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
054  // Query methods
055
056  /**
057   * Determines whether any of this range set's member ranges contains {@code value}.
058   */
059  boolean contains(C value);
060
061  /**
062   * Returns the unique range from this range set that {@linkplain Range#contains contains}
063   * {@code value}, or {@code null} if this range set does not contain {@code value}.
064   */
065  Range<C> rangeContaining(C value);
066
067  /**
068   * Returns {@code true} if there exists a non-empty range enclosed by both a member range in this
069   * range set and the specified range. This is equivalent to calling
070   * {@code subRangeSet(otherRange)} and testing whether the resulting range set is non-empty.
071   *
072   * @since 20.0
073   */
074  boolean intersects(Range<C> otherRange);
075
076  /**
077   * Returns {@code true} if there exists a member range in this range set which
078   * {@linkplain Range#encloses encloses} the specified range.
079   */
080  boolean encloses(Range<C> otherRange);
081
082  /**
083   * Returns {@code true} if for each member range in {@code other} there exists a member range in
084   * this range set which {@linkplain Range#encloses encloses} it. It follows that
085   * {@code this.contains(value)} whenever {@code other.contains(value)}. Returns {@code true} if
086   * {@code other} is empty.
087   *
088   * <p>This is equivalent to checking if this range set {@link #encloses} each of the ranges in
089   * {@code other}.
090   */
091  boolean enclosesAll(RangeSet<C> other);
092
093  /**
094   * Returns {@code true} if this range set contains no ranges.
095   */
096  boolean isEmpty();
097
098  /**
099   * Returns the minimal range which {@linkplain Range#encloses(Range) encloses} all ranges
100   * in this range set.
101   *
102   * @throws NoSuchElementException if this range set is {@linkplain #isEmpty() empty}
103   */
104  Range<C> span();
105
106  // Views
107
108  /**
109   * Returns a view of the {@linkplain Range#isConnected disconnected} ranges that make up this
110   * range set.  The returned set may be empty. The iterators returned by its
111   * {@link Iterable#iterator} method return the ranges in increasing order of lower bound
112   * (equivalently, of upper bound).
113   */
114  Set<Range<C>> asRanges();
115
116  /**
117   * Returns a descending view of the {@linkplain Range#isConnected disconnected} ranges that
118   * make up this range set. The returned set may be empty. The iterators returned by its
119   * {@link Iterable#iterator} method return the ranges in decreasing order of lower bound
120   * (equivalently, of upper bound).
121   *
122   * @since 19.0
123   */
124  Set<Range<C>> asDescendingSetOfRanges();
125
126  /**
127   * Returns a view of the complement of this {@code RangeSet}.
128   *
129   * <p>The returned view supports the {@link #add} operation if this {@code RangeSet} supports
130   * {@link #remove}, and vice versa.
131   */
132  RangeSet<C> complement();
133
134  /**
135   * Returns a view of the intersection of this {@code RangeSet} with the specified range.
136   *
137   * <p>The returned view supports all optional operations supported by this {@code RangeSet}, with
138   * the caveat that an {@link IllegalArgumentException} is thrown on an attempt to
139   * {@linkplain #add(Range) add} any range not {@linkplain Range#encloses(Range) enclosed} by
140   * {@code view}.
141   */
142  RangeSet<C> subRangeSet(Range<C> view);
143
144  // Modification
145
146  /**
147   * Adds the specified range to this {@code RangeSet} (optional operation). That is, for equal
148   * range sets a and b, the result of {@code a.add(range)} is that {@code a} will be the minimal
149   * range set for which both {@code a.enclosesAll(b)} and {@code a.encloses(range)}.
150   *
151   * <p>Note that {@code range} will be {@linkplain Range#span(Range) coalesced} with any ranges in
152   * the range set that are {@linkplain Range#isConnected(Range) connected} with it.  Moreover,
153   * if {@code range} is empty, this is a no-op.
154   *
155   * @throws UnsupportedOperationException if this range set does not support the {@code add}
156   *         operation
157   */
158  void add(Range<C> range);
159
160  /**
161   * Removes the specified range from this {@code RangeSet} (optional operation). After this
162   * operation, if {@code range.contains(c)}, {@code this.contains(c)} will return {@code false}.
163   *
164   * <p>If {@code range} is empty, this is a no-op.
165   *
166   * @throws UnsupportedOperationException if this range set does not support the {@code remove}
167   *         operation
168   */
169  void remove(Range<C> range);
170
171  /**
172   * Removes all ranges from this {@code RangeSet} (optional operation).  After this operation,
173   * {@code this.contains(c)} will return false for all {@code c}.
174   *
175   * <p>This is equivalent to {@code remove(Range.all())}.
176   *
177   * @throws UnsupportedOperationException if this range set does not support the {@code clear}
178   *         operation
179   */
180  void clear();
181
182  /**
183   * Adds all of the ranges from the specified range set to this range set (optional operation).
184   * After this operation, this range set is the minimal range set that
185   * {@linkplain #enclosesAll(RangeSet) encloses} both the original range set and {@code other}.
186   *
187   * <p>This is equivalent to calling {@link #add} on each of the ranges in {@code other} in turn.
188   *
189   * @throws UnsupportedOperationException if this range set does not support the {@code addAll}
190   *         operation
191   */
192  void addAll(RangeSet<C> other);
193
194  /**
195   * Removes all of the ranges from the specified range set from this range set (optional
196   * operation). After this operation, if {@code other.contains(c)}, {@code this.contains(c)} will
197   * return {@code false}.
198   *
199   * <p>This is equivalent to calling {@link #remove} on each of the ranges in {@code other} in
200   * turn.
201   *
202   * @throws UnsupportedOperationException if this range set does not support the {@code removeAll}
203   *         operation
204   */
205  void removeAll(RangeSet<C> other);
206
207  // Object methods
208
209  /**
210   * Returns {@code true} if {@code obj} is another {@code RangeSet} that contains the same ranges
211   * according to {@link Range#equals(Object)}.
212   */
213  @Override
214  boolean equals(@Nullable Object obj);
215
216  /**
217   * Returns {@code asRanges().hashCode()}.
218   */
219  @Override
220  int hashCode();
221
222  /**
223   * Returns a readable string representation of this range set. For example, if this
224   * {@code RangeSet} consisted of {@code Range.closed(1, 3)} and {@code Range.greaterThan(4)},
225   * this might return {@code " [1..3](4..+∞)}"}.
226   */
227  @Override
228  String toString();
229}