[Zope-dev] Hey Chris, question for you

[Casey Duncan]

Chris McDonough wrote:
> 
> > Chris:
> >
> > I am working on getting a decent query language for ZCatalog/Catalog and
> 
> Very cool...
> 
> > I have been able to make good progress, however I am running into a bit
> > of an issue that I thought you might know something about:
> >
> > In order to implement a "!=" query operator, I am trying to do the
> > following:
> 
> Tricky.
> 

Ok, I was able to get it to work by instantiating a IISet around
_unindex.keys() and passing that to difference (Thanks!), however, I
notice an interesting side effect. Let's say you have a TextIndex on
title and you do the following query:

title != 'foo*'

Which to me means: "all cataloged objects whose title do not match the
substring 'foo*'"

However, this is not what you get exactly, instead you get:

"all cataloged objects that have a non-empty title that does not match
the substring 'foo*'"

Because from what I am seeing, objects with empty (or no) titles are not
included in the index *at all*. So the set of "all objects" does not
include ones without titles. I could fix this by making all objects be
instead "All objects in the catalog" (via catalog.data.keys()) instead
of "all objects in the index", but I wanted to see if anyone had
additional thoughts about this.

-- 
| Casey Duncan
| Kaivo, Inc.
| cduncan@kaivo.com
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