NAME

       Perl::Critic::Policy::Variables::ProhibitPunctuationVars - Write "$EVAL_ERROR" instead of
       "$@".

AFFILIATION

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

DESCRIPTION

       Perl's vocabulary of punctuation variables such as $!, $., and $^ are perhaps the leading
       cause of its reputation as inscrutable line noise.  The simple alternative is to use the
       English module to give them clear names.

         $| = undef;                      #not ok

         use English qw(-no_match_vars);
         local $OUTPUT_AUTOFLUSH = undef; #ok

CONFIGURATION

       The scratch variables $_ and @_ are very common and are pretty well understood, so they
       are exempt from this policy.  The same goes for the less-frequently-used default
       filehandle "_" used by stat().  All the regexp capture variables ($1, $2, ...) are exempt
       too.  $] is exempt because there is no English equivalent and Module::CoreList is based
       upon it.

       You can add more exceptions to your configuration.  In your perlcriticrc file, add a block
       like this:

         [Variables::ProhibitPunctuationVars]
         allow = $@ $!

       The "allow" property  should  be  a  whitespace-delimited  list  of punctuation variables.

       Other configuration options  control  the  parsing  of  interpolated strings in the search
       for forbidden variables. They have  no  effect on detecting punctuation variables outside
       of interpolated  strings.

         [Variables::ProhibitPunctuationVars]
         string_mode = thorough

       The option "string_mode"  controls  whether  and  how  interpolated strings are searched
       for punctuation variables. Setting "string_mode = thorough", the default,  checks  for
       special  cases that may look like punctuation variables  but  aren't,  for  example $#foo,
       an array index count; $$bar, a scalar  dereference;  or $::baz, a global symbol.

       Setting "string_mode = disable" causes all interpolated strings  to be ignored entirely.

       Setting "string_mode = simple" uses a simple regular expression  to find matches. In this
       mode, the magic variables $$, "$'",  $# and $: are ignored within interpolated strings due
       to  the  high risk of false positives. Simple mode is  retained  from  an  earlier draft
       of the interpolated- strings code. Its use is only recommended as a workaround if bugs
       appear in thorough mode.

       The  "string_mode"  option  will  go  away  when  the  parsing   of interpolated strings
       is implemented in PPI. See  "CAVEATS"  below.

BUGS

       Punctuation variables that confuse PPI's document parsing may not be detected  correctly
       or  at  all,  and  may  prevent  detection   of subsequent ones. In particular, $" is
       known to cause difficulties in interpolated strings.

CAVEATS

       ProhibitPunctuationVars  relies   exclusively   on   PPI   to   find punctuation variables
       in code, but does all the parsing  itself  for interpolated strings. When, at some  point,
       this  functionality  is transferred to PPI, ProhibitPunctuationVars  will  cease  doing
       the interpolating  and  the  "string_mode"   option   will   go   away.

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 v5.24.1                        Perl::Critic::Policy::Variables::ProhibitPunctuationVars(3pm)