Package com.google.common.collect
Class EnumMultiset<E extends java.lang.Enum<E>>
- java.lang.Object
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- java.util.AbstractCollection<E>
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- com.google.common.collect.AbstractMultiset<E>
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- com.google.common.collect.EnumMultiset<E>
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- All Implemented Interfaces:
Multiset<E>
,java.io.Serializable
,java.lang.Iterable<E>
,java.util.Collection<E>
@GwtCompatible(emulated=true) public final class EnumMultiset<E extends java.lang.Enum<E>> extends AbstractMultiset<E> implements java.io.Serializable
Multiset implementation specialized for enum elements, supporting all single-element operations in O(1).See the Guava User Guide article on
Multiset
.- Since:
- 2.0
- See Also:
- Serialized Form
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Nested Class Summary
Nested Classes Modifier and Type Class Description (package private) class
EnumMultiset.Itr<T>
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Nested classes/interfaces inherited from class com.google.common.collect.AbstractMultiset
AbstractMultiset.ElementSet, AbstractMultiset.EntrySet
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Nested classes/interfaces inherited from interface com.google.common.collect.Multiset
Multiset.Entry<E>
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Field Summary
Fields Modifier and Type Field Description private int[]
counts
private int
distinctElements
private E[]
enumConstants
private static long
serialVersionUID
private long
size
private java.lang.Class<E>
type
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Constructor Summary
Constructors Modifier Constructor Description private
EnumMultiset(java.lang.Class<E> type)
Creates an emptyEnumMultiset
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description int
add(E element, int occurrences)
Adds a number of occurrences of an element to this multiset.(package private) void
checkIsE(java.lang.Object element)
Returnselement
cast toE
, if it actually is a nonnull E.void
clear()
int
count(java.lang.Object element)
Returns the number of occurrences of an element in this multiset (the count of the element).static <E extends java.lang.Enum<E>>
EnumMultiset<E>create(java.lang.Class<E> type)
Creates an emptyEnumMultiset
.static <E extends java.lang.Enum<E>>
EnumMultiset<E>create(java.lang.Iterable<E> elements)
Creates a newEnumMultiset
containing the specified elements.static <E extends java.lang.Enum<E>>
EnumMultiset<E>create(java.lang.Iterable<E> elements, java.lang.Class<E> type)
Returns a newEnumMultiset
instance containing the given elements.(package private) int
distinctElements()
(package private) java.util.Iterator<E>
elementIterator()
(package private) java.util.Iterator<Multiset.Entry<E>>
entryIterator()
void
forEachEntry(java.util.function.ObjIntConsumer<? super E> action)
Runs the specified action for each distinct element in this multiset, and the number of occurrences of that element.private boolean
isActuallyE(java.lang.Object o)
java.util.Iterator<E>
iterator()
private void
readObject(java.io.ObjectInputStream stream)
int
remove(java.lang.Object element, int occurrences)
Removes a number of occurrences of the specified element from this multiset.int
setCount(E element, int count)
Adds or removes the necessary occurrences of an element such that the element attains the desired count.int
size()
Returns the total number of all occurrences of all elements in this multiset.private void
writeObject(java.io.ObjectOutputStream stream)
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Methods inherited from class com.google.common.collect.AbstractMultiset
add, addAll, contains, createElementSet, createEntrySet, elementSet, entrySet, equals, hashCode, isEmpty, remove, removeAll, retainAll, setCount, toString
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Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
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Methods inherited from interface java.util.Collection
parallelStream, removeIf, stream, toArray, toArray, toArray
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Methods inherited from interface com.google.common.collect.Multiset
containsAll, forEach, spliterator
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Field Detail
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counts
private transient int[] counts
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distinctElements
private transient int distinctElements
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size
private transient long size
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serialVersionUID
@GwtIncompatible private static final long serialVersionUID
- See Also:
- Constant Field Values
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Constructor Detail
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EnumMultiset
private EnumMultiset(java.lang.Class<E> type)
Creates an emptyEnumMultiset
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Method Detail
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create
public static <E extends java.lang.Enum<E>> EnumMultiset<E> create(java.lang.Class<E> type)
Creates an emptyEnumMultiset
.
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create
public static <E extends java.lang.Enum<E>> EnumMultiset<E> create(java.lang.Iterable<E> elements)
Creates a newEnumMultiset
containing the specified elements.This implementation is highly efficient when
elements
is itself aMultiset
.- Parameters:
elements
- the elements that the multiset should contain- Throws:
java.lang.IllegalArgumentException
- ifelements
is empty
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create
public static <E extends java.lang.Enum<E>> EnumMultiset<E> create(java.lang.Iterable<E> elements, java.lang.Class<E> type)
Returns a newEnumMultiset
instance containing the given elements. Unlikecreate(Iterable)
, this method does not produce an exception on an empty iterable.- Since:
- 14.0
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isActuallyE
private boolean isActuallyE(java.lang.Object o)
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checkIsE
void checkIsE(java.lang.Object element)
Returnselement
cast toE
, if it actually is a nonnull E. Otherwise, throws either a NullPointerException or a ClassCastException as appropriate.
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distinctElements
int distinctElements()
- Specified by:
distinctElements
in classAbstractMultiset<E extends java.lang.Enum<E>>
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size
public int size()
Description copied from interface:Multiset
Returns the total number of all occurrences of all elements in this multiset.Note: this method does not return the number of distinct elements in the multiset, which is given by
entrySet().size()
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count
public int count(java.lang.Object element)
Description copied from interface:Multiset
Returns the number of occurrences of an element in this multiset (the count of the element). Note that for anObject.equals(java.lang.Object)
-based multiset, this gives the same result asCollections.frequency(java.util.Collection<?>, java.lang.Object)
(which would presumably perform more poorly).Note: the utility method
Iterables.frequency(java.lang.Iterable<?>, java.lang.Object)
generalizes this operation; it correctly delegates to this method when dealing with a multiset, but it can also accept any other iterable type.
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add
public int add(E element, int occurrences)
Description copied from interface:Multiset
Adds a number of occurrences of an element to this multiset. Note that ifoccurrences == 1
, this method has the identical effect toMultiset.add(Object)
. This method is functionally equivalent (except in the case of overflow) to the calladdAll(Collections.nCopies(element, occurrences))
, which would presumably perform much more poorly.- Specified by:
add
in interfaceMultiset<E extends java.lang.Enum<E>>
- Overrides:
add
in classAbstractMultiset<E extends java.lang.Enum<E>>
- Parameters:
element
- the element to add occurrences of; may be null only if explicitly allowed by the implementationoccurrences
- the number of occurrences of the element to add. May be zero, in which case no change will be made.- Returns:
- the count of the element before the operation; possibly zero
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remove
public int remove(java.lang.Object element, int occurrences)
Description copied from interface:Multiset
Removes a number of occurrences of the specified element from this multiset. If the multiset contains fewer than this number of occurrences to begin with, all occurrences will be removed. Note that ifoccurrences == 1
, this is functionally equivalent to the callremove(element)
.- Specified by:
remove
in interfaceMultiset<E extends java.lang.Enum<E>>
- Overrides:
remove
in classAbstractMultiset<E extends java.lang.Enum<E>>
- Parameters:
element
- the element to conditionally remove occurrences ofoccurrences
- the number of occurrences of the element to remove. May be zero, in which case no change will be made.- Returns:
- the count of the element before the operation; possibly zero
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setCount
public int setCount(E element, int count)
Description copied from interface:Multiset
Adds or removes the necessary occurrences of an element such that the element attains the desired count.- Specified by:
setCount
in interfaceMultiset<E extends java.lang.Enum<E>>
- Overrides:
setCount
in classAbstractMultiset<E extends java.lang.Enum<E>>
- Parameters:
element
- the element to add or remove occurrences of; may be null only if explicitly allowed by the implementationcount
- the desired count of the element in this multiset- Returns:
- the count of the element before the operation; possibly zero
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clear
public void clear()
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elementIterator
java.util.Iterator<E> elementIterator()
- Specified by:
elementIterator
in classAbstractMultiset<E extends java.lang.Enum<E>>
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entryIterator
java.util.Iterator<Multiset.Entry<E>> entryIterator()
- Specified by:
entryIterator
in classAbstractMultiset<E extends java.lang.Enum<E>>
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forEachEntry
public void forEachEntry(java.util.function.ObjIntConsumer<? super E> action)
Description copied from interface:Multiset
Runs the specified action for each distinct element in this multiset, and the number of occurrences of that element. For someMultiset
implementations, this may be more efficient than iterating over theMultiset.entrySet()
either explicitly or withentrySet().forEach(action)
.- Specified by:
forEachEntry
in interfaceMultiset<E extends java.lang.Enum<E>>
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iterator
public java.util.Iterator<E> iterator()
Description copied from interface:Multiset
Elements that occur multiple times in the multiset will appear multiple times in this iterator, though not necessarily sequentially.
- Specified by:
iterator
in interfacejava.util.Collection<E extends java.lang.Enum<E>>
- Specified by:
iterator
in interfacejava.lang.Iterable<E extends java.lang.Enum<E>>
- Specified by:
iterator
in interfaceMultiset<E extends java.lang.Enum<E>>
- Specified by:
iterator
in classjava.util.AbstractCollection<E extends java.lang.Enum<E>>
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writeObject
@GwtIncompatible private void writeObject(java.io.ObjectOutputStream stream) throws java.io.IOException
- Throws:
java.io.IOException
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readObject
@GwtIncompatible private void readObject(java.io.ObjectInputStream stream) throws java.io.IOException, java.lang.ClassNotFoundException
- Throws:
java.io.IOException
java.lang.ClassNotFoundException
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