org.apache.commons.functor.core.composite
Class CompositeUnaryFunction<A,T>

java.lang.Object
  org.apache.commons.functor.core.composite.CompositeUnaryFunction<A,T>

All Implemented Interfaces:

Serializable, Functor, UnaryFunction<A,T>, UnaryFunctor<A>

public class CompositeUnaryFunction<A,T>
extends Object
implements UnaryFunction<A,T>, Serializable

A UnaryFunction representing the composition of UnaryFunctions, "chaining" the output of one to the input of another. For example,

new CompositeUnaryFunction(f).of(g)

evaluates to f.evaluate(g.evaluate(obj)), and

new CompositeUnaryFunction(f).of(g).of(h)

evaluates to f.evaluate(g.evaluate(h.evaluate(obj))).

When the collection is empty, this function is an identity function.

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

Version:

$Revision: 1171157 $ $Date: 2011-09-15 18:04:31 +0200 (Thu, 15 Sep 2011) $

Author:

Rodney Waldhoff, Matt Benson

See Also:

Serialized Form

Constructor Summary

CompositeUnaryFunction(UnaryFunction<? super A,? extends T> function)
Create a new CompositeUnaryFunction.

Method Summary

boolean	equals(CompositeUnaryFunction<?,?> that) Learn whether another CompositeUnaryFunction is equal to this.
boolean	equals(Object that) Indicates whether some other object is "equal to" this functor.
T	evaluate(A obj) Evaluate this function.
int	hashCode() Returns a hash code for this functor adhering to the general Object.hashCode contract.
<P> CompositeUnaryFunction<P,T>	of(UnaryFunction<? super P,? extends A> preceding) Fluently obtain a CompositeUnaryFunction that is "this function" applied to the specified preceding function.
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

CompositeUnaryFunction

public CompositeUnaryFunction(UnaryFunction<? super A,? extends T> function)

Create a new CompositeUnaryFunction.

Parameters:

function - UnaryFunction to call

Method Detail

evaluate

public final T evaluate(A obj)

Evaluate this function.

Specified by:

evaluate in interface UnaryFunction<A,T>

Parameters:

obj - the A object to evaluate

Returns:

the T result of this evaluation

of

public final <P> CompositeUnaryFunction<P,T> of(UnaryFunction<? super P,? extends A> preceding)

Fluently obtain a CompositeUnaryFunction that is "this function" applied to the specified preceding function.

Type Parameters:

P - argument type of the resulting function.

Parameters:

preceding - UnaryFunction

Returns:

CompositeUnaryFunction

equals

public final 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 final boolean equals(CompositeUnaryFunction<?,?> that)

Learn whether another CompositeUnaryFunction is equal to this.

Parameters:

that - CompositeUnaryFunction 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