io.permazen.util

Class NavigableSets

java.lang.Object

io.permazen.util.NavigableSets

public final class NavigableSets
extends Object

Utility methods relating to NavigableSet.

Method Summary

Modifier and Type	Method and Description
static <E> NavigableSet<E>	difference(NavigableSet<E> set1, NavigableSet<E> set2) Create a read-only view of the difference of two NavigableSets that have a consistent sort order.
static <E> NavigableSet<E>	empty() Create an empty NavigableSet.
static <E> NavigableSet<E>	empty(Comparator<? super E> comparator) Create an empty NavigableSet with a specified Comparator.
static <E> NavigableSet<E>	intersection(Iterable<? extends NavigableSet<E>> sets) Create a read-only view of the intersection of two or more NavigableSets that have a consistent sort order.
static <E> NavigableSet<E>	intersection(NavigableSet<E>... sets) Create a read-only view of the intersection of two or more NavigableSets that have a consistent sort order.
static <E> NavigableSet<E>	singleton(Comparator<? super E> comparator, E value) Create a NavigableSet containing a single element.
static <E> NavigableSet<E>	singleton(E value) Create a NavigableSet containing a single element and natural ordering.
static <E> NavigableSet<E>	symmetricDifference(NavigableSet<E> set1, NavigableSet<E> set2) Create a read-only view of the symmetric difference of two NavigableSets that have a consistent sort order.
static <E> NavigableSet<E>	union(Iterable<? extends NavigableSet<E>> sets) Create a read-only view of the union of two or more NavigableSets that have a consistent sort order.
static <E> NavigableSet<E>	union(NavigableSet<E>... sets) Create a read-only view of the union of two or more NavigableSets that have a consistent sort order.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

intersection

public static <E> NavigableSet<E> intersection(Iterable<? extends NavigableSet<E>> sets)

Create a read-only view of the intersection of two or more NavigableSets that have a consistent sort order. The Comparators of the sets must all be equal (or else all null, for natural ordering).

The returned intersection iterates efficiently: a complete iteration requires O(N * M) queries, where N is the size of the smallest set, and M is the number of sets.

Type Parameters:

E - element type

Parameters:

sets - the sets to intersect

Returns:

the intersection of all sets

Throws:

IllegalArgumentException - if the sets do not have equal Comparators

IllegalArgumentException - if sets, or any NavigableSet therein, is null

intersection

@SafeVarargs
public static <E> NavigableSet<E> intersection(NavigableSet<E>... sets)

Create a read-only view of the intersection of two or more NavigableSets that have a consistent sort order. The Comparators of the sets must all be equal (or else all null, for natural ordering).

The returned intersection iterates efficiently: a complete iteration takes time O(N * M) where N is the size of the smallest set, and M is the number of sets.

Type Parameters:

E - element type

Parameters:

sets - the sets to intersect

Returns:

the intersection of all sets

Throws:

IllegalArgumentException - if the sets do not have equal Comparators

IllegalArgumentException - if sets, or any NavigableSet therein, is null

union

@SafeVarargs
public static <E> NavigableSet<E> union(NavigableSet<E>... sets)

Create a read-only view of the union of two or more NavigableSets that have a consistent sort order. The Comparators of the sets must all be equal (or else all null, for natural ordering).

Type Parameters:

E - element type

Parameters:

sets - the sets to union

Returns:

the union of all sets

Throws:

IllegalArgumentException - if the sets do not have equal Comparators

IllegalArgumentException - if sets, or any NavigableSet therein, is null

union

public static <E> NavigableSet<E> union(Iterable<? extends NavigableSet<E>> sets)

Create a read-only view of the union of two or more NavigableSets that have a consistent sort order. The Comparators of the sets must all be equal (or else all null, for natural ordering).

Type Parameters:

E - element type

Parameters:

sets - the sets to union

Returns:

the union of all sets

Throws:

IllegalArgumentException - if the sets do not have equal Comparators

IllegalArgumentException - if sets, or any NavigableSet therein, is null

difference

public static <E> NavigableSet<E> difference(NavigableSet<E> set1,
                                             NavigableSet<E> set2)

Create a read-only view of the difference of two NavigableSets that have a consistent sort order. That is, a set containing all elements contained in the first set but not the second. The Comparators of the sets must all be equal (or else all null, for natural ordering).

Type Parameters:

E - element type

Parameters:

set1 - original set

set2 - set of elements to exclude from set1

Returns:

the difference of set1 and set2

Throws:

IllegalArgumentException - if the set1 and set2 do not have equal Comparators

IllegalArgumentException - if either parameter is is null

symmetricDifference

public static <E> NavigableSet<E> symmetricDifference(NavigableSet<E> set1,
                                                      NavigableSet<E> set2)

Create a read-only view of the symmetric difference of two NavigableSets that have a consistent sort order. That is, the set containing all elements contained in the first set or the second set, but not in both sets. The Comparators of the sets must all be equal (or else all null, for natural ordering).

Type Parameters:

E - element type

Parameters:

set1 - first set

set2 - second set

Returns:

the symmetric difference of set1 and set2

Throws:

IllegalArgumentException - if the set1 and set2 do not have equal Comparators

IllegalArgumentException - if either parameter is is null

singleton

public static <E> NavigableSet<E> singleton(E value)

Create a NavigableSet containing a single element and natural ordering.

Type Parameters:

E - element type

Parameters:

value - singleton value

Returns:

singleton set

Throws:

IllegalArgumentException - if value is null or value's class has no natural ordering (i.e., does not implement Comparable)

singleton

public static <E> NavigableSet<E> singleton(Comparator<? super E> comparator,
                                            E value)

Create a NavigableSet containing a single element.

Type Parameters:

E - element type

Parameters:

comparator - comparator, or null for natural ordering

value - singleton value (possibly null)

Returns:

singleton set

Throws:

IllegalArgumentException - if comparator is null and either value is null or value's class has no natural ordering (i.e., does not implement Comparable)

empty

public static <E> NavigableSet<E> empty()

Create an empty NavigableSet. The returned set's comparator() method will return null.

Type Parameters:

E - element type

Returns:

empty set

empty

public static <E> NavigableSet<E> empty(Comparator<? super E> comparator)

Create an empty NavigableSet with a specified Comparator.

Type Parameters:

E - element type

Parameters:

comparator - comparator, or null for natural ordering

Returns:

empty set