Perl::Critic::Policy::Variables::RequireLexicalLoopIterators - Write C<for my $element {...}>. |
Perl::Critic::Policy::Variables::RequireLexicalLoopIterators - Write for my $element (@list) {...}
instead of for $element (@list) {...}
.
This Policy is part of the core Perl::Critic distribution.
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;
).
This Policy is not configurable except for the standard options.
``my() in Control Structures'' in perl5004delta
Jeffrey Ryan Thalhammer <jeff@imaginative-software.com>
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::Critic::Policy::Variables::RequireLexicalLoopIterators - Write C<for my $element {...}>. |