comment on

I suppose, the whole meaning of this example is to show how to programm efficiently - not wasting system ressources (here: CPU time).

If this is so, I'd like to put emphasis on the fact, that NO ONE here seems to see a problem in the "true" expression. Please do not use interpolation if you do not need it. Try your benchmarks with 'true' again.

Update:

Of course I did the benchmarks before posting this node. The speed differences are not extraordinary but constantly about 5%

Code:

#!/usr/bin/perl_parallel -w
# For Emacs: -*- mode:cperl; mode:folding -*-

use strict;
use warnings;

use Benchmark;

my $value = "somewhere here true is there!";

timethese
(
    5000000,
    {
            'index' => sub { index( $value, 'true' ) },
            'regex' => sub { $value =~ /true/ },
    }
);

timethese
(
    5000000,
    {
            'index' => sub { index( lc $value, 'true' ) },
            'regex' => sub { $value =~ /true/i },
    }
);
[download]

Benchmark Results (single quotes):

Benchmark: timing 5000000 iterations of index, regex...
     index:  2 wallclock secs ( 1.04 usr +  0.00 sys =  1.04 CPU) @ 48
+07692.31/s (n=5000000)
     regex:  2 wallclock secs ( 2.16 usr +  0.01 sys =  2.17 CPU) @ 23
+04147.47/s (n=5000000)
Benchmark: timing 5000000 iterations of index, regex...
     index:  3 wallclock secs ( 2.83 usr +  0.00 sys =  2.83 CPU) @ 17
+66784.45/s (n=5000000)
     regex:  4 wallclock secs ( 3.45 usr +  0.02 sys =  3.47 CPU) @ 14
+40922.19/s (n=5000000)
[download]

Benchmark Results (double quotes):

Benchmark: timing 5000000 iterations of index, regex...
     index:  1 wallclock secs ( 1.10 usr +  0.00 sys =  1.10 CPU) @ 45
+45454.55/s (n=5000000)
     regex:  2 wallclock secs ( 2.25 usr +  0.01 sys =  2.26 CPU) @ 22
+12389.38/s (n=5000000)
Benchmark: timing 5000000 iterations of index, regex...
     index:  4 wallclock secs ( 2.99 usr +  0.01 sys =  3.00 CPU) @ 16
+66666.67/s (n=5000000)
     regex:  3 wallclock secs ( 3.66 usr +  0.01 sys =  3.67 CPU) @ 13
+62397.82/s (n=5000000)
[download]

Perl:

perl_parallel -V
Summary of my perl5 (revision 5 version 8 subversion 6) configuration:
  Platform:
    osname=linux, osvers=2.6.8-24-smp, archname=i586-linux-thread-mult
+i
    uname='linux builder 2.6.8-24-smp #1 smp wed oct 6 09:16:23 utc 20
+04 i686 i686 i386 gnulinux '
    config_args='-ds -e -Dprefix=/opt/PM_perl-5.8.6 -Dvendorprefix=/op
+t/PM_perl-5.8.6 -Dinstallusrbinperl -Dusethreads -Di_db -Di_dbm -Di_n
+dbm -Di_gdbm -Duseshrplib=true -Doptimize=-O2 -g -march=i586 -mcpu=i6
+86 -fmessage-length=0 -Wall -pipe'
[download]

Bye
PetaMem All Perl: MT, NLP, NLU

In reply to Re: You don't always have to use regexes by PetaMem
in thread You don't always have to use regexes by petdance

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