Perl::Critic::Policy::InputOutput::ProhibitReadlineInForLoop(3pm)
                                           User Contributed Perl Documentation


NAME
       Perl::Critic::Policy::InputOutput::ProhibitReadlineInForLoop - Write
       "while( $line = <> ){...}" instead of "for(<>){...}".

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

DESCRIPTION
       Using the readline operator in a "for" or "foreach" loop is very slow.
       The iteration list of the loop creates a list context, which causes the
       readline operator to read the entire input stream before iteration even
       starts.  Instead, just use a "while" loop, which only reads one line at
       a time.

         for my $line ( <$file_handle> ){ do_something($line) }      #not ok
         while ( my $line = <$file_handle> ){ do_something($line) }  #ok

CONFIGURATION
       This Policy is not configurable except for the standard options.

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 v5.38.0                      2023-07-26
             Perl::Critic::Policy::InputOutput::ProhibitReadlineInForLoop(3pm)