Focusing the Mind

At my place of work 2006 started with three Unix sysadmins. It appears it's going to end with one, namely me. Today was my third day solo.

A lack of options, the saying goes, focuses the mind admirably. In my situation, that means I've been scripting like mad to make sure I get information in a timely way and don't overlook anything. And the last few days I've been coming home and writing even more code, but of a more complicated nature. Normally this would make me cranky, to be doing work programming in the evening, but since this particular project is intended only for me, I get to choose my language. I've been reacquainting myself with Common Lisp. I had forgotten how fun programming could be —

;;; Insert timed data point, returning the previous value (useful for
;;; some statistical models).
(defmethod update ((dh ts-datahistory) val &key timestamp)
  (let ((ts (if (null timestamp) (get-universal-time) timestamp)))
    (multiple-value-bind (idx daytype) (bin-index dh ts)
      (macrolet ((ref-and-set (accessor)
                   `(prog1
                     (,accessor dh idx)
                     (setf (,accessor dh idx) val))))
        (if (eq daytype 'weekday)
            (ref-and-set weekday-history-ref)
            (ref-and-set weekend-history-ref))))))

I don't know how many of my readers will understand that, but it just fills me with joy to use such a tool. Lexically scoped macros!

Next up, quality time with North & Hillard's Greek Prose Composition...