[PATCH 1/3] sorting: add the ability to sort by from and subject

[William Casarin]

David Bremner <david at tethera.net> writes:

> It seems worth mentioning that it's possible to preprocess values into
> keys (see Xapian::Enquire::set_sort_by_key). So things like Re:
> etc... could be stripped.

Hmm looks like I need to create a KeyMaker class which appears to be a
glorified (Xapian::Document -> String) callback. Shouldn't be too
difficult other than the choice of algorithm. It would have to strip:

  Re: Fwd: ... etc?

Sounds like the choice algorithm could be tricky and/or error prone?
Would need lots of tests, and like Jani said, questionable worth in
these scenarios, considering I was mainly dealing with scenarios like
these:

  From: Top News - MIT Technology Review
  From: Newest questions tagged haskell - Stack Overflow

So the current implementation would only be useful for RSS feeds,
automated bots, etc. that are non-mailing-list-email use cases.

I'm working on updates to notmuch-mode right now. I'll post a patch for
that soon for people who are interested.

- William