Re: Why article numbers?

[prj@po.cwru.edu (Paul Jarc)]

I think I should point out that Kai and I seem to be advocating
slightly different things.  Kai's suggestion, AIUI, is to use
Message-ID header fields as article IDs everywhere.  My suggestion is
to let backends decide how to identify articles, with the only
requirement being that identifiers should be eq if they are supposed
to identify the same article.  (This includes the possibility of
symbols whose names are Message-IDs, but does not require that.)

Lars Magne Ingebrigtsen <larsi@gnus.org> wrote:
> prj@po.cwru.edu (Paul Jarc) writes:
>> Don't ask for a particular number of articles.  Ask for "all unread
>> articles".
>
> That's not what the user asks for.  The user may ask for "the last
> 200 articles, whether read or unread", or "the last 5 read articles".

You're changing the question.  Originally you said:

>>> How many articles should you fetch if the user wants all unread
>>> articles?

If the user asks for "all unread articles", then Gnus can ask the
backend for "all unread articles".  If the user asks for "the last 200
articles, whether read or unread", then Gnus can ask the backend for
"the last 200 articles, whether read or unread".  If the user asks for
"the last 5 read articles", then Gnus can ask the backend for "the
last 5 read articles".

The point is that the work that benefits from knowing that article IDs
are integers does not have to be abandoned; it can simply be pushed
inside the backend.  So for backends that naturally use integers as
identifiers, there would just be a restructuring of the existing code,
with approximately zero change in performance.  Backends that have to
do extra work to assign numbers to articles would have the opportunity
to try using other types of objects as IDs, but if that strategy turns
out to be worse for whatever reason, then they can still go back to
using integers.

> "A lot of work" is an understatement

I won't argue with that.  It might even be so much work that it will
never happen, unfortunately.  But my claim is that it is possible, and
if done right, would not cause performance hits.


paul