1 /*******************************************************************************
2 * SAT4J: a SATisfiability library for Java Copyright (C) 2004-2008 Daniel Le Berre
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 *******************************************************************************/
28 package org.sat4j.tools;
29
30 import org.sat4j.core.VecInt;
31 import org.sat4j.specs.ContradictionException;
32 import org.sat4j.specs.ISolver;
33 import org.sat4j.specs.IVecInt;
34
35 /**
36 * Reader for the Extended Dimacs format proposed by Fahiem Bacchus and Toby
37 * Walsh in array representation (without the terminating 0).
38 *
39 * Adaptation of org.sat4j.reader.ExtendedDimacsReader.
40 *
41 * @author leberre
42 * @author fuhs
43 */
44 public class ExtendedDimacsArrayReader extends DimacsArrayReader {
45
46 public static final int FALSE = 1;
47
48 public static final int TRUE = 2;
49
50 public static final int NOT = 3;
51
52 public static final int AND = 4;
53
54 public static final int NAND = 5;
55
56 public static final int OR = 6;
57
58 public static final int NOR = 7;
59
60 public static final int XOR = 8;
61
62 public static final int XNOR = 9;
63
64 public static final int IMPLIES = 10;
65
66 public static final int IFF = 11;
67
68 public static final int IFTHENELSE = 12;
69
70 public static final int ATLEAST = 13;
71
72 public static final int ATMOST = 14;
73
74 public static final int COUNT = 15;
75
76 private static final long serialVersionUID = 1L;
77
78 private final GateTranslator gater;
79
80 public ExtendedDimacsArrayReader(ISolver solver) {
81 super(solver);
82 gater = new GateTranslator(solver);
83 }
84
85 /**
86 * Handles a single constraint (constraint == Extended Dimacs circuit gate).
87 *
88 * @param gateType
89 * the type of the gate in question
90 * @param output
91 * the number of the output of the gate in question
92 * @param inputs
93 * the numbers of the inputs of the gates in question; the array
94 * must have the corresponding length for the gate type unless
95 * arbitrary lengths are allowed (i.e., 0 for TRUE and FALSE,
96 * 1 for NOT, or 3 for ITE)
97 * @return true
98 */
99 @Override
100 protected boolean handleConstr(int gateType, int output, int[] inputs)
101 throws ContradictionException {
102 IVecInt literals;
103 switch (gateType) {
104 case FALSE:
105 assert inputs.length == 0;
106 gater.gateFalse(output);
107 break;
108 case TRUE:
109 assert inputs.length == 0;
110 gater.gateTrue(output);
111 break;
112 case OR:
113 literals = new VecInt(inputs);
114 gater.or(output, literals);
115 break;
116 case NOT:
117 assert inputs.length == 1;
118 gater.not(output, inputs[0]);
119 break;
120 case AND:
121 literals = new VecInt(inputs);
122 gater.and(output, literals);
123 break;
124 case XOR:
125 literals = new VecInt(inputs);
126 gater.xor(output, literals);
127 break;
128 case IFF:
129 literals = new VecInt(inputs);
130 gater.iff(output, literals);
131 break;
132 case IFTHENELSE:
133 assert inputs.length == 3;
134 gater.ite(output, inputs[0], inputs[1], inputs[2]);
135 break;
136 default:
137 throw new UnsupportedOperationException("Gate type " + gateType
138 + " not handled yet");
139 }
140 return true;
141 }
142 }