001/*
002 * Copyright (C) 2011 The Guava Authors
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
005 * in compliance with the License. You may obtain a copy of the License at
006 *
007 * http://www.apache.org/licenses/LICENSE-2.0
008 *
009 * Unless required by applicable law or agreed to in writing, software distributed under the
010 * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
011 * express or implied. See the License for the specific language governing permissions and
012 * limitations under the License.
013 */
014
015package com.google.common.collect;
016
017import com.google.common.annotations.Beta;
018import com.google.common.annotations.GwtIncompatible;
019import java.util.NoSuchElementException;
020import java.util.Set;
021import javax.annotation.Nullable;
022
023/**
024 * A set comprising zero or more {@linkplain Range#isEmpty nonempty},
025 * {@linkplain Range#isConnected(Range) disconnected} ranges of type {@code C}.
026 *
027 * <p>Implementations that choose to support the {@link #add(Range)} operation are required to
028 * ignore empty ranges and coalesce connected ranges.  For example:  <pre>   {@code
029 *
030 *   RangeSet<Integer> rangeSet = TreeRangeSet.create();
031 *   rangeSet.add(Range.closed(1, 10)); // {[1, 10]}
032 *   rangeSet.add(Range.closedOpen(11, 15)); // disconnected range; {[1, 10], [11, 15)}
033 *   rangeSet.add(Range.closedOpen(15, 20)); // connected range; {[1, 10], [11, 20)}
034 *   rangeSet.add(Range.openClosed(0, 0)); // empty range; {[1, 10], [11, 20)}
035 *   rangeSet.remove(Range.open(5, 10)); // splits [1, 10]; {[1, 5], [10, 10], [11, 20)}}</pre>
036 *
037 * <p>Note that the behavior of {@link Range#isEmpty()} and {@link Range#isConnected(Range)} may
038 * not be as expected on discrete ranges.  See the Javadoc of those methods for details.
039 *
040 * <p>For a {@link Set} whose contents are specified by a {@link Range}, see {@link ContiguousSet}.
041 *
042 * <p>See the Guava User Guide article on <a href=
043 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#rangeset">
044 * RangeSets</a>.
045 *
046 * @author Kevin Bourrillion
047 * @author Louis Wasserman
048 * @since 14.0
049 */
050@Beta
051@GwtIncompatible
052public interface RangeSet<C extends Comparable> {
053  // TODO(lowasser): consider adding default implementations of some of these methods
054
055  // Query methods
056
057  /** Determines whether any of this range set's member ranges contains {@code value}. */
058  boolean contains(C value);
059
060  /**
061   * Returns the unique range from this range set that {@linkplain Range#contains contains}
062   * {@code value}, or {@code null} if this range set does not contain {@code value}.
063   */
064  Range<C> rangeContaining(C value);
065
066  /**
067   * Returns {@code true} if there exists a non-empty range enclosed by both a member range in this
068   * range set and the specified range. This is equivalent to calling
069   * {@code subRangeSet(otherRange)} and testing whether the resulting range set is non-empty.
070   *
071   * @since 20.0
072   */
073  boolean intersects(Range<C> otherRange);
074
075  /**
076   * Returns {@code true} if there exists a member range in this range set which
077   * {@linkplain Range#encloses encloses} the specified range.
078   */
079  boolean encloses(Range<C> otherRange);
080
081  /**
082   * Returns {@code true} if for each member range in {@code other} there exists a member range in
083   * this range set which {@linkplain Range#encloses encloses} it. It follows that
084   * {@code this.contains(value)} whenever {@code other.contains(value)}. Returns {@code true} if
085   * {@code other} is empty.
086   *
087   * <p>This is equivalent to checking if this range set {@link #encloses} each of the ranges in
088   * {@code other}.
089   */
090  boolean enclosesAll(RangeSet<C> other);
091
092  /**
093   * Returns {@code true} if for each range in {@code other} there exists a member range in this
094   * range set which {@linkplain Range#encloses encloses} it. Returns {@code true} if {@code other}
095   * is empty.
096   *
097   * <p>This is equivalent to checking if this range set {@link #encloses} each range in {@code
098   * other}.
099   *
100   * @since 21.0
101   */
102  default boolean enclosesAll(Iterable<Range<C>> other) {
103    for (Range<C> range : other) {
104      if (!encloses(range)) {
105        return false;
106      }
107    }
108    return true;
109  }
110
111  /**
112   * Returns {@code true} if this range set contains no ranges.
113   */
114  boolean isEmpty();
115
116  /**
117   * Returns the minimal range which {@linkplain Range#encloses(Range) encloses} all ranges
118   * in this range set.
119   *
120   * @throws NoSuchElementException if this range set is {@linkplain #isEmpty() empty}
121   */
122  Range<C> span();
123
124  // Views
125
126  /**
127   * Returns a view of the {@linkplain Range#isConnected disconnected} ranges that make up this
128   * range set.  The returned set may be empty. The iterators returned by its
129   * {@link Iterable#iterator} method return the ranges in increasing order of lower bound
130   * (equivalently, of upper bound).
131   */
132  Set<Range<C>> asRanges();
133
134  /**
135   * Returns a descending view of the {@linkplain Range#isConnected disconnected} ranges that
136   * make up this range set. The returned set may be empty. The iterators returned by its
137   * {@link Iterable#iterator} method return the ranges in decreasing order of lower bound
138   * (equivalently, of upper bound).
139   *
140   * @since 19.0
141   */
142  Set<Range<C>> asDescendingSetOfRanges();
143
144  /**
145   * Returns a view of the complement of this {@code RangeSet}.
146   *
147   * <p>The returned view supports the {@link #add} operation if this {@code RangeSet} supports
148   * {@link #remove}, and vice versa.
149   */
150  RangeSet<C> complement();
151
152  /**
153   * Returns a view of the intersection of this {@code RangeSet} with the specified range.
154   *
155   * <p>The returned view supports all optional operations supported by this {@code RangeSet}, with
156   * the caveat that an {@link IllegalArgumentException} is thrown on an attempt to
157   * {@linkplain #add(Range) add} any range not {@linkplain Range#encloses(Range) enclosed} by
158   * {@code view}.
159   */
160  RangeSet<C> subRangeSet(Range<C> view);
161
162  // Modification
163
164  /**
165   * Adds the specified range to this {@code RangeSet} (optional operation). That is, for equal
166   * range sets a and b, the result of {@code a.add(range)} is that {@code a} will be the minimal
167   * range set for which both {@code a.enclosesAll(b)} and {@code a.encloses(range)}.
168   *
169   * <p>Note that {@code range} will be {@linkplain Range#span(Range) coalesced} with any ranges in
170   * the range set that are {@linkplain Range#isConnected(Range) connected} with it.  Moreover,
171   * if {@code range} is empty, this is a no-op.
172   *
173   * @throws UnsupportedOperationException if this range set does not support the {@code add}
174   *         operation
175   */
176  void add(Range<C> range);
177
178  /**
179   * Removes the specified range from this {@code RangeSet} (optional operation). After this
180   * operation, if {@code range.contains(c)}, {@code this.contains(c)} will return {@code false}.
181   *
182   * <p>If {@code range} is empty, this is a no-op.
183   *
184   * @throws UnsupportedOperationException if this range set does not support the {@code remove}
185   *         operation
186   */
187  void remove(Range<C> range);
188
189  /**
190   * Removes all ranges from this {@code RangeSet} (optional operation).  After this operation,
191   * {@code this.contains(c)} will return false for all {@code c}.
192   *
193   * <p>This is equivalent to {@code remove(Range.all())}.
194   *
195   * @throws UnsupportedOperationException if this range set does not support the {@code clear}
196   *         operation
197   */
198  void clear();
199
200  /**
201   * Adds all of the ranges from the specified range set to this range set (optional operation).
202   * After this operation, this range set is the minimal range set that
203   * {@linkplain #enclosesAll(RangeSet) encloses} both the original range set and {@code other}.
204   *
205   * <p>This is equivalent to calling {@link #add} on each of the ranges in {@code other} in turn.
206   *
207   * @throws UnsupportedOperationException if this range set does not support the {@code addAll}
208   *         operation
209   */
210  void addAll(RangeSet<C> other);
211
212  /**
213   * Adds all of the specified ranges to this range set (optional operation). After this operation,
214   * this range set is the minimal range set that {@linkplain #enclosesAll(RangeSet) encloses} both
215   * the original range set and each range in {@code other}.
216   *
217   * <p>This is equivalent to calling {@link #add} on each of the ranges in {@code other} in turn.
218   *
219   * @throws UnsupportedOperationException if this range set does not support the {@code addAll}
220   *     operation
221   * @since 21.0
222   */
223  default void addAll(Iterable<Range<C>> ranges) {
224    for (Range<C> range : ranges) {
225      add(range);
226    }
227  }
228
229  /**
230   * Removes all of the ranges from the specified range set from this range set (optional
231   * operation). After this operation, if {@code other.contains(c)}, {@code this.contains(c)} will
232   * return {@code false}.
233   *
234   * <p>This is equivalent to calling {@link #remove} on each of the ranges in {@code other} in
235   * turn.
236   *
237   * @throws UnsupportedOperationException if this range set does not support the {@code removeAll}
238   *         operation
239   */
240  void removeAll(RangeSet<C> other);
241
242  /**
243   * Removes all of the specified ranges from this range set (optional operation).
244   *
245   * <p>This is equivalent to calling {@link #remove} on each of the ranges in {@code other} in
246   * turn.
247   *
248   * @throws UnsupportedOperationException if this range set does not support the {@code removeAll}
249   *     operation
250   * @since 21.0
251   */
252  default void removeAll(Iterable<Range<C>> ranges) {
253    for (Range<C> range : ranges) {
254      remove(range);
255    }
256  }
257
258  // Object methods
259
260  /**
261   * Returns {@code true} if {@code obj} is another {@code RangeSet} that contains the same ranges
262   * according to {@link Range#equals(Object)}.
263   */
264  @Override
265  boolean equals(@Nullable Object obj);
266
267  /**
268   * Returns {@code asRanges().hashCode()}.
269   */
270  @Override
271  int hashCode();
272
273  /**
274   * Returns a readable string representation of this range set. For example, if this
275   * {@code RangeSet} consisted of {@code Range.closed(1, 3)} and {@code Range.greaterThan(4)},
276   * this might return {@code " [1..3](4..+∞)}"}.
277   */
278  @Override
279  String toString();
280}