I am attempting to use a Path::Iterator::Rule "Custom rule subroutine".

I have a regexp during the buildup of my rules, which determines whether the custom rule subroutine is used. If it indicates to use the subroutine, then its capture group $1 at this point holds some text that I want to match in the subroutine to filter for certain pathnames.

With the naive approach, it seems that the $1 or $var variable in my regexp is only expanded at the time of the regexp/subroutine being run. At this point, the variable is no longer valid and could have been overwritten by some other value. Naive code:

my $rule = Path::Iterator::Rule->new;
if ($id =~ /^([0-9A-F]{2})/) {
  my $int = $1;
  $rule->and( sub { m#/INT $int# } );
}
[download]

Resulting errors are many times this line:

I found that it appears to work if I use a "postponed" regular subexpression like so:

my $rule = Path::Iterator::Rule->new;
if ($id =~ /^([0-9A-F]{2})/) {
  my $int = $1;
  $rule->and( sub { m#/INT (??{ "$int" })# } );
}
[download]

Is this a correct approach? Are there other ways to interpolate a variable at the time of adding the custom rule subroutine, so that the rule doesn't refer to the variable later but rather uses the text that it used to hold?

Thanks to main work by Leo Lapworth and Olaf Alders at the Perl Toolchain Summit, we now have a setup that allows us to move the site behind a CDN ( https://www.fastly.com/ in fact ). Fastly does not require magic Javascript to execute on the clients, but will ideally still help to stem the deluge of scrapers. Together with this, there will be some likely changes:

The site will only be available under perlmonks.org. The other domains will issue HTTP redirects to that address. This means that you will have to check the hostnames in your tools and in your browsers. Using the hostnames to differentiate between user profiles will not work anymore.

The site pages will be cached for Anonymous Monk. We'll start out with a cache duration of 1 hour but will likely increase this. Fastly has an API, so maybe busting the cache for recently updated threads is possible. If you are polling Perlmonks without a login, you will likely see a more static response.

The timeline to move the site behind Fastly is to do it is likely in the next two to four weeks, depending on the availablility of myself and others.