# combines two pairs into a longer pair
sub combine_codes_and_descriptions
{
  my ($sofar, $next) = @_;
  if (!defined($sofar)) {return $next;}
  [$sofar->[0] . $next->[0], $sofar->[1] . ", " . $next->[1]]; 
}

sub multi_dim_reduce
{
  # $sofar optional
  my ($actionsub, $AoA, $combinesub, $sofar) = @_;
  if (@$AoA) {
    my $this_array = shift @$AoA;
    for my $elem (@$this_array) {
      my $subarray = [ @$AoA ];
      multi_dim_reduce($actionsub, $subarray, $combinesub,
                       $combinesub->($sofar,$elem));
    }
  } else {
    $actionsub->($sofar);
  }
}

# The main event
@data = 
(
    [
        [1, "Darth Vader"],
        [3, "Luke Skywalker"],
        [5, "Obi Wan Kenobi"],
    ],[
        [0, "Lighsabre"],
        [5, "Blaster"],
        [9, "Rocket launcher"],
    ],[
        [10, "Dagobah"],
        [14, "Kashyyyk"],
    ],
);
multi_dim_reduce(sub {my ($c,$d) = @{$_[0]}; print "$c\t$d\n";},
                 [ @data ],
                 \&combine_codes_and_descriptions);
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--
@/=map{[/./g]}qw/.h_nJ Xapou cets krht ele_ r_ra/;
map{y/X_/\n /;print}map{pop@$_}@/for@/
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