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In a word, no.

Reversing the regex is much faster.
Have a look at these benchmarks:

#!/usr/bin/perl -w use strict; use Benchmark; my $string = "<<HTML>;nbsp dont_strip_me</HTML>> <xyzfdgfghgf> ;strip_ +me"; sub reversed { my $reverse = reverse(shift); $reverse =~ s| \w* ; \s* > |>|x; return scalar reverse $reverse; } sub greedy { my $line = shift; $line =~ s|^ (.*>) \s* ; \w* |$1|x; return $line; } print "Reversed: ", reversed($string), "\n"; print "Greedy: ", greedy($string), "\n"; timethese( -10,{ reversed => sub { reversed( $string ) }, greedy => sub { greedy( $string ) }, } );

Output:

Reversed: <<HTML>;nbsp dont_strip_me</HTML>> <xyzfdgfghgf>
Greedy: <<HTML>;nbsp dont_strip_me</HTML>> <xyzfdgfghgf>
Benchmark: running greedy, reversed, each for at least 10 CPU seconds...
    greedy: 10 wallclock secs ( 9.98 usr + 0.02 sys = 10.00 CPU) @ 78480.80/s (n=784808)
  reversed: 11 wallclock secs (10.46 usr + 0.00 sys = 10.46 CPU) @ 167660.04/s (n=1753724)

As you can see, it's over twice the speed. On longer strings, the difference would be even greater.

Also, your regex is wrong. Read through perldoc:perlre (specifically, the section marked 'Warning on \1 vs $1') to discover why.


In reply to Re: Re: Re: parsing question by kilinrax
in thread parsing question by Washie101

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