scratchpad
alexm
<h2>autovivification and symbolic refs</h2>
<p>This:
<code>
$hash{'foo'} = 1;
$hash{'foo'}{'bar'} = 2;
</code>
performs:
<code>
%1 = { bar => 2 };
</code>
<p>Reference: [id://696522]</p>
<h2>[id://698212|a way to export all constants instead of listing each one]</h2>
<p>My response to [id://697835] didn't get much feedback, and it's one that I'm very proud of, so I'm adding it here, just in case someone finds it useful (it was quite entertaining to come up with).</p>
<c>
##### MyConst.pm #####
package MyConst;
use warnings;
use strict;
use Readonly ();
require Exporter;
our @ISA = qw(Exporter);
our @EXPORT = qw();
Readonly::Scalar our $const1 => 1;
Readonly::Array our @array => qw(x y z);
Readonly::Hash our %hash => (abc => 123, def => 456);
sub foo { 'foobar' }
my $package = __PACKAGE__;
no strict 'refs';
while (my $sym = each %{ "$package\::" }) {
# skip internals
next if $sym =~ /^(?:BEGIN|EXPORT|ISA)$/;
if (defined ${ $sym }) {
push @EXPORT, "\$$sym";
}
elsif (defined %{ $sym }) {
push @EXPORT, "\%$sym";
}
elsif (defined @{ $sym }) {
push @EXPORT, "\@$sym";
}
elsif (defined &{ $sym }) {
push @EXPORT, "$sym";
}
}
1;
__END__
</c>