Module problem

vinoth.ree has asked for the wisdom of the Perl Monks concerning the following question:

Package

package MYCALC;
use Exporter;

our @EXPORT = ();
our @ISA = qw(Exporter);
our @EXPORT_OK = qw(addition multi);
our %EXPORT_TAGS = (DEFAULT => [qw(&addition)],Both => [qw(&addition &
+multi)]);

sub  addition {
    return $_[0] + $_[1];
}
sub  multi {
    return $_[0] * $_[1];
}

1;
[download]

Program:

use strict;
use warnings;
my @list = qw (2 2);
use Module qw(:DEFAULT);
print addition(@list),"\n";
[download]

Above coding is my module MYCALC and the program which using this module, I have not exported any function using @EXPORT, but I have used the DEFAULT in %EXPORT_TAGS with the function addition, when I call this function from the main it says the error as,

Undefined subroutine &main::addition called at Module.pl line 25.

Why the addition function not getting called?

Comment on Module problem Select or Download Code

Replies are listed 'Best First'.
Re: Module problem by shmem (Chancellor) on Mar 09, 2009 at 09:30 UTC
I have not exported any function using @EXPORT, but I have used the DEFAULT in %EXPORT_TAG The :DEFAULT tag applies to @EXPORT. From the Exporter pod: Advanced features Specialised Import Lists If any of the entries in an import list begins with !, : or / then the list is treated as a series of specifica- tions which either add to or delete from the list of names to import. They are processed left to right. Specifica- tions are in the form: `[!]name This name only [!]:DEFAULT All names in @EXPORT [!]:tag All names in $EXPORT_TAGS{tag} anonymous li +st [!]/pattern/ All names in @EXPORT and @EXPORT_OK which m +atch` [download] A leading ! indicates that matching names should be deleted from the list of names to import. If the first specification is a deletion it is treated as though preceded by :DEFAULT. If you just want to import extra names in addition to the default set you will still need to include :DEFAULT explicitly.	[reply] [d/l]
Re: Module problem by Bloodnok (Vicar) on Mar 09, 2009 at 11:34 UTC
ree, the key thing to note in shmems reply is :DEFAULT All names in @EXPORT - since `@EXPORT` is empty in your code, I'm not be at all surprised you hit the the problem you did. A user level that continues to overstate my experience :-))	[reply] [d/l]
Re: Module problem by boom (Scribe) on Mar 10, 2009 at 03:31 UTC
The DEFAULT tag name is special and is automatically set in our modules %EXPORT_TAGS hash like this DEFAULT=>\@EXPORT.	[reply]
Re: Module problem by ig (Vicar) on Mar 10, 2009 at 08:30 UTC
but I have used the DEFAULT in %EXPORT_TAGS with the function addition... To clarify the previous answers slightly: the tag :DEFAULT is special. The import function does not look at $EXPORT_TAGS{DEFAULT} for this tag, so it doesn't matter that you have set this element in %EXPORT_TAGS. If you change DEFAULT to MYTAG (or anything other than DEFAULT) in your module and program, then your addition subroutine is imported into your main package.	[reply]