Re: "use base" or @ISA

As an aside, I hate inhererting from Exporter. My class does NOT have an ISA relationship with Exporter! (And inheriting an autoload? ouch!) Below is an alternative.

Instead of:

use vars qw( @ISA @EXPORT_OK %EXPORT_TAGS );
BEGIN {
    @ISA = qw( Exporter );
    @EXPORT_OK   = qw( ... );
    %EXPORT_TAGS = ( ... );  # if necessary
    use Exporter;
}
[download]

try:

use vars qw( @EXPORT_OK %EXPORT_TAGS );
BEGIN {
    @EXPORT_OK   = qw( ... );
    %EXPORT_TAGS = ( ... );  # if necessary
    require Exporter;
    *import = \&Exporter::import;
}
[download]

Update: s/module/class/;

Comment on Re: "use base" or @ISA Select or Download Code

Replies are listed 'Best First'.
Re^2: "use base" or @ISA by kscaldef (Pilgrim) on Aug 17, 2004 at 17:20 UTC
My module does NOT have an ISA relationship with Exporter! Really? So, how would you explain the relationship? Your module exports; it is an exporter.	[reply]
Re^3: "use base" or @ISA by simonm (Vicar) on Aug 18, 2004 at 01:45 UTC
My module does NOT have an ISA relationship with Exporter! Really? So, how would you explain the relationship? Your module exports; it is an exporter. I would say that the module "delegates to Exporter", or "uses Exporter". Delegation and composition are perfectly valid implementation mechanisms, and there's no reason to view inheritance as the one true way of sharing functionality.	[reply]
Re^4: "use base" or @ISA by TimToady (Parson) on Aug 18, 2004 at 03:02 UTC
In Perl 6 terms, it "does" Exporter rather than "is" Exporter. That is, Exporter is a role rather than a class. (It's a form of composition, really.) The Exporter role in Perl 6 would presumably supply importation as a submethod rather than a method, so that it's not inherited by subclasses. It could also be done with delegation, but in that case it "has" an Exporter object. Of course, Perl 6 might not use an Exporter class or role at all, since the standard export mechanism will be built in, and (we hope) fast.	[reply]
Re^5: "use base" or @ISA by tye (Sage) on Aug 18, 2004 at 03:53 UTC
Re^3: "use base" or @ISA by ikegami (Patriarch) on Aug 17, 2004 at 17:34 UTC
oops, that was a typo or a freudian slip or something. I meant to say my class isn't an exporter. A dog (for example) is an animal, but a dog isn't an exporter (although the package in which dog is defined might be). That's just my way of looking at things, so use the style you like the most.	[reply]
Re^2: "use base" or @ISA by Aristotle (Chancellor) on Aug 18, 2004 at 11:34 UTC
I use Exporter::Lite. It is much lighter and has a clean interface (its `import()` is simply exported). It doesn't support tags, but then I never needed them anyway. Exporter::Tidy is another alternative if you need advanced features (some of which Exporter doesn't even offer.) Makeshifts last the longest.	[reply]
Re^2: "use base" or @ISA by Prior Nacre V (Hermit) on Aug 19, 2004 at 10:58 UTC
Exporter has: `package YourModule; use Exporter qw( import );` [download] under the heading Exporting without inheriting from Exporter. Regards, PN5	[reply] [d/l]