Re: Concerning marks and the back end.

[Simon Josefsson <jas@extundo.com>]

Lloyd Zusman <ljz@asfast.com> writes:

> Lloyd Zusman <ljz@asfast.com> writes:
>
>> Simon Josefsson <jas@extundo.com> writes:
>>
>>> [ ... ]
>>>
>>> Maybe you can use this approach to accomplish something similar: set
>>> the group parameter "display" (G c) to a value that makes group
>>> entering fast (e.g. 500).  If you ever want to see older articles,
>>> enter the group with C-u SPC.  If you want to keep around a specific
>>> article even after falls outside of the 500 limit, press ! on it.
>>
>> Aha!  Yes, that would work splendidly to give me pretty much exactly
>> what I want.
>>
>> Great idea ... and now, as far as I'm concerned, Problem Solved.
>>
>> Thanks a lot.
>
> ... but then again ...
>
> I just noticed something less-than-ideal about this.  For example,
> suppose a group has 10 unread messages and 6 zillion already read
> messages.  I set the "display" paramter to 100 as discussed above, and I
> then enter the group.  I now see the 10 new unread messages interspersed
> among 90 already-read messages.
>
> Is there any way to make the "display" parameter only apply when there
> are no unread messages at all in the group?

You can set the display parameter to an array of predicates, e.g.:

[or unread (and no-unreads my-article-old-p)]

     (defun my-article-old-p ()
       "Say whether an article is old."
       (< (time-to-days (date-to-time (mail-header-date gnus-headers)))
          (- (time-to-days (current-time)) gnus-agent-expire-days)))

implementing the no-unreads function is left as an exercise. :-)

But this might not work either, as I think display predicates was
implemented as limiting, so you will fetch all article headers anyway.

But I still wonder why entering the group is slow for you.  I have
15,000 messages in my ding mailing list mailbox, which is stored on a
IMAP server, and entering it and viewing the unread and ticked
articles takes no time.  When I get several hundred thousand articles
it becomes a little slow though (long coffe break).