[Jscheme-user] hack of the day - reminder

[Ken A. <kan...@bb...>]

Dick Gabriel http://www.dreamsongs.com/ one said he was forcing himself to write one poem a day as part of becoming a better writer.  He had several hundred.  I asked if there was something like this a programmer should do.
Unfortunately, he didn't think so.  

Maybe writing a hack a day is the first step.  So here's one i started to use yesterday.  I wanted a way to remember when i had to leave.  If i set a timer and popped up a JOptionPane.showMessageDialog it would appear underneath my EMACS window, so i'd never see it.  So i decided to do a beep instead.  It actually took a while for me to get my windows machine to beep.  Here's the code.


(import "java.awt.Toolkit")
(import "java.util.Date")

;;; http://www.rgagnon.com/javadetails/java-0001.html
;;; If you are on a Windows machine you may not beep until your reg is
;;; set up right.
(define (beep) (.beep (Toolkit.getDefaultToolkit)))

(define (sleepUntil date)
  (Thread.sleep (- (.getTime date) (.getTime (Date.)))))

;;; reminder: String String -> void
(define (reminder hour:min message)
  {Example: (reminder "11:45" "meet at elevator for lunch")}
  (let* ((d (.toString (Date.)))
         (d {[(.substring d 0 11)][hour:min]:00[(.substring d 19)]}))
    (.start (Thread. (lambda ()
                       (sleepUntil (Date. d))
                       (dotimes (i 10) (beep) (Thread.sleep 100L))
                       (display {It is now [d] [message]\n}))))))