org.apache.commons.functor.adapter
Class BinaryFunctionBinaryPredicate<L,R>

java.lang.Object
  org.apache.commons.functor.adapter.BinaryFunctionBinaryPredicate<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 BinaryFunctionBinaryPredicate<L,R>
extends Object
implements BinaryPredicate<L,R>, Serializable

Adapts a Boolean-valued BinaryFunction to the BinaryPredicate interface.

Note that although this class implements Serializable, a given instance will only be truly Serializable if the underlying functor is. Attempts to serialize an instance whose delegate is not Serializable will result in an exception.

Version:

$Revision: 1156745 $ $Date: 2011-08-11 21:08:49 +0200 (Thu, 11 Aug 2011) $

Author:

Rodney Waldhoff

See Also:

Serialized Form

Constructor Summary

BinaryFunctionBinaryPredicate(BinaryFunction<? super L,? super R,Boolean> function)
Create an BinaryPredicate wrapping the given BinaryFunction.

Method Summary

static <L,R,T> BinaryFunctionBinaryPredicate<L,R>	adapt(BinaryFunction<? super L,? super R,Boolean> function) Adapt the given, possibly-null, BinaryFunction to the BinaryPredicate interface.
boolean	equals(BinaryFunctionBinaryPredicate<?,?> that) Learn whether another BinaryFunctionBinaryPredicate 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.
boolean	test(L left, R right) Evaluate this predicate.
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

Constructor Detail

BinaryFunctionBinaryPredicate

public BinaryFunctionBinaryPredicate(BinaryFunction<? super L,? super R,Boolean> function)

Create an BinaryPredicate wrapping the given BinaryFunction.

Parameters:

function - the BinaryFunction to wrap

Method Detail

test

public boolean test(L left,
                    R right)

Evaluate this predicate. Returns the boolean value of the non-null Boolean returned by the evaluate method of my underlying function. The mehod throws NullPointerException if the underlying function returns null, and ClassCastException if the underlying function returns a non-Boolean

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()

equals

public boolean equals(BinaryFunctionBinaryPredicate<?,?> that)

Learn whether another BinaryFunctionBinaryPredicate is equal to this.

Parameters:

that - BinaryFunctionBinaryPredicate 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

adapt

public static <L,R,T> BinaryFunctionBinaryPredicate<L,R> adapt(BinaryFunction<? super L,? super R,Boolean> function)

Adapt the given, possibly-null, BinaryFunction to the BinaryPredicate interface. When the given BinaryFunction is null, returns null.

Type Parameters:

L - left type

R - right type

T - result type

Parameters:

function - the possibly-null BinaryFunction to adapt

Returns:

a BinaryFunctionBinaryPredicate wrapping the given BinaryFunction, or null if the given BinaryFunction is null