Re^2: Regex to take an ip address before a comma

I think the split() solution is more efficient than the regex solution.

Tested with Perl 5.8.8 (ActiveState on WinXP)

#!/usr/bin/perl
use strict;
use warnings;
use Benchmark qw( cmpthese );

my $str = ( ('X'x15) . ',' ) x 3;

cmpthese(
    -1,
    {
        # using regex
        's///' => sub {
            my ( $first ) = $str =~ m/(.*?),/;
        },
        # using split without limit
        'split_unl' => sub {
            my ( $first ) = split( m/,/, $str );
        },
        # using split with limit
        'split_lim' => sub {
            my ( $first ) = split( m/,/, $str, 2 );
        },
        # using split with limit and slice for scalar assignment
        'split_lim_sca' => sub {
            my $first = ( split( m/,/, $str, 2 ) )[0];
        },
    }
)
[download]

my result:

                  Rate          s///     split_lim     split_unl split
+_lim_sca
s///          577066/s            --          -13%          -13%      
+    -15%
split_lim     663032/s           15%            --           -0%      
+     -2%
split_unl     663629/s           15%            0%            --      
+     -2%
split_lim_sca 679348/s           18%            2%            2%      
+      --
[download]

Or did I miss something?

Comment on Re^2: Regex to take an ip address before a comma Select or Download Code

Replies are listed 'Best First'.
Re^3: Regex to take an ip address before a comma by linuxer (Curate) on Nov 25, 2008 at 16:43 UTC
and here's my result with a perl 5.10 (cygwin on same WinXP) `Rate s/// split_lim split_unl split +_lim_sca s/// 288797/s -- -12% -12% + -15% split_lim 326805/s 13% -- -1% + -4% split_unl 330050/s 14% 1% -- + -3% split_lim_sca 339541/s 18% 4% 3% + --` [download]	[reply] [d/l]
Re^4: Regex to take an ip address before a comma by ikegami (Patriarch) on Nov 25, 2008 at 17:57 UTC
How can `split` which uses a regexp be faster than just a regexp? weird	[reply] [d/l]
Re^5: Regex to take an ip address before a comma by moritz (Cardinal) on Nov 25, 2008 at 18:13 UTC
why not? It's a different regex after all. `.*?,` has to check all items prior to the comma because `\n` isn't allowed there, whereas as simple search for `,` doesn't have to do this work.	[reply] [d/l] [select]
Re^6: Regex to take an ip address before a comma by ikegami (Patriarch) on Nov 25, 2008 at 19:07 UTC