MooX::LvalueAttribute - Lvalue accessors in Moo
Yesterday I was reading Joel’s post, where he lists great Perl things he’s seen done lately. Indeed these are great stuff. I was particulary interested by his try at playing with Lvalue accessors.
I thought that it would be a great exercise to try to implement it in Moo, as
an additional feature, trying to get rid of the AUTOLOAD. Also, I was willing
to avoid doing a tie every time an instance attribute accessor was called.
Surely, I needed to tie only once per instance and per attribute, not each
time the attribute is accessed.
So I started hacking on the code of Moo. Getting rid of the AUTOLOAD was easy, as I could change the way the accessor generator was, well, generating the, err, accessors.
Shortly after I started having issues to cache a tied variable. I asked the all-mighty Vincent Pit, and he found a solution for my tied variables, but more importanlty pointed me to Variable::Magic, which is faster, more flexible and powerful.
All I needed was to move my hacks in a proper Role, and wrap the whole in a module, and push it on CPAN. Tadaa, MooX::LvalueAttribute was born.
In the process I used play-perl to register my quests, and exchanged thoughts with Joel Berger. I think I’m going to use this website more, see if it can boost my productivity, and help me figure out what’s really important to do.
On IRC, haarg discovered a bug and recommended to use so-called fieldhashes, from Hash::Util::FieldHash::Compat. At the end of the day, I only acted as a glue between different pieces of knowledges, and that was very satisfactory.
TL:DR
MooX::LvalueAttribute is a module that provides Lvalue attributes:
package App;
use Moo;
use MooX::LvalueAttribute;
has name => (
is => 'rw',
lvalue => 1,
);
# Elsewhere
my $app = App->new(name => 'foo');
$app->name = 'Bar';
print $app->name; # BarEnjoy!
