Package it.unimi.dsi.fastutil.ints

Interface IntCollection

All Superinterfaces:
Collection<Integer>, IntIterable, Iterable<Integer>
All Known Subinterfaces:
IntBigList, IntList, IntSet, IntSortedSet
All Known Implementing Classes:
AbstractIntBigList, AbstractIntBigList.IntRandomAccessSubList, AbstractIntBigList.IntSubList, AbstractIntCollection, AbstractIntList, AbstractIntList.IntRandomAccessSubList, AbstractIntList.IntSubList, AbstractIntSet, AbstractIntSortedSet, IntArrayList, IntArraySet, IntAVLTreeSet, IntBigArrayBigList, IntBigLists.EmptyBigList, IntBigLists.ListBigList, IntBigLists.Singleton, IntBigLists.SynchronizedBigList, IntBigLists.UnmodifiableBigList, IntCollections.EmptyCollection, IntCollections.IterableCollection, IntImmutableList, IntLinkedOpenCustomHashSet, IntLinkedOpenHashSet, IntLists.EmptyList, IntLists.Singleton, IntLists.SynchronizedList, IntLists.SynchronizedRandomAccessList, IntLists.UnmodifiableList, IntLists.UnmodifiableRandomAccessList, IntMappedBigList, IntOpenCustomHashSet, IntOpenHashBigSet, IntOpenHashSet, IntRBTreeSet, IntSets.EmptySet, IntSets.Singleton, IntSets.SynchronizedSet, IntSets.UnmodifiableSet, IntSortedSets.EmptySet, IntSortedSets.Singleton, IntSortedSets.SynchronizedSortedSet, IntSortedSets.UnmodifiableSortedSet
public interface IntCollection extends Collection<Integer>, IntIterable
A type-specific Collection; provides some additional methods that use polymorphism to avoid (un)boxing.

Additionally, this class defines 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 Collections. For example, a aReferenceCollection.equals(aObjectCollection) may return different a different result then aObjectCollection.equals(aReferenceCollection), in violation of equals's contract requiring it being symmetric.

See Also:

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    add(int key)
    Ensures that this collection contains the specified element (optional operation).
    default boolean
    add(Integer key)
    Deprecated.
    Please use the corresponding type-specific method instead.
    boolean
    addAll(IntCollection c)
    Adds all elements of the given type-specific collection to this collection.
    boolean
    contains(int key)
    Returns true if this collection contains the specified element.
    default boolean
    contains(Object key)
    Deprecated.
    Please use the corresponding type-specific method instead.
    boolean
    containsAll(IntCollection c)
    Checks whether this collection contains all elements from the given type-specific collection.
    default IntIterator
    intIterator()
    Returns a primitive iterator on the elements of this collection.
    default IntStream
    intParallelStream()
    Return a parallel primitive stream over the elements, performing widening casts if needed.
    default IntSpliterator
    intSpliterator()
    Returns a primitive spliterator on the elements of this collection.
    default IntStream
    intStream()
    Return a primitive stream over the elements, performing widening casts if needed.
    IntIterator
    iterator()
    Returns a type-specific iterator on the elements of this collection.
    default Stream<Integer>
    parallelStream()
    Deprecated.
    Please use the corresponding type-specific method instead.
    boolean
    rem(int key)
    Removes a single instance of the specified element from this collection, if it is present (optional operation).
    default boolean
    remove(Object key)
    Deprecated.
    Please use (and implement) the rem() method instead.
    boolean
    removeAll(IntCollection c)
    Remove from this collection all elements in the given type-specific collection.
    default boolean
    removeIf(IntPredicate filter)
    Remove from this collection all elements which satisfy the given predicate.
    default boolean
    removeIf(IntPredicate filter)
    Remove from this collection all elements which satisfy the given predicate.
    default boolean
    removeIf(Predicate<? super Integer> filter)
    Deprecated.
    Please use the corresponding type-specific method instead.
    boolean
    retainAll(IntCollection c)
    Retains in this collection only elements from the given type-specific collection.
    default IntSpliterator
    spliterator()
    Returns a type-specific spliterator on the elements of this collection.
    default Stream<Integer>
    stream()
    Deprecated.
    Please use the corresponding type-specific method instead.
    int[]
    toArray(int[] a)
    Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array.
    int[]
    toIntArray()
    Returns a primitive type array containing the items of this collection.
    default int[]
    toIntArray(int[] a)
    Deprecated.
    Please use toArray() instead—this method is redundant and will be removed in the future.

    Methods inherited from interface java.util.Collection

    addAll, clear, containsAll, equals, hashCode, isEmpty, removeAll, retainAll, size, toArray, toArray, toArray

    Methods inherited from interface it.unimi.dsi.fastutil.ints.IntIterable

    forEach, forEach, forEach

  • Method Details

    • iterator

      IntIterator iterator()
      Returns a type-specific iterator on the elements of this collection.
      Specified by:
      iterator in interface Collection<Integer>
      Specified by:
      iterator in interface IntIterable
      Specified by:
      iterator in interface Iterable<Integer>
      Returns:
      a type-specific iterator on the elements of this collection.
      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 Collection.

    • intIterator

      default IntIterator intIterator()
      Returns a primitive iterator on the elements of this collection.

      This method is identical to iterator(), as the type-specific iterator is already compatible with the JDK's primitive iterators. It only exists for compatibility with the other primitive types' Collections that have use for widened iterators.

      Specified by:
      intIterator in interface IntIterable
      Returns:
      a primitive iterator on the elements of this collection.
      Since:
      8.5.0

    • spliterator

      default IntSpliterator spliterator()
      Returns a type-specific spliterator on the elements of this collection.

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

      Specified by:
      spliterator in interface Collection<Integer>
      Specified by:
      spliterator in interface IntIterable
      Specified by:
      spliterator in interface Iterable<Integer>
      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().

      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

      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.

    • intSpliterator

      default IntSpliterator intSpliterator()
      Returns a primitive spliterator on the elements of this collection.

      This method is identical to spliterator(), as the type-specific spliterator is already compatible with the JDK's primitive spliterators. It only exists for compatibility with the other primitive types' Collections that have use for widened spliterators.

      Specified by:
      intSpliterator in interface IntIterable
      Returns:
      a primitive spliterator on the elements of this collection.
      Since:
      8.5.0

    • add

      boolean add(int key)
      Ensures that this collection contains the specified element (optional operation).
      See Also:

    • contains

      boolean contains(int key)
      Returns true if this collection contains the specified element.
      See Also:

    • rem

      boolean rem(int key)
      Removes a single instance of the specified element from this collection, if it is present (optional operation).

      Note that this method should be called remove(), but the clash with the similarly named index-based method in the List interface forces us to use a distinguished name. For simplicity, the set interfaces reinstates remove().

      See Also:

    • add

      @Deprecated default boolean add(Integer key)
      Deprecated.
      Please use the corresponding type-specific method instead.
      Specified by:
      add in interface Collection<Integer>

    • contains

      @Deprecated default boolean contains(Object key)
      Deprecated.
      Please use the corresponding type-specific method instead.
      Specified by:
      contains in interface Collection<Integer>

    • remove

      @Deprecated default boolean remove(Object key)
      Deprecated.
      Please use (and implement) the rem() method instead.
      Specified by:
      remove in interface Collection<Integer>

    • toIntArray

      int[] toIntArray()
      Returns a primitive type array containing the items of this collection.
      Returns:
      a primitive type array containing the items of this collection.
      See Also:

    • toIntArray

      @Deprecated default int[] toIntArray(int[] a)
      Deprecated.
      Please use toArray() instead—this method is redundant and will be removed in the future.
      Returns a primitive type array containing the items of this collection.

      Note that, contrarily to Collection.toArray(Object[]), this methods just writes all elements of this collection: no special value will be added after the last one.

      Parameters:
      a - if this array is big enough, it will be used to store this collection.
      Returns:
      a primitive type array containing the items of this collection.
      See Also:

    • toArray

      int[] toArray(int[] a)
      Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array.

      Note that, contrarily to Collection.toArray(Object[]), this methods just writes all elements of this collection: no special value will be added after the last one.

      Parameters:
      a - if this array is big enough, it will be used to store this collection.
      Returns:
      a primitive type array containing the items of this collection.
      See Also:

    • addAll

      boolean addAll(IntCollection c)
      Adds all elements of the given type-specific collection to this collection.
      Parameters:
      c - a type-specific collection.
      Returns:
      true if this collection changed as a result of the call.
      See Also:

    • containsAll

      boolean containsAll(IntCollection c)
      Checks whether this collection contains all elements from the given type-specific collection.
      Parameters:
      c - a type-specific collection.
      Returns:
      true if this collection contains all elements of the argument.
      See Also:

    • removeAll

      boolean removeAll(IntCollection c)
      Remove from this collection all elements in the given type-specific collection.
      Parameters:
      c - a type-specific collection.
      Returns:
      true if this collection changed as a result of the call.
      See Also:

    • removeIf

      @Deprecated default boolean removeIf(Predicate<? super Integer> filter)
      Deprecated.
      Please use the corresponding type-specific method instead.
      Specified by:
      removeIf in interface Collection<Integer>

    • removeIf

      default boolean removeIf(IntPredicate filter)
      Remove from this collection all elements which satisfy the given predicate.
      Parameters:
      filter - a predicate which returns true for elements to be removed.
      Returns:
      true if any elements were removed.
      See Also:
      API Notes:
      Implementing classes should generally override this method, and take the default implementation of the other overloads which will delegate to this method (after proper conversions).

    • removeIf

      default boolean removeIf(IntPredicate filter)
      Remove from this collection all elements which satisfy the given predicate.

      WARNING: Overriding this method is almost always a mistake, as this overload only exists to disambiguate. Instead, override the removeIf() overload that uses the JDK's primitive predicate type (e.g. IntPredicate).

      If Java supported final default methods, this would be one, but sadly it does not.

      If you checked and are overriding the version with java.util.function.XPredicate, and still see this warning, then your IDE is incorrectly conflating this method with the proper method to override, and you can safely ignore this message.

      Parameters:
      filter - a predicate which returns true for elements to be removed.
      Returns:
      true if any elements were removed.
      See Also:

    • retainAll

      boolean retainAll(IntCollection c)
      Retains in this collection only elements from the given type-specific collection.
      Parameters:
      c - a type-specific collection.
      Returns:
      true if this collection changed as a result of the call.
      See Also:

    • stream

      @Deprecated default Stream<Integer> stream()
      Deprecated.
      Please use the corresponding type-specific method instead.
      Specified by:
      stream in interface Collection<Integer>

    • intStream

      default IntStream intStream()
      Return a primitive stream over the elements, performing widening casts if needed.
      Returns:
      a primitive stream over the elements.
      See Also:

    • parallelStream

      @Deprecated default Stream<Integer> parallelStream()
      Deprecated.
      Please use the corresponding type-specific method instead.
      Specified by:
      parallelStream in interface Collection<Integer>

    • intParallelStream

      default IntStream intParallelStream()
      Return a parallel primitive stream over the elements, performing widening casts if needed.
      Returns:
      a parallel primitive stream over the elements.
      See Also: