prompt function

[Scott Schwartz <schwartz@groucho.cs.psu.edu>]

My prompt function looks like this:

fn prompt {
  s=$status {switch($s){case [^'~'^0]*;echo '# status' $s;return $s}}
}

Previously, I didn't return the old status, which was wrong because it
gratuitously destroyed information, just what $status is there to
avoid.  On the other hand, now each time I hit return after a command
that exits with nonzero status, I get a reminder, which is overly
noisy.  This makes me suspect that 'fn prompt' is not the proper answer
to 'set notify'.  (And speaking of that, I think it would be sensible
for rc to keep track of the statuses of background jobs in $astatus.)
(I should also echo to stderr, too, don't you think?)