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


Perl-Critic documentation  | view source Contained in the Perl-Critic distribution.

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NAME

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

AFFILIATION

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

DESCRIPTION

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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

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This Policy is not configurable except for the standard options.

AUTHOR

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Jeffrey Ryan Thalhammer <jeff@imaginative-software.com>

COPYRIGHT

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Perl-Critic documentation  | view source Contained in the Perl-Critic distribution.