net.sf.jga.fn.comparison
Class ComparatorFn<T>

java.lang.Object
  net.sf.jga.fn.Functor<R>
      net.sf.jga.fn.BinaryFunctor<T,T,java.lang.Integer>
          net.sf.jga.fn.comparison.ComparatorFn<T>

All Implemented Interfaces:

java.io.Serializable, java.util.Comparator<T>, Visitable

public class ComparatorFn<T>
extends BinaryFunctor<T,T,java.lang.Integer>
implements java.util.Comparator<T>

Functor wrapper around Comparator object. Allows Comparators to be used anywhere a Functor returning an Integer could have been used. Also implements Comparator as well, so an instance of this class could be used anywhere that the constructor argument could be used.

To Serialize a ComparatorFn, the Comparator given at construction must be Serializable.

Copyright © 2002-2005 David A. Hall

Author:

David A. Hall

See Also:

Serialized Form

Nested Class Summary

static interface

ComparatorFn.Visitor Interface for classes that may interpret a ComparatorFn functor.

Constructor Summary

ComparatorFn(java.util.Comparator<T> comp)
Builds the ComparatorFn wrapped around the given Comparator.

Method Summary

void	accept(Visitor v) Calls the Visitor's visit(ComperatorFn) method, if it implements the nested Visitor interface.
int	compare(T x, T y)
java.lang.Integer	fn(T x, T y) Given arguments x and y, return the result of the Comparator's compare(x,y) method, wrapped in an Integer.
java.util.Comparator<T>	getComparator() Returns the comparator in use by this functor
java.lang.String	toString()

Methods inherited from class net.sf.jga.fn.BinaryFunctor

bind, bind0th, bind1st, bind2nd, bindNth, compose, compose, composeNth, distribute, eval, generate, generate1st, generate2nd, generateNth

Methods inherited from class net.sf.jga.fn.Functor

composeNth

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Comparator

equals

Constructor Detail

ComparatorFn

public ComparatorFn(java.util.Comparator<T> comp)

Builds the ComparatorFn wrapped around the given Comparator.

Throws:

java.lang.NullPointerException - if no Comparator is passed.

Method Detail

getComparator

public java.util.Comparator<T> getComparator()

Returns the comparator in use by this functor

fn

public java.lang.Integer fn(T x,
                            T y)

Given arguments x and y, return the result of the Comparator's compare(x,y) method, wrapped in an Integer. Whether or not a NullPointerException is thrown if either x or y are null is up to the Comparator

Specified by:

fn in class BinaryFunctor<T,T,java.lang.Integer>

Returns:

the result of the Comparator's compare(x,y) method

accept

public void accept(Visitor v)

Calls the Visitor's visit(ComperatorFn) method, if it implements the nested Visitor interface.

Specified by:

accept in interface Visitable

Overrides:

accept in class Functor<java.lang.Integer>

compare

public int compare(T x,
                   T y)

Specified by:

compare in interface java.util.Comparator<T>

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object