Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!samsung!emory!ogicse!schaefer
From: schaefer@ogicse.ogc.edu (Barton E. Schaefer)
Newsgroups: comp.mail.mush
Subject: Re: current message location after folder update
Message-ID: <6002@ogicse.ogc.edu>
Date: 6 Dec 89 21:37:11 GMT
References: <1989Dec6.031050.12607@semi.harris-atd.com> <5995@ogicse.ogc.edu> <14983@bfmny0.UU.NET>
Reply-To: schaefer@ogicse.UUCP (Barton E. Schaefer)
Organization: Oregon Graduate Institute (formerly OGC), Beaverton, OR
Lines: 36

In article <14983@bfmny0.UU.NET> tneff@bfmny0.UU.NET (Tom Neff) writes:
} One way to store the current position in a saved folder would be
} by adding a Status: flag.  The penalty is that multiple users eating
} out of the same folder could not maintain different current locations,
} but the advantage is that it's completely stable.

I considered mentioning that, but saving the current message across
*changing* folders wasn't the question -- saving it through update
of the current folder was.   But any scheme that depends on saving that
sort of information in the folder itself opens a can of worms; not only
is there the question of what to do with multiple "eaters", but of where
to place the current message when there is new mail, what to do with
that status bit if the message is saved to a different folder ("... but I
want the last message I put there to become the current message for that
folder!"), etc. etc.  At least retaining the current message within a
single session with the same folder has easily defined semantics.

Essentially, one complication is that the only difference between "update"
and "folder %" is that "update" doesn't forget the name of the previous
folder (accessed as "#").  If the temp file were never actually emptied
until quit or folder change, you could keep track of the current message
by its seek offset in the temp file (which "sort" does in 7.0whatever).
But that would be an unacceptable waste of disk space for long sessions.
A second complication is that the code organization makes it difficult
(not impossible, just difficult) to pass the information about where the
current message should end up, from the function that writes the folder
to the one that reads it back in.

Somewhere in mush's "maybe someday" clause is generalized user tagging
of messages, at which point everybody can figure this one out as most
pleases them.
-- 
Bart Schaefer     "I seem to have run into a novel problem with the electronic
                       mail.  My computer's demanding an electronic female."
schaefer@cse.ogi.edu
(used to be cse.ogc.edu)                              "Preferably brunette."