On Mon, Apr 21, 2025 at 08:04:44 +0200, to...@tuxteam.de wrote:
> If you like to disappear in rabbit holes, this [3] one is nice. If
> not, still the pic at the beginning still shows impressively an
> exponential runaway for Perl's re engine compared to Tcl's which
> uses a Thompson algorithm. Note that this was back in 2007 and
> quite possibly Perl's engine has been refined (it definitely has
> been extended) since then.
>
> Cheers
>
> [3] https://swtch.com/~rsc/regexp/regexp1.html
It still has the issue.
hobbit:~$ time perl -e '$s = "a" x 25; $r = "a?" x 25 . "a" x 25; if ($s =~ $r)
{ print "yes\n"; }'
yes
real 1.354 user 1.349 sys 0.004
That's with perl 5.36.0 from Bookworm.
