Comments on: Packages, modules and distributions

By: Version numbers should be boring

Version numbers should be boring — Thu, 06 Aug 2009 01:35:39 +0000

[...] on CPAN also have version numbers. These are specified as part of the filename. (See a prior article for a formal definition of modules and [...]

By: BenRifkah

BenRifkah — Wed, 22 Jul 2009 19:02:06 +0000

These are all good definitions of the terms although I have one point that may appear to be minor at first but may make a difference if these definitions are to be used when considering tool chain modifications. In your module definition you mention that "Compiling the module should return a true value." I think that what you're getting at is that "use"ing the module should not fail with a "foo.pm did not return a true value" exception. However, one could interpret this to mean that "perl -c foo.pm" returns true. perl -c will return true if your file doesn't return true and doesn't contain any compilation errors. Clarifying this point can potentially avoid some confusion.

By: John

John — Wed, 22 Jul 2009 14:59:33 +0000

Really excellent post. Thanks, David. This information belongs in the Perl 5 wiki if it's not there already.

Here's a similar blog post -- but for Python -- which you might find interesting: http://blog.ianbicking.org/2008/12/14/a-few-corrections-to-on-packaging/

Also, does Perl 6 use the same terms (above) as Perl 5?

By: david

david — Tue, 21 Jul 2009 01:45:39 +0000

That's a good point. I did think to say 'zero or more' modules, but it's good to be explicit about the other uses for distributions.

By: fREW Schmidt

fREW Schmidt — Mon, 20 Jul 2009 23:41:39 +0000

I'd also mention that some dist's on CPAN may have tools but not modules, or at least the modules may not be for public consumption but only for the dist's executable files.

By: hdp

hdp — Mon, 20 Jul 2009 13:41:03 +0000

I agree with all of the above, but have nothing substantial to add. Well said.

By: david

david — Mon, 20 Jul 2009 11:10:56 +0000

That's a great example!

By: Tim Heaney

Tim Heaney — Mon, 20 Jul 2009 10:30:06 +0000

It's good to define these terms too, because they are so overloaded. For example, to install a module, I might use the package manager from my distribution $ sudo apt-get install libmodule-build-perl That's not CPAN, but it's close enough in context to add confusion, if we're not careful.