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 org.checkerframework.checker.nullness.qual.Nullable; 022 023/** 024 * A set comprising zero or more {@linkplain Range#isEmpty nonempty}, {@linkplain 025 * 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: 029 * 030 * <pre>{@code 031 * RangeSet<Integer> rangeSet = TreeRangeSet.create(); 032 * rangeSet.add(Range.closed(1, 10)); // {[1, 10]} 033 * rangeSet.add(Range.closedOpen(11, 15)); // disconnected range; {[1, 10], [11, 15)} 034 * rangeSet.add(Range.closedOpen(15, 20)); // connected range; {[1, 10], [11, 20)} 035 * rangeSet.add(Range.openClosed(0, 0)); // empty range; {[1, 10], [11, 20)} 036 * rangeSet.remove(Range.open(5, 10)); // splits [1, 10]; {[1, 5], [10, 10], [11, 20)} 037 * }</pre> 038 * 039 * <p>Note that the behavior of {@link Range#isEmpty()} and {@link Range#isConnected(Range)} may not 040 * be as expected on discrete ranges. See the Javadoc of those methods for details. 041 * 042 * <p>For a {@link Set} whose contents are specified by a {@link Range}, see {@link ContiguousSet}. 043 * 044 * <p>See the Guava User Guide article on <a href= 045 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#rangeset"> RangeSets</a>. 046 * 047 * @author Kevin Bourrillion 048 * @author Louis Wasserman 049 * @since 14.0 050 */ 051@Beta 052@GwtIncompatible 053public interface RangeSet<C extends Comparable> { 054 // TODO(lowasser): consider adding default implementations of some of these methods 055 056 // Query methods 057 058 /** Determines whether any of this range set's member ranges contains {@code value}. */ 059 boolean contains(C value); 060 061 /** 062 * Returns the unique range from this range set that {@linkplain Range#contains contains} {@code 063 * 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 {@code 070 * 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 {@linkplain 078 * 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 {@code 085 * this.contains(value)} whenever {@code other.contains(value)}. Returns {@code true} if {@code 086 * 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 for each range in {@code other} there exists a member range in this 095 * range set which {@linkplain Range#encloses encloses} it. Returns {@code true} if {@code other} 096 * is empty. 097 * 098 * <p>This is equivalent to checking if this range set {@link #encloses} each range in {@code 099 * other}. 100 * 101 * @since 21.0 102 */ 103 default boolean enclosesAll(Iterable<Range<C>> other) { 104 for (Range<C> range : other) { 105 if (!encloses(range)) { 106 return false; 107 } 108 } 109 return true; 110 } 111 112 /** Returns {@code true} if this range set contains no ranges. */ 113 boolean isEmpty(); 114 115 /** 116 * Returns the minimal range which {@linkplain Range#encloses(Range) encloses} all ranges in this 117 * range set. 118 * 119 * @throws NoSuchElementException if this range set is {@linkplain #isEmpty() empty} 120 */ 121 Range<C> span(); 122 123 // Views 124 125 /** 126 * Returns a view of the {@linkplain Range#isConnected disconnected} ranges that make up this 127 * range set. The returned set may be empty. The iterators returned by its {@link 128 * Iterable#iterator} method return the ranges in increasing order of lower bound (equivalently, 129 * of upper bound). 130 */ 131 Set<Range<C>> asRanges(); 132 133 /** 134 * Returns a descending view of the {@linkplain Range#isConnected disconnected} ranges that make 135 * up this range set. The returned set may be empty. The iterators returned by its {@link 136 * Iterable#iterator} method return the ranges in decreasing order of lower bound (equivalently, 137 * of upper bound). 138 * 139 * @since 19.0 140 */ 141 Set<Range<C>> asDescendingSetOfRanges(); 142 143 /** 144 * Returns a view of the complement of this {@code RangeSet}. 145 * 146 * <p>The returned view supports the {@link #add} operation if this {@code RangeSet} supports 147 * {@link #remove}, and vice versa. 148 */ 149 RangeSet<C> complement(); 150 151 /** 152 * Returns a view of the intersection of this {@code RangeSet} with the specified range. 153 * 154 * <p>The returned view supports all optional operations supported by this {@code RangeSet}, with 155 * the caveat that an {@link IllegalArgumentException} is thrown on an attempt to {@linkplain 156 * #add(Range) add} any range not {@linkplain Range#encloses(Range) enclosed} by {@code view}. 157 */ 158 RangeSet<C> subRangeSet(Range<C> view); 159 160 // Modification 161 162 /** 163 * Adds the specified range to this {@code RangeSet} (optional operation). That is, for equal 164 * range sets a and b, the result of {@code a.add(range)} is that {@code a} will be the minimal 165 * range set for which both {@code a.enclosesAll(b)} and {@code a.encloses(range)}. 166 * 167 * <p>Note that {@code range} will be {@linkplain Range#span(Range) coalesced} with any ranges in 168 * the range set that are {@linkplain Range#isConnected(Range) connected} with it. Moreover, if 169 * {@code range} is empty, this is a no-op. 170 * 171 * @throws UnsupportedOperationException if this range set does not support the {@code add} 172 * operation 173 */ 174 void add(Range<C> range); 175 176 /** 177 * Removes the specified range from this {@code RangeSet} (optional operation). After this 178 * operation, if {@code range.contains(c)}, {@code this.contains(c)} will return {@code false}. 179 * 180 * <p>If {@code range} is empty, this is a no-op. 181 * 182 * @throws UnsupportedOperationException if this range set does not support the {@code remove} 183 * operation 184 */ 185 void remove(Range<C> range); 186 187 /** 188 * Removes all ranges from this {@code RangeSet} (optional operation). After this operation, 189 * {@code this.contains(c)} will return false for all {@code c}. 190 * 191 * <p>This is equivalent to {@code remove(Range.all())}. 192 * 193 * @throws UnsupportedOperationException if this range set does not support the {@code clear} 194 * operation 195 */ 196 void clear(); 197 198 /** 199 * Adds all of the ranges from the specified range set to this range set (optional operation). 200 * After this operation, this range set is the minimal range set that {@linkplain 201 * #enclosesAll(RangeSet) encloses} both the original range set and {@code other}. 202 * 203 * <p>This is equivalent to calling {@link #add} on each of the ranges in {@code other} in turn. 204 * 205 * @throws UnsupportedOperationException if this range set does not support the {@code addAll} 206 * operation 207 */ 208 void addAll(RangeSet<C> other); 209 210 /** 211 * Adds all of the specified ranges to this range set (optional operation). After this operation, 212 * this range set is the minimal range set that {@linkplain #enclosesAll(RangeSet) encloses} both 213 * the original range set and each range in {@code other}. 214 * 215 * <p>This is equivalent to calling {@link #add} on each of the ranges in {@code other} in turn. 216 * 217 * @throws UnsupportedOperationException if this range set does not support the {@code addAll} 218 * operation 219 * @since 21.0 220 */ 221 default void addAll(Iterable<Range<C>> ranges) { 222 for (Range<C> range : ranges) { 223 add(range); 224 } 225 } 226 227 /** 228 * Removes all of the ranges from the specified range set from this range set (optional 229 * operation). After this operation, if {@code other.contains(c)}, {@code this.contains(c)} will 230 * return {@code false}. 231 * 232 * <p>This is equivalent to calling {@link #remove} on each of the ranges in {@code other} in 233 * turn. 234 * 235 * @throws UnsupportedOperationException if this range set does not support the {@code removeAll} 236 * operation 237 */ 238 void removeAll(RangeSet<C> other); 239 240 /** 241 * Removes all of the specified ranges from this range set (optional operation). 242 * 243 * <p>This is equivalent to calling {@link #remove} on each of the ranges in {@code other} in 244 * turn. 245 * 246 * @throws UnsupportedOperationException if this range set does not support the {@code removeAll} 247 * operation 248 * @since 21.0 249 */ 250 default void removeAll(Iterable<Range<C>> ranges) { 251 for (Range<C> range : ranges) { 252 remove(range); 253 } 254 } 255 256 // Object methods 257 258 /** 259 * Returns {@code true} if {@code obj} is another {@code RangeSet} that contains the same ranges 260 * according to {@link Range#equals(Object)}. 261 */ 262 @Override 263 boolean equals(@Nullable Object obj); 264 265 /** Returns {@code asRanges().hashCode()}. */ 266 @Override 267 int hashCode(); 268 269 /** 270 * Returns a readable string representation of this range set. For example, if this {@code 271 * RangeSet} consisted of {@code Range.closed(1, 3)} and {@code Range.greaterThan(4)}, this might 272 * return {@code " [1..3](4..+∞)}"}. 273 */ 274 @Override 275 String toString(); 276}