—##############################################################################
# $Date: 2009-07-21 08:50:56 -0700 (Tue, 21 Jul 2009) $
# $Author: clonezone $
# $Revision: 3404 $
##############################################################################
use
5.006001;
use
strict;
use
warnings;
use
Readonly;
our
$VERSION
=
'1.101_001'
;
#-----------------------------------------------------------------------------
Readonly::Scalar
my
$DESC
=>
q{Readline inside "for" loop}
;
Readonly::Scalar
my
$EXPL
=> [ 211 ];
#-----------------------------------------------------------------------------
sub
supported_parameters {
return
() }
sub
default_severity {
return
$SEVERITY_HIGH
}
sub
default_themes {
return
qw< core bugs pbp >
}
sub
applies_to {
return
qw< PPI::Statement::Compound >
}
#-----------------------------------------------------------------------------
sub
violates {
my
(
$self
,
$elem
,
undef
) =
@_
;
return
if
$elem
->type() ne
'foreach'
;
my
$list
= first {
$_
->isa(
'PPI::Structure::List'
) }
$elem
->schildren()
or
return
;
if
(
my
$readline
=
$list
->find_first(
'PPI::Token::QuoteLike::Readline'
)
) {
return
$self
->violation(
$DESC
,
$EXPL
,
$readline
);
}
return
;
#ok!
}
1;
__END__
#-----------------------------------------------------------------------------
=pod
=head1 NAME
Perl::Critic::Policy::InputOutput::ProhibitReadlineInForLoop - Write C<< while( $line = <> ){...} >> instead of C<< for(<>){...} >>.
=head1 AFFILIATION
This Policy is part of the core L<Perl::Critic|Perl::Critic>
distribution.
=head1 DESCRIPTION
Using the readline operator in a C<for> or C<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 C<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
=head1 CONFIGURATION
This Policy is not configurable except for the standard options.
=head1 AUTHOR
Jeffrey Ryan Thalhammer <thaljef@cpan.org>
=head1 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.
=cut
# Local Variables:
# mode: cperl
# cperl-indent-level: 4
# fill-column: 78
# indent-tabs-mode: nil
# c-indentation-style: bsd
# End:
# ex: set ts=8 sts=4 sw=4 tw=78 ft=perl expandtab shiftround :