(defun clMatchPermutations (match_rules objects)
  (let ((match_args (car match_rules))
        (match_body (cdr match_rules))
        match_fun
        (match_results (tconc nil nil)))
    (setq match_fun (eval `(lambda ,match_args ,@match_body) (theEnvironment)))
    (mapcar (lambda (argset)
              (when (apply match_fun argset)
                (tconc match_results argset)))
            (cdar objects))
    (cdar match_results)))

One of those deep-thought days. As usual, I had interruptions every 15 minutes or so, but I managed to shrug them off. I managed to get hard-core pattern matching algorithms proven correct and implemented (though not quite debugged).

Usually when I write code I feel like I'm being lazy, as if writing code is not real work. I don't usually get the euphoric feeling that I do after grunging out a difficult line integral or somesuch. Today was a nice exception. I feel like I did bona fide intellectual work.