Perl: the 'semi' infinite loop? - perl

Question

I have here a working code, It works fine with 8 or 10 emails, but if you just put 20 emails it never finishes computing. That is, it is not an infinite loop because otherwise it would never compute anything. Also, if you use just 10 emails but ask it to make lists of more than 2, same thing happens. Yes, as pointed out, there is a while(#address) and somewhere in there, a push into address, that is the reason. I tried to replace that array into which it was pushed by another name, but i get weird errors like it picks one email from the list and it will complain that while strict references are on, i cant use that ...
I understand 100% the code up until the 'map' line. After that, not so much...
If we look at this part:
push #addresses, $address;
$moved{$address}++;
# say "pushing $address to moved"; # debug
one would say that the variable $address would have to be pushed, not into the #addresses, as that is the source of data (hence the loop as pointed out) but onto ..'moved' but, sorry, 'moved' is a hash. You can't push a variable into a hash, can you ? should then 'moved' be actually an array and not a hash? this is where i get lost
I was thinking about this instead, but ...it is just intuition, not real knowledge
push #{ $moved[$i] }, $address

Answer 1

I think I have solved it, taking as departure point the remark from 'Konerak'. Indeed the issue was a never decreasing list. Because I am not knowledgeable in reference arrays I was kind of lost, but somehow reading the code I tried to find similarity in a expected behaviour.
Therefore I created another array called #reserva and I wrote this:
push # {$reserva [$i]}, $address
instead of
push #addresses, $address;
Now, I get lists the size I want regardless of how many emails I enter. I tried with 1000 and had no problem in less than one second.
So, here is the full code
use strict;
use warnings;
use feature 'say';
use Data::Dumper;
my $only_index = 3; # Read from command line with $ARGV[0] or use Getopt::Long
my %blacklist = ( # Each key in this hash represents one index/day
'2' => [ 'a', 'b' ], # and has an arrayref of domains that have replied on
'3' => [ 'c' ], # that day. We look at all keys smaller than the current
); # index in each iteration and ignore all these domains
my #domains; # holds the domains we have already seen for each list
my #lists = ([]); # Holds all the lists
my %moved; # the addresses we moved to the back
my $i = 0;
my #addresses = <DATA>;
while (#addresses) {
my $address = shift #addresses;
chomp $address;
$address =~ m/#([a-zA-Z0-9\-.]*)\b/;
my $domain = $1;
# If the domain has answered, do not do it again
next if
grep { /$domain/ }
map { exists $blacklist{$_} ? #{ $blacklist{$_} } : () } (0..$i);
$i++ if (#{ $lists[$i] } == 2
|| (exists $moved{$address} && #addresses < 1));
if (exists $domains[$i]->{$domain}) {
push #addresses, $address;
$moved{$address}++;
# say "pushing $address to moved"; # debug
} else {
$domains[$i]->{$domain}++;
# send the email
# say "added $address to $i"; # debug
push #{ $lists[$i] }, $address;
}
}
# print Dumper \#lists; # Show all lists
print Dumper $lists[$only_index]; # Only show the selected list
1;
__DATA__
1#a
2#a
3#a
1#b
2#b
1#c
2#c
3#c
1#d
2#d
3#d
4#d
1#e
1#f
1#g
1#h
4#a
5#a
4#c

Answer 2

That's some twisty code, it's no wonder you're having trouble following it. I'm not actually sure what the body of the code is supposed to accomplish, but you can at least avoid the infinite loop by not using while (#array) - use foreach my $item (#array) instead and you'll iterate over it and avoid and bizarre behavior that will arise from modifying the array inside the loop.
chomp(#addresses); # chomp called on an array chomps each element
foreach my $address (#addresses) {
# Do work here
}