org.apache.commons.functor.core.comparator
Class IsEquivalent<T>

java.lang.Object
  org.apache.commons.functor.core.comparator.IsEquivalent<T>

All Implemented Interfaces:

Serializable, BinaryFunctor<T,T>, BinaryPredicate<T,T>, Functor

public final class IsEquivalent<T>
extends Object
implements BinaryPredicate<T,T>, Serializable

A BinaryPredicate that tests true iff the left argument is equal to the right argument under the specified Comparator. When no (or a null Comparator is specified, a Comparable Comparator is used.

Version:

$Revision: 1166340 $ $Date: 2011-09-07 21:44:28 +0200 (Wed, 07 Sep 2011) $

Author:

Rodney Waldhoff

See Also:

IsEqual, Serialized Form

Field Summary

static IsEquivalent<Comparable<?>>

INSTANCE Basic IsEquivalent instance.

Constructor Summary

IsEquivalent()
Create a new IsEquivalent.

IsEquivalent(Comparator<? super T> comparator)
Construct an IsEquivalent predicate for the given Comparator.

Method Summary

boolean	equals(IsEquivalent<?> that) Learn whether a given IsEquivalent is equal to this.
boolean	equals(Object that) Indicates whether some other object is "equal to" this functor.
int	hashCode() Returns a hash code for this functor adhering to the general Object.hashCode contract.
static <T extends Comparable<?>> IsEquivalent<T>	instance() Get a basic IsEquivalent instance.
static <T extends Comparable<?>> UnaryPredicate<T>	instance(T right) Get an IsEquivalent instance that always compares to arg.
boolean	test(T left, T right) Return true iff the left parameter is equal to the right parameter under my current Comparator.
String	toString() Returns a human readable description of this functor.

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

public static final IsEquivalent<Comparable<?>> INSTANCE

Basic IsEquivalent instance.

Constructor Detail

IsEquivalent

public IsEquivalent()

Create a new IsEquivalent.

IsEquivalent

public IsEquivalent(Comparator<? super T> comparator)

Construct an IsEquivalent predicate for the given Comparator.

Parameters:

comparator - the Comparator, when null, a Comparator for Comparables will be used.

Method Detail

test

public boolean test(T left,
                    T right)

Return true iff the left parameter is equal to the right parameter under my current Comparator. Evaluate this predicate.

Specified by:

test in interface BinaryPredicate<T,T>

Parameters:

left - the L element of the ordered pair of arguments

right - the R element of the ordered pair of arguments

Returns:

the result of this test for the given arguments

equals

public boolean equals(Object that)

Indicates whether some other object is "equal to" this functor. This method must adhere to general Object.equals contract. Additionally, this method can return true only if the specified Object implements the same functor interface and is known to produce the same results and/or side-effects for the same arguments (if any).

While implementators are strongly encouraged to override the default Object implementation of this method, note that the default Object implementation does in fact adhere to the functor equals contract.

Specified by:

equals in interface Functor

Overrides:

equals in class Object

Parameters:

that - the object to compare this functor to

Returns:

true iff the given object implements this functor interface, and is known to produce the same results and/or side-effects for the same arguments (if any).

See Also:

Functor.hashCode()

equals

public boolean equals(IsEquivalent<?> that)

Learn whether a given IsEquivalent is equal to this.

Parameters:

that - IsEquivalent to test

Returns:

boolean

hashCode

public int hashCode()

Returns a hash code for this functor adhering to the general Object.hashCode contract. Implementators are strongly encouraged but not strictly required to override the default Object implementation of this method.

Specified by:

hashCode in interface Functor

Overrides:

hashCode in class Object

Returns:

a hash code for this functor

See Also:

Functor.equals(java.lang.Object)

toString

public String toString()

Returns a human readable description of this functor. Implementators are strongly encouraged but not strictly required to override the default Object implementation of this method.

Specified by:

toString in interface Functor

Overrides:

toString in class Object

Returns:

a human readable description of this functor

instance

public static <T extends Comparable<?>> IsEquivalent<T> instance()

Get a basic IsEquivalent instance.

Parameters:

T -

Returns:

IsEquivalent

instance

public static <T extends Comparable<?>> UnaryPredicate<T> instance(T right)

Get an IsEquivalent instance that always compares to arg.

Parameters:

right - argument

Returns:

UnaryPredicate