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

java.lang.Object
  org.apache.commons.functor.adapter.BinaryPredicateBinaryFunction<L,R>

Type Parameters:

L - the left argument type.

R - the right argument type.

All Implemented Interfaces:

Serializable, BinaryFunction<L,R,Boolean>, BinaryFunctor<L,R>, Functor

public final class BinaryPredicateBinaryFunction<L,R>
extends Object
implements BinaryFunction<L,R,Boolean>, Serializable

Adapts a BinaryPredicate to the BinaryFunction interface.

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

Version:

$Revision: 1156767 $ $Date: 2011-08-11 21:38:12 +0200 (Thu, 11 Aug 2011) $

Author:

Rodney Waldhoff

See Also:

Serialized Form

Constructor Summary

BinaryPredicateBinaryFunction(BinaryPredicate<? super L,? super R> predicate)
Create a new BinaryPredicateBinaryFunction.

Method Summary

static <L,R> BinaryPredicateBinaryFunction<L,R>	adapt(BinaryPredicate<? super L,? super R> predicate) Adapt the given, possibly-null, BinaryPredicate to the BinaryFunction interface.
boolean	equals(BinaryPredicateBinaryFunction<?,?> that) Learn whether another BinaryPredicateBinaryFunction is equal to this.
boolean	equals(Object that) Indicates whether some other object is "equal to" this functor.
Boolean	evaluate(L left, R right) Evaluate this function.
int	hashCode() Returns a hash code for this functor adhering to the general Object.hashCode contract.
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

BinaryPredicateBinaryFunction

public BinaryPredicateBinaryFunction(BinaryPredicate<? super L,? super R> predicate)

Create a new BinaryPredicateBinaryFunction.

Parameters:

predicate - to adapt

Method Detail

evaluate

public Boolean evaluate(L left,
                        R right)

Evaluate this function. Returns Boolean.TRUE (Boolean.FALSE) when the test method of my underlying predicate returns true (false).

Specified by:

evaluate in interface BinaryFunction<L,R,Boolean>

Parameters:

left - the L element of the ordered pair of arguments

right - the R element of the ordered pair of arguments

Returns:

a non-null Boolean instance

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(BinaryPredicateBinaryFunction<?,?> that)

Learn whether another BinaryPredicateBinaryFunction is equal to this.

Parameters:

that - BinaryPredicateBinaryFunction 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> BinaryPredicateBinaryFunction<L,R> adapt(BinaryPredicate<? super L,? super R> predicate)

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

Type Parameters:

L - left type

R - right type

Parameters:

predicate - the possibly-null BinaryPredicate to adapt

Returns:

a BinaryPredicateBinaryFunction wrapping the given BinaryPredicate, or null if the given BinaryPredicate is null