Subject: Sorting NewsGroups w/Pine

From: Michael <[email-masked]>
Date: Thu, 20 Feb 1997 10:06:40 -0800

Hello,

I have a question about the way Unix Pine 3.95 sorts the subjects in a
NewsGroup.

I use the sort by "subject" method, which gives me a alphabetical listing
of the NewsGroup, but it is not sorted my date.

If I use "ordered-subject" the NewsGroup is sorted by date, but not
alphabetically.

Is there any way that future releases of Pine that it might combine the
sorting methods? So that the subjects are sorted alphabetically and then by
date?

Is this something in the configuration that I have overlooked?

All comments welcomed,

Michael ([email-masked])

Press CTRL + L-AMIGA + R-AMIGA to continue...

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From: Mike Brudenell <[email-masked]>
Date: Fri, 21 Feb 1997 10:05:03 +0000 (GMT)

> of the NewsGroup, but it is not sorted my date.

Correct.

> If I use "ordered-subject" the NewsGroup is sorted by date, but not

Not quite.... sorting by "Date" sorts by date.  "OrderedSubject" groups
messages sharing the same Subject text (ignoring leading "Re:"'s) 
together, and then sorts this sublist by Date.  The main aim of
OrderedSubject is to provide pseudo-threading for folders (mail or news).

I admit that I've always been semi-puzzled why the Index screen doesn't
then end up with the subjects arranged alphabetically.  However I
_suspect_ Pine is attempting to maintain the Date ordering of the start of
each thread of conversation (in case, I suppose, some thread has its
Subject changed as the discussion wanders ... this would hopefully end up
further down the Index so you'd always encounter it _after_ reading the
original material) 

If I'm right (and it _is_ only supposition) the algorithm is not simply
the obvious:

	1.  Sort articles using primary key of Subject and secondary key
	    of Date.

but is instead the more complex (and theoretically useful):

	1.  Group articles into "threads" by common Subject (ie, get
	    related articles together)

	2.  Sort each "thread" by Date (ie, order the articles within each
	    "thread" into the order they were written).

	3.  Sort the different "threads" by Date (ie, order the separate
	    conversational "threads" into chronological order by their
	    first article).

Perhaps you (or someone with a bit of spare time) would care to peer at
the source code and see if this is indeed what is happening (or else
suggest what the true algorithm is)?

Cheers,

-- 
Mike Brudenell                                         <[email-masked]>
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