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1   /*
2    * db2sa: DB2 Syntax Assistant
3    * Copyright (C) Andres Gomez Casanova
4    *
5    * This file is part of db2sa.
6    *
7    * db2sa is free software: you can redistribute it and/or modify
8    * it under the terms of the GNU Lesser General Public License as published by
9    * the Free Software Foundation; either version 3 of the License, or
10   * (at your option) any later version.
11   *
12   * db2sa is distributed in the hope that it will be useful,
13   * but WITHOUT ANY WARRANTY; without even the implied warranty of
14   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   * GNU Lesser General Public License for more details.
16   *
17   * You should have received a copy of the GNU Lesser General Public License
18   * along with this library; if not, see <http://www.gnu.org/licenses/>.
19   *
20   * Contact:
21   * a n g o c a  at  y a h o o  dot  c o m
22   * Cra. 45 No 61 - 31, Bogota, Colombia.
23   *
24   * Author:   $LastChangedBy: angoca $:
25   * Date:     $LastChangedDate: 2009-06-11 23:52:28 +0200 (Thu, 11 Jun 2009) $:
26   * Revision: $LastChangedRevision: 225 $:
27   * URL:      $HeadURL: https://db2sa.svn.sourceforge.net/svnroot/db2sa/branches/db2sa_beta/source-code/src/main/java/name/angoca/db2sa/core/syntax/graph/StartingToken.java $:
28   */
29  package name.angoca.db2sa.core.syntax.graph;
30  
31  import java.util.List;
32  
33  import name.angoca.db2sa.Constants;
34  
35  /**
36   * This token represents the first token in the grammar (the starting node in
37   * the graph.) All the possible ways starts from this token.<br/>
38   * <b>Control Version</b><br />
39   * <ul>
40   * <li>0.0.1 Class creation.</li>
41   * <li>0.0.2 Recommendations from PMD.</li>
42   * <li>0.0.3 Change constant value.</li>
43   * <li>0.0.4 Starting and ending token as constants.</li>
44   * <li>0.0.5 equals from super.</li>
45   * <li>0.0.6 equals different super.</li>
46   * <li>0.0.7 part equals super.</li>
47   * <li>1.0.0 Moved to version 1.</li>
48   * </ul>
49   * 
50   * @author Andres Gomez Casanova <a
51   *         href="mailto:a n g o c a at y a h o o dot c o m">(AngocA)</a>
52   * @version 1.0.0 2009-07-19
53   */
54  public class StartingToken extends GraphToken {
55  
56      /**
57       * Constructor that defines the starting node. Its name is STARTING_TOKEN
58       * and this works as a reserved name token.
59       */
60      public StartingToken() {
61          super(Constants.STARTING_TOKEN, true);
62      }
63  
64      /*
65       * (non-Javadoc)
66       * 
67       * @see
68       * name.angoca.db2sa.core.syntax.graph.GraphToken#equals(java.lang.Object)
69       */
70      @Override
71      public final boolean equals(final Object/* ? */object) {
72          // The equals was designed not to be symmetric with its parent.
73          // TODO test a.equals(b) y b.equals(a)
74          boolean equals = false;
75          if (object instanceof StartingToken) {
76              final GraphToken token = (GraphToken) object;
77              final List<GraphToken> ways = token.getWays();
78              if (token.getName().compareTo(this.getName()) == 0
79                      && token.isReservedWord() == this.isReservedWord()
80                      && ways.size() == this.getWays().size()) {
81                  equals = super.equals(token);
82              }
83          }
84          return equals;
85      }
86  
87      /*
88       * (non-Javadoc)
89       * 
90       * @see java.lang.Object#hashCode()
91       */
92      @Override
93      public final int hashCode() {
94          return Constants.STARTING_TOKEN.hashCode() * -1;
95      }
96  
97      /**
98       * Returns a string representation of an starting token. The representation
99       * is: {START NODE}
100      * 
101      * @see java.lang.Object#toString()
102      * @return String representation of an starting token.
103      */
104     @Override
105     public final String/* ! */toString() {
106         return "{START NODE}"; //$NON-NLS-1$
107     }
108 }