Check out Smart::Comments module in Perl [1]. It allows the specially-formatted comments to produce debugging output. From the synopsis: use Smart::Comme

Check out Smart::Comments module in Perl [1]. It allows the specially-formatted comments to produce debugging output. From the synopsis: use Smart::Comments; my $var = suspect_value(); ### $var ### got: $var ### Now computing value... # and when looping: for my $big_num (@big_nums) { ### Factoring... done factor($big_num); } while ($error > $tolerance) { ### Refining---> done refine_approximation() } for (my $i=0; $i<$MAX_INT; $i++) { ### Working===[%] done do_something_expensive_with($i); } [1] https://metacpan.org/module/Smart::Comments https://metacpan.org/module/Smart::Comments