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package io.github.andyalvarez.primitive;
import java.util.*;
import java.util.function.IntFunction;
import java.util.function.IntPredicate;
import java.util.stream.IntStream;
import java.util.stream.StreamSupport;
/**
* The root interface in the collection hierarchy. A collection
* represents a group of objects, known as its elements. Some
* collections allow duplicate elements and others do not. Some are ordered
* and others unordered. The JDK does not provide any direct
* implementations of this interface: it provides implementations of more
* specific subinterfaces like {@code Set} and {@code List}. This interface
* is typically used to pass collections around and manipulate them where
* maximum generality is desired.
*
* Bags or multisets (unordered collections that may contain
* duplicate elements) should implement this interface directly.
*
*
All general-purpose {@code Collection} implementation classes (which
* typically implement {@code Collection} indirectly through one of its
* subinterfaces) should provide two "standard" constructors: a void (no
* arguments) constructor, which creates an empty collection, and a
* constructor with a single argument of type {@code Collection}, which
* creates a new collection with the same elements as its argument. In
* effect, the latter constructor allows the user to copy any collection,
* producing an equivalent collection of the desired implementation type.
* There is no way to enforce this convention (as interfaces cannot contain
* constructors) but all of the general-purpose {@code Collection}
* implementations in the Java platform libraries comply.
*
*
Certain methods are specified to be
* optional. If a collection implementation doesn't implement a
* particular operation, it should define the corresponding method to throw
* {@code UnsupportedOperationException}. Such methods are marked "optional
* operation" in method specifications of the collections interfaces.
*
*
Some collection implementations
* have restrictions on the elements that they may contain.
* For example, some implementations prohibit null elements,
* and some have restrictions on the types of their elements. Attempting to
* add an ineligible element throws an unchecked exception, typically
* {@code NullPointerException} or {@code ClassCastException}. Attempting
* to query the presence of an ineligible element may throw an exception,
* or it may simply return false; some implementations will exhibit the former
* behavior and some will exhibit the latter. More generally, attempting an
* operation on an ineligible element whose completion would not result in
* the insertion of an ineligible element into the collection may throw an
* exception or it may succeed, at the option of the implementation.
* Such exceptions are marked as "optional" in the specification for this
* interface.
*
*
It is up to each collection to determine its own synchronization
* policy. In the absence of a stronger guarantee by the
* implementation, undefined behavior may result from the invocation
* of any method on a collection that is being mutated by another
* thread; this includes direct invocations, passing the collection to
* a method that might perform invocations, and using an existing
* iterator to examine the collection.
*
*
Many methods in Collections Framework interfaces are defined in
* terms of the {@link Object#equals(Object) equals} method. For example,
* the specification for the {@link #contains(int) contains(Object o)}
* method says: "returns {@code true} if and only if this collection
* contains at least one element {@code e} such that
* {@code (o==null ? e==null : o.equals(e))}." This specification should
* not be construed to imply that invoking {@code Collection.contains}
* with a non-null argument {@code o} will cause {@code o.equals(e)} to be
* invoked for any element {@code e}. Implementations are free to implement
* optimizations whereby the {@code equals} invocation is avoided, for
* example, by first comparing the hash codes of the two elements. (The
* {@link Object#hashCode()} specification guarantees that two objects with
* unequal hash codes cannot be equal.) More generally, implementations of
* the various Collections Framework interfaces are free to take advantage of
* the specified behavior of underlying {@link Object} methods wherever the
* implementor deems it appropriate.
*
*
Some collection operations which perform recursive traversal of the
* collection may fail with an exception for self-referential instances where
* the collection directly or indirectly contains itself. This includes the
* {@code clone()}, {@code equals()}, {@code hashCode()} and {@code toString()}
* methods. Implementations may optionally handle the self-referential scenario,
* however most current implementations do not do so.
*
*
View Collections
*
* Most collections manage storage for elements they contain. By contrast, view
* collections themselves do not store elements, but instead they rely on a
* backing collection to store the actual elements. Operations that are not handled
* by the view collection itself are delegated to the backing collection. Examples of
* view collections include the wrapper collections returned by methods such as
* {@link Collections#checkedCollection Collections.checkedCollection}, and
* {@link Collections#unmodifiableCollection Collections.unmodifiableCollection}.
* Other examples of view collections include collections that provide a
* different representation of the same elements, for example, as
* provided by {@link List#subList List.subList},
* {@link NavigableSet#subSet NavigableSet.subSet}, or
* {@link Map#entrySet Map.entrySet}.
* Any changes made to the backing collection are visible in the view collection.
* Correspondingly, any changes made to the view collection — if changes
* are permitted — are written through to the backing collection.
* Although they technically aren't collections, instances of
* {@link Iterator} and {@link ListIterator} can also allow modifications
* to be written through to the backing collection, and in some cases,
* modifications to the backing collection will be visible to the Iterator
* during iteration.
*
*
Unmodifiable Collections
*
* Certain methods of this interface are considered "destructive" and are called
* "mutator" methods in that they modify the group of objects contained within
* the collection on which they operate. They can be specified to throw
* {@code UnsupportedOperationException} if this collection implementation
* does not support the operation. Such methods should (but are not required
* to) throw an {@code UnsupportedOperationException} if the invocation would
* have no effect on the collection. For example, consider a collection that
* does not support the {@link #add add} operation. What will happen if the
* {@link #addAll addAll} method is invoked on this collection, with an empty
* collection as the argument? The addition of zero elements has no effect,
* so it is permissible for this collection simply to do nothing and not to throw
* an exception. However, it is recommended that such cases throw an exception
* unconditionally, as throwing only in certain cases can lead to
* programming errors.
*
*
An unmodifiable collection is a collection, all of whose
* mutator methods (as defined above) are specified to throw
* {@code UnsupportedOperationException}. Such a collection thus cannot be
* modified by calling any methods on it. For a collection to be properly
* unmodifiable, any view collections derived from it must also be unmodifiable.
* For example, if a List is unmodifiable, the List returned by
* {@link List#subList List.subList} is also unmodifiable.
*
*
An unmodifiable collection is not necessarily immutable. If the
* contained elements are mutable, the entire collection is clearly
* mutable, even though it might be unmodifiable. For example, consider
* two unmodifiable lists containing mutable elements. The result of calling
* {@code list1.equals(list2)} might differ from one call to the next if
* the elements had been mutated, even though both lists are unmodifiable.
* However, if an unmodifiable collection contains all immutable elements,
* it can be considered effectively immutable.
*
*
Unmodifiable View Collections
*
* An unmodifiable view collection is a collection that is unmodifiable
* and that is also a view onto a backing collection. Its mutator methods throw
* {@code UnsupportedOperationException}, as described above, while
* reading and querying methods are delegated to the backing collection.
* The effect is to provide read-only access to the backing collection.
* This is useful for a component to provide users with read access to
* an internal collection, while preventing them from modifying such
* collections unexpectedly. Examples of unmodifiable view collections
* are those returned by the
* {@link Collections#unmodifiableCollection Collections.unmodifiableCollection},
* {@link Collections#unmodifiableList Collections.unmodifiableList}, and
* related methods.
*
*
Note that changes to the backing collection might still be possible,
* and if they occur, they are visible through the unmodifiable view. Thus,
* an unmodifiable view collection is not necessarily immutable. However,
* if the backing collection of an unmodifiable view is effectively immutable,
* or if the only reference to the backing collection is through an
* unmodifiable view, the view can be considered effectively immutable.
*
*
This interface is a member of the
*
* Java Collections Framework.
*
*
* The default method implementations (inherited or otherwise) do not applyAsInt any
* synchronization protocol. If a {@code Collection} implementation has a
* specific synchronization protocol, then it must override default
* implementations to applyAsInt that protocol.
*
* @author Josh Bloch
* @author Neal Gafter
* @see Set
* @see List
* @see Map
* @see SortedSet
* @see SortedMap
* @see HashSet
* @see TreeSet
* @see ArrayList
* @see LinkedList
* @see Vector
* @see Collections
* @see Arrays
* @see AbstractCollection
* @since 1.2
*/
public interface IntCollection extends IntIterable {
// Query Operations
/**
* Returns the number of elements in this collection. If this collection
* contains more than {@code Integer.MAX_VALUE} elements, returns
* {@code Integer.MAX_VALUE}.
*
* @return the number of elements in this collection
*/
int size();
/**
* Returns {@code true} if this collection contains no elements.
*
* @return {@code true} if this collection contains no elements
*/
boolean isEmpty();
/**
* Returns {@code true} if this collection contains the specified element.
* More formally, returns {@code true} if and only if this collection
* contains at least one element {@code e} such that
* {@code Objects.equals(o, e)}.
*
* @param o element whose presence in this collection is to be tested
* @return {@code true} if this collection contains the specified
* element
* @throws ClassCastException if the type of the specified element
* is incompatible with this collection
* (optional)
* @throws NullPointerException if the specified element is null and this
* collection does not permit null elements
* (optional)
*/
boolean contains(int o);
/**
* Returns an iterator over the elements in this collection. There are no
* guarantees concerning the order in which the elements are returned
* (unless this collection is an instance of some class that provides a
* guarantee).
*
* @return an {@code Iterator} over the elements in this collection
*/
PrimitiveIterator.OfInt iterator();
/**
* Returns an array containing all of the elements in this collection.
* If this collection makes any guarantees as to what order its elements
* are returned by its iterator, this method must return the elements in
* the same order. The returned array's {@linkplain Class#getComponentType
* runtime component type} is {@code Object}.
*
*
The returned array will be "safe" in that no references to it are
* maintained by this collection. (In other words, this method must
* allocate a new array even if this collection is backed by an array).
* The caller is thus free to modify the returned array.
*
* This method acts as a bridge between array-based and collection-based APIs.
* It returns an array whose runtime type is {@code Object[]}.
* Use {@link #toArray(int[]) toArray(T[])} to reuse an existing
* array, or use {@link #toArray(IntFunction)} to control the runtime type
* of the array.
*
* @return an array, whose {@linkplain Class#getComponentType runtime component
* type} is {@code Object}, containing all of the elements in this collection
*/
int[] toArray();
/**
* Returns an array containing all of the elements in this collection;
* the runtime type of the returned array is that of the specified array.
* If the collection fits in the specified array, it is returned therein.
* Otherwise, a new array is allocated with the runtime type of the
* specified array and the size of this collection.
*
*
If this collection fits in the specified array with room to spare
* (i.e., the array has more elements than this collection), the element
* in the array immediately following the end of the collection is set to
* {@code null}. (This is useful in determining the length of this
* collection only if the caller knows that this collection does
* not contain any {@code null} elements.)
*
*
If this collection makes any guarantees as to what order its elements
* are returned by its iterator, this method must return the elements in
* the same order.
*
* This method acts as a bridge between array-based and collection-based APIs.
* It allows an existing array to be reused under certain circumstances.
* Use {@link #toArray()} to create an array whose runtime type is {@code Object[]},
* or use {@link #toArray(IntFunction)} to control the runtime type of
* the array.
*
*
Suppose {@code x} is a collection known to contain only strings.
* The following code can be used to dump the collection into a previously
* allocated {@code String} array:
*
*
* String[] y = new String[SIZE];
* ...
* y = x.toArray(y);
*
* The return value is reassigned to the variable {@code y}, because a
* new array will be allocated and returned if the collection {@code x} has
* too many elements to fit into the existing array {@code y}.
*
*
Note that {@code toArray(new Object[0])} is identical in function to
* {@code toArray()}.
*
* @param a the array into which the elements of this collection are to be
* stored, if it is big enough; otherwise, a new array of the same
* runtime type is allocated for this purpose.
* @return an array containing all of the elements in this collection
* @throws ArrayStoreException if the runtime type of any element in this
* collection is not assignable to the {@linkplain Class#getComponentType
* runtime component type} of the specified array
* @throws NullPointerException if the specified array is null
*/
int[] toArray(int[] a);
/**
* Returns an array containing all of the elements in this collection,
* using the provided {@code generator} function to allocate the returned array.
*
*
If this collection makes any guarantees as to what order its elements
* are returned by its iterator, this method must return the elements in
* the same order.
*
*
* This method acts as a bridge between array-based and collection-based APIs.
* It allows creation of an array of a particular runtime type. Use
* {@link #toArray()} to create an array whose runtime type is {@code Object[]},
* or use {@link #toArray(int[]) toArray(T[])} to reuse an existing array.
*
*
Suppose {@code x} is a collection known to contain only strings.
* The following code can be used to dump the collection into a newly
* allocated array of {@code String}:
*
*
* String[] y = x.toArray(String[]::new);
*
*
* The default implementation calls the generator function with zero
* and then passes the resulting array to {@link #toArray(int[]) toArray(T[])}.
*
* @param generator a function which produces a new array of the desired
* type and the provided length
* @return an array containing all of the elements in this collection
* @throws ArrayStoreException if the runtime type of any element in this
* collection is not assignable to the {@linkplain Class#getComponentType
* runtime component type} of the generated array
* @throws NullPointerException if the generator function is null
* @since 11
*/
default int[] toArray(IntFunction generator) {
return toArray(generator.apply(0));
}
// Modification Operations
/**
* Ensures that this collection contains the specified element (optional
* operation). Returns {@code true} if this collection changed as a
* result of the call. (Returns {@code false} if this collection does
* not permit duplicates and already contains the specified element.)
*
* Collections that support this operation may place limitations on what
* elements may be added to this collection. In particular, some
* collections will refuse to add {@code null} elements, and others will
* impose restrictions on the type of elements that may be added.
* Collection classes should clearly specify in their documentation any
* restrictions on what elements may be added.
*
* If a collection refuses to add a particular element for any reason
* other than that it already contains the element, it must throw
* an exception (rather than returning {@code false}). This preserves
* the invariant that a collection always contains the specified element
* after this call returns.
*
* @param e element whose presence in this collection is to be ensured
* @return {@code true} if this collection changed as a result of the
* call
* @throws UnsupportedOperationException if the {@code add} operation
* is not supported by this collection
* @throws ClassCastException if the class of the specified element
* prevents it from being added to this collection
* @throws NullPointerException if the specified element is null and this
* collection does not permit null elements
* @throws IllegalArgumentException if some property of the element
* prevents it from being added to this collection
* @throws IllegalStateException if the element cannot be added at this
* time due to insertion restrictions
*/
boolean add(int e);
/**
* Removes a single instance of the specified element from this
* collection, if it is present (optional operation). More formally,
* removes an element {@code e} such that
* {@code Objects.equals(o, e)}, if
* this collection contains one or more such elements. Returns
* {@code true} if this collection contained the specified element (or
* equivalently, if this collection changed as a result of the call).
*
* @param o element to be removed from this collection, if present
* @return {@code true} if an element was removed as a result of this call
* @throws ClassCastException if the type of the specified element
* is incompatible with this collection
* (optional)
* @throws NullPointerException if the specified element is null and this
* collection does not permit null elements
* (optional)
* @throws UnsupportedOperationException if the {@code remove} operation
* is not supported by this collection
*/
boolean remove(int o);
// Bulk Operations
/**
* Returns {@code true} if this collection contains all of the elements
* in the specified collection.
*
* @param c collection to be checked for containment in this collection
* @return {@code true} if this collection contains all of the elements
* in the specified collection
* @throws ClassCastException if the types of one or more elements
* in the specified collection are incompatible with this
* collection
* (optional)
* @throws NullPointerException if the specified collection contains one
* or more null elements and this collection does not permit null
* elements
* (optional),
* or if the specified collection is null.
* @see #contains(int)
*/
boolean containsAll(IntCollection c);
/**
* Adds all of the elements in the specified collection to this collection
* (optional operation). The behavior of this operation is undefined if
* the specified collection is modified while the operation is in progress.
* (This implies that the behavior of this call is undefined if the
* specified collection is this collection, and this collection is
* nonempty.)
*
* @param c collection containing elements to be added to this collection
* @return {@code true} if this collection changed as a result of the call
* @throws UnsupportedOperationException if the {@code addAll} operation
* is not supported by this collection
* @throws ClassCastException if the class of an element of the specified
* collection prevents it from being added to this collection
* @throws NullPointerException if the specified collection contains a
* null element and this collection does not permit null elements,
* or if the specified collection is null
* @throws IllegalArgumentException if some property of an element of the
* specified collection prevents it from being added to this
* collection
* @throws IllegalStateException if not all the elements can be added at
* this time due to insertion restrictions
* @see #add(int)
*/
boolean addAll(IntCollection c);
/**
* Adds all of the elements in the specified array to this collection
* (optional operation). The behavior of this operation is undefined if
* the specified collection is modified while the operation is in progress.
* (This implies that the behavior of this call is undefined if the
* specified collection is this collection, and this collection is
* nonempty.)
*
* @param array array containing elements to be added to this collection
* @return {@code true} if this collection changed as a result of the call
* @throws UnsupportedOperationException if the {@code addAll} operation
* is not supported by this collection
* @throws ClassCastException if the class of an element of the specified
* collection prevents it from being added to this collection
* @throws NullPointerException if the specified collection contains a
* null element and this collection does not permit null elements,
* or if the specified collection is null
* @throws IllegalArgumentException if some property of an element of the
* specified collection prevents it from being added to this
* collection
* @throws IllegalStateException if not all the elements can be added at
* this time due to insertion restrictions
* @see #add(int)
*/
boolean addAll(int[] array);
/**
* Removes all of this collection's elements that are also contained in the
* specified collection (optional operation). After this call returns,
* this collection will contain no elements in common with the specified
* collection.
*
* @param c collection containing elements to be removed from this collection
* @return {@code true} if this collection changed as a result of the
* call
* @throws UnsupportedOperationException if the {@code removeAll} method
* is not supported by this collection
* @throws ClassCastException if the types of one or more elements
* in this collection are incompatible with the specified
* collection
* (optional)
* @throws NullPointerException if this collection contains one or more
* null elements and the specified collection does not support
* null elements
* (optional),
* or if the specified collection is null
* @see #remove(int)
* @see #contains(int)
*/
boolean removeAll(IntCollection c);
/**
* Removes all of the elements of this collection that satisfy the given
* predicate. Errors or runtime exceptions thrown during iteration or by
* the predicate are relayed to the caller.
*
*
* The default implementation traverses all elements of the collection using
* its {@link #iterator}. Each matching element is removed using
* {@link Iterator#remove()}. If the collection's iterator does not
* support removal then an {@code UnsupportedOperationException} will be
* thrown on the first matching element.
*
* @param filter a predicate which returns {@code true} for elements to be
* removed
* @return {@code true} if any elements were removed
* @throws NullPointerException if the specified filter is null
* @throws UnsupportedOperationException if elements cannot be removed
* from this collection. Implementations may throw this exception if a
* matching element cannot be removed or if, in general, removal is not
* supported.
* @since 1.8
*/
default boolean removeIf(IntPredicate filter) {
Objects.requireNonNull(filter);
boolean removed = false;
final var each = iterator();
while (each.hasNext()) {
if (filter.test(each.nextInt())) {
each.remove();
removed = true;
}
}
return removed;
}
/**
* Returns whether any elements of this collection match the provided
* predicate. May not evaluate the predicate on all elements if not
* necessary for determining the result. If the collection is empty then
*
* {@code false} is returned and the predicate is not evaluated.
*
* @param predicate a predicate to apply to elements of this collection
* @return {@code true} if any element of this collections matches the predicate
*/
default boolean anyMatch(IntPredicate predicate) {
Objects.requireNonNull(predicate);
final var it = iterator();
while (it.hasNext()) {
if(predicate.test(it.nextInt())) {
return true;
}
}
return false;
}
/**
* Returns whether none elements of this collection match the provided
* predicate. May not evaluate the predicate on all elements if not
* necessary for determining the result. If the collection is empty then
* {@code true} is returned and the predicate is not evaluated.
*
* @param predicate a predicate to apply to elements of this collection
* @return {@code true} if none element of this collections matches the predicate
*/
default boolean noneMatch(IntPredicate predicate) {
Objects.requireNonNull(predicate);
final var it = iterator();
while (it.hasNext()) {
if(predicate.test(it.nextInt())) {
return false;
}
}
return true;
}
/**
* Returns whether all elements of this collection match the provided
* predicate. May not evaluate the predicate on all elements if not
* necessary for determining the result. If the collection is empty then
* {@code true} is returned and the predicate is not evaluated.
*
* @param predicate a predicate to apply to elements of this collection
* @return {@code true} if all elements of this collections matches the predicate
*/
default boolean allMatch(IntPredicate predicate) {
Objects.requireNonNull(predicate);
final var it = iterator();
while (it.hasNext()) {
if(!predicate.test(it.nextInt())) {
return false;
}
}
return true;
}
/**
* Retains only the elements in this collection that are contained in the
* specified collection (optional operation). In other words, removes from
* this collection all of its elements that are not contained in the
* specified collection.
*
* @param c collection containing elements to be retained in this collection
* @return {@code true} if this collection changed as a result of the call
* @throws UnsupportedOperationException if the {@code retainAll} operation
* is not supported by this collection
* @throws ClassCastException if the types of one or more elements
* in this collection are incompatible with the specified
* collection
* (optional)
* @throws NullPointerException if this collection contains one or more
* null elements and the specified collection does not permit null
* elements
* (optional),
* or if the specified collection is null
* @see #remove(int)
* @see #contains(int)
*/
boolean retainAll(IntCollection c);
/**
* Removes all of the elements from this collection (optional operation).
* The collection will be empty after this method returns.
*
* @throws UnsupportedOperationException if the {@code clear} operation
* is not supported by this collection
*/
void clear();
// Comparison and hashing
/**
* Compares the specified object with this collection for equality.
*
* While the {@code Collection} interface adds no stipulations to the
* general contract for the {@code Object.equals}, programmers who
* implement the {@code Collection} interface "directly" (in other words,
* create a class that is a {@code Collection} but is not a {@code Set}
* or a {@code List}) must exercise care if they choose to override the
* {@code Object.equals}. It is not necessary to do so, and the simplest
* course of action is to rely on {@code Object}'s implementation, but
* the implementor may wish to implement a "value comparison" in place of
* the default "reference comparison." (The {@code List} and
* {@code Set} interfaces mandate such value comparisons.)
*
* The general contract for the {@code Object.equals} method states that
* equals must be symmetric (in other words, {@code a.equals(b)} if and
* only if {@code b.equals(a)}). The contracts for {@code List.equals}
* and {@code Set.equals} state that lists are only equal to other lists,
* and sets to other sets. Thus, a custom {@code equals} method for a
* collection class that implements neither the {@code List} nor
* {@code Set} interface must return {@code false} when this collection
* is compared to any list or set. (By the same logic, it is not possible
* to write a class that correctly implements both the {@code Set} and
* {@code List} interfaces.)
*
* @param o object to be compared for equality with this collection
* @return {@code true} if the specified object is equal to this
* collection
*
* @see Object#equals(Object)
* @see Set#equals(Object)
* @see List#equals(Object)
*/
boolean equals(Object o);
/**
* Returns the hash code value for this collection. While the
* {@code Collection} interface adds no stipulations to the general
* contract for the {@code Object.hashCode} method, programmers should
* take note that any class that overrides the {@code Object.equals}
* method must also override the {@code Object.hashCode} method in order
* to satisfy the general contract for the {@code Object.hashCode} method.
* In particular, {@code c1.equals(c2)} implies that
* {@code c1.hashCode()==c2.hashCode()}.
*
* @return the hash code value for this collection
*
* @see Object#hashCode()
* @see Object#equals(Object)
*/
int hashCode();
/**
* Creates a {@link Spliterator} over the elements in this collection.
*
* Implementations should document characteristic values reported by the
* spliterator. Such characteristic values are not required to be reported
* if the spliterator reports {@link Spliterator#SIZED} and this collection
* contains no elements.
*
*
The default implementation should be overridden by subclasses that
* can return a more efficient spliterator. In order to
* preserve expected laziness behavior for the {@link #stream()} and
* {@link #parallelStream()} methods, spliterators should either have the
* characteristic of {@code IMMUTABLE} or {@code CONCURRENT}, or be
* late-binding.
* If none of these is practical, the overriding class should describe the
* spliterator's documented policy of binding and structural interference,
* and should override the {@link #stream()} and {@link #parallelStream()}
* methods to create streams using a {@code Supplier} of the spliterator,
* as in:
*
{@code
* Stream s = StreamSupport.stream(() -> spliterator(), spliteratorCharacteristics)
* }
* These requirements ensure that streams produced by the
* {@link #stream()} and {@link #parallelStream()} methods will reflect the
* contents of the collection as of initiation of the terminal stream
* operation.
*
*
* The default implementation creates a
* late-binding spliterator
* from the collection's {@code Iterator}. The spliterator inherits the
* fail-fast properties of the collection's iterator.
*
* The created {@code Spliterator} reports {@link Spliterator#SIZED}.
*
*
* The created {@code Spliterator} additionally reports
* {@link Spliterator#SUBSIZED}.
*
*
If a spliterator covers no elements then the reporting of additional
* characteristic values, beyond that of {@code SIZED} and {@code SUBSIZED},
* does not aid clients to control, specialize or simplify computation.
* However, this does enable shared use of an immutable and empty
* spliterator instance (see {@link Spliterators#emptySpliterator()}) for
* empty collections, and enables clients to determine if such a spliterator
* covers no elements.
*
* @return a {@code Spliterator} over the elements in this collection
* @since 1.8
*/
@Override
default Spliterator.OfInt spliterator() {
return Spliterators.spliterator(iterator(), size(), 0);
}
/**
* Returns a sequential {@code Stream} with this collection as its source.
*
*
This method should be overridden when the {@link #spliterator()}
* method cannot return a spliterator that is {@code IMMUTABLE},
* {@code CONCURRENT}, or late-binding. (See {@link #spliterator()}
* for details.)
*
*
* The default implementation creates a sequential {@code Stream} from the
* collection's {@code Spliterator}.
*
* @return a sequential {@code Stream} over the elements in this collection
* @since 1.8
*/
default IntStream stream() {
return StreamSupport.intStream(spliterator(), false);
}
/**
* Returns a possibly parallel {@code Stream} with this collection as its
* source. It is allowable for this method to return a sequential stream.
*
*
This method should be overridden when the {@link #spliterator()}
* method cannot return a spliterator that is {@code IMMUTABLE},
* {@code CONCURRENT}, or late-binding. (See {@link #spliterator()}
* for details.)
*
*
* The default implementation creates a parallel {@code Stream} from the
* collection's {@code Spliterator}.
*
* @return a possibly parallel {@code Stream} over the elements in this
* collection
* @since 1.8
*/
default IntStream parallelStream() {
return StreamSupport.intStream(spliterator(), true);
}
}