I have a custom template engine (too late for using a generic one from CPAN or elsewhere), it has to be able to process marked up stuff through a function that processes the contents of a tag and/or the params of that tag. The tags are html like. There are some issues with this code though, the part which selects the html like attributes doesn't work on all versions of perl, i.e. the first (.*?) block. If I split that into two matches first w/o that block, and then one more with it works, but it's about twice as slow. Anyway even if it's not splitted it performs miserably on some boxes. Any ideas about optimizing this regex: 
my $re = qr/$this->{mask_start}\Q$key\E(.*?)$this->{mask_end}(.*?)$thi
+s->{mask_start_close}\Q$key\E$this->{mask_end_close}/is; 

while ($this->{template} =~ /$re/) { 
  my $params = $this->mask_block_params($1, $2); 
  my $html = &$callback($key, $params); 
  $this->{template} = $` . $html . $'; 
}

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Using s/$&/$html/; on the last line instead of $` . $html . $' doesn't make much difference.

In reply to Regex speed issue by mtsachev

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