Build all packages removed dependencies of libtest-exception-perl libtest-warn-perl...

[dh-make-perl] / dev / i386 / libperl-critic-perl / libperl-critic-perl-1.088 / lib / Perl / Critic / Policy / Subroutines / ProhibitExplicitReturnUndef.pm

diff --git a/dev/i386/libperl-critic-perl/libperl-critic-perl-1.088/lib/Perl/Critic/Policy/Subroutines/ProhibitExplicitReturnUndef.pm b/dev/i386/libperl-critic-perl/libperl-critic-perl-1.088/lib/Perl/Critic/Policy/Subroutines/ProhibitExplicitReturnUndef.pm
new file mode 100644 (file)
index 0000000..1ab60b4
--- /dev/null
+++ b/dev/i386/libperl-critic-perl/libperl-critic-perl-1.088/lib/Perl/Critic/Policy/Subroutines/ProhibitExplicitReturnUndef.pm
@@ -0,0 +1,148 @@
+##############################################################################
+#      $URL: http://perlcritic.tigris.org/svn/perlcritic/trunk/Perl-Critic/lib/Perl/Critic/Policy/Subroutines/ProhibitExplicitReturnUndef.pm $
+#     $Date: 2008-07-03 10:19:10 -0500 (Thu, 03 Jul 2008) $
+#   $Author: clonezone $
+# $Revision: 2489 $
+##############################################################################
+
+package Perl::Critic::Policy::Subroutines::ProhibitExplicitReturnUndef;
+
+use 5.006001;
+use strict;
+use warnings;
+use Readonly;
+
+use Perl::Critic::Utils qw{ :severities :classification };
+use base 'Perl::Critic::Policy';
+
+our $VERSION = '1.088';
+
+#-----------------------------------------------------------------------------
+
+Readonly::Scalar my $DESC => q{"return" statement with explicit "undef"};
+Readonly::Scalar my $EXPL => [ 199 ];
+
+#-----------------------------------------------------------------------------
+
+sub supported_parameters { return ()                 }
+sub default_severity     { return $SEVERITY_HIGHEST  }
+sub default_themes       { return qw(core pbp bugs)  }
+sub applies_to           { return 'PPI::Token::Word' }
+
+#-----------------------------------------------------------------------------
+
+sub violates {
+    my ( $self, $elem, undef ) = @_;
+    return if ($elem ne 'return');
+    return if is_hash_key($elem);
+
+    my $sib = $elem->snext_sibling();
+    return if !$sib;
+    return if !$sib->isa('PPI::Token::Word');
+    return if $sib ne 'undef';
+
+    # Must be 'return undef'
+    return $self->violation( $DESC, $EXPL, $elem );
+}
+
+1;
+
+__END__
+
+#-----------------------------------------------------------------------------
+
+=pod
+
+=head1 NAME
+
+Perl::Critic::Policy::Subroutines::ProhibitExplicitReturnUndef - Return failure with bare C<return> instead of C<return undef>.
+
+=head1 AFFILIATION
+
+This Policy is part of the core L<Perl::Critic> distribution.
+
+
+=head1 DESCRIPTION
+
+Returning C<undef> upon failure from a subroutine is pretty common.
+But if the subroutine is called in list context, an explicit C<return
+undef;> statement will return a one-element list containing
+C<(undef)>.  Now if that list is subsequently put in a boolean context
+to test for failure, then it evaluates to true.  But you probably
+wanted it to be false.
+
+  sub read_file {
+      my $file = shift;
+      -f $file || return undef;  #file doesn't exist!
+
+      #Continue reading file...
+  }
+
+  #and later...
+
+  if ( my @data = read_file($filename) ){
+
+      # if $filename doesn't exist,
+      # @data will be (undef),
+      # but I'll still be in here!
+
+      process(@data);
+  }
+  else{
+
+      # This is my error handling code.
+      # I probably want to be in here
+      # if $filname doesn't exist.
+
+      die "$filename not found";
+  }
+
+The solution is to just use a bare C<return> statement whenever you
+want to return failure.  In list context, Perl will then give you an
+empty list (which is false), and C<undef> in scalar context (which is
+also false).
+
+  sub read_file {
+      my $file = shift;
+      -f $file || return;  #DWIM!
+
+      #Continue reading file...
+  }
+
+
+=head1 CONFIGURATION
+
+This Policy is not configurable except for the standard options.
+
+
+=head1 NOTES
+
+You can fool this policy pretty easily by hiding C<undef> in a boolean
+expression.  But don't bother trying.  In fact, using return values to
+indicate failure is pretty poor technique anyway.  Consider using
+C<die> or C<croak> with C<eval>, or the L<Error> module for a much
+more robust exception-handling model.  Conway has a real nice
+discussion on error handling in chapter 13 of PBP.
+
+=head1 AUTHOR
+
+Jeffrey Ryan Thalhammer <thaljef@cpan.org>
+
+=head1 COPYRIGHT
+
+Copyright (c) 2005-2008 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 :