This is a project I have been keeping in the back of my mind for a while now. At present I do not have the resources to devote, but it is my hope that this will change. I feel strongly that that ZCatalog should have a general query language on par with an SQL where clause. Much of the work to implement this exists in various places, it really just needs fleshing out and tying together.
I totally agree.
I have also been waiting for the ZCatalog changes that have just taken place in 2.3.1. Now that this has happened, it may be a good time to start the discussion in the Fishbowl. I would be willing to draft this proposal, but it will be a few weeks before I realistically can do it.
If you'd be willing to take it on, I think many people would give you attaboys for years to come! ;-) It doesn't seem to be on the roadmap here, so if you choose to write the proposal, I'll help in any way I can by review or contributing code. BTW, some changes are coming to the way we allow contributions to the Zope codebase which have the potential to reduce the DC "drag factor" for this and other similar projects. - C