Select Code to Download

#!/usr/bin/perl
use Benchmark qw/cmpthese/;

...
    neg_look=> q{$text=$defaulttext; $text =~ s/(?<!\w)foo(?!\w)//g;},
    pos_look=> q{$text=$defaulttext; $text =~ s/(?<=[^\w])foo(?=[^\w])
+//g;},
});

          Rate    pos_look  neg_look  slash_b
pos_look 27894/s     --        -8%     -35%
neg_look 30441/s     9%         --     -29%
slash_b  42662/s    53%        40%      --

$text= q/foo bar foo/;
($tmp = $text) =~ s/\bfoo\b//g;
print $tmp,"\n";
...
 bar
 bar
foo bar foo