edu.emory.mathcs.backport.java.util
public interface NavigableSet extends SortedSet
The return values of navigation methods may be ambiguous in implementations that permit {@code null} elements. However, even in this case the result can be disambiguated by checking {@code contains(null)}. To avoid such issues, implementations of this interface are encouraged to not permit insertion of {@code null} elements. (Note that sorted sets of java.lang.Comparable elements intrinsically do not permit {@code null}.)
Methods
subSet(E, E)
,
headSet(E)
, and
tailSet(E)
are specified to return {@code SortedSet} to allow existing
implementations of {@code SortedSet} to be compatibly retrofitted to
implement {@code NavigableSet}, but extensions and implementations
of this interface are encouraged to override these methods to return
{@code NavigableSet}.
This interface is a member of the Java Collections Framework.
Since: 1.6
Method Summary | |
---|---|
Object | ceiling(Object e)
Returns the least element in this set greater than or equal to
the given element, or {@code null} if there is no such element.
|
Iterator | descendingIterator()
Returns an iterator over the elements in this set, in descending order.
|
NavigableSet | descendingSet()
Returns a reverse order view of the elements contained in this set.
|
Object | floor(Object e)
Returns the greatest element in this set less than or equal to
the given element, or {@code null} if there is no such element.
|
NavigableSet | headSet(Object toElement, boolean inclusive)
Returns a view of the portion of this set whose elements are less than
(or equal to, if {@code inclusive} is true) {@code toElement}. |
SortedSet | headSet(Object toElement)
{@inheritDoc }
Equivalent to {@code headSet(toElement, false)}. |
Object | higher(Object e)
Returns the least element in this set strictly greater than the
given element, or {@code null} if there is no such element.
|
Iterator | iterator()
Returns an iterator over the elements in this set, in ascending order.
|
Object | lower(Object e)
Returns the greatest element in this set strictly less than the
given element, or {@code null} if there is no such element.
|
Object | pollFirst()
Retrieves and removes the first (lowest) element,
or returns {@code null} if this set is empty.
|
Object | pollLast()
Retrieves and removes the last (highest) element,
or returns {@code null} if this set is empty.
|
NavigableSet | subSet(Object fromElement, boolean fromInclusive, Object toElement, boolean toInclusive)
Returns a view of the portion of this set whose elements range from
{@code fromElement} to {@code toElement}. |
SortedSet | subSet(Object fromElement, Object toElement)
{@inheritDoc }
Equivalent to {@code subSet(fromElement, true, toElement, false)}. |
NavigableSet | tailSet(Object fromElement, boolean inclusive)
Returns a view of the portion of this set whose elements are greater
than (or equal to, if {@code inclusive} is true) {@code fromElement}.
|
SortedSet | tailSet(Object fromElement)
{@inheritDoc }
Equivalent to {@code tailSet(fromElement, true)}. |
Parameters: e the value to match
Returns: the least element greater than or equal to {@code e}, or {@code null} if there is no such element
Throws: ClassCastException if the specified element cannot be compared with the elements currently in the set NullPointerException if the specified element is null and this set does not permit null elements
Returns: an iterator over the elements in this set, in descending order
The returned set has an ordering equivalent to
Collections.reverseOrder
(comparator()).
The expression {@code s.descendingSet().descendingSet()} returns a
view of {@code s} essentially equivalent to {@code s}.
Returns: a reverse order view of this set
Parameters: e the value to match
Returns: the greatest element less than or equal to {@code e}, or {@code null} if there is no such element
Throws: ClassCastException if the specified element cannot be compared with the elements currently in the set NullPointerException if the specified element is null and this set does not permit null elements
The returned set will throw an {@code IllegalArgumentException} on an attempt to insert an element outside its range.
Parameters: toElement high endpoint of the returned set inclusive {@code true} if the high endpoint is to be included in the returned view
Returns: a view of the portion of this set whose elements are less than (or equal to, if {@code inclusive} is true) {@code toElement}
Throws: ClassCastException if {@code toElement} is not compatible with this set's comparator (or, if the set has no comparator, if {@code toElement} does not implement java.lang.Comparable). Implementations may, but are not required to, throw this exception if {@code toElement} cannot be compared to elements currently in the set. NullPointerException if {@code toElement} is null and this set does not permit null elements IllegalArgumentException if this set itself has a restricted range, and {@code toElement} lies outside the bounds of the range
Equivalent to {@code headSet(toElement, false)}.
Throws: ClassCastException {@inheritDoc } NullPointerException {@inheritDoc } IllegalArgumentException {@inheritDoc }
Parameters: e the value to match
Returns: the least element greater than {@code e}, or {@code null} if there is no such element
Throws: ClassCastException if the specified element cannot be compared with the elements currently in the set NullPointerException if the specified element is null and this set does not permit null elements
Returns: an iterator over the elements in this set, in ascending order
Parameters: e the value to match
Returns: the greatest element less than {@code e}, or {@code null} if there is no such element
Throws: ClassCastException if the specified element cannot be compared with the elements currently in the set NullPointerException if the specified element is null and this set does not permit null elements
Returns: the first element, or {@code null} if this set is empty
Returns: the last element, or {@code null} if this set is empty
The returned set will throw an {@code IllegalArgumentException} on an attempt to insert an element outside its range.
Parameters: fromElement low endpoint of the returned set fromInclusive {@code true} if the low endpoint is to be included in the returned view toElement high endpoint of the returned set toInclusive {@code true} if the high endpoint is to be included in the returned view
Returns: a view of the portion of this set whose elements range from {@code fromElement}, inclusive, to {@code toElement}, exclusive
Throws: ClassCastException if {@code fromElement} and {@code toElement} cannot be compared to one another using this set's comparator (or, if the set has no comparator, using natural ordering). Implementations may, but are not required to, throw this exception if {@code fromElement} or {@code toElement} cannot be compared to elements currently in the set. NullPointerException if {@code fromElement} or {@code toElement} is null and this set does not permit null elements IllegalArgumentException if {@code fromElement} is greater than {@code toElement}; or if this set itself has a restricted range, and {@code fromElement} or {@code toElement} lies outside the bounds of the range.
Equivalent to {@code subSet(fromElement, true, toElement, false)}.
Throws: ClassCastException {@inheritDoc } NullPointerException {@inheritDoc } IllegalArgumentException {@inheritDoc }
The returned set will throw an {@code IllegalArgumentException} on an attempt to insert an element outside its range.
Parameters: fromElement low endpoint of the returned set inclusive {@code true} if the low endpoint is to be included in the returned view
Returns: a view of the portion of this set whose elements are greater than or equal to {@code fromElement}
Throws: ClassCastException if {@code fromElement} is not compatible with this set's comparator (or, if the set has no comparator, if {@code fromElement} does not implement java.lang.Comparable). Implementations may, but are not required to, throw this exception if {@code fromElement} cannot be compared to elements currently in the set. NullPointerException if {@code fromElement} is null and this set does not permit null elements IllegalArgumentException if this set itself has a restricted range, and {@code fromElement} lies outside the bounds of the range
Equivalent to {@code tailSet(fromElement, true)}.
Throws: ClassCastException {@inheritDoc } NullPointerException {@inheritDoc } IllegalArgumentException {@inheritDoc }