Subject: bug#57079: 29.0.50; Performance of seq-uniq is not very good

From: Lars Ingebrigtsen <[email-masked]>
Date: Tue, 09 Aug 2022 19:21:24 +0200

Eli Zaretskii <[email-masked]> writes:

> No one said that was a problem in these cases.

I haven't audited the callers, but changing code that used to be
non-destructive to be destructive isn't to be taken lightly.

Anyway, I've now made seq-uniq faster.  This used to take 27 seconds,
and now takes 1.4s.

(let ((list (seq-map-indexed (lambda (_ i)
			       i)
			     (make-list 10000 nil))))
  (setq list (append list list))
  ;;(benchmark-run 10 (gnus-delete-duplicates list))
  (benchmark-run 10 (seq-uniq list))
  )