Re: how do i implement double-dispatching?

[cl1motorsports <cwlambert76@yahoo.com>]

> thanks for all of your suggestions. after careful consideration i decided
> to change the above Accept_Visitor procedure to:
> 
> procedure Accept_Vistor(V:in out Visitor_Record'Class; Node : in Parse_Tree_Node_Record'Class) is
> begin
>   if Node in Equal_Op'Class then
> 	Visit(V, Equal_Op(Node));
>   elsif Node in Number_Node'Class then
> 	Visit(V, Number_Node(Node));
>   ...
>   end if;
> end Accept_Visitor;
> 
> now it only dynamically dispatches on the Visitor_Record'Class and the
> Node parameter is determined at compile time. I don't think i would have
> figured that out by myself (at least not at this point in time).

Okay. now it works when the Visitor type, Visit() procedures and the
Accept_Visitor() procedure is in a separate package from the parse tree.
but when i try to combine the 2 into one package i get
an error about multiple dispatching on all of the Visit() procedures.
what is my scope issue with being in the same package that doesn't apply
to them being in 2 packages?

Charles