NAME

       Perl::Critic::Policy::Variables::RequireLocalizedPunctuationVars - Magic variables should
       be assigned as "local".

AFFILIATION

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

DESCRIPTION

       Punctuation variables (and their English.pm equivalents) are global variables.  Messing
       with globals is dangerous in a complex program as it can lead to very subtle and hard to
       fix bugs.  If you must change a magic variable in a non-trivial program, do it in a local
       scope.

       For example, to slurp a filehandle into a scalar, it's common to set the record separator
       to undef instead of a newline.  If you choose to do this (instead of using Path::Tiny!)
       then be sure to localize the global and change it for as short a time as possible.

           # BAD:
           $/ = undef;
           my $content = <$fh>;

           # BETTER:
           my $content;
           {
               local $/ = undef;
               $content = <$fh>;
           }

           # A popular idiom:
           my $content = do { local $/ = undef; <$fh> };

       This policy also allows the use of "my".  Perl prevents using "my" with "proper"
       punctuation variables, but allows $a, @ARGV, the names declared by English, etc.  This is
       not a good coding practice, however it is not the concern of this specific policy to
       complain about that.

       There are exemptions for $_ and @_, and the English equivalent $ARG.

CONFIGURATION

       You can configure your own exemptions using the "allow" option:

           [Variables::RequireLocalizedPunctuationVars]
           allow = @ARGV $ARGV

       These are added to the default exemptions.

CREDITS

       Initial development of this policy was supported by a grant from the Perl Foundation.

AUTHOR

       Chris Dolan <cdolan@cpan.org>

COPYRIGHT

       Copyright (c) 2007-2011 Chris Dolan.  Many 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 v5.20.2                Perl::Critic::Policy::Variables::RequireLocalizedPunctuationVars(3pm)