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PETDANCE / Perl-Critic-1.150 / lib / Perl / Critic / Policy / ControlStructures / ProhibitLabelsWithSpecialBlockNames.pm 

            

              
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package Perl::Critic::Policy::ControlStructures::ProhibitLabelsWithSpecialBlockNames;
use 5.010001;
use strict;
use warnings;
use Readonly;
use Perl::Critic::Utils qw{ :severities hashify };
use parent 'Perl::Critic::Policy';
our $VERSION = '1.150';
Readonly::Hash my %SPECIAL_BLOCK_NAMES =>
    hashify( qw< BEGIN END INIT CHECK UNITCHECK > );
#-----------------------------------------------------------------------------
Readonly::Scalar my $DESC => q<Special block name used as label.>;
Readonly::Scalar my $EXPL =>
    q<Use a label that cannot be confused with BEGIN, END, CHECK, INIT, or UNITCHECK blocks.>;
#-----------------------------------------------------------------------------
sub supported_parameters { return ()                      }
sub default_severity     { return $SEVERITY_HIGH          }
sub default_themes       { return qw< core bugs >         }
sub applies_to           { return qw< PPI::Token::Label > }
#-----------------------------------------------------------------------------
sub violates {
    my ($self, $elem, undef) = @_;
    # Does the function call have enough arguments?
    my $label = $elem->content();
    $label =~ s/ \s* : \z //xms;
    return if not $SPECIAL_BLOCK_NAMES{ $label };
    return $self->violation( $DESC, $EXPL, $elem );
}
1;
#-----------------------------------------------------------------------------
__END__
=for stopwords Lauen O'Regan
=pod
=head1 NAME
Perl::Critic::Policy::ControlStructures::ProhibitLabelsWithSpecialBlockNames - Don't use labels that are the same as the special block names.
=head1 AFFILIATION
This Policy is part of the core L<Perl::Critic|Perl::Critic>
distribution.
=head1 DESCRIPTION
When using one of the special Perl blocks C<BEGIN>, C<END>, C<CHECK>,
C<INIT>, and C<UNITCHECK>, it is easy to mistakenly add a colon to the
end of the block name.  E.g.:
    # a BEGIN block that gets executed at compile time.
    BEGIN { <...code...> }
    # an ordinary labeled block that gets executed at run time.
    BEGIN: { <...code...> }
The labels "BEGIN:", "END:", etc. are probably errors.  This policy
prohibits the special Perl block names from being used as labels.
=head1 CONFIGURATION
This Policy is not configurable except for the standard options.
=head1 SEE ALSO
The Perl Buzz article on this issue at
L<http://perlbuzz.com/2008/05/colons-invalidate-your-begin-and-end-blocks.html>.
=head1 ACKNOWLEDGMENT
Randy Lauen for identifying the problem.
=head1 AUTHOR
Mike O'Regan
=head1 COPYRIGHT
Copyright (c) 2008-2011 Mike O'Regan.  All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.
=cut
# Local Variables:
#   mode: cperl
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# End:
# ex: set ts=8 sts=4 sw=4 tw=78 ft=perl expandtab shiftround :