[VPM] testing two refs for same target
Peter Scott
Peter at PSDT.com
Sat Jul 5 10:22:03 CDT 2003
At 12:15 AM 7/5/2003 -0700, Darren Duncan wrote:
>Actually, if a user is declaring more than once that a node is a child of
>another, this would likely be considered an error, but it is one that my
>current input checking routines don't look for.
Ah, then a hash would be ideal:
$child{$obj} ? error("Object is already a child") : ($child{$obj} = $obj);
> A hash would be ideal except that I am interested in maintaining the
> order of all the child nodes under a parent.
tie %child, "Tie::IxHash";
>I may probably end up using both an array and a hash which both list the
>same items, for different reasons.
>
> >Strange sort of inheritance relationship you've got going there...
>
>I should clarify that there is technically no inheritence being used
>here. All of the "nodes" are each separate objects, all of which are in
>the same class.
I misspoke. I meant the parent-child relationships you were talking about.
But we should reserver 'inheritance' for class relationships, so in your
case it's a container tree, or... someone help me out with the proper term
here.
>SQL::ObjectModel is conceptually similar to an XML DOM, which has a tree
>of nodes, except that it is more specialized in its content. If it were
>practical to do so I may even change it later to subclass an XML DOM
>implementation or something. But I probably won't since I don't need most
>of the DOM features and they take up space.
--
Peter Scott
peter at psdt.com
http://www.perldebugged.com
More information about the Victoria-pm
mailing list