Here's the code: 
use Benchmark 'cmpthese';
use Regexp::Keep;
my $s = "abc.def.ghi.jkl";
cmpthese(-5, {
  japhy => sub { (my $x = $s) =~ s/.*\K\..*// },
  old   => sub { (my $x = $s) =~ s/(.*)\..*/$1/ },
});

[download]
In 5.6.1: 
old   = 40280.54/s
japhy = 74338.79/s

[download]
And with 5.8.0 (using the module, NOT my patch): 
old   =  58188.18/s
japhy = 102409.25/s

[download]
So there's an appreciable speed-up.

_____________________________________________________
Jeff[japhy]Pinyan: Perl, regex, and perl hacker, who'd like a job (NYC-area)
s++=END;++y(;-P)}y js++=;shajsj<++y(p-q)}?print:??;

In reply to Regexp::Keep benchmark by japhy
in thread New regex trick... by japhy

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