Dear Monks

The /p modifier introduced in 5.10 makes ${^PREMATCH}, {$^MATCH}, and ${^POSTMATCH} available for use after matching. It is assumed it is faster than using $`, $& and $'. But when I benchmark this code: 

pl@nereida:~/src/perl/perltesting$ cat ./timeregexpwithp.pl
#!/usr/local/lib/perl/5.10.1/bin//perl5.10.1 -w
use strict;
use Benchmark qw{:all};

cmpthese(
  1000000,
  {
    p => q{'hola juan' =~ /ju/p; my ($a, $b, $c) = (${^PREMATCH}, ${^M
+ATCH}, ${^POSTMATCH} ) },
    oldway => q{'hola juan' =~ /ju/; my ($a, $b, $c) = ($`, $&, $') }
  }
);

cmpthese(
  10000000,
  {
    pnoassign => q{'hola juan' =~ /ju/p; },
    oldwaynoassign => q{'hola juan' =~ /ju/; }
  }
);

[download]
I've got: 
pl@nereida:~/src/perl/perltesting$ ./timeregexpwithp.pl
           Rate      p oldway
p      892857/s     --    -6%
oldway 952381/s     7%     --
                    Rate oldwaynoassign      pnoassign
oldwaynoassign 3184713/s             --            -1%
pnoassign      3225806/s             1%             --

[download]
It seems that the old way is faster. Any explanations?

Thanks

In reply to The /p modifier in Perl5.10 regexps by casiano

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