// @(#)$Id: CompareTo.java,v 1.13 2007/02/08 14:05:50 leavens Exp $
// Copyright (C) 2005 Iowa State University
//
// This file is part of the runtime library of the Java Modeling Language.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public License
// as published by the Free Software Foundation; either version 2.1,
// of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with JML; see the file LesserGPL.txt. If not, write to the Free
// Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
// 02110-1301 USA.
package org.jmlspecs.unfinished.resolve;
/** Objects with a compareTo operation. Unlike {@link
* java.lang.Comparable}, this operation is not assumed to be a total
* order, and may be partial.
*
* @version $Revision: 1.13 $
* @author Gary T. Leavens
* @see TotallyOrderedCompareTo
*/
public interface CompareTo {
/** Compare this to obj, returning negative if this is
* strictly less than obj, 0 if they are equal, and
* positive otherwise.
*/
/*@ public behavior
@ requires obj != null;
@ ensures isComparableTo(obj);
@ ensures (* returns if this is comparable to obj *);
@ signals_only UndefinedException, ClassCastException;
@ signals (UndefinedException e)
@ (* no comparison between this and obj is defined *)
@ && e != null;
@ signals (ClassCastException e)
@ (* obj's type prevents it from being compared to this *)
@ && e != null;
@*/
/*@ pure @*/ int compareTo(/*@ non_null @*/ Object obj)
throws UndefinedException, ClassCastException, NullPointerException;
/** Tells whether this has a defined comparision with obj.
*/
/*@
@ public normal_behavior
@ ensures \result <==>
@ (* there is a defined comparison between obj and this *);
@ also
@ public model_program {
@ try {
@ int r = this.compareTo(obj);
@ } catch (UndefinedException e) {
@ return false;
@ } catch (ClassCastException e) {
@ return false;
@ }
@ return true;
@ }
pure model boolean isComparableTo(non_null Object obj);
@*/
}