Re: How to get plist properties list?

[Stefan Monnier <monnier@iro.umontreal.ca>]

>     (dotimes (i length (reverse properties))
>       (if (divisible-by-2-or-0-p i)
>           (push (elt plist i) properties)))))

This is another example of a dotimes+elt loop, i.e. a loop where you
end up with an unwarranted O(n²) complexity (i.e. a performance bug).

>     (while (/= n (length plist))
>       (push (elt plist n) properties)
>       (setq n (+ 2 n)))
>     properties))

Same problem here.

> But maybe there is some more simpler way to get plist properties list?

Probably not the simplest but this should work:

    (defun plist-keys (plist)
      (let (keys iskey)
        (dolist (x plist)
          (if (setq iskey (not iskey)) (push x keys)))
        (nreverse keys)))

The simplest might be:

    (map-keys plist)


-- Stefan