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.specs;
29
30 import java.io.Serializable;
31
32 /**
33 * Interface to the solver main steps. Useful for integrating search
34 * visualization or debugging.
35 *
36 * (that class moved from org.sat4j.minisat.core in earlier version of SAT4J).
37 *
38 * @author daniel
39 * @since 2.1
40 */
41 public interface SearchListener extends Serializable {
42
43 /**
44 * decision variable
45 *
46 * @param p
47 */
48 void assuming(int p);
49
50 /**
51 * Unit propagation
52 *
53 * @param p
54 * @param reason
55 * TODO
56 */
57 void propagating(int p, IConstr reason);
58
59 /**
60 * backtrack on a decision variable
61 *
62 * @param p
63 */
64 void backtracking(int p);
65
66 /**
67 * adding forced variable (conflict driven assignment)
68 */
69 void adding(int p);
70
71 /**
72 * learning a new clause
73 *
74 * @param c
75 */
76 void learn(IConstr c);
77
78 /**
79 * delete a clause
80 */
81 void delete(int[] clause);
82
83 /**
84 * a conflict has been found.
85 *
86 * @param confl
87 * TODO
88 * @param dlevel
89 * TODO
90 * @param trailLevel TODO
91 *
92 */
93 void conflictFound(IConstr confl, int dlevel, int trailLevel);
94
95 /**
96 * a conflict has been found while propagating values.
97 *
98 * @param p
99 * the conflicting value.
100 */
101 void conflictFound(int p);
102
103 /**
104 * a solution is found.
105 *
106 */
107 void solutionFound();
108
109 /**
110 * starts a propagation
111 */
112 void beginLoop();
113
114 /**
115 * Start the search.
116 *
117 */
118 void start();
119
120 /**
121 * End the search.
122 *
123 * @param result
124 * the result of the search.
125 */
126 void end(Lbool result);
127
128 /**
129 * The solver restarts the search.
130 */
131 void restarting();
132
133 /**
134 * The solver is asked to backjump to a given decision level.
135 *
136 * @param backjumpLevel
137 */
138 void backjump(int backjumpLevel);
139 }