ETOOBUSY 🚀 minimal blogging for the impatient
Sub::Util
TL;DR
Getting the name of a sub and other amenities with Sub::Util.
After writing about Sub::Import I also decided to give
Sub::Util a try. It actually popped up while I was looking for
Sub::Import’s because it does something… in the same area.
Let’s expand the example from the last time:
#!/usr/bin/env perl
use 5.024;
use warnings;
use experimental qw< postderef signatures >;
no warnings qw< experimental::postderef experimental::signatures >;
use FindBin '$Bin';
use lib "$Bin/local/lib/perl5", "$Bin/lib";
use Sub::Import 'MIME::Base64', encode_base64 => {-as => 'e64'},
use Sub::Util qw< subname set_subname >;
say 'e64 is currently ', subname(\&e64);
set_subname('e64, but for messing up!', \&e64);
say 'e64 is now known as "', subname(\&e64), '" in the right circles';
Output:
e64 is currently MIME::Base64::encode_base64
e64 is now known as "main::e64, but for messing up!" in the right circles
Sub::Util contains a few functions, two of which are related to a
sub’s name. The first one, subname, tells you what’s the current
name of a sub reference:
say 'e64 is currently ', subname(\&e64);
# e64 is currently MIME::Base64::encode_base64
The other one is set_subname, which allows to set the name but only
for consumption by subname or other introspection code. In other
terms, it does not install a sub with that name, it only record the
association between the provided sub reference and a string. Which means
that… the name can be whatever string!
This is why this works:
set_subname('e64, but for messing up!', \&e64);
say 'e64 is now known as "', subname(\&e64), '" in the right circles';
# e64 is now known as "main::e64, but for messing up!" in the right circles
I think this is brilliant!