http://www.perlmonks.org?node_id=873677


in reply to Advice on style

I wouldn't inherit from Exporter at all, so I would get rid of @ISA=qw(Exporter). Exporter can export its own import() function into your module since v5.57 == Perl 5.8.3 (released 2004-01-14), so there is no need to inherit from Exporter any more. I would not use require, because it requires more typing than use and it is processed at runtime, not at compile time. use Exporter 'import'; is all you need to use Exporter's features from your module. Fall back to ...

use Exporter; use vars qw(@ISA @EXPORT); @ISA=qw(Exporter); @EXPORT=qw( ... );

... only if you need to support really old Perl versions.

Note that there are several Exporter replacements, Sub::Exporter has some very interesting features, but it can export "only" subs, no variables.

Regarding style, I prefer the following: pragmas first, followed by core and CPAN modules, followed by my own modules (mostly application specific). So, a typical module would look like this:

package MyApp::Foo; use strict; use warnings; use parent 'MyApp::BaseClass'; # only for OOP classes use Carp qw( croak ); # only when needed use DBI; # only when needed use CGI; # only when needed use MyApp::Tools; use MyApp::Utils; our $SVNID=q$Id$; # SVN expands this li +ne our $VERSION=sprintf('%d',q$Revision$=~/(\d+)/); # SVN expands this li +ne our @EXPORT=qw( ... ); # not for OOP classes, only when needed our @EXPORT_OK=qw( ... ); # not for OOP classes, only when needed our %EXPORT_TAGS=( ... ); # not for OOP classes, only when needed # more globals, if required # subs here 1;

Alexander

--
Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)