// traverse the ring and add the shortcut links to it.

*operation* void build_shortcuts()
*traverse*
  *from* Ring
  *through* -> *, source, *
  *to-stop* VNode
*carry* *in* Ring* ring = (@ this @)
*along*
  *from* Ring
  *through* -> *, source, *
  *to-stop* VNode
*carry* *in* VirtualAdjacency* adj
*along*
  *from* VirtualAdjacency
  *through* -> *, source, *
  *to-stop* VNode
*at* VirtualAdjacency adj = (@ this @)
*wrapper* VNode
  (@ 
     VNode_ParList* shortcut_vnodes = get_phys_node()->all_vnodes_but(this);
     VNode_ParList* jump_vnodes = adj->get_jump_vnodes();
     ring->connect_shortcuts(shortcut_vnodes, jump_vnodes, ring->get_nextdefault(adj)->get_source());
  @)


// add to the ring shortcuts from the vnodes in "vnodelist1" to the
// the nodes in "vnodelist2" and to "next_vnode".

*operation* void connect_shortcuts(VNode_ParList* vnodelist1, VNode_ParList* vnodelist2, VNode* next_vnode)
*wrapper* Ring
  (@ 
     VNode_list_iterator next_vnode1(*vnodelist1);
     VNode* each_vnode1;

     while (each_vnode1 = next_vnode1()) {
       VNode_list_iterator next_vnode2(*vnodelist2);
       VNode* each_vnode2;
       while (each_vnode2 = next_vnode2()) {
	  check_shortcut(each_vnode1, each_vnode2);
       }
       check_shortcut(each_vnode1, next_vnode);
     }
  @)


// this operation returns all the vnodes of the current node
// except 'vnode'.

*operation* VNode_ParList* all_vnodes_but(VNode* vnode)
*init* (@ new VNode_ParList() @)
*traverse*
  *from* Node
  *to-stop* VNode
*wrapper* VNode
  (@ if (this != vnode)
         return_val->append(this);
   @)




// add a shortcut from vnode1 to vnode2

*operation* void add_shortcut(VNode* vnode1, VNode* vnode2)
*wrapper* Ring
  (@ VirtualAdjacency* adj1 = this->find(vnode1);
     adj1->add_shortcut(vnode2);
  @)

*operation* void add_shortcut(VNode* vnode)
*wrapper* VirtualAdjacency
  (@
     VirtualNeighbor* shortcut_neigh = 
                        new VirtualNeighbor(vnode, new DemReal(0.0),
						   new DemReal(0.0),
						   new DemReal(0.0));
     this->get_shortcuts()->append(shortcut_neigh);
   @)


// check to see if link vnode1 to vnode2 is a shortcut link, and
// if it is then add it to the ring.

*operation* void check_shortcut(VNode* vnode1, VNode* vnode2)
*wrapper* Ring
  (@
     int add = 0;
     VirtualAdjacency* next_adj;
     VNode* next_vnode = vnode2;
     VNode* furthest_source;
     next_adj = this->find(vnode2);
     do {
       furthest_source = furthest_possible_source(next_vnode);
       if (in_ring_order(furthest_source, vnode1, next_vnode)) {
	 add = 1;
	 break;
       }
       next_adj = this->get_nextdefault(next_adj);
       next_vnode = next_adj->get_source();
     }while (next_vnode != vnode1);

     if (add)
       add_shortcut(vnode1, vnode2);
  @)