1 /*******************************************************************************
2 * SAT4J: a SATisfiability library for Java Copyright (C) 2004, 2012 Artois University and CNRS
3 *
4 * All rights reserved. This program and the accompanying materials
5 * are made available under the terms of the Eclipse Public License v1.0
6 * which accompanies this distribution, and is available at
7 * http://www.eclipse.org/legal/epl-v10.html
8 *
9 * Alternatively, the contents of this file may be used under the terms of
10 * either the GNU Lesser General Public License Version 2.1 or later (the
11 * "LGPL"), in which case the provisions of the LGPL are applicable instead
12 * of those above. If you wish to allow use of your version of this file only
13 * under the terms of the LGPL, and not to allow others to use your version of
14 * this file under the terms of the EPL, indicate your decision by deleting
15 * the provisions above and replace them with the notice and other provisions
16 * required by the LGPL. If you do not delete the provisions above, a recipient
17 * may use your version of this file under the terms of the EPL or the LGPL.
18 *
19 * Based on the original MiniSat specification from:
20 *
21 * An extensible SAT solver. Niklas Een and Niklas Sorensson. Proceedings of the
22 * Sixth International Conference on Theory and Applications of Satisfiability
23 * Testing, LNCS 2919, pp 502-518, 2003.
24 *
25 * See www.minisat.se for the original solver in C++.
26 *
27 * Contributors:
28 * CRIL - initial API and implementation
29 *******************************************************************************/
30 package org.sat4j.tools;
31
32 import org.sat4j.core.VecInt;
33 import org.sat4j.specs.ContradictionException;
34 import org.sat4j.specs.ISolver;
35 import org.sat4j.specs.IVecInt;
36
37 /**
38 * Reader for the Extended Dimacs format proposed by Fahiem Bacchus and Toby
39 * Walsh in array representation (without the terminating 0).
40 *
41 * Adaptation of org.sat4j.reader.ExtendedDimacsReader.
42 *
43 * @author leberre
44 * @author fuhs
45 */
46 public class ExtendedDimacsArrayReader extends DimacsArrayReader {
47
48 public static final int FALSE = 1;
49
50 public static final int TRUE = 2;
51
52 public static final int NOT = 3;
53
54 public static final int AND = 4;
55
56 public static final int NAND = 5;
57
58 public static final int OR = 6;
59
60 public static final int NOR = 7;
61
62 public static final int XOR = 8;
63
64 public static final int XNOR = 9;
65
66 public static final int IMPLIES = 10;
67
68 public static final int IFF = 11;
69
70 public static final int IFTHENELSE = 12;
71
72 public static final int ATLEAST = 13;
73
74 public static final int ATMOST = 14;
75
76 public static final int COUNT = 15;
77
78 private static final long serialVersionUID = 1L;
79
80 private final GateTranslator gater;
81
82 public ExtendedDimacsArrayReader(ISolver solver) {
83 super(solver);
84 this.gater = new GateTranslator(solver);
85 }
86
87 /**
88 * Handles a single constraint (constraint == Extended Dimacs circuit gate).
89 *
90 * @param gateType
91 * the type of the gate in question
92 * @param output
93 * the number of the output of the gate in question
94 * @param inputs
95 * the numbers of the inputs of the gates in question; the array
96 * must have the corresponding length for the gate type unless
97 * arbitrary lengths are allowed (i.e., 0 for TRUE and FALSE, 1
98 * for NOT, or 3 for ITE)
99 * @return true
100 */
101 @Override
102 protected boolean handleConstr(int gateType, int output, int[] inputs)
103 throws ContradictionException {
104 IVecInt literals;
105 switch (gateType) {
106 case FALSE:
107 assert inputs.length == 0;
108 this.gater.gateFalse(output);
109 break;
110 case TRUE:
111 assert inputs.length == 0;
112 this.gater.gateTrue(output);
113 break;
114 case OR:
115 literals = new VecInt(inputs);
116 this.gater.or(output, literals);
117 break;
118 case NOT:
119 assert inputs.length == 1;
120 this.gater.not(output, inputs[0]);
121 break;
122 case AND:
123 literals = new VecInt(inputs);
124 this.gater.and(output, literals);
125 break;
126 case XOR:
127 literals = new VecInt(inputs);
128 this.gater.xor(output, literals);
129 break;
130 case IFF:
131 literals = new VecInt(inputs);
132 this.gater.iff(output, literals);
133 break;
134 case IFTHENELSE:
135 assert inputs.length == 3;
136 this.gater.ite(output, inputs[0], inputs[1], inputs[2]);
137 break;
138 default:
139 throw new UnsupportedOperationException("Gate type " + gateType
140 + " not handled yet");
141 }
142 return true;
143 }
144 }