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perl::critic::policy::variables::prohibitpackagevars(3) [centos man page]

Perl::Critic::Policy::Variables::ProhibitPackageVars(3) User Contributed Perl DocumentationPerl::Critic::Policy::Variables::ProhibitPackageVars(3)

NAME

       Perl::Critic::Policy::Variables::ProhibitPackageVars - Eliminate globals declared with "our" or "use vars".

AFFILIATION

       This Policy is part of the core Perl::Critic distribution.

DESCRIPTION

       Conway suggests avoiding package variables completely, because they expose your internals to other packages.  Never use a package variable
       when a lexical variable will suffice.  If your package needs to keep some dynamic state, consider using an object or closures to keep the
       state private.

       This policy assumes that you're using "strict vars" so that naked variable declarations are not package variables by default.  Thus, it
       complains you declare a variable with "our" or "use vars", or if you make reference to variable with a fully-qualified package name.

	   $Some::Package::foo = 1;    # not ok
	   our $foo	       = 1;    # not ok
	   use vars '$foo';	       # not ok
	   $foo = 1;		       # not allowed by 'strict'
	   local $foo = 1;	       # bad taste, but technically ok.
	   use vars '$FOO';	       # ok, because it's ALL CAPS
	   my $foo = 1; 	       # ok

       In practice though, its not really practical to prohibit all package variables.	Common variables like $VERSION and @EXPORT need to be
       global, as do any variables that you want to Export.  To work around this, the Policy overlooks any variables that are in ALL_CAPS.  This
       forces you to put all your exported variables in ALL_CAPS too, which seems to be the usual practice anyway.

CONFIGURATION

       There is room for exceptions.  Some modules, like the core File::Find module, use package variables as their only interface, and others
       like Data::Dumper use package variables as their most common interface.	These module can be specified from your .perlcriticrc file, and
       the policy will ignore them.

	   [Variables::ProhibitPackageVars]
	   packages = Data::Dumper File::Find FindBin Log::Log4perl

       This is the default setting.  Using "packages ="  will override these defaults.

       You can also add packages to the defaults like so:

	   [Variables::ProhibitPackageVars]
	   add_packages = My::Package

       You can add package "main" to the list of packages, but that will only OK variables explicitly in the "main" package.

SEE ALSO

       Perl::Critic::Policy::Variables::ProhibitPunctuationVars

       Perl::Critic::Policy::Variables::ProhibitLocalVars

AUTHOR

       Jeffrey Ryan Thalhammer <jeff@imaginative-software.com>

COPYRIGHT

       Copyright (c) 2005-2011 Imaginative Software Systems.  All rights reserved.

       This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.  The full text of this license
       can be found in the LICENSE file included with this module.

perl v5.16.3							    2014-06-09		   Perl::Critic::Policy::Variables::ProhibitPackageVars(3)

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Perl::Critic::Policy::Variables::RequireLexicalLoopIteraUser(Contributed Perl DocumPerl::Critic::Policy::Variables::RequireLexicalLoopIterators(3)

NAME

       Perl::Critic::Policy::Variables::RequireLexicalLoopIterators - Write "for my $element (@list) {...}" instead of "for $element (@list)
       {...}".

AFFILIATION

       This Policy is part of the core Perl::Critic distribution.

DESCRIPTION

       This policy asks you to use "my"-style lexical loop iterator variables:

	   foreach my $zed (...) {
	       ...
	   }

       Unless you use "my", "for"/"foreach" loops use a global variable with its value "local" to the block. In other words,

	   foreach $zed (...) {
	       ...
	   }

       is more-or-less equivalent to

	   {
	       local $zed
	       foreach $zed (...) {
		   ...
	       }
	   }

       This may not seem like a big deal until you see code like

	   my $bicycle;
	   for $bicycle (@things_attached_to_the_bike_rack) {
	       if (
		       $bicycle->is_red()
		   and $bicycle->has_baseball_card_in_spokes()
		   and $bicycle->has_bent_kickstand()
	       ) {
		   $bicycle->remove_lock();

		   last;
	       }
	   }

	   if ( $bicycle and $bicycle->is_unlocked() ) {
	       ride_home($bicycle);
	   }

       which is not going to allow you to arrive in time for dinner with your family because the $bicycle outside the loop is not changed by the
       loop. You may have unlocked your bicycle, but you can't remember which one it was.

       Lexical loop variables were introduced in Perl 5.004. This policy does not report violations on code which explicitly specifies an earlier
       version of Perl (e.g. "require 5.002;").

CONFIGURATION

       This Policy is not configurable except for the standard options.

SEE ALSO

       "Foreach Loops" in perlsyn

       "my() in Control Structures" in perl5004delta

AUTHOR

       Jeffrey Ryan Thalhammer <jeff@imaginative-software.com>

COPYRIGHT

       Copyright (c) 2005-2011 Imaginative Software Systems.  All rights reserved.

       This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.  The full text of this license
       can be found in the LICENSE file included with this module.

perl v5.16.3							    2014-06-09	   Perl::Critic::Policy::Variables::RequireLexicalLoopIterators(3)
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