--- jsr166/src/main/java/util/Deque.java 2005/05/02 17:34:02 1.7
+++ jsr166/src/main/java/util/Deque.java 2005/05/14 02:22:28 1.8
@@ -37,9 +37,9 @@ package java.util;
*
* |
* Throws exception |
- * Returns special value |
+ * Special value |
* Throws exception |
- * Returns special value |
+ * Special value |
*
*
* | Insert |
@@ -77,29 +77,29 @@ package java.util;
* Equivalent Deque Method |
*
*
- * | {@link java.util.Queue#offer offer(e)} |
- * {@link #offerLast offerLast(e)} |
- *
- *
* | {@link java.util.Queue#add add(e)} |
* {@link #addLast addLast(e)} |
*
*
- * | {@link java.util.Queue#poll poll()} |
- * {@link #pollFirst pollFirst()} |
+ * {@link java.util.Queue#offer offer(e)} |
+ * {@link #offerLast offerLast(e)} |
*
*
* | {@link java.util.Queue#remove remove()} |
* {@link #removeFirst removeFirst()} |
*
*
- * | {@link java.util.Queue#peek peek()} |
- * {@link #peek peekFirst()} |
+ * {@link java.util.Queue#poll poll()} |
+ * {@link #pollFirst pollFirst()} |
*
*
* | {@link java.util.Queue#element element()} |
* {@link #getFirst getFirst()} |
*
+ *
+ * | {@link java.util.Queue#peek peek()} |
+ * {@link #peek peekFirst()} |
+ *
*
*
* Deques can also be used as LIFO (Last-In-First-Out) stacks. This
@@ -134,9 +134,10 @@ package java.util;
*
*
This interface provides two methods to remove interior
* elements, {@link #removeFirstOccurrence removeFirstOccurrence} and
- * {@link #removeLastOccurrence removeLastOccurrence}. Unlike the
- * {@link List} interface, this interface does not provide support for
- * indexed access to elements.
+ * {@link #removeLastOccurrence removeLastOccurrence}.
+ *
+ *
Unlike the {@link List} interface, this interface does not
+ * provide support for indexed access to elements.
*
*
While Deque implementations are not strictly required
* to prohibit the insertion of null elements, they are strongly
@@ -163,215 +164,237 @@ package java.util;
public interface Deque extends Queue {
/**
+ * Inserts the specified element at the front of this deque if it is
+ * possible to do so immediately without violating capacity restrictions.
+ * When using a capacity-restricted deque, it is generally preferable to
+ * use method {@link #offerFirst}.
+ *
+ * @param e the element to add
+ * @throws IllegalStateException if the element cannot be added at this
+ * time due to capacity restrictions
+ * @throws NullPointerException if the specified element is null and this
+ * deque does not permit null elements
+ * @throws ClassCastException if the class of the specified element
+ * prevents it from being added to this deque
+ * @throws IllegalArgumentException if some property of the specified
+ * element prevents it from being added to this deque
+ */
+ void addFirst(E e);
+
+ /**
+ * Inserts the specified element at the end of this deque if it is
+ * possible to do so immediately without violating capacity restrictions.
+ * When using a capacity-restricted deque, it is generally preferable to
+ * use method {@link #offerLast}.
+ *
+ * @param e the element to add
+ * @throws IllegalStateException if the element cannot be added at this
+ * time due to capacity restrictions
+ * @throws NullPointerException if the specified element is null and this
+ * deque does not permit null elements
+ * @throws ClassCastException if the class of the specified element
+ * prevents it from being added to this deque
+ * @throws IllegalArgumentException if some property of the specified
+ * element prevents it from being added to this deque
+ */
+ void addLast(E e);
+
+ /**
* Inserts the specified element at the front of this deque unless it would
* violate capacity restrictions. When using a capacity-restricted deque,
- * this method is generally preferable to method addFirst, which
- * can fail to insert an element only by throwing an exception.
+ * this method is generally preferable to the {@link #addFirst} method,
+ * which can fail to insert an element only by throwing an exception.
*
- * @param e the element to insert
+ * @param e the element to add
* @return true if it was possible to insert the element,
- * else false
+ * else false
* @throws NullPointerException if the specified element is null and this
- * deque does not permit null elements
+ * deque does not permit null elements
+ * @throws ClassCastException if the class of the specified element
+ * prevents it from being added to this deque
+ * @throws IllegalArgumentException if some property of the specified
+ * element prevents it from being added to this deque
*/
boolean offerFirst(E e);
/**
* Inserts the specified element at the end of this deque unless it would
* violate capacity restrictions. When using a capacity-restricted deque,
- * this method is generally preferable to method addLast which
- * can fail to insert an element only by throwing an exception.
+ * this method is generally preferable to the {@link #addLast} method,
+ * which can fail to insert an element only by throwing an exception.
*
- * @param e the element to insert
+ * @param e the element to add
* @return true if it was possible to insert the element,
- * else false
+ * else false
* @throws NullPointerException if the specified element is null and this
- * deque does not permit null elements
+ * deque does not permit null elements
+ * @throws ClassCastException if the class of the specified element
+ * prevents it from being added to this deque
+ * @throws IllegalArgumentException if some property of the specified
+ * element prevents it from being added to this deque
*/
boolean offerLast(E e);
/**
- * Inserts the specified element at the front of this deque unless it
- * would violate capacity restrictions.
+ * Retrieves and removes the first element of this deque. This method
+ * differs from {@link #pollFirst} only in that it throws an exception
+ * if this deque is empty.
*
- * @param e the element to insert
- * @throws IllegalStateException if it was not possible to insert
- * the element due to capacity restrictions
- * @throws NullPointerException if the specified element is null and this
- * deque does not permit null elements
+ * @return the head of this deque
+ * @throws NoSuchElementException if this deque is empty
*/
- void addFirst(E e);
+ E removeFirst();
/**
- * Inserts the specified element at the end of this deque unless it would
- * violate capacity restrictions.
+ * Retrieves and removes the last element of this deque. This method
+ * differs from {@link #pollLast} only in that it throws an exception if
+ * this deque is empty.
*
- * @param e the element to insert
- * @throws IllegalStateException if it was not possible to insert
- * the element due to capacity restrictions
- * @throws NullPointerException if the specified element is null and this
- * deque does not permit null elements
+ * @return the tail of this deque
+ * @throws NoSuchElementException if this deque is empty
*/
- void addLast(E e);
+ E removeLast();
/**
- * Retrieves and removes the first element of this deque, or
- * null if this deque is empty.
+ * Retrieves and removes the first element of this deque,
+ * or returns null if this deque is empty.
*
- * @return the first element of this deque, or null if
- * this deque is empty
+ * @return the head of this deque, or null if this deque is empty
*/
E pollFirst();
/**
- * Retrieves and removes the last element of this deque, or
- * null if this deque is empty.
+ * Retrieves and removes the last element of this deque,
+ * or returns null if this deque is empty.
*
- * @return the last element of this deque, or null if
- * this deque is empty
+ * @return the tail of this deque, or null if this deque is empty
*/
E pollLast();
/**
- * Retrieves and removes the first element of this deque. This method
- * differs from the {@link #pollFirst} method only in that it throws an
+ * Retrieves, but does not remove, the first element of this deque.
+ * This method differs from {@link #peekFirst} only in that it throws an
* exception if this deque is empty.
*
- * @return the first element of this deque
+ * @return the head of this deque
* @throws NoSuchElementException if this deque is empty
*/
- E removeFirst();
+ E getFirst();
/**
- * Retrieves and removes the last element of this deque. This method
- * differs from the {@link #pollLast} method only in that it throws an
+ * Retrieves, but does not remove, the last element of this deque.
+ * This method differs from {@link #peekLast} only in that it throws an
* exception if this deque is empty.
*
- * @return the last element of this deque
+ * @return the tail of this deque
* @throws NoSuchElementException if this deque is empty
*/
- E removeLast();
+ E getLast();
/**
* Retrieves, but does not remove, the first element of this deque,
- * returning null if this deque is empty.
+ * or returns null if this deque is empty.
*
- * @return the first element of this deque, or null if
- * this deque is empty
+ * @return the head of this deque, or null if this deque is empty
*/
E peekFirst();
/**
* Retrieves, but does not remove, the last element of this deque,
- * returning null if this deque is empty.
+ * or returns null if this deque is empty.
*
- * @return the last element of this deque, or null if this deque
- * is empty
+ * @return the tail of this deque, or null if this deque is empty
*/
E peekLast();
/**
- * Retrieves, but does not remove, the first element of this
- * deque. This method differs from the {@link #peekFirst} method only
- * in that it throws an exception if this deque is empty.
- *
- * @return the first element of this deque
- * @throws NoSuchElementException if this deque is empty
- */
- E getFirst();
-
- /**
- * Retrieves, but does not remove, the last element of this
- * deque. This method differs from the {@link #peekLast} method only
- * in that it throws an exception if this deque is empty.
- *
- * @return the last element of this deque
- * @throws NoSuchElementException if this deque is empty
- */
- E getLast();
-
- /**
- * Removes the first occurrence of the specified element in this
- * deque. If the deque does not contain the element, it is
- * unchanged. More formally, removes the first element e
- * such that (o==null ? e==null : o.equals(e)) (if
- * such an element exists).
+ * Removes the first occurrence of the specified element from this deque.
+ * If the deque does not contain the element, it is unchanged.
+ * More formally, removes the first element e such that
+ * (o==null ? e==null : o.equals(e)) (if such an element exists).
+ * Returns true if this deque contained the specified element (or
+ * equivalently, if this deque changed as a result of the call).
*
* @param o element to be removed from this deque, if present
- * @return true if the deque contained the specified element
+ * @return true if an element was removed as a result of this call
* @throws NullPointerException if the specified element is null and this
- * deque does not permit null elements
+ * deque does not permit null elements (optional)
+ * @throws ClassCastException if the class of the specified element
+ * is incompatible with this collection (optional)
*/
boolean removeFirstOccurrence(Object o);
/**
- * Removes the last occurrence of the specified element in this
- * deque. If the deque does not contain the element, it is
- * unchanged. More formally, removes the last element e
- * such that (o==null ? e==null : o.equals(e)) (if
- * such an element exists).
+ * Removes the last occurrence of the specified element from this deque.
+ * If the deque does not contain the element, it is unchanged.
+ * More formally, removes the last element e such that
+ * (o==null ? e==null : o.equals(e)) (if such an element exists).
+ * Returns true if this deque contained the specified element (or
+ * equivalently, if this deque changed as a result of the call).
*
* @param o element to be removed from this deque, if present
- * @return true if the deque contained the specified element
+ * @return true if an element was removed as a result of this call
* @throws NullPointerException if the specified element is null and this
- * deque does not permit null elements
+ * deque does not permit null elements (optional)
+ * @throws ClassCastException if the class of the specified element
+ * is incompatible with this collection (optional)
*/
boolean removeLastOccurrence(Object o);
-
// *** Queue methods ***
/**
* Inserts the specified element into the queue represented by this deque
- * unless it would violate capacity restrictions. In other words, inserts
- * the specified element at the end of this deque. When using a
- * capacity-restricted deque, this method is generally preferable to the
- * {@link #add} method, which can fail to insert an element only by
- * throwing an exception.
- *
- * This method is equivalent to {@link #offerLast}.
- *
- * @param e the element to insert
- * @return true if it was possible to insert the element,
- * else false
- * @throws NullPointerException if the specified element is null and this
- * deque does not permit null elements
- */
- boolean offer(E e);
-
- /**
- * Inserts the specified element into the queue represented by this
- * deque unless it would violate capacity restrictions. In other words,
- * inserts the specified element as the last element of this deque.
+ * (in other words, at the tail of this deque) if it is possible to do so
+ * immediately without violating capacity restrictions, returning
+ * true upon success and throwing an
+ * IllegalStateException if no space is currently available.
+ * When using a capacity-restricted deque, it is generally preferable to
+ * use {@link #offer(Object) offer}.
*
- *
This method is equivalent to {@link #addLast}.
+ *
This method is equivalent to {@link #addLast(Object) addLast}.
*
- * @param e the element to insert
+ * @param e the element to add
* @return true (as per the spec for {@link Collection#add})
- * @throws IllegalStateException if it was not possible to insert
- * the element due to capacity restrictions
+ * @throws IllegalStateException if the element cannot be added at this
+ * time due to capacity restrictions
* @throws NullPointerException if the specified element is null and this
- * deque does not permit null elements
+ * deque does not permit null elements
+ * @throws ClassCastException if the class of the specified element
+ * prevents it from being added to this deque
+ * @throws IllegalArgumentException if some property of the specified
+ * element prevents it from being added to this deque
*/
boolean add(E e);
/**
- * Retrieves and removes the head of the queue represented by
- * this deque, or null if this deque is empty. In other words,
- * retrieves and removes the first element of this deque, or null
- * if this deque is empty.
+ * Inserts the specified element into the queue represented by this deque
+ * (in other words, at the tail of this deque) if it is possible to do so
+ * immediately without violating capacity restrictions, returning
+ * true upon success and false if no space is currently
+ * available. When using a capacity-restricted deque, this method is
+ * generally preferable to the {@link #add} method, which can fail to
+ * insert an element only by throwing an exception.
*
- *
This method is equivalent to {@link #pollFirst()}.
+ *
This method is equivalent to {@link #offerLast}.
*
- * @return the first element of this deque, or null if
- * this deque is empty
+ * @param e the element to add
+ * @return true if the element was added to this deque, else
+ * false
+ * @throws NullPointerException if the specified element is null and this
+ * deque does not permit null elements
+ * @throws ClassCastException if the class of the specified element
+ * prevents it from being added to this deque
+ * @throws IllegalArgumentException if some property of the specified
+ * element prevents it from being added to this deque
*/
- E poll();
+ boolean offer(E e);
/**
- * Retrieves and removes the head of the queue represented by this deque.
- * This method differs from the {@link #poll} method only in that it
- * throws an exception if this deque is empty.
+ * Retrieves and removes the head of the queue represented by this deque
+ * (in other words, the first element of this deque).
+ * This method differs from {@link #poll} only in that it throws an
+ * exception if this deque is empty.
*
*
This method is equivalent to {@link #removeFirst()}.
*
@@ -381,20 +404,22 @@ public interface Deque extends Queue<
E remove();
/**
- * Retrieves, but does not remove, the head of the queue represented by
- * this deque, returning null if this deque is empty.
+ * Retrieves and removes the head of the queue represented by this deque
+ * (in other words, the first element of this deque), or returns
+ * null if this deque is empty.
*
- * This method is equivalent to {@link #peekFirst()}.
+ *
This method is equivalent to {@link #pollFirst()}.
*
- * @return the head of the queue represented by this deque, or
- * null if this deque is empty
+ * @return the first element of this deque, or null if
+ * this deque is empty
*/
- E peek();
+ E poll();
/**
* Retrieves, but does not remove, the head of the queue represented by
- * this deque. This method differs from the {@link #peek} method only in
- * that it throws an exception if this deque is empty.
+ * this deque (in other words, the first element of this deque).
+ * This method differs from {@link #peek} only in that it throws an
+ * exception if this deque is empty.
*
*
This method is equivalent to {@link #getFirst()}.
*
@@ -403,21 +428,39 @@ public interface Deque extends Queue<
*/
E element();
+ /**
+ * Retrieves, but does not remove, the head of the queue represented by
+ * this deque (in other words, the first element of this deque), or
+ * returns null if this deque is empty.
+ *
+ * This method is equivalent to {@link #peekFirst()}.
+ *
+ * @return the head of the queue represented by this deque, or
+ * null if this deque is empty
+ */
+ E peek();
+
// *** Stack methods ***
/**
- * Pushes an element onto the stack represented by this deque. In other
- * words, inserts the element at the front of this deque unless it would
- * violate capacity restrictions.
+ * Pushes an element onto the stack represented by this deque (in other
+ * words, at the head of this deque) if it is possible to do so
+ * immediately without violating capacity restrictions, returning
+ * true upon success and throwing an
+ * IllegalStateException if no space is currently available.
*
*
This method is equivalent to {@link #addFirst}.
*
* @param e the element to push
- * @throws IllegalStateException if it was not possible to insert
- * the element due to capacity restrictions
+ * @throws IllegalStateException if the element cannot be added at this
+ * time due to capacity restrictions
* @throws NullPointerException if the specified element is null and this
- * deque does not permit null elements
+ * deque does not permit null elements
+ * @throws ClassCastException if the class of the specified element
+ * prevents it from being added to this deque
+ * @throws IllegalArgumentException if some property of the specified
+ * element prevents it from being added to this deque
*/
void push(E e);
@@ -428,13 +471,54 @@ public interface Deque extends Queue<
* This method is equivalent to {@link #removeFirst()}.
*
* @return the element at the front of this deque (which is the top
- * of the stack represented by this deque)
+ * of the stack represented by this deque)
* @throws NoSuchElementException if this deque is empty
*/
E pop();
- // *** Collection Method ***
+ // *** Collection methods ***
+
+ /**
+ * Removes the first occurrence of the specified element from this deque.
+ * If the deque does not contain the element, it is unchanged.
+ * More formally, removes the first element e such that
+ * (o==null ? e==null : o.equals(e)) (if such an element exists).
+ * Returns true if this deque contained the specified element (or
+ * equivalently, if this deque changed as a result of the call).
+ *
+ *
This method is equivalent to {@link #removeFirstOccurrence}.
+ *
+ * @param o element to be removed from this deque, if present
+ * @return true if an element was removed as a result of this call
+ * @throws NullPointerException if the specified element is null and this
+ * deque does not permit null elements (optional)
+ * @throws ClassCastException if the class of the specified element
+ * is incompatible with this collection (optional)
+ */
+ boolean remove(Object o);
+
+ /**
+ * Returns true if this deque contains the specified element.
+ * More formally, returns true if and only if this deque
+ * contains at least one element e such that (o==null ?
+ * e==null : o.equals(e)).
+ *
+ * @param o element whose presence in this deque is to be tested
+ * @return true if this deque contains the specified element
+ * @throws ClassCastException if the type of the specified element
+ * is incompatible with this deque (optional)
+ * @throws NullPointerException if the specified element is null and this
+ * deque does not permit null elements (optional)
+ */
+ boolean contains(Object o);
+
+ /**
+ * Returns the number of elements in this deque.
+ *
+ * @return the number of elements in this deque
+ */
+ public int size();
/**
* Returns an iterator over the elements in this deque. The elements