com.google.common.collect.ContiguousSet Maven / Gradle / Ivy
/*
* Copyright (C) 2010 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
* or implied. See the License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static java.util.Objects.requireNonNull;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.errorprone.annotations.DoNotCall;
import java.util.Collections;
import java.util.NoSuchElementException;
import java.util.Set;
/**
* A sorted set of contiguous values in a given {@link DiscreteDomain}. Example:
*
* {@code
* ContiguousSet.create(Range.closed(5, 42), DiscreteDomain.integers())
* }
*
* Note that because bounded ranges over {@code int} and {@code long} values are so common, this
* particular example can be written as just:
*
*
{@code
* ContiguousSet.closed(5, 42)
* }
*
* Warning: Be extremely careful what you do with conceptually large instances (such as
* {@code ContiguousSet.create(Range.greaterThan(0), DiscreteDomain.integers()}). Certain operations
* on such a set can be performed efficiently, but others (such as {@link Set#hashCode} or {@link
* Collections#frequency}) can cause major performance problems.
*
* @author Gregory Kick
* @since 10.0
*/
@GwtCompatible(emulated = true)
@SuppressWarnings("rawtypes") // allow ungenerified Comparable types
@ElementTypesAreNonnullByDefault
public abstract class ContiguousSet extends ImmutableSortedSet {
/**
* Returns a {@code ContiguousSet} containing the same values in the given domain {@linkplain
* Range#contains contained} by the range.
*
* @throws IllegalArgumentException if neither range nor the domain has a lower bound, or if
* neither has an upper bound
* @since 13.0
*/
public static ContiguousSet create(
Range range, DiscreteDomain domain) {
checkNotNull(range);
checkNotNull(domain);
Range effectiveRange = range;
try {
if (!range.hasLowerBound()) {
effectiveRange = effectiveRange.intersection(Range.atLeast(domain.minValue()));
}
if (!range.hasUpperBound()) {
effectiveRange = effectiveRange.intersection(Range.atMost(domain.maxValue()));
}
} catch (NoSuchElementException e) {
throw new IllegalArgumentException(e);
}
boolean empty;
if (effectiveRange.isEmpty()) {
empty = true;
} else {
/*
* requireNonNull is safe because the effectiveRange operations above would have thrown or
* effectiveRange.isEmpty() would have returned true.
*/
C afterLower = requireNonNull(range.lowerBound.leastValueAbove(domain));
C beforeUpper = requireNonNull(range.upperBound.greatestValueBelow(domain));
// Per class spec, we are allowed to throw CCE if necessary
empty = Range.compareOrThrow(afterLower, beforeUpper) > 0;
}
return empty
? new EmptyContiguousSet(domain)
: new RegularContiguousSet(effectiveRange, domain);
}
/**
* Returns a nonempty contiguous set containing all {@code int} values from {@code lower}
* (inclusive) to {@code upper} (inclusive). (These are the same values contained in {@code
* Range.closed(lower, upper)}.)
*
* @throws IllegalArgumentException if {@code lower} is greater than {@code upper}
* @since 23.0
*/
public static ContiguousSet closed(int lower, int upper) {
return create(Range.closed(lower, upper), DiscreteDomain.integers());
}
/**
* Returns a nonempty contiguous set containing all {@code long} values from {@code lower}
* (inclusive) to {@code upper} (inclusive). (These are the same values contained in {@code
* Range.closed(lower, upper)}.)
*
* @throws IllegalArgumentException if {@code lower} is greater than {@code upper}
* @since 23.0
*/
public static ContiguousSet closed(long lower, long upper) {
return create(Range.closed(lower, upper), DiscreteDomain.longs());
}
/**
* Returns a contiguous set containing all {@code int} values from {@code lower} (inclusive) to
* {@code upper} (exclusive). If the endpoints are equal, an empty set is returned. (These are the
* same values contained in {@code Range.closedOpen(lower, upper)}.)
*
* @throws IllegalArgumentException if {@code lower} is greater than {@code upper}
* @since 23.0
*/
public static ContiguousSet closedOpen(int lower, int upper) {
return create(Range.closedOpen(lower, upper), DiscreteDomain.integers());
}
/**
* Returns a contiguous set containing all {@code long} values from {@code lower} (inclusive) to
* {@code upper} (exclusive). If the endpoints are equal, an empty set is returned. (These are the
* same values contained in {@code Range.closedOpen(lower, upper)}.)
*
* @throws IllegalArgumentException if {@code lower} is greater than {@code upper}
* @since 23.0
*/
public static ContiguousSet closedOpen(long lower, long upper) {
return create(Range.closedOpen(lower, upper), DiscreteDomain.longs());
}
final DiscreteDomain domain;
ContiguousSet(DiscreteDomain domain) {
super(Ordering.natural());
this.domain = domain;
}
@Override
public ContiguousSet headSet(C toElement) {
return headSetImpl(checkNotNull(toElement), false);
}
/** @since 12.0 */
@GwtIncompatible // NavigableSet
@Override
public ContiguousSet headSet(C toElement, boolean inclusive) {
return headSetImpl(checkNotNull(toElement), inclusive);
}
@Override
public ContiguousSet subSet(C fromElement, C toElement) {
checkNotNull(fromElement);
checkNotNull(toElement);
checkArgument(comparator().compare(fromElement, toElement) <= 0);
return subSetImpl(fromElement, true, toElement, false);
}
/** @since 12.0 */
@GwtIncompatible // NavigableSet
@Override
public ContiguousSet subSet(
C fromElement, boolean fromInclusive, C toElement, boolean toInclusive) {
checkNotNull(fromElement);
checkNotNull(toElement);
checkArgument(comparator().compare(fromElement, toElement) <= 0);
return subSetImpl(fromElement, fromInclusive, toElement, toInclusive);
}
@Override
public ContiguousSet tailSet(C fromElement) {
return tailSetImpl(checkNotNull(fromElement), true);
}
/** @since 12.0 */
@GwtIncompatible // NavigableSet
@Override
public ContiguousSet tailSet(C fromElement, boolean inclusive) {
return tailSetImpl(checkNotNull(fromElement), inclusive);
}
/*
* These methods perform most headSet, subSet, and tailSet logic, besides parameter validation.
*/
@SuppressWarnings("MissingOverride") // Supermethod does not exist under GWT.
abstract ContiguousSet headSetImpl(C toElement, boolean inclusive);
@SuppressWarnings("MissingOverride") // Supermethod does not exist under GWT.
abstract ContiguousSet subSetImpl(
C fromElement, boolean fromInclusive, C toElement, boolean toInclusive);
@SuppressWarnings("MissingOverride") // Supermethod does not exist under GWT.
abstract ContiguousSet tailSetImpl(C fromElement, boolean inclusive);
/**
* Returns the set of values that are contained in both this set and the other.
*
* This method should always be used instead of {@link Sets#intersection} for {@link
* ContiguousSet} instances.
*/
public abstract ContiguousSet intersection(ContiguousSet other);
/**
* Returns a range, closed on both ends, whose endpoints are the minimum and maximum values
* contained in this set. This is equivalent to {@code range(CLOSED, CLOSED)}.
*
* @throws NoSuchElementException if this set is empty
*/
public abstract Range range();
/**
* Returns the minimal range with the given boundary types for which all values in this set are
* {@linkplain Range#contains(Comparable) contained} within the range.
*
* Note that this method will return ranges with unbounded endpoints if {@link BoundType#OPEN}
* is requested for a domain minimum or maximum. For example, if {@code set} was created from the
* range {@code [1..Integer.MAX_VALUE]} then {@code set.range(CLOSED, OPEN)} must return {@code
* [1..∞)}.
*
* @throws NoSuchElementException if this set is empty
*/
public abstract Range range(BoundType lowerBoundType, BoundType upperBoundType);
@Override
@GwtIncompatible // NavigableSet
ImmutableSortedSet createDescendingSet() {
return new DescendingImmutableSortedSet<>(this);
}
/** Returns a shorthand representation of the contents such as {@code "[1..100]"}. */
@Override
public String toString() {
return range().toString();
}
/**
* Not supported. {@code ContiguousSet} instances are constructed with {@link #create}. This
* method exists only to hide {@link ImmutableSet#builder} from consumers of {@code
* ContiguousSet}.
*
* @throws UnsupportedOperationException always
* @deprecated Use {@link #create}.
*/
@Deprecated
@DoNotCall("Always throws UnsupportedOperationException")
public static ImmutableSortedSet.Builder builder() {
throw new UnsupportedOperationException();
}
}