perl::critic::policy::controlstructures::prohibitmutatinglistfun(3pm) [debian man page]

Perl::Critic::Policy::ControlStructures::ProhibitMutatinUsertContributePerl::Critic::Policy::ControlStructures::ProhibitMutatingListFunctions(3pm)

NAME

       Perl::Critic::Policy::ControlStructures::ProhibitMutatingListFunctions - Don't modify "$_" in list functions.

AFFILIATION

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

DESCRIPTION

       "map", "grep" and other list operators are intended to transform arrays into other arrays by applying code to the array elements one by
       one.  For speed, the elements are referenced via a $_ alias rather than copying them.  As a consequence, if the code block of the "map" or
       "grep" modify $_ in any way, then it is actually modifying the source array.  This IS technically allowed, but those side effects can be
       quite surprising, especially when the array being passed is @_ or perhaps "values(%ENV)"!  Instead authors should restrict in-place array
       modification to "for(@array) { ... }" constructs instead, or use "List::MoreUtils::apply()".

CONFIGURATION

       By default, this policy applies to the following list functions:

	   map grep
	   List::Util qw(first)
	   List::MoreUtils qw(any all none notall true false firstidx
			      first_index lastidx last_index insert_after
			      insert_after_string)

       This list can be overridden the .perlcriticrc file like this:

	   [ControlStructures::ProhibitMutatingListFunctions]
	   list_funcs = map grep List::Util::first

       Or, one can just append to the list like so:

	   [ControlStructures::ProhibitMutatingListFunctions]
	   add_list_funcs = Foo::Bar::listmunge

LIMITATIONS

       This policy deliberately does not apply to "for (@array) { ... }" or "List::MoreUtils::apply()".

       Currently, the policy only detects explicit external module usage like this:

	   my @out = List::MoreUtils::any {s/^foo//} @in;

       and not like this:

	   use List::MoreUtils qw(any);
	   my @out = any {s/^foo//} @in;

       This policy looks only for modifications of $_.	Other naughtiness could include modifying $a and $b in "sort" and the like.  That's beyond
       the scope of this policy.

SEE ALSO

       There is discussion of this policy at <http://perlmonks.org/index.pl?node_id=743445>.

AUTHOR

       Chris Dolan <cdolan@cpan.org>

       Michael Wolf <MichaelRWolf@att.net>

COPYRIGHT

       Copyright (c) 2006-2011 Chris Dolan.

       This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

perl v5.14.2							    201Perl::Critic::Policy::ControlStructures::ProhibitMutatingListFunctions(3pm)

Perl::Critic::Policy::Subroutines::ProhibitUnusedPrivateUseroContributed PPerl::Critic::Policy::Subroutines::ProhibitUnusedPrivateSubroutines(3pm)

NAME

       Perl::Critic::Policy::Subroutines::ProhibitUnusedPrivateSubroutines - Prevent unused private subroutines.

AFFILIATION

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

DESCRIPTION

       By convention Perl authors (like authors in many other languages) indicate private methods and variables by inserting a leading underscore
       before the identifier.  This policy catches such subroutines which are not used in the file which declares them.

       This module defines a 'use' of a subroutine as a subroutine or method call to it (other than from inside the subroutine itself), a
       reference to it (i.e.  "my $foo = &_foo"), a "goto" to it outside the subroutine itself (i.e.  "goto &_foo"), or the use of the
       subroutine's name as an even-numbered argument to "use overload".

CONFIGURATION

       You can define what a private subroutine name looks like by specifying a regular expression for the "private_name_regex" option in your
       .perlcriticrc:

	   [Subroutines::ProhibitUnusedPrivateSubroutines]
	   private_name_regex = _(?!_)w+

       The above example is a way of saying that subroutines that start with a double underscore are not considered to be private.  (Perl::Critic,
       in its implementation, uses leading double underscores to indicate a distribution-private subroutine -- one that is allowed to be invoked
       by other Perl::Critic modules, but not by anything outside of Perl::Critic.)

       You can configure additional subroutines to accept by specifying them in a space-delimited list to the "allow" option:

	   [Subroutines::ProhibitUnusedPrivateSubroutines]
	   allow = _bar _baz

       These are added to the default list of exemptions from this policy. So the above allows "sub _bar {}" and "sub _baz {}", even if they are
       not referred to in the module that defines them.

HISTORY

       This policy is derived from Perl::Critic::Policy::Subroutines::ProtectPrivateSubs, which looks at the other side of the problem.

BUGS

       Does not forbid "sub Foo::_foo{}" because it does not know (and can not assume) what is in the "Foo" package.

SEE ALSO

       Perl::Critic::Policy::Subroutines::ProtectPrivateSubs.

AUTHOR

       Chris Dolan <cdolan@cpan.org>

COPYRIGHT

       Copyright (c) 2009-2011 Thomas R. Wyant, III.

       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 v5.14.2							    2012-0Perl::Critic::Policy::Subroutines::ProhibitUnusedPrivateSubroutines(3pm)