ItemsetCompare.h

/**************************************************************************
 * Copyright (c) 2007 Clifford Conley Owens III                           *
 *                                                                        *
 * This file is part of Biorithm.                                         *
 *                                                                        *
 * Biorithm is free software: you can redistribute it and/or modify       *
 * it under the terms of the GNU General Public License as published by   *
 * the Free Software Foundation, either version 3 of the License, or      *
 * (at your option) any later version.                                    *
 *                                                                        *
 * Biorithm is distributed in the hope that it will be useful,            *
 * but WITHOUT ANY WARRANTY; without even the implied warranty of         *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the          *
 * GNU General Public License for more details.                           *
 *                                                                        *
 * You should have received a copy of the GNU General Public License      *
 * along with Biorithm.  If not, see <http://www.gnu.org/licenses/>.      *
 *                                                                        *
 **************************************************************************/

#ifndef ITEMSETCOMPARE_H
#define ITEMSETCOMPARE_H

// ---------------------------- Internal Headers ---------------------------- //

#include "Itemset.h"

int compare(const Itemset* is1, const Itemset* is2);

// The hash template
template<typename T> struct hash
{

};

// The less than template
template<typename T> struct ltis
{

};

// The less than operator
template<> struct ltis<const Itemset*>
{
    bool operator()(const Itemset* is1, const Itemset* is2) const
    {
        if (is1 && is2)
        {
            return compare(is1, is2) < 0;
        }
        return false;
    }
};

// The hash function
template<> struct hash<const Itemset*>
{
   size_t operator()(const Itemset* is) const
   {
      unsigned long ret = 0;
      for (unsigned int i = 0; i < (*is).getSize(); i++)
      {
          ret = (113 * ret) + (*is)[i];
      }
      return (size_t)ret;
   }
};

// The equal function
struct eqis
{
    bool operator()(const Itemset* is1, const Itemset* is2) const
    {
        if (is1 && is2)
        {
            return !compare(is1, is2);
        }
        return false;
    }
};

#endif