[Xapian-discuss] Sorting by a custom expr

[Olly Betts]

On Fri, Jan 20, 2006 at 07:00:27AM -0300, Carlos Pita wrote:
> What about bias functors? Can you give me some clue on
> using them?

A bias functor is exactly what you're looking for.

The implementation is currently incomplete.  It's really just a
prototype for the idea which I wrote while I was at Ananova, the idea
being to give a relevance boost to more recent news articles, with the
boost exponentially decaying for older articles.  However, the
management decided they wanted a different approach so it never got
finished.

What's needed is a class you derive from to specify the bias functor,
rather like how Xapian::Weight and Xapian::MatchDecider work.

It's been on my list of "things that really should be sorted out" for
a while, so hopefully I should get to it soon.

Cheers,
    Olly