org.deri.iris.utils.equivalence
Class TermEquivalence

java.lang.Object
  org.deri.iris.utils.equivalence.TermEquivalence

All Implemented Interfaces:

IEquivalentTerms

public class TermEquivalence
extends Object
implements IEquivalentTerms

An utility class to define equivalence between terms. Uses the disjoint-set data structure.

Author:

Adrian Marte

See Also:

DisjointSets

Constructor Summary

TermEquivalence()
Creates a new term equivalence relation.

Method Summary

boolean	areEquivalent(ITerm x, ITerm y) Checks if the specified terms are equivalent.
boolean	equals(Object obj)
ITerm	findRepresentative(ITerm term) Returns a representative term for the specified terms.
Set<ITerm>	getEquivalent(ITerm term) Returns the set of terms which are equivalent to the specified term.
int	hashCode()
void	setEquivalent(ITerm x, ITerm y) Defines the specified terms as equivalent.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

TermEquivalence

public TermEquivalence()

Creates a new term equivalence relation.

Method Detail

areEquivalent

public boolean areEquivalent(ITerm x,
                             ITerm y)

Description copied from interface: IEquivalentTerms

Checks if the specified terms are equivalent.

Specified by:

areEquivalent in interface IEquivalentTerms

Parameters:

x - The first term.

y - The second term.

Returns:

true if the two given terms are equivalent, false otherwise.

setEquivalent

public void setEquivalent(ITerm x,
                          ITerm y)

Description copied from interface: IEquivalentTerms

Defines the specified terms as equivalent.

Specified by:

setEquivalent in interface IEquivalentTerms

Parameters:

x - The first term.

y - The second term.

findRepresentative

public ITerm findRepresentative(ITerm term)

Description copied from interface: IEquivalentTerms

Returns a representative term for the specified terms. If two terms are equivalent, they have the same representative term.

Specified by:

findRepresentative in interface IEquivalentTerms

Parameters:

term - The term.

Returns:

The representative term for the specified term.

getEquivalent

public Set<ITerm> getEquivalent(ITerm term)

Description copied from interface: IEquivalentTerms

Returns the set of terms which are equivalent to the specified term. The set also contains the term itself.

Specified by:

getEquivalent in interface IEquivalentTerms

Parameters:

term - The term.

Returns:

The set of terms which are equivalent to the specified term. The set also contains the term itself.

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object