// @(#)$Id: Comparator.refines-spec,v 1.3 2006/01/24 17:09:48 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 java.util;

public interface Comparator {

    // FIXME -- complete these specs - what about null arguments?
    // what about purity?

    /*@ also public behavior
      @ ensures o==this ==> \result;
      @*/
    //@ pure
    public boolean equals(/*@ nullable @*/ java.lang.Object o);

    /*@
      @ ensures o == oo ==> \result == 0;
      @*/
    //@ pure
    public int compare(java.lang.Object o, java.lang.Object oo);
}