Something changed in 5.22. $My::{$symbol} can return a code reference or -1 instead of a glob.
The following is therefore needed:
sub get_code_ref_by_fqn { # Fully qualified name
my ($fqn) = @_;
my @pkg_name_parts = split /::/, $fqn;
my $symbol = pop(@pkg_name_parts);
my $pkg = \%::;
for (@pkg_name_parts) {
$pkg = $pkg->{$_.'::'}
or return undef;
}
my $glob_or_code = $pkg->{$symbol}
or return undef;
return $glob_or_code if ref($glob_or_code);
return undef if ref(\$glob_or_code) ne 'GLOB';
return *$glob_or_code{CODE};
}
But you know what, let's just leave those dirty details to Perl.
sub get_code_ref_by_fqn { # Fully qualified name
my ($fqn) = @_;
no strict qw( refs );
return undef if !defined(&$fqn);
return \&$fqn;
}
Above tested using
use 5.012;
use warnings;
sub Foo::Bar::y;
sub Foo::Bar::z { }
say get_code_ref_by_fqn('Foo::Bar::x') // '[undef]';
say get_code_ref_by_fqn('Foo::Bar::y') // '[undef]';
say get_code_ref_by_fqn('Foo::Bar::z') // '[undef]';