Module 'use' chains

Vaati has asked for the wisdom of the Perl Monks concerning the following question:

Replies are listed 'Best First'.
Re: Module 'use' chains by tilly (Archbishop) on Aug 10, 2006 at 02:03 UTC
First of all, this is a really bad idea. There is a reason that Exporter recommends not sticking stuff into @EXPORT. And that reason is that when you have a problem with a function, you've just made it very hard to figure out where that function is from. But if you wish to do this, and if every one of the modules used Exporter, then this module will do what you want. `package Include; use base Exporter; use A; push @EXPORT, @A::EXPORT; use B; push @EXPORT, @B::EXPORT; use C; push @EXPORT, @C::EXPORT; 1;` [download] But again. This is a bad idea. Read Code Complete and muse on "loose coupling" to understand why.	[reply] [d/l]
Re^2: Module 'use' chains by merlyn (Sage) on Aug 10, 2006 at 03:01 UTC
I'm not sure if that would work, exactly. Perhaps you want Automatically add all defined functions to your @EXPORT instead. -- Randal L. Schwartz, Perl hacker Be sure to read my standard disclaimer if this is a reply.	[reply]
Re^3: Module 'use' chains by tilly (Archbishop) on Aug 10, 2006 at 03:05 UTC
Mine would work, with caveats. Yours works without caveats. So you have the more effective bad solution. merlyn++	[reply]
Re^2: Module 'use' chains by Vaati (Sexton) on Aug 10, 2006 at 02:29 UTC
Keen, thank you for your response. It was very helpful. I know this is dangerous, and in truth I'd rather not do it. However, I've run into a scenario where I in herited a 4K+ line script. I'm in the process of refactoring it now and have busted it up into about 8 modules. The reason why I thought this would be useful is becuase I can't figure out how to "deeply" compile test this. So "undefined" subroutines are going to drive me to heroin at this point becuase perl -c always reports good. And it seems that if I copy/paste the entire chain of 'uses' into all 8 modules it gets really, really confused and can't find all the subs.	[reply]
Re^3: Module 'use' chains by graq (Curate) on Aug 10, 2006 at 07:49 UTC
Sounds to me like you have done a good job in starting to modularise a script, but that some further redesign is required. Without knowing the exact problem, I can't be sure or specific, but if it were me I would sit down with a pad and paper (or some equivalent) to try to re-think the process flow of the script - and how I can make the modules more modular. -=( Graq )=-	[reply]
Re: Module 'use' chains by davorg (Chancellor) on Aug 10, 2006 at 08:14 UTC
I think you're looking for Toolkit.pm. -- <http://dave.org.uk> "The first rule of Perl club is you do not talk about Perl club." -- Chip Salzenberg	[reply]
Re^2: Module 'use' chains by Vaati (Sexton) on Aug 10, 2006 at 13:07 UTC
Thank you all very much for your help, it has been invaluable. I really appreciate it. PS: BTW Randal congrats on the OpenSource award.	[reply]
Re: Module 'use' chains by bbfu (Curate) on Aug 10, 2006 at 05:24 UTC
A simpler method is to just leave off the package line in your Include module. The module automatically starts in the package of the caller, and thus the chain-included modules will automatically export to the correct place. Read more... (2 kB) bbfu Black flowers blossom Fearless on my breath	[reply] [d/l] [select]
Re^2: Module 'use' chains by ikegami (Patriarch) on Aug 10, 2006 at 05:40 UTC
That will only work the first time `use` is called. Replace `use Include;` with `BEGIN { do 'Include.pl'; }`	[reply] [d/l] [select]
Re^2: Module 'use' chains by tilly (Archbishop) on Aug 10, 2006 at 05:33 UTC
Perl really works like that? (Tests.) Ugh. But note that that only works if the package is used only from within one package.	[reply]
Re^3: Module 'use' chains by bbfu (Curate) on Aug 10, 2006 at 05:42 UTC
You're right. I should have tested it more thoroughly. bbfu Black flowers blossom Fearless on my breath	[reply]
Re: Module 'use' chains by sgt (Deacon) on Aug 10, 2006 at 20:29 UTC
actually this question is perl hack #34 by Damian Conway; it mentions Filter::Macro and Toolkit	[reply]
Re: Module 'use' chains by Moron (Curate) on Aug 11, 2006 at 09:21 UTC
If the intention is to site-extend the set of core modules then I'd be more inclined to require a file called something like SiteCore.pl and maintain a single set of use statements there, the requirement of this file being then a project standard. This is also a way to manage your own software that has to run on old as well as new perl versions where the core set has changed in between. -M Free your mind	[reply]