Hi

This is my version for solving this. Probably very similar to some of the answers above.

use Modern::Perl;
use Data::Dumper;

    #some ranges, for testing purposes.
my @array = (2,3,4,10,11,12,13,20,21,22,34,35,36,37,38);
my $prev = undef;
my @ranges;
my $index = -1;

    #Build Array of array.
    #One Array ref for each contiguous range
foreach my $val ( sort {$a <=> $b } @array ) 
{

    if (!defined($prev) || $val != $prev +1 ) 
    {
        $index++;
        $ranges[$index] = [$val];
        
    }
    else
    {
        push @{ $ranges[$index] }, $val;
    }
    $prev = $val;
}
print Dumper(\@ranges);


    #loop though each range (array ref), and get the first and last el
+ement 
    #for each range
foreach my $a_range (@ranges)
{
    say "range: ", $a_range->[0], '..', $a_range->[-1];
}
[download]

Output

$VAR1 = [
          [
            2,
            3,
            4
          ],
          [
            10,
            11,
            12,
            13
          ],
          [
            20,
            21,
            22
          ],
          [
            34,
            35,
            36,
            37,
            38
          ]
        ];
range: 2..4
range: 10..13
range: 20..22
range: 34..38
[download]

Arnaud.