(defun (flash	$old-spt
    (save-window-excursion
	(delete-other-windows)
	(do-flash)
    )
))
(defun (do-flash	$k  $up	$spurt
    (switch-to-buffer "flash")
    (draw)
    ; put enough whitespace at top to leave 12 lines visible at bottom
    (beginning-of-file)
    (provide-prefix-argument (- (window-height) 12)
	(insert-character '\n')
    )
    (setq-default &tip (dot))
    (setq $k 140)
    (while (-- $k)
	; move faster during last iterations
	(if (! (% $k (if (< $k 90) 7 11)))
	    (setq $up (! $up))
	)
	; use last few iterations to pull out
	(if (< $k 10)
	    (setq $up 0))
	; only spurt during the middle iterations
	(setq $spurt (& (< $k 60) (> $k 15) (> (% $k 16) 7)))
	(beginning-of-file)
	(sit-for 0)
	(nuke-line)
	(goto-character &tip)
	(if $up
	    (progn
		(previous-line)
		(nuke-line)
	    )
	    (stream)
	)
	(stream)
	(setq &tip (dot))
    )
    (beginning-of-file)
))

; generate nonblank line '*' if $spurt is true, else blank line
(defun (stream
    (if $spurt
	(insert-string "	       *")
    )
    (newline)
))

; delete the current line including its terminating newline
(defun (nuke-line
    (beginning-of-line)
    (if (! (looking-at "^\n"))
	(kill-to-end-of-line))
    (delete-next-character)
))
(defun (draw
    (erase-buffer)
    (insert-string
"	     /-----\\\n"
"	    +	    \\\n"
"	    |	     \\\n"
"	    |	    +/\n"
"	    |	    |\n"
"	    |	    |\n"
"	    |	    |\n"
"	    |	    |\n"
"	    |	    |\n"
"	    |	    |\n"
"	    |	    |\n"
"	    |	    |\n"
"	    |	    |\n"
"	    |	    |\n"
"	    |	    |\n"
"	    |	    |\n"
    )
))