Re^5: Remove all non alphanumeric characters excluding space, underscore and minus sign (Benchmark--)

Thanks. I was short on time and posted with code I wouldn't use myself because it seemed to demonstrate the problem with the prior code. When I use Benchmark myself, I arrange for a way to test the code being benchmarked for exactly these types of reasons.

I was fooled by seeing a 200% difference but I still should've rejected the code when the run time per operation was that low.

Sorry for posting "in a hurry". Thanks for the correction. :)

- tye

Comment on Re^5: Remove all non alphanumeric characters excluding space, underscore and minus sign (Benchmark--)

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Re^6: Remove all non alphanumeric characters excluding space, underscore and minus sign (Benchmark--) by Tux (Canon) on Feb 13, 2012 at 22:22 UTC
I so much stand corrected! When I wrote it, I meant `my $string = pack "C*" => map { 32 + int rand 95 } 0..1280; cmpthese (-1, { subsingle => sub { (my $s = $string) =~ s/[^a-zA-Z0-9 _-]//g }, subplus => sub { (my $s = $string) =~ s/[^a-zA-Z0-9 _-]+//g }, tran => sub { (my $s = $string) =~ tr/a-zA-Z0-9 _-//cd }, });` [download] Which gives completely different results indeed: $ perl5.8.8 test.pl Rate subsingle subplus tran subsingle 9514/s -- -2% -90% subplus 9660/s 2% -- -90% tran 92839/s 876% 861% -- $ perl5.10.1 test.pl Rate subsingle subplus tran subsingle 7802/s -- -9% -92% subplus 8574/s 10% -- -91% tran 99211/s 1172% 1057% -- $ perl5.12.3 test.pl Rate subsingle subplus tran subsingle 5191/s -- -17% -95% subplus 6279/s 21% -- -94% tran 99211/s 1811% 1480% -- $ perl5.14.1 test.pl Rate subsingle subplus tran subsingle 6081/s -- -18% -94% subplus 7450/s 23% -- -92% tran 97303/s 1500% 1206% -- $ bleadperl test.pl Rate subsingle subplus tran subsingle 6221/s -- -12% -94% subplus 7096/s 14% -- -93% tran 97303/s 1464% 1271% -- $ [download] So the plus indeed speeds up the substitute and `tr`, even in /c mode, is fastest Enjoy, Have FUN! H.Merijn	[reply] [d/l] [select]

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Re^6: Remove all non alphanumeric characters excluding space, underscore and minus sign (Benchmark--)
by Tux (Canon) on Feb 13, 2012 at 22:22 UTC

I so much stand corrected! When I wrote it, I meant

my $string  = pack "C*" => map { 32 + int rand 95 } 0..1280;

cmpthese (-1, {
    subsingle   => sub { (my $s = $string) =~ s/[^a-zA-Z0-9 _-]//g  },
    subplus     => sub { (my $s = $string) =~ s/[^a-zA-Z0-9 _-]+//g },
    tran        => sub { (my $s = $string) =~ tr/a-zA-Z0-9 _-//cd   },
    });
[download]

Which gives completely different results indeed:

$ perl5.8.8 test.pl
             Rate subsingle   subplus      tran
subsingle  9514/s        --       -2%      -90%
subplus    9660/s        2%        --      -90%
tran      92839/s      876%      861%        --
$ perl5.10.1 test.pl
             Rate subsingle   subplus      tran
subsingle  7802/s        --       -9%      -92%
subplus    8574/s       10%        --      -91%
tran      99211/s     1172%     1057%        --
$ perl5.12.3 test.pl
             Rate subsingle   subplus      tran
subsingle  5191/s        --      -17%      -95%
subplus    6279/s       21%        --      -94%
tran      99211/s     1811%     1480%        --
$ perl5.14.1 test.pl
             Rate subsingle   subplus      tran
subsingle  6081/s        --      -18%      -94%
subplus    7450/s       23%        --      -92%
tran      97303/s     1500%     1206%        --
$ bleadperl test.pl
             Rate subsingle   subplus      tran
subsingle  6221/s        --      -12%      -94%
subplus    7096/s       14%        --      -93%
tran      97303/s     1464%     1271%        --
$
[download]

So the plus indeed speeds up the substitute and tr, even in /c mode, is fastest

Enjoy, Have FUN! H.Merijn

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