com.google.common.collect

Class ImmutableSortedSet<E>

java.lang.Object

com.google.common.collect.ImmutableCollection<E>

com.google.common.collect.ImmutableSet<E>

com.google.common.collect.ImmutableSortedSet<E>

All Implemented Interfaces:

Serializable, Iterable<E>, Collection<E>, NavigableSet<E>, Set<E>, SortedSet<E>

Direct Known Subclasses:

ContiguousSet

@GwtCompatible(serializable=true,
               emulated=true)
public abstract class ImmutableSortedSet<E>
extends ImmutableSet<E>
implements NavigableSet<E>

An immutable SortedSet that stores its elements in a sorted array. Some instances are ordered by an explicit comparator, while others follow the natural sort ordering of their elements. Either way, null elements are not supported.

Unlike Collections.unmodifiableSortedSet(java.util.SortedSet<T>), which is a view of a separate collection that can still change, an instance of ImmutableSortedSet contains its own private data and will never change. This class is convenient for public static final sets ("constant sets") and also lets you easily make a "defensive copy" of a set provided to your class by a caller.

The sets returned by the headSet(E), tailSet(E), and subSet(E, E) methods share the same array as the original set, preventing that array from being garbage collected. If this is a concern, the data may be copied into a correctly-sized array by calling copyOfSorted(java.util.SortedSet<E>).

Note on element equivalence: The ImmutableCollection.contains(Object), ImmutableCollection.containsAll(Collection), and ImmutableSet.equals(Object) implementations must check whether a provided object is equivalent to an element in the collection. Unlike most collections, an ImmutableSortedSet doesn't use Object.equals(java.lang.Object) to determine if two elements are equivalent. Instead, with an explicit comparator, the following relation determines whether elements x and y are equivalent:

   {(x, y) | comparator.compare(x, y) == 0}

With natural ordering of elements, the following relation determines whether two elements are equivalent:

   {(x, y) | x.compareTo(y) == 0}

Warning: Like most sets, an ImmutableSortedSet will not function correctly if an element is modified after being placed in the set. For this reason, and to avoid general confusion, it is strongly recommended to place only immutable objects into this collection.

Note: Although this class is not final, it cannot be subclassed as it has no public or protected constructors. Thus, instances of this type are guaranteed to be immutable.

See the Guava User Guide article on immutable collections.

Since:

2.0 (imported from Google Collections Library; implements NavigableSet since 12.0)

Author:

Jared Levy, Louis Wasserman

See Also:

ImmutableSet, Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ImmutableSortedSet.Builder<E> A builder for creating immutable sorted set instances, especially public static final sets ("constant sets"), with a given comparator.

Method Summary

Methods

Modifier and Type	Method and Description
static <E> ImmutableSortedSet.Builder<E>	builder() Deprecated. Use naturalOrder(), which offers better type-safety.
E	ceiling(E e)
Comparator<? super E>	comparator() Returns the comparator that orders the elements, which is Ordering.natural() when the natural ordering of the elements is used.
static <E> ImmutableSortedSet<E>	copyOf(Collection<? extends E> elements) Returns an immutable sorted set containing the given elements sorted by their natural ordering.
static <E> ImmutableSortedSet<E>	copyOf(Comparator<? super E> comparator, Collection<? extends E> elements) Returns an immutable sorted set containing the given elements sorted by the given Comparator.
static <E> ImmutableSortedSet<E>	copyOf(Comparator<? super E> comparator, Iterable<? extends E> elements) Returns an immutable sorted set containing the given elements sorted by the given Comparator.
static <E> ImmutableSortedSet<E>	copyOf(Comparator<? super E> comparator, Iterator<? extends E> elements) Returns an immutable sorted set containing the given elements sorted by the given Comparator.
static <E extends Comparable<? super E>> ImmutableSortedSet<E>	copyOf(E[] elements) Returns an immutable sorted set containing the given elements sorted by their natural ordering.
static <E> ImmutableSortedSet<E>	copyOf(Iterable<? extends E> elements) Returns an immutable sorted set containing the given elements sorted by their natural ordering.
static <E> ImmutableSortedSet<E>	copyOf(Iterator<? extends E> elements) Returns an immutable sorted set containing the given elements sorted by their natural ordering.
static <E> ImmutableSortedSet<E>	copyOfSorted(SortedSet<E> sortedSet) Returns an immutable sorted set containing the elements of a sorted set, sorted by the same Comparator.
abstract UnmodifiableIterator<E>	descendingIterator()
ImmutableSortedSet<E>	descendingSet()
E	first()
E	floor(E e)
ImmutableSortedSet<E>	headSet(E toElement)
ImmutableSortedSet<E>	headSet(E toElement, boolean inclusive)
E	higher(E e)
abstract UnmodifiableIterator<E>	iterator() Returns an unmodifiable iterator across the elements in this collection.
E	last()
E	lower(E e)
static <E extends Comparable<?>> ImmutableSortedSet.Builder<E>	naturalOrder() Returns a builder that creates immutable sorted sets whose elements are ordered by their natural ordering.
static <E> ImmutableSortedSet<E>	of() Returns the empty immutable sorted set.
static <E extends Comparable<? super E>> ImmutableSortedSet<E>	of(E element) Returns an immutable sorted set containing a single element.
static <E extends Comparable<? super E>> ImmutableSortedSet<E>	of(E e1, E e2) Returns an immutable sorted set containing the given elements sorted by their natural ordering.
static <E extends Comparable<? super E>> ImmutableSortedSet<E>	of(E e1, E e2, E e3) Returns an immutable sorted set containing the given elements sorted by their natural ordering.
static <E extends Comparable<? super E>> ImmutableSortedSet<E>	of(E e1, E e2, E e3, E e4) Returns an immutable sorted set containing the given elements sorted by their natural ordering.
static <E extends Comparable<? super E>> ImmutableSortedSet<E>	of(E e1, E e2, E e3, E e4, E e5) Returns an immutable sorted set containing the given elements sorted by their natural ordering.
static <E extends Comparable<? super E>> ImmutableSortedSet<E>	of(E e1, E e2, E e3, E e4, E e5, E e6, E... remaining) Returns an immutable sorted set containing the given elements sorted by their natural ordering.
static <E> ImmutableSortedSet.Builder<E>	orderedBy(Comparator<E> comparator) Returns a builder that creates immutable sorted sets with an explicit comparator.
E	pollFirst() Deprecated. Unsupported operation.
E	pollLast() Deprecated. Unsupported operation.
static <E extends Comparable<?>> ImmutableSortedSet.Builder<E>	reverseOrder() Returns a builder that creates immutable sorted sets whose elements are ordered by the reverse of their natural ordering.
ImmutableSortedSet<E>	subSet(E fromElement, boolean fromInclusive, E toElement, boolean toInclusive)
ImmutableSortedSet<E>	subSet(E fromElement, E toElement)
ImmutableSortedSet<E>	tailSet(E fromElement)
ImmutableSortedSet<E>	tailSet(E fromElement, boolean inclusive)

Methods inherited from class com.google.common.collect.ImmutableSet

equals, hashCode

Methods inherited from class com.google.common.collect.ImmutableCollection

add, addAll, asList, clear, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Set

add, addAll, clear, contains, containsAll, equals, hashCode, isEmpty, remove, removeAll, retainAll, size, toArray, toArray

Method Detail

of

public static <E> ImmutableSortedSet<E> of()

Returns the empty immutable sorted set.

of

public static <E extends Comparable<? super E>> ImmutableSortedSet<E> of(E element)

Returns an immutable sorted set containing a single element.

of

public static <E extends Comparable<? super E>> ImmutableSortedSet<E> of(E e1,
                                                         E e2)

Returns an immutable sorted set containing the given elements sorted by their natural ordering. When multiple elements are equivalent according to Comparable.compareTo(T), only the first one specified is included.

Throws:

NullPointerException - if any element is null

of

public static <E extends Comparable<? super E>> ImmutableSortedSet<E> of(E e1,
                                                         E e2,
                                                         E e3)

Returns an immutable sorted set containing the given elements sorted by their natural ordering. When multiple elements are equivalent according to Comparable.compareTo(T), only the first one specified is included.

Throws:

NullPointerException - if any element is null

of

public static <E extends Comparable<? super E>> ImmutableSortedSet<E> of(E e1,
                                                         E e2,
                                                         E e3,
                                                         E e4)

Returns an immutable sorted set containing the given elements sorted by their natural ordering. When multiple elements are equivalent according to Comparable.compareTo(T), only the first one specified is included.

Throws:

NullPointerException - if any element is null

of

public static <E extends Comparable<? super E>> ImmutableSortedSet<E> of(E e1,
                                                         E e2,
                                                         E e3,
                                                         E e4,
                                                         E e5)

Returns an immutable sorted set containing the given elements sorted by their natural ordering. When multiple elements are equivalent according to Comparable.compareTo(T), only the first one specified is included.

Throws:

NullPointerException - if any element is null

of

public static <E extends Comparable<? super E>> ImmutableSortedSet<E> of(E e1,
                                                         E e2,
                                                         E e3,
                                                         E e4,
                                                         E e5,
                                                         E e6,
                                                         E... remaining)

Returns an immutable sorted set containing the given elements sorted by their natural ordering. When multiple elements are equivalent according to Comparable.compareTo(T), only the first one specified is included.

Throws:

NullPointerException - if any element is null

Since:

3.0 (source-compatible since 2.0)

copyOf

public static <E extends Comparable<? super E>> ImmutableSortedSet<E> copyOf(E[] elements)

Returns an immutable sorted set containing the given elements sorted by their natural ordering. When multiple elements are equivalent according to Comparable.compareTo(T), only the first one specified is included.

Throws:

NullPointerException - if any of elements is null

Since:

3.0

copyOf

public static <E> ImmutableSortedSet<E> copyOf(Iterable<? extends E> elements)

Returns an immutable sorted set containing the given elements sorted by their natural ordering. When multiple elements are equivalent according to compareTo(), only the first one specified is included. To create a copy of a SortedSet that preserves the comparator, call copyOfSorted(java.util.SortedSet<E>) instead. This method iterates over elements at most once.

Note that if s is a Set<String>, then ImmutableSortedSet.copyOf(s) returns an ImmutableSortedSet<String> containing each of the strings in s, while ImmutableSortedSet.of(s) returns an ImmutableSortedSet<Set<String>> containing one element (the given set itself).

Despite the method name, this method attempts to avoid actually copying the data when it is safe to do so. The exact circumstances under which a copy will or will not be performed are undocumented and subject to change.

This method is not type-safe, as it may be called on elements that are not mutually comparable.

Throws:

ClassCastException - if the elements are not mutually comparable

NullPointerException - if any of elements is null

copyOf

public static <E> ImmutableSortedSet<E> copyOf(Collection<? extends E> elements)

Returns an immutable sorted set containing the given elements sorted by their natural ordering. When multiple elements are equivalent according to compareTo(), only the first one specified is included. To create a copy of a SortedSet that preserves the comparator, call copyOfSorted(java.util.SortedSet<E>) instead. This method iterates over elements at most once.

Note that if s is a Set<String>, then ImmutableSortedSet.copyOf(s) returns an ImmutableSortedSet<String> containing each of the strings in s, while ImmutableSortedSet.of(s) returns an ImmutableSortedSet<Set<String>> containing one element (the given set itself).

Note: Despite what the method name suggests, if elements is an ImmutableSortedSet, it may be returned instead of a copy.

This method is not type-safe, as it may be called on elements that are not mutually comparable.

This method is safe to use even when elements is a synchronized or concurrent collection that is currently being modified by another thread.

Throws:

ClassCastException - if the elements are not mutually comparable

NullPointerException - if any of elements is null

Since:

7.0 (source-compatible since 2.0)

copyOf

public static <E> ImmutableSortedSet<E> copyOf(Iterator<? extends E> elements)

Returns an immutable sorted set containing the given elements sorted by their natural ordering. When multiple elements are equivalent according to compareTo(), only the first one specified is included.

This method is not type-safe, as it may be called on elements that are not mutually comparable.

Throws:

ClassCastException - if the elements are not mutually comparable

NullPointerException - if any of elements is null

copyOf

public static <E> ImmutableSortedSet<E> copyOf(Comparator<? super E> comparator,
                               Iterator<? extends E> elements)

Returns an immutable sorted set containing the given elements sorted by the given Comparator. When multiple elements are equivalent according to compareTo(), only the first one specified is included.

Throws:

NullPointerException - if comparator or any of elements is null

copyOf

public static <E> ImmutableSortedSet<E> copyOf(Comparator<? super E> comparator,
                               Iterable<? extends E> elements)

Returns an immutable sorted set containing the given elements sorted by the given Comparator. When multiple elements are equivalent according to compare(), only the first one specified is included. This method iterates over elements at most once.

Despite the method name, this method attempts to avoid actually copying the data when it is safe to do so. The exact circumstances under which a copy will or will not be performed are undocumented and subject to change.

Throws:

NullPointerException - if comparator or any of elements is null

copyOf

public static <E> ImmutableSortedSet<E> copyOf(Comparator<? super E> comparator,
                               Collection<? extends E> elements)

Returns an immutable sorted set containing the given elements sorted by the given Comparator. When multiple elements are equivalent according to compareTo(), only the first one specified is included.

Despite the method name, this method attempts to avoid actually copying the data when it is safe to do so. The exact circumstances under which a copy will or will not be performed are undocumented and subject to change.

This method is safe to use even when elements is a synchronized or concurrent collection that is currently being modified by another thread.

Throws:

NullPointerException - if comparator or any of elements is null

Since:

7.0 (source-compatible since 2.0)

copyOfSorted

public static <E> ImmutableSortedSet<E> copyOfSorted(SortedSet<E> sortedSet)

Returns an immutable sorted set containing the elements of a sorted set, sorted by the same Comparator. That behavior differs from copyOf(Iterable), which always uses the natural ordering of the elements.

Despite the method name, this method attempts to avoid actually copying the data when it is safe to do so. The exact circumstances under which a copy will or will not be performed are undocumented and subject to change.

This method is safe to use even when sortedSet is a synchronized or concurrent collection that is currently being modified by another thread.

Throws:

NullPointerException - if sortedSet or any of its elements is null

orderedBy

public static <E> ImmutableSortedSet.Builder<E> orderedBy(Comparator<E> comparator)

Returns a builder that creates immutable sorted sets with an explicit comparator. If the comparator has a more general type than the set being generated, such as creating a SortedSet<Integer> with a Comparator<Number>, use the ImmutableSortedSet.Builder constructor instead.

Throws:

NullPointerException - if comparator is null

reverseOrder

public static <E extends Comparable<?>> ImmutableSortedSet.Builder<E> reverseOrder()

Returns a builder that creates immutable sorted sets whose elements are ordered by the reverse of their natural ordering.

naturalOrder

public static <E extends Comparable<?>> ImmutableSortedSet.Builder<E> naturalOrder()

Returns a builder that creates immutable sorted sets whose elements are ordered by their natural ordering. The sorted sets use Ordering.natural() as the comparator. This method provides more type-safety than builder(), as it can be called only for classes that implement Comparable.

comparator

public Comparator<? super E> comparator()

Returns the comparator that orders the elements, which is Ordering.natural() when the natural ordering of the elements is used. Note that its behavior is not consistent with SortedSet.comparator(), which returns null to indicate natural ordering.

Specified by:

comparator in interface SortedSet<E>

iterator

public abstract UnmodifiableIterator<E> iterator()

Description copied from class: ImmutableCollection

Returns an unmodifiable iterator across the elements in this collection.

Specified by:

iterator in interface Iterable<E>

Specified by:

iterator in interface Collection<E>

Specified by:

iterator in interface NavigableSet<E>

Specified by:

iterator in interface Set<E>

Specified by:

iterator in class ImmutableSet<E>

headSet

public ImmutableSortedSet<E> headSet(E toElement)

This method returns a serializable ImmutableSortedSet.

The SortedSet.headSet(E) documentation states that a subset of a subset throws an IllegalArgumentException if passed a toElement greater than an earlier toElement. However, this method doesn't throw an exception in that situation, but instead keeps the original toElement.

Specified by:

headSet in interface NavigableSet<E>

Specified by:

headSet in interface SortedSet<E>

headSet

@GwtIncompatible(value="NavigableSet")
public ImmutableSortedSet<E> headSet(E toElement,
                                                 boolean inclusive)

Specified by:

headSet in interface NavigableSet<E>

Since:

12.0

subSet

public ImmutableSortedSet<E> subSet(E fromElement,
                           E toElement)

This method returns a serializable ImmutableSortedSet.

The SortedSet.subSet(E, E) documentation states that a subset of a subset throws an IllegalArgumentException if passed a fromElement smaller than an earlier fromElement. However, this method doesn't throw an exception in that situation, but instead keeps the original fromElement. Similarly, this method keeps the original toElement, instead of throwing an exception, if passed a toElement greater than an earlier toElement.

Specified by:

subSet in interface NavigableSet<E>

Specified by:

subSet in interface SortedSet<E>

subSet

@GwtIncompatible(value="NavigableSet")
public ImmutableSortedSet<E> subSet(E fromElement,
                                                boolean fromInclusive,
                                                E toElement,
                                                boolean toInclusive)

Specified by:

subSet in interface NavigableSet<E>

Since:

12.0

tailSet

public ImmutableSortedSet<E> tailSet(E fromElement)

This method returns a serializable ImmutableSortedSet.

The SortedSet.tailSet(E) documentation states that a subset of a subset throws an IllegalArgumentException if passed a fromElement smaller than an earlier fromElement. However, this method doesn't throw an exception in that situation, but instead keeps the original fromElement.

Specified by:

tailSet in interface NavigableSet<E>

Specified by:

tailSet in interface SortedSet<E>

tailSet

@GwtIncompatible(value="NavigableSet")
public ImmutableSortedSet<E> tailSet(E fromElement,
                                                 boolean inclusive)

Specified by:

tailSet in interface NavigableSet<E>

Since:

12.0

lower

@GwtIncompatible(value="NavigableSet")
public E lower(E e)

Specified by:

lower in interface NavigableSet<E>

Since:

12.0

floor

@GwtIncompatible(value="NavigableSet")
public E floor(E e)

Specified by:

floor in interface NavigableSet<E>

Since:

12.0

ceiling

@GwtIncompatible(value="NavigableSet")
public E ceiling(E e)

Specified by:

ceiling in interface NavigableSet<E>

Since:

12.0

higher

@GwtIncompatible(value="NavigableSet")
public E higher(E e)

Specified by:

higher in interface NavigableSet<E>

Since:

12.0

first

public E first()

Specified by:

first in interface SortedSet<E>

last

public E last()

Specified by:

last in interface SortedSet<E>

pollFirst

@Deprecated
@GwtIncompatible(value="NavigableSet")
public final E pollFirst()

Deprecated. Unsupported operation.

Guaranteed to throw an exception and leave the set unmodified.

Specified by:

pollFirst in interface NavigableSet<E>

Throws:

UnsupportedOperationException - always

Since:

12.0

pollLast

@Deprecated
@GwtIncompatible(value="NavigableSet")
public final E pollLast()

Deprecated. Unsupported operation.

Guaranteed to throw an exception and leave the set unmodified.

Specified by:

pollLast in interface NavigableSet<E>

Throws:

UnsupportedOperationException - always

Since:

12.0

descendingSet

@GwtIncompatible(value="NavigableSet")
public ImmutableSortedSet<E> descendingSet()

Specified by:

descendingSet in interface NavigableSet<E>

Since:

12.0

descendingIterator

@GwtIncompatible(value="NavigableSet")
public abstract UnmodifiableIterator<E> descendingIterator()

Specified by:

descendingIterator in interface NavigableSet<E>

Since:

12.0

builder

@Deprecated
public static <E> ImmutableSortedSet.Builder<E> builder()

Deprecated. Use naturalOrder(), which offers better type-safety.

Not supported. Use naturalOrder(), which offers better type-safety, instead. This method exists only to hide ImmutableSet.builder() from consumers of ImmutableSortedSet.

Throws:

UnsupportedOperationException - always