Perl::Critic::Policy::ControlStructures::ProhibitUntilBlocks - Write C<while(! $condition)> instead of C<until($condition)>.

Perl-Critic documentation Contained in the Perl-Critic distribution.

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NAME

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Perl::Critic::Policy::ControlStructures::ProhibitUntilBlocks - Write while(! $condition) instead of until($condition).

AFFILIATION

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

DESCRIPTION

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Conway discourages using until because it leads to double-negatives that are hard to understand. Instead, reverse the logic and use while.

    until($condition)     { do_something() } #not ok
    until(! $no_flag)     { do_something() } #really bad
    while( ! $condition)  { do_something() } #ok

This Policy only covers the block-form of until. For the postfix variety, see ProhibitPostfixControls.

CONFIGURATION

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This Policy is not configurable except for the standard options.

SEE ALSO

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Perl::Critic::Policy::ControlStructures::ProhibitPostfixControls

AUTHOR

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

COPYRIGHT

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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 documentation Contained in the Perl-Critic distribution. 
##############################################################################
#      $URL: http://perlcritic.tigris.org/svn/perlcritic/trunk/distributions/Perl-Critic/lib/Perl/Critic/Policy/ControlStructures/ProhibitUntilBlocks.pm $
#     $Date: 2011-05-15 16:34:46 -0500 (Sun, 15 May 2011) $
#   $Author: clonezone $
# $Revision: 4078 $
##############################################################################

package Perl::Critic::Policy::ControlStructures::ProhibitUntilBlocks;

use 5.006001;
use strict;
use warnings;
use Readonly;

use Perl::Critic::Utils qw{ :severities };
use base 'Perl::Critic::Policy';

our $VERSION = '1.116';

#-----------------------------------------------------------------------------

Readonly::Scalar my $DESC => q{"until" block used};
Readonly::Scalar my $EXPL => [ 97 ];

#-----------------------------------------------------------------------------

sub supported_parameters { return ()                    }
sub default_severity     { return $SEVERITY_LOW         }
sub default_themes       { return qw(core pbp cosmetic) }
sub applies_to           { return 'PPI::Statement'      }

#-----------------------------------------------------------------------------

sub violates {
    my ( $self, $elem, undef ) = @_;
    if ( $elem->first_element() eq 'until' ) {
        return $self->violation( $DESC, $EXPL, $elem );
    }
    return;    #ok!
}

1;

__END__

#-----------------------------------------------------------------------------


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