my @numbers = qw( 22 19 8 22 4 2 8 12 5 6 21 23 1 );

print  "Input(@numbers)\n";
printf "Output(%s)\n", numbers_to_ranges(@numbers);

sub numbers_to_ranges {
 map$x[$_]=$_,@_;$_="@x";s@^ +@@;s*(\d+)( (\d+))+*\1-\3*g;s- +-, -g;$_
}

__END__

[Results]
Input(22 19 8 22 4 2 8 12 5 6 21 23 1)
Output(1-2, 4-6, 8, 12, 19, 21-23