/*license*\
XBN-Java Library
Copyright (c) 2014, Jeff Epstein (aliteralmind __DASH__ github __AT__ yahoo __DOT__ com)
This software is dual-licensed under the:
- Lesser General Public License (LGPL) version 3.0 or, at your option, any later version;
- Apache Software License (ASL) version 2.0.
Either license may be applied at your discretion. More information may be found at
- http://en.wikipedia.org/wiki/Multi-licensing.
The text of both licenses is available in the root directory of this project, under the names "LICENSE_lgpl-3.0.txt" and "LICENSE_asl-2.0.txt". The latest copies may be downloaded at:
- LGPL 3.0: https://www.gnu.org/licenses/lgpl-3.0.txt
- ASL 2.0: http://www.apache.org/licenses/LICENSE-2.0.txt
\*license*/
package com.github.xbn.examples.lang.functor;
/**
<p>Implementing a <a href="http://stackoverflow.com/questions/7369460/help-with-understanding-a-function-object-or-functor-in-java/22163940#22163940">functor</a> with an Enum.</p>
<p>{@code java com.github.xbn.examples.lang.functor.FunctorAsEnum1of2}</p>
* @see com.github.xbn.examples.lang.functor.FunctorAsEnum2of2
* @since 0.1.0
* @author Copyright (C) 2014, Jeff Epstein ({@code aliteralmind __DASH__ github __AT__ yahoo __DOT__ com}), dual-licensed under the LGPL (version 3.0 or later) or the ASL (version 2.0). See source code for details. <a href="http://xbnjava.aliteralmind.com">{@code http://xbnjava.aliteralmind.com}</a>, <a href="https://github.com/aliteralmind/xbnjava">{@code https://github.com/aliteralmind/xbnjava}</a>
**/
public class FunctorAsEnum1of2 {
public static final void main(String[] ignored) {
CardinalDirection.WEST.move(3);
CardinalDirection.NORTH.move(2);
CardinalDirection.EAST.move(15);
}
}
enum CardinalDirection {
NORTH(new MoveNorth()),
SOUTH(new MoveSouth()),
EAST(new MoveEast()),
WEST(new MoveWest());
private final MoveInDirection dirFunc;
CardinalDirection(MoveInDirection dirFunc) {
if(dirFunc == null) {
throw new NullPointerException("dirFunc");
}
this.dirFunc = dirFunc;
}
public void move(int steps) {
dirFunc.move(steps);
}
}
interface MoveInDirection {
void move(int steps);
}
class MoveNorth implements MoveInDirection {
public void move(int steps) {
System.out.println("Moved " + steps + " steps north.");
}
}
class MoveSouth implements MoveInDirection {
public void move(int steps) {
System.out.println("Moved " + steps + " steps south.");
}
}
class MoveEast implements MoveInDirection {
public void move(int steps) {
System.out.println("Moved " + steps + " steps east.");
}
}
class MoveWest implements MoveInDirection {
public void move(int steps) {
System.out.println("Moved " + steps + " steps west.");
}
}