qr{^[A-Za-z_][A-Za-z0-9_]*(?:::[A-Za-z0-9_]+)*$}

##</code><code>##

#!/usr/bin/env perl

use strict;
use warnings;

use Test::More;

my @modules = qw{
    strict
    autodie::exception::system
    utf8
    B
    App::Prove::State::Result::Test
    CPAN::Meta::History::Meta_1_0
    Encode::KR::2022_KR
};

plan tests => 0+@modules;

my $re = qr{^[A-Za-z_][A-Za-z0-9_]*(?:::[A-Za-z0-9_]+)*$};

for my $mod (@modules) {
    is $mod =~ $re, !!1, "Testing $mod";
}

##</code><code>##

1..7
ok 1 - Testing strict
ok 2 - Testing autodie::exception::system
ok 3 - Testing utf8
ok 4 - Testing B
ok 5 - Testing App::Prove::State::Result::Test
ok 6 - Testing CPAN::Meta::History::Meta_1_0
ok 7 - Testing Encode::KR::2022_KR