[Evolution] Tip: Using vfolders for boolean searches

[Thomas Frayne <tomf sjpc org>]

Periodically Evolution gets requests for boolean searches and boolean
criteria for filters and vfolders.  These requests have always been
rejected on the grounds that the user "can" use the undocumented (by
Evolution; Scheme documentation is available, but has no hints how to
use Scheme expressions in Evolution) Expression criteria.  

I have just noticed a way to bypass this problem, but it would still be
much more convenient to have boolean searches and criteria implemented
directly by Evolution.

The idea is to use the ability to base a vfolder on another vfolder.  

I set up a vfolder, "recent, important, unread" to use any of the
criteria:
  Received date after 2 days ago,
  Sent date after 1 day ago,
  Status is important,
  Status is not read.
I based the vfolder on all local folders plus Inbox and Sent.

Then I set up a second vfolder, "Alice recent, important, unread", based
on "recent, important, unread" to filter out all the messages my wife is
not interested in, by using all of the criteria:
  Recipients does not contain linux
  Subject does not contain hylafax
  Sender does not contain redhat
  etc.


Evolution could simplify this procedure markedly, e.g., by adding an
"And" button at the bottom of the vfolder edit box.  When this button is
clicked, expand the box with another
Add-criterion-Execute-actions-vFolder-sources section.  The first
section could be executed if any criteria are met, and the second
section, if all criteria are met.

If this enhancement were implemented, I could set up a single vFolder to
select all recent, important, or unread messages which my wife wants to
see, without using an auxiliary vFolder.

The documentation could be improved by referencing the Scheme
documentation and providing a few examples of Scheme expressions, with
descriptions of what they do, in the Evolution documents.  A reference
and a few examples of regular expressions in filters would also be
appreciated; they don't seem to work as I expected.  Finally,
implementing regular expressions in the vFolder editor would be useful.