org.jgrapht.experimental.equivalence

Class EquivalenceSet<E,C>

java.lang.Object

org.jgrapht.experimental.equivalence.EquivalenceSet<E,C>

Type Parameters:

E - the type of the elements in the set

C - the type of the context the element is compared against, e.g. a Graph

public class EquivalenceSet<E,C>
extends Object

EquivalenceSet is a Set of elements which have been determined to be equivalent using EquivalenceComparator. The class makes sure the set size will be one or more.

1. The group can only be created using the factory method createGroupWithElement().
2. The equals and hashcode of a group uses the EquivalenceComparator on one of the group members, thus it is actually checking whether the "other" is in the same group.

Since:

Jul 21, 2005

Author:

Assaf

Field Summary

Fields

Modifier and Type	Field and Description
protected C	comparatorContext
protected Set<E>	elementsSet Contains the current elements of the group
protected EquivalenceComparator<? super E,? super C>	eqComparator The comparator used to define the group

Constructor Summary

Constructors

Constructor and Description
EquivalenceSet(E aElement, EquivalenceComparator<? super E,? super C> aEqComparator, C aComparatorContext) Constructs a new EquivalenceSet, filled with the aElement parameter and a reference to the comparator which is used.

Method Summary

Methods

Modifier and Type	Method and Description
void	add(E element) Adds an element to the group.
boolean	equals(Object other) Uses the equivalenceCompare() of the comparator to compare a representation of this group, taken using this.getRepresentative(), and a representation of the other object, which may be the object itself, or, if it is an equivalence group too, other.getRepresentative()
boolean	equivalentTo(E aOther, C aOtherContext)
C	getContext()
E	getRepresentative() Returns an arbitrary object from the group.
int	hashCode() Uses a representative to calculate the group hashcode using equivalenceHashcode().
int	size()
Object[]	toArray() Returns the elements of the group.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

eqComparator

protected EquivalenceComparator<? super E,? super C> eqComparator

The comparator used to define the group

comparatorContext

protected C comparatorContext

elementsSet

protected Set<E> elementsSet

Contains the current elements of the group

Constructor Detail

EquivalenceSet

public EquivalenceSet(E aElement,
              EquivalenceComparator<? super E,? super C> aEqComparator,
              C aComparatorContext)

Constructs a new EquivalenceSet, filled with the aElement parameter and a reference to the comparator which is used.

Method Detail

getRepresentative

public E getRepresentative()

Returns an arbitrary object from the group. There is no guarantee as to which will be returned, and whether the same will be returned on the next call.

getContext

public C getContext()

size

public int size()

add

public void add(E element)

Adds an element to the group. It does not check it for equivalance . You must make sure it does, using equals().

equivalentTo

public boolean equivalentTo(E aOther,
                   C aOtherContext)

equals

public boolean equals(Object other)

Uses the equivalenceCompare() of the comparator to compare a representation of this group, taken using this.getRepresentative(), and a representation of the other object, which may be the object itself, or, if it is an equivalence group too, other.getRepresentative()

Overrides:

equals in class Object

hashCode

public int hashCode()

Uses a representative to calculate the group hashcode using equivalenceHashcode().

Overrides:

hashCode in class Object

See Also:

Object.hashCode()

toString

public String toString()

Overrides:

toString in class Object

toArray

public Object[] toArray()

Returns the elements of the group. The order of the elements in the returned array is not guaranteed. In other words, two calls to the same object may return different order.