View Javadoc

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 pseudo boolean algorithms described in:
20  * A fast pseudo-Boolean constraint solver Chai, D.; Kuehlmann, A.
21  * Computer-Aided Design of Integrated Circuits and Systems, IEEE Transactions on
22  * Volume 24, Issue 3, March 2005 Page(s): 305 - 317
23  * 
24  * and 
25  * Heidi E. Dixon, 2004. Automating Pseudo-Boolean Inference within a DPLL 
26  * Framework. Ph.D. Dissertation, University of Oregon.
27  *******************************************************************************/
28  package org.sat4j.pb.reader;
29  
30  import java.io.IOException;
31  import java.text.ParseException;
32  
33  import org.sat4j.core.VecInt;
34  import org.sat4j.pb.IPBSolver;
35  import org.sat4j.reader.ParseFormatException;
36  import org.sat4j.specs.IVecInt;
37  
38  /**
39   * @author anne
40   *
41   */
42  public class OPBEclipseReader2007 extends OPBReader2007 {
43  
44  	/**
45  	 * 
46  	 */
47  	private static final long serialVersionUID = 1L;
48  
49  	private IVecInt varExplain = new VecInt();
50  	/**
51  	 * @param solver
52  	 */
53  	public OPBEclipseReader2007(IPBSolver solver) {
54  		super(solver);
55  	}
56  
57      /**
58       * callback called before we read the list for variables explanation
59       */
60      protected void beginListOfVariables() {
61      }
62  
63      /**
64       * callback called after we've read the list for variable explanation
65       */
66      protected void endListOfVariables() {
67      }
68  
69      /**
70       * read the list for variables explanation (if any) calls beginListOfVariables and
71       * endListOfVariables
72       * 
73       * @throws IOException
74       * @throws ParseException
75       */
76      @Override
77  	protected void readVariablesExplanation()  throws IOException, ParseFormatException{
78          char c;
79          StringBuffer var = new StringBuffer();
80  
81          // read variables line (if any)
82          // if the problem is unsatisfiable, and if these variables are part of the reason of the conflict
83          // then an explanation should be produced for these variables
84  
85          skipSpaces();
86          c = get();
87          if (c != 'e') {
88              // no variables line
89              putback(c);
90              return;
91          }
92  
93          hasVariablesExplanation = true;
94          if (get() == 'x' && get() == 'p' && get() == 'l' && get() == 'a' && get() == 'i' && get() == 'n' && get() == ':') {
95              beginListOfVariables(); // callback
96  
97              while (!eof()) {
98  				readIdentifier(var);
99  				varExplain.push(translateVarToId(var.toString()));
100 				
101                 skipSpaces();
102                 c = get();
103                 if (c == ';')
104                     break; // end of list of variables
105                 putback(c);
106             }
107 
108             endListOfVariables();
109         } else
110             throw new ParseFormatException(
111                     "input format error: 'explain:' expected");
112 
113 	}
114 
115     @Override
116 	public IVecInt getListOfVariables() {
117         if (hasVariablesExplanation){
118         	IVecInt tmp = new VecInt();
119             varExplain.moveTo(tmp);
120             return tmp;
121         }
122         return null;
123     }
124 
125     
126 }