Re: epg and expired recipient keys

[Katsumi Yamaoka <yamaoka@jpl.org>]

>>>>> In <867itvcdve.fsf@hondo.cadr.de> Wolfram Fenske wrote:

> How about a version that uses the "dolist" macro?  I think this makes
> the code a lot clearer.  Plus, it's shorter.

> (defun mml2015-epg-find-usable-key (keys usage)
>   (catch 'found
>     (dolist (key keys)
>       (dolist (sub (epg-key-sub-key-list key))
> 	(when (and (memq usage (epg-sub-key-capability sub))
>                    (not (memq (epg-sub-key-validity sub) '(revoked expired))))
> 	  (throw 'found key))))))

It looks good and will probably make the code slow not so much.
I mean dolist is generally slower than well-designed while loop.
For instance:

(benchmark
    10000
  (let ((alist mm-mime-mule-charset-alist)
	sub rest)
    (while alist
      (setq sub (car alist))
      (while sub
	(setq rest (cons (car sub) rest)
	      sub (cdr sub)))
      (setq alist (cdr alist)))
    (nreverse rest)))
0.5125889778137207
0.5080130100250244
0.5140340328216553
0.5127580165863037
0.5110170841217041

(benchmark
    10000
  (let (rest)
    (dolist (sub mm-mime-mule-charset-alist (nreverse rest))
      (dolist (elem sub)
	(setq rest (cons elem rest))))))
0.6363399028778076
0.6323390007019043
0.6358840465545654
0.6289501190185547
0.6397740840911865

I used Lars' benchmark.el[1] and XEmacs 21.4.20 for those tests.

[1] http://quimby.gnus.org/elisp/benchmark.el