| 9 |
|
/** |
| 10 |
|
* A {@link SortedSet} extended with navigation methods reporting |
| 11 |
|
* closest matches for given search targets. Methods <tt>lower</tt>, |
| 12 |
< |
* <tt>floor</tt>, <tt>ceiling</tt>, and <tt>higher</tt> return keys |
| 12 |
> |
* <tt>floor</tt>, <tt>ceiling</tt>, and <tt>higher</tt> return elements |
| 13 |
|
* respectively less than, less than or equal, greater than or equal, |
| 14 |
< |
* and greater than a given key, returning <tt>null</tt> if there is |
| 15 |
< |
* no such key. A <tt>NavigableSet</tt> may be viewed and traversed |
| 14 |
> |
* and greater than a given element, returning <tt>null</tt> if there is |
| 15 |
> |
* no such element. A <tt>NavigableSet</tt> may be viewed and traversed |
| 16 |
|
* in either ascending or descending order. The <tt>Collection</tt> |
| 17 |
|
* <tt>iterator</tt> method returns an ascending <tt>Iterator</tt> and |
| 18 |
< |
* the additional method <tt>descendingIterator</tt> returns |
| 18 |
> |
* the additional method <tt>descendingIterator</tt> returns a |
| 19 |
|
* descending iterator. The performance of ascending traversals is |
| 20 |
|
* likely to be faster than descending traversals. This interface |
| 21 |
|
* additionally defines methods <tt>pollFirst</tt> and |
| 22 |
< |
* <t>pollLast</tt> that return and remove the lowest and highest key, |
| 23 |
< |
* if one exists, else returning <tt>null</tt>. |
| 22 |
> |
* <tt>pollLast</tt> that return and remove the lowest and highest |
| 23 |
> |
* element, if one exists, else returning <tt>null</tt>. |
| 24 |
|
* Methods <tt>navigableSubSet</tt>, <tt>navigableHeadSet</tt>, and |
| 25 |
|
* <tt>navigableTailSet</tt> differ from the similarly named |
| 26 |
|
* <tt>SortedSet</tt> methods only in that the returned sets |
| 30 |
|
* implementations that permit <tt>null</tt> elements. However, even |
| 31 |
|
* in this case the result can be disambiguated by checking |
| 32 |
|
* <tt>contains(null)</tt>. To avoid such issues, implementations of |
| 33 |
< |
* this interface are encouraged <em>not</em> to permit insertion of |
| 33 |
> |
* this interface are encouraged to <em>not</em> permit insertion of |
| 34 |
|
* <tt>null</tt> elements. (Note that sorted sets of {@link |
| 35 |
|
* Comparable} elements intrinsically do not permit <tt>null</tt>.) |
| 36 |
|
* |
| 37 |
+ |
* <p>This interface is a member of the |
| 38 |
+ |
* <a href="{@docRoot}/../guide/collections/index.html"> |
| 39 |
+ |
* Java Collections Framework</a>. |
| 40 |
+ |
* |
| 41 |
|
* @author Doug Lea |
| 42 |
|
* @param <E> the type of elements maintained by this set |
| 43 |
+ |
* @since 1.6 |
| 44 |
|
*/ |
| 45 |
|
public interface NavigableSet<E> extends SortedSet<E> { |
| 46 |
|
/** |
| 47 |
< |
* Returns an element greater than or equal to the given element, or |
| 48 |
< |
* <tt>null</tt> if there is no such element. |
| 49 |
< |
* |
| 47 |
> |
* Returns the greatest element in this set strictly less than the |
| 48 |
> |
* given element, or <tt>null</tt> if there is no such element. |
| 49 |
> |
* |
| 50 |
|
* @param e the value to match |
| 51 |
< |
* @return an element greater than or equal to given element, or |
| 52 |
< |
* <tt>null</tt> if there is no such element. |
| 53 |
< |
* @throws ClassCastException if e cannot be compared with the elements |
| 54 |
< |
* currently in the set. |
| 55 |
< |
* @throws NullPointerException if e is <tt>null</tt> |
| 56 |
< |
* and this set does not permit <tt>null</tt> elements |
| 51 |
> |
* @return the greatest element less than <tt>e</tt>, |
| 52 |
> |
* or <tt>null</tt> if there is no such element |
| 53 |
> |
* @throws ClassCastException if the specified element cannot be |
| 54 |
> |
* compared with the elements currently in the set |
| 55 |
> |
* @throws NullPointerException if the specified element is null |
| 56 |
> |
* and this set does not permit null elements |
| 57 |
|
*/ |
| 58 |
< |
E ceiling(E e); |
| 58 |
> |
E lower(E e); |
| 59 |
|
|
| 60 |
|
/** |
| 61 |
< |
* Returns an element strictly less than the given element, or |
| 62 |
< |
* <tt>null</tt> if there is no such element. |
| 63 |
< |
* |
| 61 |
> |
* Returns the greatest element in this set less than or equal to |
| 62 |
> |
* the given element, or <tt>null</tt> if there is no such element. |
| 63 |
> |
* |
| 64 |
|
* @param e the value to match |
| 65 |
< |
* @return the greatest element less than the given element, or |
| 66 |
< |
* <tt>null</tt> if there is no such element. |
| 67 |
< |
* @throws ClassCastException if e cannot be compared with the elements |
| 68 |
< |
* currently in the set. |
| 69 |
< |
* @throws NullPointerException if e is <tt>null</tt> |
| 70 |
< |
* and this set does not permit <tt>null</tt> elements |
| 65 |
> |
* @return the greatest element less than or equal to <tt>e</tt>, |
| 66 |
> |
* or <tt>null</tt> if there is no such element |
| 67 |
> |
* @throws ClassCastException if the specified element cannot be |
| 68 |
> |
* compared with the elements currently in the set |
| 69 |
> |
* @throws NullPointerException if the specified element is null |
| 70 |
> |
* and this set does not permit null elements |
| 71 |
|
*/ |
| 72 |
< |
E lower(E e); |
| 72 |
> |
E floor(E e); |
| 73 |
|
|
| 74 |
|
/** |
| 75 |
< |
* Returns an element less than or equal to the given element, or |
| 76 |
< |
* <tt>null</tt> if there is no such element. |
| 77 |
< |
* |
| 75 |
> |
* Returns the least element in this set greater than or equal to |
| 76 |
> |
* the given element, or <tt>null</tt> if there is no such element. |
| 77 |
> |
* |
| 78 |
|
* @param e the value to match |
| 79 |
< |
* @return the greatest element less than or equal to given |
| 80 |
< |
* element, or <tt>null</tt> if there is no such element. |
| 81 |
< |
* @throws ClassCastException if e cannot be compared with the elements |
| 82 |
< |
* currently in the set. |
| 83 |
< |
* @throws NullPointerException if e is <tt>null</tt>. |
| 84 |
< |
* and this set does not permit <tt>null</tt> elements |
| 79 |
> |
* @return the least element greater than or equal to <tt>e</tt>, |
| 80 |
> |
* or <tt>null</tt> if there is no such element |
| 81 |
> |
* @throws ClassCastException if the specified element cannot be |
| 82 |
> |
* compared with the elements currently in the set |
| 83 |
> |
* @throws NullPointerException if the specified element is null |
| 84 |
> |
* and this set does not permit null elements |
| 85 |
|
*/ |
| 86 |
< |
E floor(E e); |
| 86 |
> |
E ceiling(E e); |
| 87 |
|
|
| 88 |
|
/** |
| 89 |
< |
* Returns an element strictly greater than the given element, or |
| 90 |
< |
* <tt>null</tt> if there is no such element. |
| 91 |
< |
* |
| 89 |
> |
* Returns the least element in this set strictly greater than the |
| 90 |
> |
* given element, or <tt>null</tt> if there is no such element. |
| 91 |
> |
* |
| 92 |
|
* @param e the value to match |
| 93 |
< |
* @return the least element greater than the given element, or |
| 94 |
< |
* <tt>null</tt> if there is no such element. |
| 95 |
< |
* @throws ClassCastException if e cannot be compared with the elements |
| 96 |
< |
* currently in the set. |
| 97 |
< |
* @throws NullPointerException if e is <tt>null</tt> |
| 98 |
< |
* and this set does not permit <tt>null</tt> elements |
| 93 |
> |
* @return the least element greater than <tt>e</tt>, |
| 94 |
> |
* or <tt>null</tt> if there is no such element |
| 95 |
> |
* @throws ClassCastException if the specified element cannot be |
| 96 |
> |
* compared with the elements currently in the set |
| 97 |
> |
* @throws NullPointerException if the specified element is null |
| 98 |
> |
* and this set does not permit null elements |
| 99 |
|
*/ |
| 100 |
|
E higher(E e); |
| 101 |
|
|
| 102 |
|
/** |
| 103 |
|
* Retrieves and removes the first (lowest) element. |
| 104 |
|
* |
| 105 |
< |
* @return the first element, or <tt>null</tt> if empty. |
| 105 |
> |
* @return the first element, or <tt>null</tt> if this set is empty |
| 106 |
|
*/ |
| 107 |
|
E pollFirst(); |
| 108 |
|
|
| 109 |
|
/** |
| 110 |
|
* Retrieves and removes the last (highest) element. |
| 111 |
|
* |
| 112 |
< |
* @return the last element, or <tt>null</tt> if empty. |
| 112 |
> |
* @return the last element, or <tt>null</tt> if this set is empty |
| 113 |
|
*/ |
| 114 |
|
E pollLast(); |
| 115 |
|
|
| 116 |
|
/** |
| 117 |
< |
* Returns an iterator over the elements in this collection, in |
| 118 |
< |
* descending order. |
| 119 |
< |
* |
| 120 |
< |
* @return an <tt>Iterator</tt> over the elements in this collection |
| 117 |
> |
* Returns an iterator over the elements in this set, in |
| 118 |
> |
* descending order. |
| 119 |
> |
* |
| 120 |
> |
* @return an <tt>Iterator</tt> over the elements in this set |
| 121 |
|
*/ |
| 122 |
|
Iterator<E> descendingIterator(); |
| 123 |
|
|
| 125 |
|
* Returns a view of the portion of this set whose elements range |
| 126 |
|
* from <tt>fromElement</tt>, inclusive, to <tt>toElement</tt>, |
| 127 |
|
* exclusive. (If <tt>fromElement</tt> and <tt>toElement</tt> are |
| 128 |
< |
* equal, the returned navigable set is empty.) The returned |
| 129 |
< |
* navigable set is backed by this set, so changes in the returned |
| 130 |
< |
* navigable set are reflected in this set, and vice-versa. |
| 128 |
> |
* equal, the returned set is empty.) The returned set is backed |
| 129 |
> |
* by this set, so changes in the returned set are reflected in |
| 130 |
> |
* this set, and vice-versa. The returned set supports all |
| 131 |
> |
* optional set operations that this set supports. |
| 132 |
> |
* |
| 133 |
> |
* <p>The returned set will throw an <tt>IllegalArgumentException</tt> |
| 134 |
> |
* on an attempt to insert an element outside its range. |
| 135 |
|
* |
| 136 |
< |
* @param fromElement low endpoint (inclusive) of the subSet. |
| 137 |
< |
* @param toElement high endpoint (exclusive) of the subSet. |
| 136 |
> |
* @param fromElement low endpoint (inclusive) of the returned set |
| 137 |
> |
* @param toElement high endpoint (exclusive) of the returned set |
| 138 |
|
* @return a view of the portion of this set whose elements range from |
| 139 |
< |
* <tt>fromElement</tt>, inclusive, to <tt>toElement</tt>, |
| 131 |
< |
* exclusive. |
| 139 |
> |
* <tt>fromElement</tt>, inclusive, to <tt>toElement</tt>, exclusive |
| 140 |
|
* @throws ClassCastException if <tt>fromElement</tt> and |
| 141 |
< |
* <tt>toElement</tt> cannot be compared to one another using |
| 142 |
< |
* this set's comparator (or, if the set has no comparator, |
| 143 |
< |
* using natural ordering). |
| 144 |
< |
* @throws IllegalArgumentException if <tt>fromElement</tt> is |
| 145 |
< |
* greater than <tt>toElement</tt>. |
| 141 |
> |
* <tt>toElement</tt> cannot be compared to one another using this |
| 142 |
> |
* set's comparator (or, if the set has no comparator, using |
| 143 |
> |
* natural ordering). Implementations may, but are not required |
| 144 |
> |
* to, throw this exception if <tt>fromElement</tt> or |
| 145 |
> |
* <tt>toElement</tt> cannot be compared to elements currently in |
| 146 |
> |
* the set. |
| 147 |
|
* @throws NullPointerException if <tt>fromElement</tt> or |
| 148 |
< |
* <tt>toElement</tt> is <tt>null</tt> |
| 149 |
< |
* and this set does not permit <tt>null</tt> elements |
| 148 |
> |
* <tt>toElement</tt> is null and this set does |
| 149 |
> |
* not permit null elements |
| 150 |
> |
* @throws IllegalArgumentException if <tt>fromElement</tt> is |
| 151 |
> |
* greater than <tt>toElement</tt>; or if this set itself |
| 152 |
> |
* has a restricted range, and <tt>fromElement</tt> or |
| 153 |
> |
* <tt>toElement</tt> lies outside the bounds of the range. |
| 154 |
|
*/ |
| 155 |
|
NavigableSet<E> navigableSubSet(E fromElement, E toElement); |
| 156 |
|
|
| 157 |
|
/** |
| 158 |
|
* Returns a view of the portion of this set whose elements are |
| 159 |
< |
* strictly less than <tt>toElement</tt>. The returned navigable |
| 160 |
< |
* set is backed by this set, so changes in the returned navigable |
| 161 |
< |
* set are reflected in this set, and vice-versa. |
| 162 |
< |
* @param toElement high endpoint (exclusive) of the headSet. |
| 159 |
> |
* strictly less than <tt>toElement</tt>. The returned set is |
| 160 |
> |
* backed by this set, so changes in the returned set are |
| 161 |
> |
* reflected in this set, and vice-versa. The returned set |
| 162 |
> |
* supports all optional set operations that this set supports. |
| 163 |
> |
* |
| 164 |
> |
* <p>The returned set will throw an <tt>IllegalArgumentException</tt> |
| 165 |
> |
* on an attempt to insert an element outside its range. |
| 166 |
> |
* |
| 167 |
> |
* @param toElement high endpoint (exclusive) of the returned set |
| 168 |
|
* @return a view of the portion of this set whose elements are strictly |
| 169 |
< |
* less than toElement. |
| 169 |
> |
* less than <tt>toElement</tt> |
| 170 |
|
* @throws ClassCastException if <tt>toElement</tt> is not compatible |
| 171 |
|
* with this set's comparator (or, if the set has no comparator, |
| 172 |
< |
* if <tt>toElement</tt> does not implement <tt>Comparable</tt>). |
| 173 |
< |
* @throws NullPointerException if <tt>toElement</tt> is <tt>null</tt> |
| 174 |
< |
* and this set does not permit <tt>null</tt> elements |
| 172 |
> |
* if <tt>toElement</tt> does not implement {@link Comparable}). |
| 173 |
> |
* Implementations may, but are not required to, throw this |
| 174 |
> |
* exception if <tt>toElement</tt> cannot be compared to elements |
| 175 |
> |
* currently in the set. |
| 176 |
> |
* @throws NullPointerException if <tt>toElement</tt> is null and |
| 177 |
> |
* this set does not permit null elements |
| 178 |
> |
* @throws IllegalArgumentException if this set itself has a |
| 179 |
> |
* restricted range, and <tt>toElement</tt> lies outside the |
| 180 |
> |
* bounds of the range |
| 181 |
|
*/ |
| 182 |
|
NavigableSet<E> navigableHeadSet(E toElement); |
| 183 |
|
|
| 184 |
|
/** |
| 185 |
|
* Returns a view of the portion of this set whose elements are |
| 186 |
|
* greater than or equal to <tt>fromElement</tt>. The returned |
| 187 |
< |
* navigable set is backed by this set, so changes in the returned |
| 188 |
< |
* navigable set are reflected in this set, and vice-versa. |
| 189 |
< |
* @param fromElement low endpoint (inclusive) of the tailSet. |
| 190 |
< |
* @return a view of the portion of this set whose elements are |
| 191 |
< |
* greater than or equal to <tt>fromElement</tt>. |
| 192 |
< |
* @throws ClassCastException if <tt>fromElement</tt> is not |
| 193 |
< |
* compatible with this set's comparator (or, if the set has no |
| 194 |
< |
* comparator, if <tt>fromElement</tt> does not implement |
| 195 |
< |
* <tt>Comparable</tt>). |
| 196 |
< |
* @throws NullPointerException if <tt>fromElement</tt> is <tt>null</tt> |
| 197 |
< |
* and this set does not permit <tt>null</tt> elements |
| 187 |
> |
* set is backed by this set, so changes in the returned set are |
| 188 |
> |
* reflected in this set, and vice-versa. The returned set |
| 189 |
> |
* supports all optional set operations that this set supports. |
| 190 |
> |
* |
| 191 |
> |
* <p>The returned set will throw an <tt>IllegalArgumentException</tt> |
| 192 |
> |
* on an attempt to insert an element outside its range. |
| 193 |
> |
* |
| 194 |
> |
* @param fromElement low endpoint (inclusive) of the returned set |
| 195 |
> |
* @return a view of the portion of this set whose elements are greater |
| 196 |
> |
* than or equal to <tt>fromElement</tt> |
| 197 |
> |
* @throws ClassCastException if <tt>fromElement</tt> is not compatible |
| 198 |
> |
* with this set's comparator (or, if the set has no comparator, |
| 199 |
> |
* if <tt>fromElement</tt> does not implement {@link Comparable}). |
| 200 |
> |
* Implementations may, but are not required to, throw this |
| 201 |
> |
* exception if <tt>fromElement</tt> cannot be compared to elements |
| 202 |
> |
* currently in the set. |
| 203 |
> |
* @throws NullPointerException if <tt>fromElement</tt> is null |
| 204 |
> |
* and this set does not permit null elements |
| 205 |
> |
* @throws IllegalArgumentException if this set itself has a |
| 206 |
> |
* restricted range, and <tt>fromElement</tt> lies outside the |
| 207 |
> |
* bounds of the range |
| 208 |
|
*/ |
| 209 |
|
NavigableSet<E> navigableTailSet(E fromElement); |
| 210 |
|
} |
