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Perl::Critic::Policy::InputOutput::ProhibitReadlineInForLoop(3) | User Contributed Perl Documentation | Perl::Critic::Policy::InputOutput::ProhibitReadlineInForLoop(3) |
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 <thaljef@cpan.org>
COPYRIGHT¶
Copyright (c) 2005-2009 Jeffrey Ryan Thalhammer. 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.
2010-12-13 | perl v5.10.1 |