#!perl
use strict;
use warnings;
use feature qw/ say /;
use Data::Dumper;
use Algorithm::Permute;

## Some code here that produces @prdct ...

my $product = Algorithm::Permute->new( \@prdct );

say Dumper( $product ); # did you get what you expected?

while ( my @res = $product->next ) {
  say Dumper( @res ); # now did you get what you expected?
  # do something else ...
}