blob: ac937a548d1e8497f89a937b1f16adbf24236a56 [file] [log] [blame]
package com.googlecode.prolog_cafe.lang;
/**
* Initial continuation goal.<br>
* That is to say, this <code>Success</code> will be executed
* every time the Prolog Cafe system finds an answer.
*
* @author Mutsunori Banbara (banbara@kobe-u.ac.jp)
* @author Naoyuki Tamura (tamura@kobe-u.ac.jp)
* @version 1.0
*/
public class Success extends Operation {
public static final Success SUCCESS = new Success();
private Success() {}
/**
* Backtracks and returns a next clause
* after invoking the <code>PrologControl.success()</code>.
* @param engine Prolog engine
* @see PrologControl#success
*/
public Operation exec(Prolog engine) {
engine.control.success();
return engine.fail();
}
/** Returns a string representation of this <code>Success</code>. */
public String toString(){ return "Success"; }
}