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1   /*
2    * #%L
3    * prolobjectlink-jpi-jtrolog
4    * %%
5    * Copyright (C) 2012 - 2018 WorkLogic Project
6    * %%
7    * This program is free software: you can redistribute it and/or modify
8    * it under the terms of the GNU Lesser General Public License as
9    * published by the Free Software Foundation, either version 2.1 of the
10   * License, or (at your option) any later version.
11   * 
12   * This program 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 General Lesser Public License for more details.
16   * 
17   * You should have received a copy of the GNU General Lesser Public
18   * License along with this program.  If not, see
19   * <http://www.gnu.org/licenses/lgpl-2.1.html>.
20   * #L%
21   */
22  package jTrolog.terms;
23  
24  import jTrolog.errors.InvalidTermException;
25  
26  /**
27   * This class represents a variable term. Variables are identified by a name
28   * (which must starts with an upper case letter) or the anonymous ('_') name.
29   * 
30   * @see Term
31   */
32  @SuppressWarnings({ "serial" })
33  public class Var extends Term {
34  
35  	public final static String ANY = "_".intern();
36  
37  	private String name;
38  	public final int nrInStruct;
39  
40  	/**
41  	 * needed to implement Wrapper Objects. Do not use to stringToStructList ANY
42  	 * Vars
43  	 */
44  	Var() {
45  		type = Term.VAR;
46  		nrInStruct = 0;
47  	}
48  
49  	/**
50  	 * Creates a variable identified by a name.
51  	 * 
52  	 * @param n
53  	 *            varaible name if n is "_" the variable is anonymous.
54  	 * @param nr
55  	 *            its variable number of its root parent Struct.
56  	 */
57  	public Var(String n, int nr) throws InvalidTermException {
58  		type = Term.VAR;
59  		name = n.intern();
60  		nrInStruct = nr;
61  	}
62  
63  	public boolean equals(Object t) {
64  		return t instanceof Var && nrInStruct == ((Var) t).nrInStruct;
65  	}
66  
67  	public int hashCode() {
68  		return nrInStruct;
69  	}
70  
71  	/**
72  	 * Tests if this variable is ANY
73  	 */
74  	public boolean isAnonymous() {
75  		return name == ANY;
76  	}
77  
78  	/**
79  	 * Gets the string representation of this variable.
80  	 */
81  	public String toString() {
82  		return name;
83  	}
84  
85  	public String toStringSmall() {
86  		return name;
87  	}
88  
89  }