Class ImmutableMultiset<E>

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  ImmutableMultiset.Builder<E>
      A builder for creating immutable multiset instances, especially public static final multisets ("constant multisets").
    • Method Summary

      All Methods Static Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      int add​(E element, int occurrences)
      Deprecated.
      Unsupported operation.
      ImmutableList<E> asList()
      Returns an ImmutableList containing the same elements, in the same order, as this collection.
      static <E> ImmutableMultiset.Builder<E> builder()
      Returns a new builder.
      boolean contains​(java.lang.Object object)
      Determines whether this multiset contains the specified element.
      static <E> ImmutableMultiset<E> copyOf​(E[] elements)
      Returns an immutable multiset containing the given elements, in the "grouped iteration order" described in the class documentation.
      static <E> ImmutableMultiset<E> copyOf​(java.lang.Iterable<? extends E> elements)
      Returns an immutable multiset containing the given elements, in the "grouped iteration order" described in the class documentation.
      static <E> ImmutableMultiset<E> copyOf​(java.util.Iterator<? extends E> elements)
      Returns an immutable multiset containing the given elements, in the "grouped iteration order" described in the class documentation.
      abstract ImmutableSet<E> elementSet()
      Returns the set of distinct elements contained in this multiset.
      ImmutableSet<Multiset.Entry<E>> entrySet()
      Returns a view of the contents of this multiset, grouped into Multiset.Entry instances, each providing an element of the multiset and the count of that element.
      boolean equals​(java.lang.Object object)
      Compares the specified object with this multiset for equality.
      int hashCode()
      Returns the hash code for this multiset.
      UnmodifiableIterator<E> iterator()
      Returns an unmodifiable iterator across the elements in this collection.
      static <E> ImmutableMultiset<E> of()
      Returns the empty immutable multiset.
      static <E> ImmutableMultiset<E> of​(E e1)
      Returns an immutable multiset containing a single element.
      static <E> ImmutableMultiset<E> of​(E e1, E e2)
      Returns an immutable multiset containing the given elements, in order.
      static <E> ImmutableMultiset<E> of​(E e1, E e2, E e3)
      Returns an immutable multiset containing the given elements, in the "grouped iteration order" described in the class documentation.
      static <E> ImmutableMultiset<E> of​(E e1, E e2, E e3, E e4)
      Returns an immutable multiset containing the given elements, in the "grouped iteration order" described in the class documentation.
      static <E> ImmutableMultiset<E> of​(E e1, E e2, E e3, E e4, E e5)
      Returns an immutable multiset containing the given elements, in the "grouped iteration order" described in the class documentation.
      static <E> ImmutableMultiset<E> of​(E e1, E e2, E e3, E e4, E e5, E e6, E... others)
      Returns an immutable multiset containing the given elements, in the "grouped iteration order" described in the class documentation.
      int remove​(java.lang.Object element, int occurrences)
      Deprecated.
      Unsupported operation.
      int setCount​(E element, int count)
      Deprecated.
      Unsupported operation.
      boolean setCount​(E element, int oldCount, int newCount)
      Deprecated.
      Unsupported operation.
      static <E> java.util.stream.Collector<E,​?,​ImmutableMultiset<E>> toImmutableMultiset()
      Returns a Collector that accumulates the input elements into a new ImmutableMultiset.
      static <T extends @Nullable java.lang.Object,​E>
      java.util.stream.Collector<T,​?,​ImmutableMultiset<E>>
      toImmutableMultiset​(java.util.function.Function<? super T,​? extends E> elementFunction, java.util.function.ToIntFunction<? super T> countFunction)
      Returns a Collector that accumulates elements into an ImmutableMultiset whose elements are the result of applying elementFunction to the inputs, with counts equal to the result of applying countFunction to the inputs.
      java.lang.String toString()
      • Methods inherited from class java.util.AbstractCollection

        containsAll, isEmpty, size
      • Methods inherited from class java.lang.Object

        clone, finalize, getClass, notify, notifyAll, wait, wait, wait
      • Methods inherited from interface java.util.Collection

        addAll, clear, isEmpty, parallelStream, removeIf, stream, toArray, toArray, toArray
    • Method Detail

      • toImmutableMultiset

        public static <E> java.util.stream.Collector<E,​?,​ImmutableMultiset<E>> toImmutableMultiset()
        Returns a Collector that accumulates the input elements into a new ImmutableMultiset. Elements iterate in order by the first appearance of that element in encounter order.
        Since:
        21.0
      • toImmutableMultiset

        public static <T extends @Nullable java.lang.Object,​E> java.util.stream.Collector<T,​?,​ImmutableMultiset<E>> toImmutableMultiset​(java.util.function.Function<? super T,​? extends E> elementFunction,
                                                                                                                                                          java.util.function.ToIntFunction<? super T> countFunction)
        Returns a Collector that accumulates elements into an ImmutableMultiset whose elements are the result of applying elementFunction to the inputs, with counts equal to the result of applying countFunction to the inputs.

        If the mapped elements contain duplicates (according to Object.equals(java.lang.Object)), the first occurrence in encounter order appears in the resulting multiset, with count equal to the sum of the outputs of countFunction.applyAsInt(t) for each t mapped to that element.

        Since:
        22.0
      • of

        public static <E> ImmutableMultiset<E> of()
        Returns the empty immutable multiset.

        Performance note: the instance returned is a singleton.

      • of

        public static <E> ImmutableMultiset<E> of​(E e1)
        Returns an immutable multiset containing a single element.
        Throws:
        java.lang.NullPointerException - if the element is null
        Since:
        6.0 (source-compatible since 2.0)
      • of

        public static <E> ImmutableMultiset<E> of​(E e1,
                                                  E e2)
        Returns an immutable multiset containing the given elements, in order.
        Throws:
        java.lang.NullPointerException - if any element is null
        Since:
        6.0 (source-compatible since 2.0)
      • of

        public static <E> ImmutableMultiset<E> of​(E e1,
                                                  E e2,
                                                  E e3)
        Returns an immutable multiset containing the given elements, in the "grouped iteration order" described in the class documentation.
        Throws:
        java.lang.NullPointerException - if any element is null
        Since:
        6.0 (source-compatible since 2.0)
      • of

        public static <E> ImmutableMultiset<E> of​(E e1,
                                                  E e2,
                                                  E e3,
                                                  E e4)
        Returns an immutable multiset containing the given elements, in the "grouped iteration order" described in the class documentation.
        Throws:
        java.lang.NullPointerException - if any element is null
        Since:
        6.0 (source-compatible since 2.0)
      • of

        public static <E> ImmutableMultiset<E> of​(E e1,
                                                  E e2,
                                                  E e3,
                                                  E e4,
                                                  E e5)
        Returns an immutable multiset containing the given elements, in the "grouped iteration order" described in the class documentation.
        Throws:
        java.lang.NullPointerException - if any element is null
        Since:
        6.0 (source-compatible since 2.0)
      • of

        public static <E> ImmutableMultiset<E> of​(E e1,
                                                  E e2,
                                                  E e3,
                                                  E e4,
                                                  E e5,
                                                  E e6,
                                                  E... others)
        Returns an immutable multiset containing the given elements, in the "grouped iteration order" described in the class documentation.
        Throws:
        java.lang.NullPointerException - if any element is null
        Since:
        6.0 (source-compatible since 2.0)
      • copyOf

        public static <E> ImmutableMultiset<E> copyOf​(E[] elements)
        Returns an immutable multiset containing the given elements, in the "grouped iteration order" described in the class documentation.
        Throws:
        java.lang.NullPointerException - if any of elements is null
        Since:
        6.0
      • copyOf

        public static <E> ImmutableMultiset<E> copyOf​(java.lang.Iterable<? extends E> elements)
        Returns an immutable multiset containing the given elements, in the "grouped iteration order" described in the class documentation.
        Throws:
        java.lang.NullPointerException - if any of elements is null
      • copyOf

        public static <E> ImmutableMultiset<E> copyOf​(java.util.Iterator<? extends E> elements)
        Returns an immutable multiset containing the given elements, in the "grouped iteration order" described in the class documentation.
        Throws:
        java.lang.NullPointerException - if any of elements is null
      • asList

        public ImmutableList<EasList()
        Description copied from class: ImmutableCollection
        Returns an ImmutableList containing the same elements, in the same order, as this collection.

        Performance note: in most cases this method can return quickly without actually copying anything. The exact circumstances under which the copy is performed are undefined and subject to change.

        Overrides:
        asList in class ImmutableCollection<E>
      • contains

        public boolean contains​(@CheckForNull
                                java.lang.Object object)
        Description copied from interface: Multiset
        Determines whether this multiset contains the specified element.

        This method refines Collection.contains(java.lang.Object) to further specify that it may not throw an exception in response to element being null or of the wrong type.

        Specified by:
        contains in interface java.util.Collection<E>
        Specified by:
        contains in interface Multiset<E>
        Specified by:
        contains in class ImmutableCollection<E>
        Parameters:
        object - the element to check for
        Returns:
        true if this multiset contains at least one occurrence of the element
      • add

        @CanIgnoreReturnValue
        @Deprecated
        public final int add​(E element,
                             int occurrences)
        Deprecated.
        Unsupported operation.
        Guaranteed to throw an exception and leave the collection unmodified.
        Specified by:
        add in interface Multiset<E>
        Parameters:
        element - the element to add occurrences of; may be null only if explicitly allowed by the implementation
        occurrences - 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
        Throws:
        java.lang.UnsupportedOperationException - always
      • remove

        @CanIgnoreReturnValue
        @Deprecated
        public final int remove​(@CheckForNull
                                java.lang.Object element,
                                int occurrences)
        Deprecated.
        Unsupported operation.
        Guaranteed to throw an exception and leave the collection unmodified.
        Specified by:
        remove in interface Multiset<E>
        Parameters:
        element - the element to conditionally remove occurrences of
        occurrences - 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
        Throws:
        java.lang.UnsupportedOperationException - always
      • setCount

        @CanIgnoreReturnValue
        @Deprecated
        public final int setCount​(E element,
                                  int count)
        Deprecated.
        Unsupported operation.
        Guaranteed to throw an exception and leave the collection unmodified.
        Specified by:
        setCount in interface Multiset<E>
        Parameters:
        element - the element to add or remove occurrences of; may be null only if explicitly allowed by the implementation
        count - the desired count of the element in this multiset
        Returns:
        the count of the element before the operation; possibly zero
        Throws:
        java.lang.UnsupportedOperationException - always
      • setCount

        @CanIgnoreReturnValue
        @Deprecated
        public final boolean setCount​(E element,
                                      int oldCount,
                                      int newCount)
        Deprecated.
        Unsupported operation.
        Guaranteed to throw an exception and leave the collection unmodified.
        Specified by:
        setCount in interface Multiset<E>
        Parameters:
        element - the element to conditionally set the count of; may be null only if explicitly allowed by the implementation
        oldCount - the expected present count of the element in this multiset
        newCount - the desired count of the element in this multiset
        Returns:
        true if the condition for modification was met. This implies that the multiset was indeed modified, unless oldCount == newCount.
        Throws:
        java.lang.UnsupportedOperationException - always
      • equals

        public boolean equals​(@CheckForNull
                              java.lang.Object object)
        Description copied from interface: Multiset
        Compares the specified object with this multiset for equality. Returns true if the given object is also a multiset and contains equal elements with equal counts, regardless of order.
        Specified by:
        equals in interface java.util.Collection<E>
        Specified by:
        equals in interface Multiset<E>
        Overrides:
        equals in class java.lang.Object
      • hashCode

        public int hashCode()
        Description copied from interface: Multiset
        Returns the hash code for this multiset. This is defined as the sum of
        
         ((element == null) ? 0 : element.hashCode()) ^ count(element)
         

        over all distinct elements in the multiset. It follows that a multiset and its entry set always have the same hash code.

        Specified by:
        hashCode in interface java.util.Collection<E>
        Specified by:
        hashCode in interface Multiset<E>
        Overrides:
        hashCode in class java.lang.Object
      • toString

        public java.lang.String toString()
        Description copied from interface: Multiset

        It is recommended, though not mandatory, that this method return the result of invoking Multiset.toString() on the Multiset.entrySet(), yielding a result such as [a x 3, c, d x 2, e].

        Specified by:
        toString in interface Multiset<E>
        Overrides:
        toString in class java.util.AbstractCollection<E>
      • elementSet

        public abstract ImmutableSet<EelementSet()
        Description copied from interface: Multiset
        Returns the set of distinct elements contained in this multiset. The element set is backed by the same data as the multiset, so any change to either is immediately reflected in the other. The order of the elements in the element set is unspecified.

        If the element set supports any removal operations, these necessarily cause all occurrences of the removed element(s) to be removed from the multiset. Implementations are not expected to support the add operations, although this is possible.

        A common use for the element set is to find the number of distinct elements in the multiset: elementSet().size().

        Specified by:
        elementSet in interface Multiset<E>
        Returns:
        a view of the set of distinct elements in this multiset
        Since:
        21.0 (present with return type Set since 2.0)
      • entrySet

        public ImmutableSet<Multiset.Entry<E>> entrySet()
        Description copied from interface: Multiset
        Returns a view of the contents of this multiset, grouped into Multiset.Entry instances, each providing an element of the multiset and the count of that element. This set contains exactly one entry for each distinct element in the multiset (thus it always has the same size as the Multiset.elementSet()). The order of the elements in the element set is unspecified.

        The entry set is backed by the same data as the multiset, so any change to either is immediately reflected in the other. However, multiset changes may or may not be reflected in any Entry instances already retrieved from the entry set (this is implementation-dependent). Furthermore, implementations are not required to support modifications to the entry set at all, and the Entry instances themselves don't even have methods for modification. See the specific implementation class for more details on how its entry set handles modifications.

        Specified by:
        entrySet in interface Multiset<E>
        Returns:
        a set of entries representing the data of this multiset