Re: Endless loop by dispatching

[Michael Erdmann <michael.erdmann@snafu.de>]

Jean-Pierre Rosen wrote:

> 
> You missed the point :-)
>
I understood this mean while. It seems that the case A.Object(This) does
not change the tag. I have checked the RM but i found nothing, but this
seems to be accepted as normal behaviour in the community.


> Serialize is a general entry point, which dispatches to Write. If you call it again from Write, it will redispatch
> to Write, hence the loop.
> 
> Now do you think that Write of B is really Serialize of A, plus something else?
> Isn't it *Write* of A, plus something else? If you change your package to
> 
> package body B is
> 
>     procedure Write(
>        This : in Object ) is
>     begin
>        A.Write( A.Object( This ) );
>        Put_Line( "Q =" & Natural'Image(This.Q));
>     end Write;
> 
> end B;
> 
> It will be OK.


> 
> Oh, by the way, why do you need Serialize at all? Since all it does is call Write, why don't you
> call Write directly?
> 

Maybe the conseded code i have sent was missleading. Since the
procedure Serialize is intended to do more then just i put it
here as pseudocode:

procedure Serialze( this : in Object'Class ) is

     Serialize( Super( This ) );

     F := Get( Attribute( this'Tag ) )
     while F /= null loop
        Unbounded_String'Output( S, F.Name );
        Write( This, F.Id );
        F := Next(...);
     end loop;

end Serialize:

Using write directly is possible but then i have to put the code of
serialze everwhere were i want to do the trick. I there would be 
something like the Super operation yielding the references to the
super class then everthing would be fine, i guess!

Michael