Section A.14.  Answers for Chapter 15

A.14. Answers for Chapter 15

A.14.1. Exercise 1

The module Oogaboogoo/date.pm looks like this:

package Oogaboogoo::date;
use strict;
use Exporter;
our @ISA = qw(Exporter);
our @EXPORT = qw(day mon);

my @day = qw(ark dip wap sen pop sep kir);
my @mon = qw(diz pod bod rod sip wax lin sen kun fiz nap dep);

sub day {
  my $num = shift @_;
  die "$num is not a valid day number"
    unless $num >= 0 and $num <= 6;
  $day[$num];
}

sub mon {
  my $num = shift @_;
  die "$num is not a valid month number"
    unless $num >= 0 and $num <= 11;
  $mon[$num];
}

1;

The main program now looks like this:

use strict;
use Oogaboogoo::date qw(day mon);

my($sec, $min, $hour, $mday, $mon, $year, $wday) = localtime;
my $day_name = day($wday);
my $mon_name = mon($mon);
$year += 1900;
print "Today is $day_name, $mon_name $mday, $year.\n";

A.14.2. Exercise 2

Most of this answer is the same as the previous answer. We just need to add the parts for the export tag all.

our @EXPORT = qw(day mon);
our %EXPORT_TAGS = ( all => \@EXPORT );

Everything that we put in %EXPORT_TAGS has to also be in either @EXPORT or @EXPORT_OK. For the all tag, we use a reference to @EXPORT directly. If we don't like that, we can make a fresh copy so the two do not reference each other.

our @EXPORT = qw(day mon);
our %EXPORT_TAGS = ( all => [ @EXPORT ] );

Modify the program from the previous exercise to use the import tag by prefacing it with a colon in the import list.

The main program now starts off like this:

use strict;
use Oogaboogoo::date qw(:all);