org.apache.commons.functor.core
Class IsEqual<L,R>

java.lang.Object
  org.apache.commons.functor.core.IsEqual<L,R>

Type Parameters:

L - the left argument type.

R - the right argument type.

All Implemented Interfaces:

Serializable, BinaryFunctor<L,R>, BinaryPredicate<L,R>, Functor

public final class IsEqual<L,R>
extends Object
implements BinaryPredicate<L,R>, Serializable

Tests true iff its arguments are equal or both null.

This relation is an equivalence relation on the set of objects that adhere to the Object.equals contract.

Version:

$Revision: 1160389 $ $Date: 2011-08-22 21:31:15 +0200 (Mon, 22 Aug 2011) $

Author:

Rodney Waldhoff

See Also:

Serialized Form

Field Summary

static IsEqual<Object,Object>

INSTANCE Basic IsEqual instance.

Constructor Summary

IsEqual()
Create a new IsEqual.

Method Summary

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 <L,R> IsEqual<L,R>	instance() Get an IsEqual instance.
boolean	test(L left, R right) Evaluate this predicate.
static <L,R> UnaryPredicate<L>	to(R object) Get an IsEqual UnaryPredicate.
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 IsEqual<Object,Object> INSTANCE

Basic IsEqual instance.

Constructor Detail

IsEqual

public IsEqual()

Create a new IsEqual.

Method Detail

test

public boolean test(L left,
                    R right)

Evaluate this predicate.

Specified by:

test in interface BinaryPredicate<L,R>

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()

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 <L,R> IsEqual<L,R> instance()

Get an IsEqual instance.

Type Parameters:

L - the left argument type.

R - the right argument type.

Returns:

IsEqual

to

public static <L,R> UnaryPredicate<L> to(R object)

Get an IsEqual UnaryPredicate.

Type Parameters:

L - the left argument type.

R - the right argument type.

Parameters:

object - bound comparison object

Returns:

UnaryPredicate