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Comparing jsr166/src/jsr166x/NavigableMap.java (file contents):
Revision 1.2 by dl, Tue Sep 7 11:37:57 2004 UTC vs.
Revision 1.10 by jsr166, Sat Dec 29 23:55:19 2012 UTC

# Line 1 | Line 1
1   /*
2   * Written by Doug Lea with assistance from members of JCP JSR-166
3   * Expert Group and released to the public domain, as explained at
4 < * http://creativecommons.org/licenses/publicdomain
4 > * http://creativecommons.org/publicdomain/zero/1.0/
5   */
6  
7   package jsr166x;
# Line 9 | Line 9 | package jsr166x;
9   import java.util.*;
10  
11   /**
12 < * A {@link SortedMap} extended with navigation methods returning
13 < * key-value pairs holding the closest matches for given search
14 < * targets. Methods <tt>lowerEntry</tt>, <tt>floorEntry</tt>,
15 < * <tt>ceilingEntry</tt>, and <tt>higherEntry</tt> return
16 < * <tt>Map.Entry</tt> objects associated with keys respectively less
17 < * than, less than or equal, greater than or equal, and greater than a
18 < * given key, returning <tt>null</tt> if there is no such key.  These
19 < * methods are designed for locating, not traversing entries. To
20 < * traverse, use view iterators and/or <tt>submap</tt>. This interface
21 < * additionally defines methods <tt>firstEntry</tt>,
12 > * A {@link SortedMap} extended with navigation methods returning the
13 > * closest matches for given search targets. Methods
14 > * <tt>lowerEntry</tt>, <tt>floorEntry</tt>, <tt>ceilingEntry</tt>,
15 > * and <tt>higherEntry</tt> return <tt>Map.Entry</tt> objects
16 > * associated with keys respectively less than, less than or equal,
17 > * greater than or equal, and greater than a given key, returning
18 > * <tt>null</tt> if there is no such key.  Similarly, methods
19 > * <tt>lowerKey</tt>, <tt>floorKey</tt>, <tt>ceilingKey</tt>, and
20 > * <tt>higherKey</tt> return only the associated keys. All of these
21 > * methods are designed for locating, not traversing entries.
22 > *
23 > * <p>A <tt>NavigableMap</tt> may be viewed and traversed in either
24 > * ascending or descending key order.  The <tt>Map</tt> methods
25 > * <tt>keySet</tt> and <tt>entrySet</tt> return ascending views, and
26 > * the additional methods <tt>descendingKeySet</tt> and
27 > * <tt>descendingEntrySet</tt> return descending views. The
28 > * performance of ascending traversals is likely to be faster than
29 > * descending traversals.  Notice that it is possible to perform
30 > * subrannge traversals in either direction using <tt>SubMap</tt>.
31 > *
32 > * <p>This interface additionally defines methods <tt>firstEntry</tt>,
33   * <tt>pollFirstEntry</tt>, <tt>lastEntry</tt>, and
34   * <tt>pollLastEntry</tt> that return and/or remove the least and
35   * greatest mappings, if any exist, else returning <tt>null</tt>.
36   *
37 < * <p> Implementations of these methods are expected to return
38 < * <tt>Map.Entry</tt> pairs representing snapshots of mappings at the
39 < * time they were produced, and thus generally do <em>not</em> support
40 < * the optional <tt>Entry.setValue</tt> method. Note however that it
41 < * is possible to change mappings in the associated map using method
42 < * <tt>put</tt>.
37 > * <p>Implementations of entry-returning methods are expected to
38 > * return <tt>Map.Entry</tt> pairs representing snapshots of mappings
39 > * at the time they were produced, and thus generally do <em>not</em>
40 > * support the optional <tt>Entry.setValue</tt> method. Note however
41 > * that it is possible to change mappings in the associated map using
42 > * method <tt>put</tt>.
43   *
44   * @author Doug Lea
45   * @param <K> the type of keys maintained by this map
46 < * @param <V> the type of mapped values
46 > * @param <V> the type of mapped values
47   */
48   public interface NavigableMap<K,V> extends SortedMap<K,V> {
49      /**
50       * Returns a key-value mapping associated with the least key
51       * greater than or equal to the given key, or <tt>null</tt> if there is
52 <     * no such entry.
53 <     *
54 <     * @param key the key.
52 >     * no such entry.
53 >     *
54 >     * @param key the key
55       * @return an Entry associated with ceiling of given key, or <tt>null</tt>
56 <     * if there is no such Entry.
56 >     * if there is no such Entry
57       * @throws ClassCastException if key cannot be compared with the keys
58 <     *            currently in the map.
58 >     *            currently in the map
59       * @throws NullPointerException if key is <tt>null</tt> and this map
60 <     * does not support <tt>null</tt> keys.
60 >     * does not support <tt>null</tt> keys
61       */
62      public Map.Entry<K,V> ceilingEntry(K key);
63  
64      /**
65 +     * Returns least key greater than or equal to the given key, or
66 +     * <tt>null</tt> if there is no such key.
67 +     *
68 +     * @param key the key
69 +     * @return the ceiling key, or <tt>null</tt>
70 +     * if there is no such key
71 +     * @throws ClassCastException if key cannot be compared with the keys
72 +     *            currently in the map
73 +     * @throws NullPointerException if key is <tt>null</tt> and this map
74 +     * does not support <tt>null</tt> keys
75 +     */
76 +    public K ceilingKey(K key);
77 +
78 +    /**
79       * Returns a key-value mapping associated with the greatest
80       * key strictly less than the given key, or <tt>null</tt> if there is no
81 <     * such entry.
82 <     *
83 <     * @param key the key.
81 >     * such entry.
82 >     *
83 >     * @param key the key
84       * @return an Entry with greatest key less than the given
85 <     * key, or <tt>null</tt> if there is no such Entry.
85 >     * key, or <tt>null</tt> if there is no such Entry
86       * @throws ClassCastException if key cannot be compared with the keys
87 <     *            currently in the map.
87 >     *            currently in the map
88       * @throws NullPointerException if key is <tt>null</tt> and this map
89 <     * does not support <tt>null</tt> keys.
89 >     * does not support <tt>null</tt> keys
90       */
91      public Map.Entry<K,V> lowerEntry(K key);
92  
93      /**
94 <     * Returns a key-value mapping associated with the greatest
95 <     * key less than or equal to the given key, or <tt>null</tt> if there is no
96 <     * such entry.
97 <     *
98 <     * @param key the key.
94 >     * Returns the greatest key strictly less than the given key, or
95 >     * <tt>null</tt> if there is no such key.
96 >     *
97 >     * @param key the key
98 >     * @return the greatest key less than the given
99 >     * key, or <tt>null</tt> if there is no such key
100 >     * @throws ClassCastException if key cannot be compared with the keys
101 >     *            currently in the map
102 >     * @throws NullPointerException if key is <tt>null</tt> and this map
103 >     * does not support <tt>null</tt> keys
104 >     */
105 >    public K lowerKey(K key);
106 >
107 >    /**
108 >     * Returns a key-value mapping associated with the greatest key
109 >     * less than or equal to the given key, or <tt>null</tt> if there
110 >     * is no such entry.
111 >     *
112 >     * @param key the key
113       * @return an Entry associated with floor of given key, or <tt>null</tt>
114 <     * if there is no such Entry.
114 >     * if there is no such Entry
115       * @throws ClassCastException if key cannot be compared with the keys
116 <     *            currently in the map.
116 >     *            currently in the map
117       * @throws NullPointerException if key is <tt>null</tt> and this map
118 <     * does not support <tt>null</tt> keys.
118 >     * does not support <tt>null</tt> keys
119       */
120      public Map.Entry<K,V> floorEntry(K key);
121  
122      /**
123 <     * Returns a key-value mapping associated with the least
124 <     * key strictly greater than the given key, or <tt>null</tt> if there is no
125 <     * such entry.
126 <     *
127 <     * @param key the key.
123 >     * Returns the greatest key
124 >     * less than or equal to the given key, or <tt>null</tt> if there
125 >     * is no such key.
126 >     *
127 >     * @param key the key
128 >     * @return the floor of given key, or <tt>null</tt> if there is no
129 >     * such key
130 >     * @throws ClassCastException if key cannot be compared with the keys
131 >     *            currently in the map
132 >     * @throws NullPointerException if key is <tt>null</tt> and this map
133 >     * does not support <tt>null</tt> keys
134 >     */
135 >    public K floorKey(K key);
136 >
137 >    /**
138 >     * Returns a key-value mapping associated with the least key
139 >     * strictly greater than the given key, or <tt>null</tt> if there
140 >     * is no such entry.
141 >     *
142 >     * @param key the key
143       * @return an Entry with least key greater than the given key, or
144 <     * <tt>null</tt> if there is no such Entry.
144 >     * <tt>null</tt> if there is no such Entry
145       * @throws ClassCastException if key cannot be compared with the keys
146 <     *            currently in the map.
146 >     *            currently in the map
147       * @throws NullPointerException if key is <tt>null</tt> and this map
148 <     * does not support <tt>null</tt> keys.
148 >     * does not support <tt>null</tt> keys
149       */
150      public Map.Entry<K,V> higherEntry(K key);
151  
152      /**
153 +     * Returns the least key strictly greater than the given key, or
154 +     * <tt>null</tt> if there is no such key.
155 +     *
156 +     * @param key the key
157 +     * @return the least key greater than the given key, or
158 +     * <tt>null</tt> if there is no such key
159 +     * @throws ClassCastException if key cannot be compared with the keys
160 +     *            currently in the map
161 +     * @throws NullPointerException if key is <tt>null</tt> and this map
162 +     * does not support <tt>null</tt> keys
163 +     */
164 +    public K higherKey(K key);
165 +
166 +    /**
167       * Returns a key-value mapping associated with the least
168       * key in this map, or <tt>null</tt> if the map is empty.
169 <     *
170 <     * @return an Entry with least key, or <tt>null</tt>
171 <     * if the map is empty.
169 >     *
170 >     * @return an Entry with least key, or <tt>null</tt>
171 >     * if the map is empty
172       */
173      public Map.Entry<K,V> firstEntry();
174  
175      /**
176       * Returns a key-value mapping associated with the greatest
177       * key in this map, or <tt>null</tt> if the map is empty.
178 <     *
178 >     *
179       * @return an Entry with greatest key, or <tt>null</tt>
180 <     * if the map is empty.
180 >     * if the map is empty
181       */
182      public Map.Entry<K,V> lastEntry();
183  
184      /**
185       * Removes and returns a key-value mapping associated with
186       * the least key in this map, or <tt>null</tt> if the map is empty.
187 <     *
187 >     *
188       * @return the removed first entry of this map, or <tt>null</tt>
189 <     * if the map is empty.
189 >     * if the map is empty
190       */
191      public Map.Entry<K,V> pollFirstEntry();
192  
193      /**
194       * Removes and returns a key-value mapping associated with
195       * the greatest key in this map, or <tt>null</tt> if the map is empty.
196 <     *
196 >     *
197       * @return the removed last entry of this map, or <tt>null</tt>
198 <     * if the map is empty.
198 >     * if the map is empty
199       */
200      public Map.Entry<K,V> pollLastEntry();
201  
202      /**
203 +     * Returns a set view of the keys contained in this map, in
204 +     * descending key order.  The set is backed by the map, so changes
205 +     * to the map are reflected in the set, and vice-versa.  If the
206 +     * map is modified while an iteration over the set is in progress
207 +     * (except through the iterator's own <tt>remove</tt> operation),
208 +     * the results of the iteration are undefined.  The set supports
209 +     * element removal, which removes the corresponding mapping from
210 +     * the map, via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
211 +     * <tt>removeAll</tt> <tt>retainAll</tt>, and <tt>clear</tt>
212 +     * operations.  It does not support the add or <tt>addAll</tt>
213 +     * operations.
214 +     *
215 +     * @return a set view of the keys contained in this map
216 +     */
217 +    Set<K> descendingKeySet();
218 +
219 +    /**
220 +     * Returns a set view of the mappings contained in this map, in
221 +     * descending key order.  Each element in the returned set is a
222 +     * <tt>Map.Entry</tt>.  The set is backed by the map, so changes to
223 +     * the map are reflected in the set, and vice-versa.  If the map
224 +     * is modified while an iteration over the set is in progress
225 +     * (except through the iterator's own <tt>remove</tt> operation,
226 +     * or through the <tt>setValue</tt> operation on a map entry
227 +     * returned by the iterator) the results of the iteration are
228 +     * undefined.  The set supports element removal, which removes the
229 +     * corresponding mapping from the map, via the
230 +     * <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
231 +     * <tt>removeAll</tt>, <tt>retainAll</tt> and <tt>clear</tt>
232 +     * operations.  It does not support the <tt>add</tt> or
233 +     * <tt>addAll</tt> operations.
234 +     *
235 +     * @return a set view of the mappings contained in this map
236 +     */
237 +    Set<Map.Entry<K, V>> descendingEntrySet();
238 +
239 +    /**
240       * Returns a view of the portion of this map whose keys range from
241       * <tt>fromKey</tt>, inclusive, to <tt>toKey</tt>, exclusive.  (If
242       * <tt>fromKey</tt> and <tt>toKey</tt> are equal, the returned sorted map
243       * is empty.)  The returned sorted map is backed by this map, so changes
244       * in the returned sorted map are reflected in this map, and vice-versa.
245 <
246 <     * @param fromKey low endpoint (inclusive) of the subMap.
247 <     * @param toKey high endpoint (exclusive) of the subMap.
245 >     *
246 >     * @param fromKey low endpoint (inclusive) of the subMap
247 >     * @param toKey high endpoint (exclusive) of the subMap
248       *
249       * @return a view of the portion of this map whose keys range from
250 <     * <tt>fromKey</tt>, inclusive, to <tt>toKey</tt>, exclusive.
250 >     * <tt>fromKey</tt>, inclusive, to <tt>toKey</tt>, exclusive
251       *
252       * @throws ClassCastException if <tt>fromKey</tt> and
253       * <tt>toKey</tt> cannot be compared to one another using this
254       * map's comparator (or, if the map has no comparator, using
255 <     * natural ordering).
255 >     * natural ordering)
256       * @throws IllegalArgumentException if <tt>fromKey</tt> is greater
257 <     * than <tt>toKey</tt>.
257 >     * than <tt>toKey</tt>
258       * @throws NullPointerException if <tt>fromKey</tt> or
259       * <tt>toKey</tt> is <tt>null</tt> and this map does not support
260 <     * <tt>null</tt> keys.
260 >     * <tt>null</tt> keys
261       */
262      public NavigableMap<K,V> subMap(K fromKey, K toKey);
263  
# Line 160 | Line 265 | public interface NavigableMap<K,V> exten
265       * Returns a view of the portion of this map whose keys are strictly less
266       * than <tt>toKey</tt>.  The returned sorted map is backed by this map, so
267       * changes in the returned sorted map are reflected in this map, and
268 <     * vice-versa.  
269 <     * @param toKey high endpoint (exclusive) of the headMap.
268 >     * vice-versa.
269 >     * @param toKey high endpoint (exclusive) of the headMap
270       * @return a view of the portion of this map whose keys are strictly
271 <     *                less than <tt>toKey</tt>.
271 >     *                less than <tt>toKey</tt>
272       *
273       * @throws ClassCastException if <tt>toKey</tt> is not compatible
274       *         with this map's comparator (or, if the map has no comparator,
275 <     *         if <tt>toKey</tt> does not implement <tt>Comparable</tt>).
275 >     *         if <tt>toKey</tt> does not implement <tt>Comparable</tt>)
276       * @throws NullPointerException if <tt>toKey</tt> is <tt>null</tt>
277 <     * and this map does not support <tt>null</tt> keys.
277 >     * and this map does not support <tt>null</tt> keys
278       */
279      public NavigableMap<K,V> headMap(K toKey);
280  
# Line 178 | Line 283 | public interface NavigableMap<K,V> exten
283       * greater than or equal to <tt>fromKey</tt>.  The returned sorted
284       * map is backed by this map, so changes in the returned sorted
285       * map are reflected in this map, and vice-versa.
286 <     * @param fromKey low endpoint (inclusive) of the tailMap.
286 >     * @param fromKey low endpoint (inclusive) of the tailMap
287       * @return a view of the portion of this map whose keys are greater
288 <     *                than or equal to <tt>fromKey</tt>.
288 >     *                than or equal to <tt>fromKey</tt>
289       * @throws ClassCastException if <tt>fromKey</tt> is not compatible
290       *         with this map's comparator (or, if the map has no comparator,
291 <     *         if <tt>fromKey</tt> does not implement <tt>Comparable</tt>).
291 >     *         if <tt>fromKey</tt> does not implement <tt>Comparable</tt>)
292       * @throws NullPointerException if <tt>fromKey</tt> is <tt>null</tt>
293 <     * and this map does not support <tt>null</tt> keys.
293 >     * and this map does not support <tt>null</tt> keys
294       */
295 <    public NavigableMap<K,V>  tailMap(K fromKey);
295 >    public NavigableMap<K,V> tailMap(K fromKey);
296   }

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