Next steps

Default exports

Note that the module in the synopsis doesn't export anything by default. If people load "MyUtils" like this:

use MyUtils;

Then they haven't imported any functions. You can specify a default set of functions to be exported like this:

package MyUtils;

use Exporter::Shiny qw( frobnicate );

our @EXPORT = qw( frobnicate );

sub frobnicate { ... }

1;

Or, if you want to be a superstar rock god:

package MyUtils;

use Exporter::Shiny our @EXPORT = qw( frobnicate );

sub frobnicate { ... }

1;

Tags

You can provide tags for people to use:

package MyUtils;

use Exporter::Shiny qw( frobnicate red green blue );

our %EXPORT_TAGS = (
   utils   => [qw/ frobnicate /],
   colours => [qw/ red green blue /],
);

sub frobnicate { ... }
sub red        { ... }
sub green      { ... }
sub blue       { ... }

1;

And people can now import your functions like this:

use MyUtils ":colours";

Or this:

use MyUtils "-colours";

Or take advantage of the fact that Perl magically quotes barewords preceded by a hyphen:

use MyUtils -colours;

Two tags are automatically defined for you: "-default" (which is just the same as @EXPORT) and "-all" (which is the union of @EXPORT and @EXPORT_OK). If you don't like them, then you can override them:

our %EXPORT_TAGS = (
   default => \@some_other_stuff,
   all     => \@more_stuff,
);

Generators

Exporting normally just works by copying a sub from your package into your caller's package. But sometimes it's useful instead to generate a custom sub to insert into your caller's package. This is pretty easy to do.

package MyUtils;

use Exporter::Shiny qw( frobnicate );

sub _generate_frobnicate {
   my ( $me, $name, $args, $globals ) = @_;
   my $caller = $globals->{into};

   return sub {
       ...;  # your code here
   };
}

1;

The parameter $me here is a string containing the package name which is being imported from; $caller is the destination package; $name is the name of the sub (in this case "frobnicate"); and $args is a custom argument for this function. (By convention, $args is normally a hashref.)

# The hashref { foo => 42 } is $args above.
#
use MyUtils "frobnicate" => { foo => 42 };

Avoiding Exporter::Shiny

Exporter::Shiny is a tiny shim around Exporter::Tiny. It should mostly do what you want, but you may sometimes prefer to use Exporter::Tiny directly.

The example in the synopsis could have been written as:

package MyUtils;

use parent "Exporter::Tiny";
our @EXPORT_OK = qw( frobnicate );

sub frobnicate {
   ...;   # your code here
}

1;

What Exporter::Shiny does is mostly just to set @EXPORT_OK for you and set up inheritance from the base class (Exporter::Tiny).

Exporter::Shiny also sets $INC{'MyUtils.pm'} for you, which in usually makes little difference, but is useful in some edge cases.