/* Poly_Gen_Relation Java class declaration and implementation.
   Copyright (C) 2001-2009 Roberto Bagnara <bagnara@cs.unipr.it>

This file is part of the Parma Polyhedra Library (PPL).

The PPL is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3 of the License, or (at your
option) any later version.

The PPL 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 General Public License
for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1307, USA.

For the most up-to-date information see the Parma Polyhedra Library
site: http://www.cs.unipr.it/ppl/ . */

package parma_polyhedra_library;

//! The relation between a polyhedron and a generator
/*! \ingroup PPL_CXX_interface
  This class implements conjunctions of assertions on the relation
  between a polyhedron and a generator.
*/
public class Poly_Gen_Relation {

    public static final int NOTHING = 0;
    public static final int SUBSUMES = 1;

    //! Holds the value of the possible relations.
    private int mask_value;

    //! Constructs from a integer value.
    public Poly_Gen_Relation(int val) {
	mask_value = val;
    }

    //! The assertion that says nothing.
    public static Poly_Gen_Relation nothing() {
	return new Poly_Gen_Relation(Poly_Gen_Relation.NOTHING);
    }

    //! Adding the generator would not change the polyhedron.
    public static Poly_Gen_Relation subsumes() {
	return new  Poly_Gen_Relation(Poly_Gen_Relation.SUBSUMES);
    }

    //! True if and only if \p *this implies \p y.
    public boolean implies(Poly_Gen_Relation y) {
	return (this.mask_value & y.mask_value) ==  y.mask_value;
    }
}
