-- Copyright 2003, Trustees of Indiana University
-- Please see the license in the file ../LICENSE

class ADJ_LIST_EDGE_ITERATOR
   
inherit JITERATOR[BASIC_EDGE]

create make_from_adjacency_list_impl


feature {NONE}

   graph : ADJACENCY_LIST
   v_iter : ADJ_LIST_VERTEX_ITERATOR
   out_edge_iter : JITERATOR[BASIC_EDGE]
   source: INTEGER
   
feature {ADJACENCY_LIST}
   make_from_adjacency_list_impl (g: ADJACENCY_LIST) 
      is
      do
         graph := g
      end

feature -- Access

   start is
      local
         go_out : BOOLEAN
      do
         v_iter := graph.vertices
         v_iter.start
         
         from until go_out
         loop
            if v_iter.off then
               go_out := true
            else
               out_edge_iter := graph.out_edges(v_iter.item)
               out_edge_iter.start
               if out_edge_iter.off then
                  v_iter.forth
               else
                  go_out := true
               end
            end
         end
      end

   item: BASIC_EDGE is
      do
         Result := 
            out_edge_iter.item
      end

   forth is
      local
         go_out : BOOLEAN
      do
         out_edge_iter.forth
         if out_edge_iter.off then
            from until go_out
            loop
               v_iter.forth
               if v_iter.off then
                  go_out := true
               else
                  out_edge_iter := graph.out_edges(v_iter.item)
                  out_edge_iter.start
                  if not out_edge_iter.off then
                     go_out := true
                  end
               end
            end
         end
      end

   off: BOOLEAN is
      do
         Result := v_iter.off
      end
   
end -- ADJ_LIST_OUT_EDGE_ITERATOR