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ELLIOTJS / Perl-Critic-1.099_002 / lib / Perl / Critic / Policy / ControlStructures / ProhibitCascadingIfElse.pm 

            

              
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##############################################################################
#      $URL: http://perlcritic.tigris.org/svn/perlcritic/trunk/distributions/Perl-Critic/lib/Perl/Critic/Policy/ControlStructures/ProhibitCascadingIfElse.pm $
#     $Date: 2009-06-27 20:02:58 -0400 (Sat, 27 Jun 2009) $
#   $Author: clonezone $
# $Revision: 3373 $
##############################################################################
package Perl::Critic::Policy::ControlStructures::ProhibitCascadingIfElse;
use 5.006001;
use strict;
use warnings;
use Readonly;
use Perl::Critic::Utils qw{ :severities };
use base 'Perl::Critic::Policy';
our $VERSION = '1.099_002';
#-----------------------------------------------------------------------------
Readonly::Scalar my $DESC => q{Cascading if-elsif chain};
Readonly::Scalar my $EXPL => [ 117, 118 ];
#-----------------------------------------------------------------------------
sub supported_parameters {
    return (
        {
            name            => 'max_elsif',
            description     => 'The maximum number of alternatives that will be allowed.',
            default_string  => '2',
            behavior        => 'integer',
            integer_minimum => 1,
        },
    );
}
sub default_severity { return $SEVERITY_MEDIUM                      }
sub default_themes   { return qw( core pbp maintenance complexity ) }
sub applies_to       { return 'PPI::Statement::Compound'            }
#-----------------------------------------------------------------------------
sub violates {
    my ( $self, $elem, undef ) = @_;
    return if ($elem->type() ne 'if');
    if ( _count_elsifs($elem) > $self->{_max_elsif} ) {
        return $self->violation( $DESC, $EXPL, $elem );
    }
    return;    #ok!
}
sub _count_elsifs {
    my $elem = shift;
    return
      grep { $_->isa('PPI::Token::Word') && $_->content() eq 'elsif' } $elem->schildren();
}
1;
__END__
#-----------------------------------------------------------------------------
=pod
=for stopwords lookup
=head1 NAME
Perl::Critic::Policy::ControlStructures::ProhibitCascadingIfElse - Don't write long "if-elsif-elsif-elsif-elsif...else" chains.
=head1 AFFILIATION
This Policy is part of the core L<Perl::Critic|Perl::Critic>
distribution.
=head1 DESCRIPTION
Long C<if-elsif> chains are hard to digest, especially if they are
longer than a single page or screen.  If testing for equality, use a
hash lookup instead.  See L<Switch|Switch> for another approach.
    if ($condition1) {         #ok
        $foo = 1;
    }
    elsif ($condition2) {      #ok
        $foo = 2;
    }
    elsif ($condition3) {      #ok
        $foo = 3;
    }
    elsif ($condition4) {      #too many!
        $foo = 4;
    }
    else {                     #ok
        $foo = $default;
    }
=head1 CONFIGURATION
This policy can be configured with a maximum number of C<elsif>
alternatives to allow.  The default is 2.  This can be specified via a
C<max_elsif> item in the F<.perlcriticrc> file:
    [ControlStructures::ProhibitCascadingIfElse]
    max_elsif = 3
=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 :