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From: schaefer@ogccse.ogc.edu (Barton E. Schaefer)
Newsgroups: comp.mail.mush
Subject: Re: goto-msg considered harmful
Message-ID: <5603@ogccse.ogc.edu>
Date: 14 Nov 89 05:49:30 GMT
References: <424@mohawk.cs.utexas.edu>
Reply-To: schaefer@ogccse.UUCP (Barton E. Schaefer)
Organization: Oregon Graduate Center, Beaverton, OR
Lines: 55

In article <424@mohawk.cs.utexas.edu> bryan@cs.utexas.edu writes:
} 
} cmd waiting 'update -N;await'
} bind a macro '[line-mode]waiting\ng`headers :n`\nn'
} 
} where 'g' is bound to goto-msg.  [....]  Unfortunately,
} this fails when the system mailbox contains only the [one] new message
} [...] because goto-msg detects that there is only one message in
} the mailbox, prints 'Not enough messages' and returns an error [....]
} 
} This special case behavior doesn't seem to me to have any use.

The -list commands ([save-list] etc.) used to have this problem as
well.  (Some of them still may, I hardly ever have only one message
in my mailbox so I seldom notice.)  This is a throwback to the days
before mush had macros, when refusing to do this kind of operation
on a one-message folder seemed "helpful" (don't let the user type
something that won't work).  We've been repairing these as we find
(or remember) them.

} Of course, this wouldn't be a problem if there were a line-mode goto command.

You can use

    cmd goto "from -"
    bind a macro '[line-mode]waiting|goto\n[display-next]'

which has the drawback of printing the header summaries of the new
messages twice before displaying the first new message.

} As far as I can see, there is no way to explicitly change the current message
} pointer in line mode without doing anything else.  [....]  Why is this?

It's because all the line-mode commands that "affect" messages will
change the current message automatically.  "Affect" here is sort
of a difficult concept to classify; just displaying the message's
header summary isn't enough (pick, headers), but almost anything
else is.  The "from +" and "from -" special cases are as close as
mush gets to a line-mode goto.

This probably won't help bryan, but more recent beta versions of
mush support options to "pick" to take head and/or tail of a list
of messages.  So even if [goto-msg] worked, I'd rewrite this as

    cmd waiting 'update -N ; await'
    cmd first 'pick +1 | next'
    bind-macro a '[line-mode]waiting | first\n'

except that I wouldn't use 'a' as the trigger-key; too easy to set
off an update -N accidentally when I really wouldn't want one.
-- 
Bart Schaefer          "Sometimes I think the surest sign that intelligent life
                        exists elsewhere in the universe is that none of it has
schaefer@cse.ogc.edu        tried to contact us."                     -- Calvin
(soon to be cse.ogi.edu)