Perl::Critic::Policy::CodeLayout::RequireTrailingCommas - Put a comma at the end of every multi-line list declaration, including the last one.


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

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NAME

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Perl::Critic::Policy::CodeLayout::RequireTrailingCommas - Put a comma at the end of every multi-line list declaration, including the last one.

AFFILIATION

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

DESCRIPTION

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Conway suggests that all elements in a multi-line list should be separated by commas, including the last element. This makes it a little easier to re-order the list by cutting and pasting.

    my @list = ($foo,
                $bar,
                $baz);  #not ok

    my @list = ($foo,
                $bar,
                $baz,); #ok




CONFIGURATION

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This Policy is not configurable except for the standard options.

NOTES

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In the PPI parlance, a "list" is almost anything with parentheses. I've tried to make this Policy smart by targeting only "lists" that have at least one element and are being assigned to something. However, there may be some edge cases that I haven't covered. If you find one, send me a note.

AUTHOR

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

COPYRIGHT

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

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

package Perl::Critic::Policy::CodeLayout::RequireTrailingCommas;

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

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

our $VERSION = '1.116';

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

Readonly::Scalar my $DESC => q{List declaration without trailing comma};
Readonly::Scalar my $EXPL => [ 17 ];

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

sub supported_parameters { return ()                     }
sub default_severity     { return $SEVERITY_LOWEST       }
sub default_themes       { return qw(core pbp cosmetic)  }
sub applies_to           { return 'PPI::Structure::List' }

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

sub violates {
    my ( $self, $elem, undef ) = @_;
    $elem =~ m{ \n }xms || return;

    # Is it an assignment of some kind?
    my $sib = $elem->sprevious_sibling();
    return if !$sib;
    $sib->isa('PPI::Token::Operator') && $sib =~ m{ = }xms || return;

    # List elements are children of an expression
    my $expr = $elem->schild(0);
    return if !$expr;

    # Does the list have more than 1 element?
    # This means list element, not PPI element.
    my @children = $expr->schildren();
    return if 1 >= grep {    $_->isa('PPI::Token::Operator')
                          && $_ eq $COMMA } @children;

    # Is the final element a comma?
    my $final = $children[-1];
    if ( ! ($final->isa('PPI::Token::Operator') && $final eq $COMMA) ) {
        return $self->violation( $DESC, $EXPL, $elem );
    }

    return; #ok!
}

1;

__END__

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