#!/usr/local/bin/perl -w
use strict;
use Data::Dumper;

my @arr = ([1,2],[3,4,[5,6]],7);

my $list = flatten(\@arr);
print Dumper($list);

sub flatten
{
    my $data = Dumper(shift);
    $data =~ s/(\$\w+\s+=\s+)|[\n\[\];]//gm; # massage the output
    return [eval "$data"];
}

##</code><code>##

$VAR1 = [
          1,
          2,
          3,
          4,
          5,
          6,
          7
        ];