// traverse the input network and make a list of the nodes in
// the network. We want only one copy of a node that appears
// in the network. This list is used to build a new network with
// pointers.

*operation* Node_List* all_nodes()
*init* (@ new Node_List() @)
*traverse*
  *from* InputNetwork
  *to-stop* InputAdjacency
*wrapper* InputAdjacency
  (@ InputNode* in_node = get_source();
     if (!(return_val->id_member(in_node))) {
       Node* node = new Node(in_node->get_id(), new VNode_ParList());
       return_val->append(node);
     }
   @)


// find the position of a node with the same id as "node" in the
// list of nodes. If there is no such node, the function returns 0.

*operation* int id_member(InputNode* node)
*init* (@ 0 @)
*traverse* 
  *from* Node_List
  *to-stop* Node
*carry* *inout* int count = (@ 0 @)
*along*
  *from* Node_List
  *to-stop* Node  
*wrapper* Node
  (@ 
     count++;
     if (this->get_id()->g_equal(node->get_id()))
       return_val = count;
  @)


// use the list of nodes "nodelist" to build a new network where
// there is only one copy of each node.

*operation* Network* rebuild_network(Node_List*& nodelist)
*wrapper* InputNetwork
  (@
     nodelist = this->all_nodes();
     Network* new_net = new Network(new Adjacency_ParList());
     this->traverse_net(nodelist, new_net);
     return_val = new_net;
   @)


// this is the function that actually does the work for the network
// rebuilt.

*operation* void traverse_net(Node_List* nodelist, Network* net)
*traverse*
  *from* InputNetwork
  *to-stop* InputAdjacency
*wrapper* InputAdjacency
  (@
     int pos = nodelist->id_member(get_source());
     if (pos == 0) {
       cout << "***Error!\n";
       exit(1);
     }
     Node* node = nodelist->n_th(pos);
     Neighbor_ParList* neighbors = new Neighbor_ParList();
     Adjacency* new_adj = new Adjacency(node, neighbors, new DemNumber(0));
     this->update_neighbors(nodelist, new_adj);
     net->get_adjacencies()->append(new_adj);
   @)


// add neighbors to the adjacency "adj", using the list of nodes

*operation* void update_neighbors(Node_List* nodelist, Adjacency* adj)
*traverse*
  *from* InputAdjacency
  *through* -> *, neighbors, *
  *to-stop* InputNeighbor
*wrapper* InputNeighbor
  (@ 
     int pos = nodelist->id_member(get_node());
     Node* node = nodelist->n_th(pos);
     Neighbor* new_neighbor = new Neighbor(node, get_capacity());
     adj->get_neighbors()->append(new_neighbor);
   @)