TurtleDB
A mini distributed database system
src/ca/uqac/dim/turtledb/Value.java
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00001 /*-------------------------------------------------------------------------
00002     Simple distributed database engine
00003     Copyright (C) 2012  Sylvain Hallé
00004 
00005     This program is free software: you can redistribute it and/or modify
00006     it under the terms of the GNU General Public License as published by
00007     the Free Software Foundation, either version 3 of the License, or
00008     (at your option) any later version.
00009 
00010     This program is distributed in the hope that it will be useful,
00011     but WITHOUT ANY WARRANTY; without even the implied warranty of
00012     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00013     GNU General Public License for more details.
00014 
00015     You should have received a copy of the GNU General Public License
00016     along with this program.  If not, see <http://www.gnu.org/licenses/>.
00017  -------------------------------------------------------------------------*/
00018 package ca.uqac.dim.turtledb;
00019 
00020 public class Value extends Literal
00021 {
00022   private String m_value;
00023   
00024   public Value(String s)
00025   {
00026     m_value = s;
00027   }
00028   
00029   @Override
00030   public String toString()
00031   {
00032     return m_value;
00033   }
00034   
00035   @Override
00036   public boolean equals(Object o)
00037   {
00038     if (o == null)
00039       return false;
00040     if (!(o instanceof Value))
00041       return false;
00042     return equals((Value) o);
00043   }
00044   
00045   public boolean equals(Value v)
00046   {
00047     if (v == null)
00048       return false;
00049     return m_value.compareTo(v.m_value) == 0;
00050   }
00051   
00052   @Override
00053   public int hashCode()
00054   {
00055     return m_value.hashCode();
00056   }
00057   
00058   @Override
00059   public int compareTo(Literal o)
00060   {
00061     if (o instanceof Attribute)
00062       return 1; // All attributes go before all values
00063     assert o instanceof Value;
00064     return compareTo((Value) o);
00065   }
00066   
00067   public int compareTo(Value o)
00068   {
00069     int compare_value = m_value.compareTo(o.m_value);
00070     if (compare_value < 0)
00071       return -1;
00072     if (compare_value > 0)
00073       return 1;
00074     return 0;
00075   }
00076 }