements are
69   * added at the end of the deque and removed from the beginning.  The methods
70 < * inherited from the <tt>Queue</tt> interface are precisely equivalent to
71 < * <tt>Deque</tt> methods as indicated in the following table:
70 > * inherited from the {@code Queue} interface are precisely equivalent to
71 > * {@code Deque} methods as indicated in the following table:
72   *
73   * <p>
74   * <table BORDER CELLPADDING=3 CELLSPACING=1>
75   *  <tr>
76 < *    <td ALIGN=CENTER> <b><tt>Queue</tt> Method</b></td>
77 < *    <td ALIGN=CENTER> <b>Equivalent <tt>Deque</tt> Method</b></td>
76 > *    <td ALIGN=CENTER> <b>{@code Queue} Method</b></td>
77 > *    <td ALIGN=CENTER> <b>Equivalent {@code Deque} Method</b></td>
78   *  </tr>
79   *  <tr>
80   *    <td>{@link java.util.Queue#add add(e)}</td>
# Line 106 | Line 106 | package java.util;
106   * interface should be used in preference to the legacy {@link Stack} class.
107   * When a deque is used as a stack, elements are pushed and popped from the
108   * beginning of the deque.  Stack methods are precisely equivalent to
109 < * <tt>Deque</tt> methods as indicated in the table below:
109 > * {@code Deque} methods as indicated in the table below:
110   *
111   * <p>
112   * <table BORDER CELLPADDING=3 CELLSPACING=1>
113   *  <tr>
114   *    <td ALIGN=CENTER> <b>Stack Method</b></td>
115 < *    <td ALIGN=CENTER> <b>Equivalent <tt>Deque</tt> Method</b></td>
115 > *    <td ALIGN=CENTER> <b>Equivalent {@code Deque} Method</b></td>
116   *  </tr>
117   *  <tr>
118   *    <td>{@link #push push(e)}</td>
# Line 139 | Line 139 | package java.util;
139   * <p>Unlike the {@link List} interface, this interface does not
140   * provide support for indexed access to elements.
141   *
142 < * <p>While <tt>Deque</tt> implementations are not strictly required
142 > * <p>While {@code Deque} implementations are not strictly required
143   * to prohibit the insertion of null elements, they are strongly
144 < * encouraged to do so.  Users of any <tt>Deque</tt> implementations
144 > * encouraged to do so.  Users of any {@code Deque} implementations
145   * that do allow null elements are strongly encouraged <i>not</i> to
146   * take advantage of the ability to insert nulls.  This is so because
147 < * <tt>null</tt> is used as a special return value by various methods
147 > * {@code null} is used as a special return value by various methods
148   * to indicated that the deque is empty.
149   *
150 < * <p><tt>Deque</tt> implementations generally do not define
151 < * element-based versions of the <tt>equals</tt> and <tt>hashCode</tt>
150 > * <p>{@code Deque} implementations generally do not define
151 > * element-based versions of the {@code equals} and {@code hashCode}
152   * methods, but instead inherit the identity-based versions from class
153 < * <tt>Object</tt>.
153 > * {@code Object}.
154   *
155   * <p>This interface is a member of the <a
156   * href="{@docRoot}/../technotes/guides/collections/index.html"> Java Collections
# Line 207 | Line 207 | public interface Deque<E> extends Queue<
207       * which can fail to insert an element only by throwing an exception.
208       *
209       * @param e the element to add
210 <     * @return <tt>true</tt> if the element was added to this deque, else
211 <     *         <tt>false</tt>
210 >     * @return {@code true} if the element was added to this deque, else
211 >     *         {@code false}
212       * @throws ClassCastException if the class of the specified element
213       *         prevents it from being added to this deque
214       * @throws NullPointerException if the specified element is null and this
# Line 225 | Line 225 | public interface Deque<E> extends Queue<
225       * which can fail to insert an element only by throwing an exception.
226       *
227       * @param e the element to add
228 <     * @return <tt>true</tt> if the element was added to this deque, else
229 <     *         <tt>false</tt>
228 >     * @return {@code true} if the element was added to this deque, else
229 >     *         {@code false}
230       * @throws ClassCastException if the class of the specified element
231       *         prevents it from being added to this deque
232       * @throws NullPointerException if the specified element is null and this
# Line 258 | Line 258 | public interface Deque<E> extends Queue<
258  
259      /**
260       * Retrieves and removes the first element of this deque,
261 <     * or returns <tt>null</tt> if this deque is empty.
261 >     * or returns {@code null} if this deque is empty.
262       *
263 <     * @return the head of this deque, or <tt>null</tt> if this deque is empty
263 >     * @return the head of this deque, or {@code null} if this deque is empty
264       */
265      E pollFirst();
266  
267      /**
268       * Retrieves and removes the last element of this deque,
269 <     * or returns <tt>null</tt> if this deque is empty.
269 >     * or returns {@code null} if this deque is empty.
270       *
271 <     * @return the tail of this deque, or <tt>null</tt> if this deque is empty
271 >     * @return the tail of this deque, or {@code null} if this deque is empty
272       */
273      E pollLast();
274  
# Line 295 | Line 295 | public interface Deque<E> extends Queue<
295  
296      /**
297       * Retrieves, but does not remove, the first element of this deque,
298 <     * or returns <tt>null</tt> if this deque is empty.
298 >     * or returns {@code null} if this deque is empty.
299       *
300 <     * @return the head of this deque, or <tt>null</tt> if this deque is empty
300 >     * @return the head of this deque, or {@code null} if this deque is empty
301       */
302      E peekFirst();
303  
304      /**
305       * Retrieves, but does not remove, the last element of this deque,
306 <     * or returns <tt>null</tt> if this deque is empty.
306 >     * or returns {@code null} if this deque is empty.
307       *
308 <     * @return the tail of this deque, or <tt>null</tt> if this deque is empty
308 >     * @return the tail of this deque, or {@code null} if this deque is empty
309       */
310      E peekLast();
311  
312      /**
313       * Removes the first occurrence of the specified element from this deque.
314       * If the deque does not contain the element, it is unchanged.
315 <     * More formally, removes the first element <tt>e</tt> such that
315 >     * More formally, removes the first element {@code e} such that
316       * <tt>(o==null&nbsp;?&nbsp;e==null&nbsp;:&nbsp;o.equals(e))</tt>
317       * (if such an element exists).
318 <     * Returns <tt>true</tt> if this deque contained the specified element
318 >     * Returns {@code true} if this deque contained the specified element
319       * (or equivalently, if this deque changed as a result of the call).
320       *
321       * @param o element to be removed from this deque, if present
322 <     * @return <tt>true</tt> if an element was removed as a result of this call
322 >     * @return {@code true} if an element was removed as a result of this call
323       * @throws ClassCastException if the class of the specified element
324       *         is incompatible with this deque (optional)
325       * @throws NullPointerException if the specified element is null and this
# Line 330 | Line 330 | public interface Deque<E> extends Queue<
330      /**
331       * Removes the last occurrence of the specified element from this deque.
332       * If the deque does not contain the element, it is unchanged.
333 <     * More formally, removes the last element <tt>e</tt> such that
333 >     * More formally, removes the last element {@code e} such that
334       * <tt>(o==null&nbsp;?&nbsp;e==null&nbsp;:&nbsp;o.equals(e))</tt>
335       * (if such an element exists).
336 <     * Returns <tt>true</tt> if this deque contained the specified element
336 >     * Returns {@code true} if this deque contained the specified element
337       * (or equivalently, if this deque changed as a result of the call).
338       *
339       * @param o element to be removed from this deque, if present
340 <     * @return <tt>true</tt> if an element was removed as a result of this call
340 >     * @return {@code true} if an element was removed as a result of this call
341       * @throws ClassCastException if the class of the specified element
342       *         is incompatible with this deque (optional)
343       * @throws NullPointerException if the specified element is null and this
# Line 351 | Line 351 | public interface Deque<E> extends Queue<
351       * Inserts the specified element into the queue represented by this deque
352       * (in other words, at the tail of this deque) if it is possible to do so
353       * immediately without violating capacity restrictions, returning
354 <     * <tt>true</tt> upon success and throwing an
355 <     * <tt>IllegalStateException</tt> if no space is currently available.
354 >     * {@code true} upon success and throwing an
355 >     * {@code IllegalStateException} if no space is currently available.
356       * When using a capacity-restricted deque, it is generally preferable to
357       * use {@link #offer(Object) offer}.
358       *
359       * <p>This method is equivalent to {@link #addLast}.
360       *
361       * @param e the element to add
362 <     * @return <tt>true</tt> (as specified by {@link Collection#add})
362 >     * @return {@code true} (as specified by {@link Collection#add})
363       * @throws IllegalStateException if the element cannot be added at this
364       *         time due to capacity restrictions
365       * @throws ClassCastException if the class of the specified element
# Line 375 | Line 375 | public interface Deque<E> extends Queue<
375       * Inserts the specified element into the queue represented by this deque
376       * (in other words, at the tail of this deque) if it is possible to do so
377       * immediately without violating capacity restrictions, returning
378 <     * <tt>true</tt> upon success and <tt>false</tt> if no space is currently
378 >     * {@code true} upon success and {@code false} if no space is currently
379       * available.  When using a capacity-restricted deque, this method is
380       * generally preferable to the {@link #add} method, which can fail to
381       * insert an element only by throwing an exception.
# Line 383 | Line 383 | public interface Deque<E> extends Queue<
383       * <p>This method is equivalent to {@link #offerLast}.
384       *
385       * @param e the element to add
386 <     * @return <tt>true</tt> if the element was added to this deque, else
387 <     *         <tt>false</tt>
386 >     * @return {@code true} if the element was added to this deque, else
387 >     *         {@code false}
388       * @throws ClassCastException if the class of the specified element
389       *         prevents it from being added to this deque
390       * @throws NullPointerException if the specified element is null and this
# Line 410 | Line 410 | public interface Deque<E> extends Queue<
410      /**
411       * Retrieves and removes the head of the queue represented by this deque
412       * (in other words, the first element of this deque), or returns
413 <     * <tt>null</tt> if this deque is empty.
413 >     * {@code null} if this deque is empty.
414       *
415       * <p>This method is equivalent to {@link #pollFirst()}.
416       *
417 <     * @return the first element of this deque, or <tt>null</tt> if
417 >     * @return the first element of this deque, or {@code null} if
418       *         this deque is empty
419       */
420      E poll();
# Line 435 | Line 435 | public interface Deque<E> extends Queue<
435      /**
436       * Retrieves, but does not remove, the head of the queue represented by
437       * this deque (in other words, the first element of this deque), or
438 <     * returns <tt>null</tt> if this deque is empty.
438 >     * returns {@code null} if this deque is empty.
439       *
440       * <p>This method is equivalent to {@link #peekFirst()}.
441       *
442       * @return the head of the queue represented by this deque, or
443 <     *         <tt>null</tt> if this deque is empty
443 >     *         {@code null} if this deque is empty
444       */
445      E peek();
446  
# Line 451 | Line 451 | public interface Deque<E> extends Queue<
451       * Pushes an element onto the stack represented by this deque (in other
452       * words, at the head of this deque) if it is possible to do so
453       * immediately without violating capacity restrictions, returning
454 <     * <tt>true</tt> upon success and throwing an
455 <     * <tt>IllegalStateException</tt> if no space is currently available.
454 >     * {@code true} upon success and throwing an
455 >     * {@code IllegalStateException} if no space is currently available.
456       *
457       * <p>This method is equivalent to {@link #addFirst}.
458       *
# Line 486 | Line 486 | public interface Deque<E> extends Queue<
486      /**
487       * Removes the first occurrence of the specified element from this deque.
488       * If the deque does not contain the element, it is unchanged.
489 <     * More formally, removes the first element <tt>e</tt> such that
489 >     * More formally, removes the first element {@code e} such that
490       * <tt>(o==null&nbsp;?&nbsp;e==null&nbsp;:&nbsp;o.equals(e))</tt>
491       * (if such an element exists).
492 <     * Returns <tt>true</tt> if this deque contained the specified element
492 >     * Returns {@code true} if this deque contained the specified element
493       * (or equivalently, if this deque changed as a result of the call).
494       *
495       * <p>This method is equivalent to {@link #removeFirstOccurrence}.
496       *
497       * @param o element to be removed from this deque, if present
498 <     * @return <tt>true</tt> if an element was removed as a result of this call
498 >     * @return {@code true} if an element was removed as a result of this call
499       * @throws ClassCastException if the class of the specified element
500       *         is incompatible with this deque (optional)
501       * @throws NullPointerException if the specified element is null and this
# Line 504 | Line 504 | public interface Deque<E> extends Queue<
504      boolean remove(Object o);
505  
506      /**
507 <     * Returns <tt>true</tt> if this deque contains the specified element.
508 <     * More formally, returns <tt>true</tt> if and only if this deque contains
509 <     * at least one element <tt>e</tt> such that
507 >     * Returns {@code true} if this deque contains the specified element.
508 >     * More formally, returns {@code true} if and only if this deque contains
509 >     * at least one element {@code e} such that
510       * <tt>(o==null&nbsp;?&nbsp;e==null&nbsp;:&nbsp;o.equals(e))</tt>.
511       *
512       * @param o element whose presence in this deque is to be tested
513 <     * @return <tt>true</tt> if this deque contains the specified element
513 >     * @return {@code true} if this deque contains the specified element
514       * @throws ClassCastException if the type of the specified element
515       *         is incompatible with this deque (optional)
516       * @throws NullPointerException if the specified element is null and this

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines