Package it.unimi.dsi.fastutil.objects

Interface ReferenceSet<K>

All Superinterfaces:
Collection<K>, Iterable<K>, ObjectIterable<K>, ReferenceCollection<K>, Set<K>
All Known Subinterfaces:
ReferenceSortedSet<K>
All Known Implementing Classes:
AbstractReferenceSet, AbstractReferenceSortedSet, ReferenceArraySet, ReferenceLinkedOpenHashSet, ReferenceOpenHashBigSet, ReferenceOpenHashSet, ReferenceSets.EmptySet, ReferenceSets.Singleton, ReferenceSets.SynchronizedSet, ReferenceSets.UnmodifiableSet, ReferenceSortedSets.EmptySet, ReferenceSortedSets.Singleton, ReferenceSortedSets.SynchronizedSortedSet, ReferenceSortedSets.UnmodifiableSortedSet
public interface ReferenceSet<K> extends ReferenceCollection<K>, Set<K>
A type-specific Set; provides some additional methods that use polymorphism to avoid (un)boxing.

Additionally, this interface strengthens (again) iterator().

This interface specifies reference equality semantics (members will be compared equal with == instead of equals), which may result in breaks in contract if attempted to be used with non reference-equality semantics based Sets. For example, a aReferenceSet.equals(aObjectSet) may return different a different result then aObjectSet.equals(aReferenceSet), in violation of equals's contract requiring it being symmetric.

See Also:

  • Method Details

    • iterator

      ObjectIterator<K> iterator()
      Returns a type-specific iterator on the elements of this set.
      Specified by:
      iterator in interface Collection<K>
      Specified by:
      iterator in interface Iterable<K>
      Specified by:
      iterator in interface ObjectIterable<K>
      Specified by:
      iterator in interface ReferenceCollection<K>
      Specified by:
      iterator in interface Set<K>
      Returns:
      a type-specific iterator on the elements of this set.
      See Also:
      API Notes:
      This specification strengthens the one given in Iterable.iterator(), which was already strengthened in the corresponding type-specific class, but was weakened by the fact that this interface extends Set.

      Also, this is generally the only iterator method subclasses should override.

    • spliterator

      default ObjectSpliterator<K> spliterator()
      Returns a type-specific spliterator on the elements of this set.

      Set spliterators must report at least Spliterator.DISTINCT.

      See Set.spliterator() for more documentation on the requirements of the returned spliterator.

      Specified by:
      spliterator in interface Collection<K>
      Specified by:
      spliterator in interface Iterable<K>
      Specified by:
      spliterator in interface ObjectIterable<K>
      Specified by:
      spliterator in interface ReferenceCollection<K>
      Specified by:
      spliterator in interface Set<K>
      Returns:
      a type-specific spliterator on the elements of this collection.
      Since:
      8.5.0
      API Notes:
      This specification strengthens the one given in Collection.spliterator(), which was already strengthened in the corresponding type-specific class, but was weakened by the fact that this interface extends Set.

      Also, this is generally the only spliterator method subclasses should override.

      Implementation Specification:
      The default implementation returns a late-binding spliterator (see Spliterator for documentation on what binding policies mean) that wraps this instance's type specific iterator().

      Additionally, it reports Spliterator.SIZED and Spliterator.DISTINCT.

      Implementation Notes:
      As this default implementation wraps the iterator, and Iterator is an inherently linear API, the returned spliterator will yield limited performance gains when run in parallel contexts, as the returned spliterator's trySplit() will have linear runtime.

    • of

      static <K> ReferenceSet<K> of()
      Returns an immutable empty set.
      Returns:
      an immutable empty set.

    • of

      static <K> ReferenceSet<K> of(K e)
      Returns an immutable set with the element given.
      Parameters:
      e - an element.
      Returns:
      an immutable set containing e.

    • of

      static <K> ReferenceSet<K> of(K e0, K e1)
      Returns an immutable set with the elements given.
      Parameters:
      e0 - the first element.
      e1 - the second element.
      Returns:
      an immutable set containing e0 and e1.
      Throws:
      IllegalArgumentException - if there were duplicate entries.

    • of

      static <K> ReferenceSet<K> of(K e0, K e1, K e2)
      Returns an immutable set with the elements given.
      Parameters:
      e0 - the first element.
      e1 - the second element.
      e2 - the third element.
      Returns:
      an immutable set containing e0, e1, and e2.
      Throws:
      IllegalArgumentException - if there were duplicate entries.

    • of

      @SafeVarargs static <K> ReferenceSet<K> of(K... a)
      Returns an immutable list with the elements given.
      Parameters:
      a - the list of elements that will be in the final set.
      Returns:
      an immutable set containing the elements in a.
      Throws:
      IllegalArgumentException - if there are any duplicate entries.