use Perl

Some modules will have very little take-up, but when you need them, you need them. Hence, my Data::FetchPath, which should be on a mirror near you soon.

For a whole variety of reasons I sometimes find I need to know where in a data structure a particular piece of data is. I've used it for Prolog-style data unification and changing data structures on the fly, but I also sometimes use it for digging into complex objects and I want to know which path in a DBIx::Class resultsource holds a given value.

use Data::FetchPath 'path';

# find all http:// https:// urls
my $paths = path($complex_data_structure, qr{^https?://});
foreach my $path (@$paths) {
    print eval "\$complex_data_structure->$path\n";
}

The data structure only supports array and hashrefs and the value you match against must be a scalar or a regex. Though as I was trying to explain this to my brother, I realized that I should add support for callbacks. For example, if you wanted to know how many values in an array of arrays are prime:

print scalar @{ path($AoA, sub { is_prime(shift) }) };

Callbacks should be trivial to add, but I need to get some sleep.

And yes, it handles circular data structures. That was my first bug with it. It's a bit hackish, but it does the job.

As is usually the case with most of my new code, you can get it from github.