Class ImmutableSet<E>

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  ImmutableSet.Builder<E>
      A builder for creating ImmutableSet instances.
    • Method Summary

      All Methods Static Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      ImmutableList<E> asList()
      Returns an ImmutableList containing the same elements, in the same order, as this collection.
      static <E> ImmutableSet.Builder<E> builder()
      Returns a new builder.
      static <E> ImmutableSet.Builder<E> builderWithExpectedSize​(int expectedSize)
      Returns a new builder, expecting the specified number of distinct elements to be added.
      static <E> ImmutableSet<E> copyOf​(E[] elements)
      Returns an immutable set containing each of elements, minus duplicates, in the order each appears first in the source array.
      static <E> ImmutableSet<E> copyOf​(java.lang.Iterable<? extends E> elements)
      Returns an immutable set containing each of elements, minus duplicates, in the order each appears first in the source iterable.
      static <E> ImmutableSet<E> copyOf​(java.util.Collection<? extends E> elements)
      Returns an immutable set containing each of elements, minus duplicates, in the order each appears first in the source collection.
      static <E> ImmutableSet<E> copyOf​(java.util.Iterator<? extends E> elements)
      Returns an immutable set containing each of elements, minus duplicates, in the order each appears first in the source iterator.
      boolean equals​(java.lang.Object object)  
      int hashCode()  
      abstract UnmodifiableIterator<E> iterator()
      Returns an unmodifiable iterator across the elements in this collection.
      static <E> ImmutableSet<E> of()
      Returns the empty immutable set.
      static <E> ImmutableSet<E> of​(E element)
      Returns an immutable set containing element.
      static <E> ImmutableSet<E> of​(E e1, E e2)
      Returns an immutable set containing the given elements, minus duplicates, in the order each was first specified.
      static <E> ImmutableSet<E> of​(E e1, E e2, E e3)
      Returns an immutable set containing the given elements, minus duplicates, in the order each was first specified.
      static <E> ImmutableSet<E> of​(E e1, E e2, E e3, E e4)
      Returns an immutable set containing the given elements, minus duplicates, in the order each was first specified.
      static <E> ImmutableSet<E> of​(E e1, E e2, E e3, E e4, E e5)
      Returns an immutable set containing the given elements, minus duplicates, in the order each was first specified.
      static <E> ImmutableSet<E> of​(E e1, E e2, E e3, E e4, E e5, E e6, E... others)
      Returns an immutable set containing the given elements, minus duplicates, in the order each was first specified.
      • Methods inherited from class java.util.AbstractCollection

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

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

        parallelStream, removeIf, stream, toArray
      • Methods inherited from interface java.lang.Iterable

        forEach
      • Methods inherited from interface java.util.Set

        add, addAll, clear, contains, containsAll, isEmpty, remove, removeAll, retainAll, size, spliterator, toArray, toArray
    • Method Detail

      • of

        public static <E> ImmutableSet<E> of()
        Returns the empty immutable set. Preferred over Collections.emptySet() for code consistency, and because the return type conveys the immutability guarantee.

        Performance note: the instance returned is a singleton.

      • of

        public static <E> ImmutableSet<E> of​(E element)
        Returns an immutable set containing element. Preferred over Collections.singleton(T) for code consistency, null rejection, and because the return type conveys the immutability guarantee.
      • of

        public static <E> ImmutableSet<E> of​(E e1,
                                             E e2)
        Returns an immutable set containing the given elements, minus duplicates, in the order each was first specified. That is, if multiple elements are equal, all except the first are ignored.
      • of

        public static <E> ImmutableSet<E> of​(E e1,
                                             E e2,
                                             E e3)
        Returns an immutable set containing the given elements, minus duplicates, in the order each was first specified. That is, if multiple elements are equal, all except the first are ignored.
      • of

        public static <E> ImmutableSet<E> of​(E e1,
                                             E e2,
                                             E e3,
                                             E e4)
        Returns an immutable set containing the given elements, minus duplicates, in the order each was first specified. That is, if multiple elements are equal, all except the first are ignored.
      • of

        public static <E> ImmutableSet<E> of​(E e1,
                                             E e2,
                                             E e3,
                                             E e4,
                                             E e5)
        Returns an immutable set containing the given elements, minus duplicates, in the order each was first specified. That is, if multiple elements are equal, all except the first are ignored.
      • of

        @SafeVarargs
        public static <E> ImmutableSet<E> of​(E e1,
                                             E e2,
                                             E e3,
                                             E e4,
                                             E e5,
                                             E e6,
                                             E... others)
        Returns an immutable set containing the given elements, minus duplicates, in the order each was first specified. That is, if multiple elements are equal, all except the first are ignored.

        The array others must not be longer than Integer.MAX_VALUE - 6.

        Since:
        3.0 (source-compatible since 2.0)
      • copyOf

        public static <E> ImmutableSet<E> copyOf​(java.util.Collection<? extends E> elements)
        Returns an immutable set containing each of elements, minus duplicates, in the order each appears first in the source collection.

        Performance note: This method will sometimes recognize that the actual copy operation is unnecessary; for example, copyOf(copyOf(anArrayList)) will copy the data only once. This reduces the expense of habitually making defensive copies at API boundaries. However, the precise conditions for skipping the copy operation are undefined.

        Throws:
        java.lang.NullPointerException - if any of elements is null
        Since:
        7.0 (source-compatible since 2.0)
      • copyOf

        public static <E> ImmutableSet<E> copyOf​(java.lang.Iterable<? extends E> elements)
        Returns an immutable set containing each of elements, minus duplicates, in the order each appears first in the source iterable. This method iterates over elements only once.

        Performance note: This method will sometimes recognize that the actual copy operation is unnecessary; for example, copyOf(copyOf(anArrayList)) should copy the data only once. This reduces the expense of habitually making defensive copies at API boundaries. However, the precise conditions for skipping the copy operation are undefined.

        Throws:
        java.lang.NullPointerException - if any of elements is null
      • copyOf

        public static <E> ImmutableSet<E> copyOf​(java.util.Iterator<? extends E> elements)
        Returns an immutable set containing each of elements, minus duplicates, in the order each appears first in the source iterator.
        Throws:
        java.lang.NullPointerException - if any of elements is null
      • copyOf

        public static <E> ImmutableSet<E> copyOf​(E[] elements)
        Returns an immutable set containing each of elements, minus duplicates, in the order each appears first in the source array.
        Throws:
        java.lang.NullPointerException - if any of elements is null
        Since:
        3.0
      • equals

        public boolean equals​(@CheckForNull
                              java.lang.Object object)
        Specified by:
        equals in interface java.util.Collection<E>
        Specified by:
        equals in interface java.util.Set<E>
        Overrides:
        equals in class java.lang.Object
      • hashCode

        public int hashCode()
        Specified by:
        hashCode in interface java.util.Collection<E>
        Specified by:
        hashCode in interface java.util.Set<E>
        Overrides:
        hashCode in class java.lang.Object
      • iterator

        public abstract UnmodifiableIterator<Eiterator()
        Description copied from class: ImmutableCollection
        Returns an unmodifiable iterator across the elements in this collection.
        Specified by:
        iterator in interface java.util.Collection<E>
        Specified by:
        iterator in interface java.lang.Iterable<E>
        Specified by:
        iterator in interface java.util.Set<E>
        Specified by:
        iterator in class ImmutableCollection<E>
      • 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>
      • builderWithExpectedSize

        @Beta
        public static <E> ImmutableSet.Builder<E> builderWithExpectedSize​(int expectedSize)
        Returns a new builder, expecting the specified number of distinct elements to be added.

        If expectedSize is exactly the number of distinct elements added to the builder before ImmutableSet.Builder.build() is called, the builder is likely to perform better than an unsized builder() would have.

        It is not specified if any performance benefits apply if expectedSize is close to, but not exactly, the number of distinct elements added to the builder.

        Since:
        23.1