Using selective import/export for modules

Perl files

============ Inside a module file ============
unit module Sustenance;

sub eat-apples  is export(:apples,  :eat)   { … }
sub eat-oranges is export(:oranges, :eat)   { … }
sub eat-bananas is export(:bananas, :eat)   { … }
sub drink-water is export(:water,   :drink) { … }
sub drink-coke  is export(:coke,    :drink) { … }

=========== Inside your main script ==========
use Sustenance :apples;           # only makes eat-apples available.
use Sustenance :apples, :oranges; # only makes eat-apples and eat-oranges available
use Sustenance :eat;              # makes eat-apples, eat-oranges, and eat-bananas available
use Sustenance :drink;            # makes drink-water, drink-coke available
use Sustenance :apples, :water;   # makes eat apples and drink-water available
use Sustenance :eat, :drink;      # makes all of the subs available
use Sustenance :ALL;              # also makes all of the subs available