Perl::Critic::Policy::CodeLayout::ProhibitTrailingWhitespace - Don't use whitespace at the end of lines.

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

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NAME

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Perl::Critic::Policy::CodeLayout::ProhibitTrailingWhitespace - Don't use whitespace at the end of lines.

AFFILIATION

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

DESCRIPTION

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Anything that is not readily visually detectable is a bad thing in general, and more specifically, as different people edit the same code, their editors may automatically strip out trailing whitespace, causing spurious differences between different versions of the same file (i.e. code in a source control system).

CONFIGURATION

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This Policy is not configurable except for the standard options.

AUTHOR

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Elliot Shank <perl@galumph.com>

COPYRIGHT

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Copyright (c) 2007-2011 Elliot Shank.

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/CodeLayout/ProhibitTrailingWhitespace.pm $
#     $Date: 2011-05-15 16:34:46 -0500 (Sun, 15 May 2011) $
#   $Author: clonezone $
# $Revision: 4078 $
##############################################################################

package Perl::Critic::Policy::CodeLayout::ProhibitTrailingWhitespace;

use 5.006001;
use strict;
use warnings;
use English qw(-no_match_vars);
use Readonly;

use charnames qw{};

use PPI::Token::Whitespace;
use Perl::Critic::Utils qw{ :characters :severities };

use base 'Perl::Critic::Policy';

our $VERSION = '1.116';

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

Readonly::Scalar my $EXPL => q{Don't use whitespace at the end of lines};

## no critic (RequireInterpolationOfMetachars)
Readonly::Hash my %C_STYLE_ESCAPES =>
    (
        ord "\t" => q{\t},
        ord "\n" => q{\n},
        ord "\r" => q{\r},
        ord "\f" => q{\f},
        ord "\b" => q{\b},
        ord "\a" => q{\a},
        ord "\e" => q{\e},
    );
## use critic

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

sub supported_parameters { return qw{ }                    }
sub default_severity     { return $SEVERITY_LOWEST         }
sub default_themes       { return qw( core maintenance )   }
sub applies_to           { return 'PPI::Token::Whitespace' }

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

sub violates {
    my ( $self, $token, undef ) = @_;

    if ( $token->content() =~ m< ( (?! \n) \s )+ \n >xms ) {
        my $extra_whitespace = $1;

        my $description = q{Found "};
        $description .=
            join
                $EMPTY,
                map { _escape($_) } split $EMPTY, $extra_whitespace;
        $description .= q{" at the end of the line};

        return $self->violation( $description, $EXPL, $token );
    }

    return;
}

sub _escape {
    my $character = shift;
    my $ordinal = ord $character;

    if (my $c_escape = $C_STYLE_ESCAPES{$ordinal}) {
        return $c_escape;
    }


    # Apparently, the charnames.pm that ships with older perls does not
    # support the C<viacode> function, and newer versions of the module are
    # not distributed separately from perl itself So if the C<viacode> method
    # is not supported, then just substitute something.


    ## no critic (RequireInterpolationOfMetachars)
    if ( charnames->can( 'viacode' ) ) {
        return q/\N{/ . charnames::viacode($ordinal) . q/}/;
    }
    else {
        return '\N{WHITESPACE CHAR}';
    }
}

1;

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

__END__


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