Re: What's missing in ELisp that makes people want to use cl-lib?

[Dmitry Gutov]

On 14/11/2023 04:44, João Távora wrote:
> On Tue, Nov 14, 2023 at 2:27 AM João Távora <joaotavora@gmail.com 
> <mailto:joaotavora@gmail.com>> wrote:
>
>
>
>     The case in the CL world against generic functions' performance
>     is often not that the dispatch is slow, but that
>
>
> That said, it still matters, of course.  Here's your non-destructive
> seq-difference-3 but with many small lists:
>
> (setq cc (make-list 12 "blabla"))
> (setq list2 (make-list 12 "shooveedoowaa"))

> ;; (4.225398191 31 2.3103362619999928)
> (benchmark-run 1000000 (cl-set-difference cc list2 :test #'equal))
>
> ;; (6.959332908 56 4.235225837999991)
> (benchmark-run 1000000 (seq-difference-3 cc list2))

And if the list has just 1 element (or zero?), the gap would be even 
larger. Yes, generic dispatch has a cost.

Only seeing a 1.6x difference here is a nice surprise, actually.

> And of course the destructive version still wins by 10x
>
> ;; (0.676608019 4 0.26997238299998116)
> (benchmark-run 1000000 (cl-nset-difference cc list2 :test #'equal))

No doubt.