#include "treeprop.h"

/******************************************************************************
 Tree property checker.
 File name :set_utilities.c
 Author    :Christos Stamelos.
 Version   :II
 Date      :14 Jan 1991.
******************************************************************************/

/* This file contains the functionallity for set manipulation  */

/* The specific type of set is :

   Item_set = < item > Lc
              <cardinality> DemNumber
              <members> List( DemIdent ). */

int belongs_to_set(DemIdent* id, DemIdent_list* iset)
{
  DemIdent_list_iterator next_arg(*iset);
  DemIdent_ each_arg;

  while(each_arg=next_arg())
   if (id->g_equal(each_arg)) 
    return 1;

  return 0;
}


DemIdent_list* DemIdent_list::intersec(DemIdent_list* iset)
{
 DemIdent_list_iterator next_arg(*this);
 DemIdent_  each_arg;

 DemIdent_list* intersec_set = new DemIdent_list();

 while(each_arg=next_arg())
  if ( belongs_to_set(each_arg,iset) )
   intersec_set->append(each_arg);

  return intersec_set;

}

int DemIdent_list::is_empty_set()
{
 if( this->list_length() )
  return 0;
 else
  return 1;
}

DemIdent_list* DemIdent_list::set_difference(DemIdent_list *iset)
{
 DemIdent_list_iterator next_arg(*this);
 DemIdent_ each_arg;

 DemIdent_list* difference_set = new DemIdent_list();

 while(each_arg=next_arg())
  if( !belongs_to_set(each_arg,iset) )
   difference_set->append(each_arg);

 return difference_set;

}

DemIdent_list* DemIdent_list::replace_subset_with_element(DemIdent_list* iset, DemIdent *element)
{
  DemIdent_list* new_list = new DemIdent_list( );
   
  new_list =  this->set_difference( iset ) ;

  new_list->append(element);

  return new_list;

}