/*******************************************************************************
* SAT4J: a SATisfiability library for Java Copyright (C) 2004-2008 Daniel Le Berre
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU Lesser General Public License Version 2.1 or later (the
* "LGPL"), in which case the provisions of the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of the LGPL, and not to allow others to use your version of
* this file under the terms of the EPL, indicate your decision by deleting
* the provisions above and replace them with the notice and other provisions
* required by the LGPL. If you do not delete the provisions above, a recipient
* may use your version of this file under the terms of the EPL or the LGPL.
*
* Based on the original MiniSat specification from:
*
* An extensible SAT solver. Niklas Een and Niklas Sorensson. Proceedings of the
* Sixth International Conference on Theory and Applications of Satisfiability
* Testing, LNCS 2919, pp 502-518, 2003.
*
* See www.minisat.se for the original solver in C++.
*
*******************************************************************************/
package org.sat4j.tools;
import org.sat4j.core.VecInt;
import org.sat4j.specs.ContradictionException;
import org.sat4j.specs.ISolver;
import org.sat4j.specs.IVecInt;
/**
* Reader for the Extended Dimacs format proposed by Fahiem Bacchus and Toby
* Walsh in array representation (without the terminating 0).
*
* Adaptation of org.sat4j.reader.ExtendedDimacsReader.
*
* @author leberre
* @author fuhs
*/
public class ExtendedDimacsArrayReader extends DimacsArrayReader {
public static final int FALSE = 1;
public static final int TRUE = 2;
public static final int NOT = 3;
public static final int AND = 4;
public static final int NAND = 5;
public static final int OR = 6;
public static final int NOR = 7;
public static final int XOR = 8;
public static final int XNOR = 9;
public static final int IMPLIES = 10;
public static final int IFF = 11;
public static final int IFTHENELSE = 12;
public static final int ATLEAST = 13;
public static final int ATMOST = 14;
public static final int COUNT = 15;
private static final long serialVersionUID = 1L;
private final GateTranslator gater;
public ExtendedDimacsArrayReader(ISolver solver) {
super(solver);
gater = new GateTranslator(solver);
}
/**
* Handles a single constraint (constraint == Extended Dimacs circuit gate).
*
* @param gateType
* the type of the gate in question
* @param output
* the number of the output of the gate in question
* @param inputs
* the numbers of the inputs of the gates in question; the array
* must have the corresponding length for the gate type unless
* arbitrary lengths are allowed (i.e., 0 for TRUE and FALSE,
* 1 for NOT, or 3 for ITE)
* @return true
*/
@Override
protected boolean handleConstr(int gateType, int output, int[] inputs)
throws ContradictionException {
IVecInt literals;
switch (gateType) {
case FALSE:
assert inputs.length == 0;
gater.gateFalse(output);
break;
case TRUE:
assert inputs.length == 0;
gater.gateTrue(output);
break;
case OR:
literals = new VecInt(inputs);
gater.or(output, literals);
break;
case NOT:
assert inputs.length == 1;
gater.not(output, inputs[0]);
break;
case AND:
literals = new VecInt(inputs);
gater.and(output, literals);
break;
case XOR:
literals = new VecInt(inputs);
gater.xor(output, literals);
break;
case IFF:
literals = new VecInt(inputs);
gater.iff(output, literals);
break;
case IFTHENELSE:
assert inputs.length == 3;
gater.ite(output, inputs[0], inputs[1], inputs[2]);
break;
default:
throw new UnsupportedOperationException("Gate type " + gateType
+ " not handled yet");
}
return true;
}
}