#include "semcheck.h"

/***********************************************************************
*               find_nullable_vertices.pp                              *
*                                                                      *
*    nullable    : set treated of Adjacency 0                          *
*   nonnullable : set treated of Adjacency 1                           *
************************************************************************/
#define NULLABLE    1
#define UNKNOWN     2
#define NONEMPTY    3
void Cd_graph::find_nullable_vertices()
{
    adjacencies->find_nullable_vertices();
}
void Adjacency_Nlist::find_nullable_vertices()
{
    int done =0;
    while (done == 0)
    {
        done = 1;
        Adjacency_list_iterator   next(*this);
        Adjacency*                each;
        while (each = next())
           each->find_nullable_vertices(this,each,done);
    }
}

void Adjacency::find_nullable_vertices(Adjacency_Nlist* adjs,Adjacency*curr,int& done)
{
   if (this->get_treated()!=NULL) return;
   ns->find_nullable_vertices(adjs,this,done);
}

void Neighbors::find_nullable_vertices(Adjacency_Nlist* adjs,Adjacency*curr,int& done)
{
}

void Neighbors_wc::find_nullable_vertices(Adjacency_Nlist* adjs,Adjacency*curr,int& done)
{
}

void Repetit_n::find_nullable_vertices(Adjacency_Nlist* adjs,Adjacency*curr,int& done)
{
   sandwiched->find_nullable_vertices(adjs,curr,done);
}

void Kernel_Sandwich::find_nullable_vertices(Adjacency_Nlist* adjs,Adjacency*curr,int& done)
{
     int r1 = NULLABLE;
     int r2 = NULLABLE;
     int r3 = NULLABLE;
     first->nullable(r1);
     second->nullable(r2);
     inner->nullable(adjs,r3);
     if ((r1==NULLABLE) && (r2==NULLABLE) && (r3==NULLABLE))
     {
         curr->set_treated(new DemNumber(NULLABLE));
         done = 0;
     }
     else
     if ((r1==NONEMPTY) || (r2==NONEMPTY) || (r2==NONEMPTY))
     {
        curr->set_treated(new DemNumber(NONEMPTY));
        done = 0;
     }
}

void Construct_ns::find_nullable_vertices(Adjacency_Nlist* adjs,Adjacency*curr,int& done)
{
   this->Neighbors_wc::find_nullable_vertices(adjs,curr,done);
   int r = NULLABLE;
   this->get_construct_ns()->nullable(adjs,r);
   if (r==NULLABLE)
   {
         curr->set_treated(new DemNumber(NULLABLE));
         done = 0;
   }
   else
   if (r==NONEMPTY)
   {
        curr->set_treated(new DemNumber(NONEMPTY));
        done = 0;
   }

}

void Alternat_ns::find_nullable_vertices(Adjacency_Nlist* adjs,Adjacency*curr,int& done)
{
   this->Neighbors_wc::find_nullable_vertices(adjs,curr,done);
   int r = NULLABLE;
   alternat_ns->nullable(adjs,r);

   if (r==NULLABLE)
   {
         curr->set_treated(new DemNumber(NULLABLE));
         done = 0;
   }
   else
   if (r==NONEMPTY)
   {
        curr->set_treated(new DemNumber(NONEMPTY));
        done = 0;
   }

}

void Syntax_vertex_List::nullable(int& r)
{
        Syntax_vertex_list_iterator   next(*this);
        Syntax_vertex *               each;
        while (each = next())
          each->nullable(r);
}
void Syntax_vertex::nullable(int& r)
{
}

void Regular_syntax::nullable(int& r)
{
     r = NONEMPTY;
}

void Term_Bar_list::nullable(Adjacency_Nlist* adjs,int &r)
{
     Term_list_iterator next(*this);
     Term*              each;
     int r2;
     int unknown = 0;
     while( each = next())
     {
        each->nullable(adjs,r2);
        if (r2==NULLABLE)
        {
          r = NULLABLE;
          return;
        }
        else
        if (r2==UNKNOWN)
           unknown = 1;
     }
     if (unknown)
       r = UNKNOWN;
     else
       r = NONEMPTY;
}

void Term::nullable(Adjacency_Nlist* adjs,int &r)
{
   vertex->nullable(adjs,r);
}

void Vertex::nullable(Adjacency_Nlist* adjs,int &r)
{
   adjs->check_nullable(this,r);
}

void Adjacency_Nlist::check_nullable(Vertex * v,int & r)
{
     Adjacency_list_iterator next(*this);
     Adjacency*              each;
     while (each = next())
     {
        if (each->get_source()->g_equal(v))
           if (each->get_treated()==NULL)
           {
              r = UNKNOWN;
              return;
           }
           else
           if (each->get_treated()->get_val()==NULLABLE)
           {
              r = NULLABLE;
              return;
           }
           else
           {
              r = NONEMPTY;
              return;
           }
     }
     r = NONEMPTY;
}

void Kernel::nullable(Adjacency_Nlist* adjs,int &r)
{
   if (nonempty)
      nonempty->nullable(adjs,r);
   else
      r=NULLABLE;
}

void Any_vertex_List::nullable(Adjacency_Nlist* adjs,int &r)
{
    Any_vertex_list_iterator  next(*this);
    Any_vertex*               each;
    int r2;
    while(each= next())
    {
      each->nullable(adjs,r2);
      if (r2 == NONEMPTY)
      {
         r = NONEMPTY;
         return;
      }
      else
      if (r2 == UNKNOWN)
      {
         r = UNKNOWN;
         return;
      }
    }
    r = NULLABLE;
}

void Any_vertex::nullable(Adjacency_Nlist* adjs,int &r)
{
}


void Regular_syntax::nullable(Adjacency_Nlist* adjs,int &r)
{
    r = NONEMPTY;
}


void Optional_term::nullable(Adjacency_Nlist* adjs,int &r)
{
   return;
}

void Opt_labeled_term::nullable(Adjacency_Nlist* adjs,int &r)
{
    vertex->nullable(adjs,r);
}