[Zope3-dev] RFC: should z.a.c.attribute.AttributeIndex index None values?

[Gary Poster]

On Nov 17, 2006, at 10:23 AM, Adam Groszer wrote:

> Hello,
>
> Solutions:
>
> a: No, do not keep None values in the catalog
>    the current implementation works like this
>    you are unable to ask the catalog for objects having None
>    properties
> b: Yes, keep None values in the catalog
>    you can ask the catalog for objects having None properties
> c: Let's keep the existing one that does not index None and have an
>    AttributeIndexAlsoNone class which will index None values

Did you see my reply in the other thread?

If you make indexes keep track of None, it will need to be done in a  
separate data structure because of the key homogeneity issues.  This  
is a less efficient approach than the zc.catalog approach.  It can be  
done either way.

I recommend that you use zc.catalog, rather than reinventing  
something that solves your problem.

I suppose I don't care much, since we don't use the standard zope  
value and keyword indexes anyway; if you must add the None feature,  
then I only care, from a "let's not screw up our community software"  
perspective, that it be implemented in a safe way.  Keep your BTree  
keys homogenous.

Gary