-- File:	GraphTools_BFSIterator.cdl
-- Created:	Mon Oct 12 12:58:52 1992
-- Author:	Denis PASCAL
--		<dp@bravox>
---Copyright:	 Matra Datavision 1992


generic class BFSIterator from GraphTools 
                         (Graph     as any;
                          Vertex    as any;
			  VHasher   as any;
                          VIterator as any)
			  
--generic class BFSIterator from GraphTools
--            (Graph     as any;
--    	       Vertex    as any;
--    	       VHasher   as MapHasher from TCollection (Vertex);
--	       VIterator as VertexIterator (Graph,Vertex))

---Purpose: This generic class  implement the Breadth First Search
    --          algorithm from a Vertex with   an iterator to  reached
    --          adjacent vertices of  a given  one.   The interface of
    --          this algorithm is made as an iterator.

raises NoMoreObject from Standard,
       NoSuchObject from Standard

    class BFSMap instantiates IndexedMap from TCollection (Vertex,VHasher); 
                                        
is

    Create
    returns BFSIterator;
	---Purpose: Create an empty iterator.

    Perform (me : in out; G : Graph; V : Vertex);
	---Purpose: Initializes the research from <V> member vertex of <G>.
        ---Level: Public

    More (me) returns Boolean from Standard;
	---Purpose: Returns True if there are other vertices.
        ---Level: Public
    
    Next(me : in out) 
    	---Purpose: Set the iterator to the next vertex.
        ---Level: Public
    raises NoMoreObject from Standard;

    Value(me) returns any Vertex 
	---Purpose: returns   the vertex value  for the current
	--          position of the iterator.
        ---Level: Public
	---C++: return const &
    raises NoSuchObject from Standard;

fields

    myVisited      : BFSMap  from GraphTools;
    myCurrentIndex : Integer from Standard;
    
end BFSIterator;