Re^2: Comparing Regular Expressions

Your benchmark is bogus.

Realize that s/// actually modifies the string it's operating on. After the first iteration, there will be no spaces around commas left in $text.

Furthermore, you assign to $TestText, but you never actually use its value.

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Re^3: Comparing Regular Expressions by Sewi (Friar) on Sep 01, 2009 at 07:13 UTC
You're completly right. Thank you for the hints. `perl -le '$text = <STDIN>; $T=time; for (1..$ARGV[0]) { my $TestText = + $text; $TestText =~ s/\s+,\s+\|\s+,\|,\s+/,/g; } print time - $T; $T=t +ime; $TestText=$text; for (1..$ARGV[0]) { my $TestText = $text; $Test +Text =~ s/\s,\s/,/g; } print time - $T;' 1000000 </tmp/text.file` [download] This should correct all bugs.	[reply] [d/l]

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Re^3: Comparing Regular Expressions
by Sewi (Friar) on Sep 01, 2009 at 07:13 UTC

perl -le '$text = <STDIN>; $T=time; for (1..$ARGV[0]) { my $TestText =
+ $text; $TestText =~ s/\s+,\s+|\s+,|,\s+/,/g; } print time - $T; $T=t
+ime; $TestText=$text; for (1..$ARGV[0]) { my $TestText = $text; $Test
+Text =~ s/\s*,\s*/,/g; } print time - $T;' 1000000 </tmp/text.file
[download]

[reply]
[d/l]