perl::critic::policy::errorhandling::requirecarping(3pm) [debian man page]
Perl::Critic::Policy::ErrorHandling::RequireCarping(3pm)User Contributed Perl DocumentatioPerl::Critic::Policy::ErrorHandling::RequireCarping(3pm) NAME
Perl::Critic::Policy::ErrorHandling::RequireCarping - Use functions from Carp instead of "warn" or "die". AFFILIATION
This Policy is part of the core Perl::Critic distribution. DESCRIPTION
The "die" and "warn" functions both report the file and line number where the exception occurred. But if someone else is using your subroutine, they usually don't care where your code blew up. Instead, they want to know where their code invoked the subroutine. The Carp module provides alternative methods that report the exception from the caller's file and line number. By default, this policy will not complain about "die" or "warn", if it can determine that the message will always result in a terminal newline. Since perl suppresses file names and line numbers in this situation, it is assumed that no stack traces are desired either and none of the Carp functions are necessary. die "oops" if $explosion; #not ok warn "Where? Where?!" if $tiger; #not ok open my $mouth, '<', 'food' or die 'of starvation'; #not ok if (! $dentist_appointment) { warn "You have bad breath! "; #ok } die "$clock not set. " if $no_time; #ok my $message = "$clock not set. "; die $message if $no_time; #not ok, not obvious CONFIGURATION
By default, this policy allows uses of "die" and "warn" ending in an explicit newline. If you give this policy an "allow_messages_ending_with_newlines" option in your .perlcriticrc with a false value, then this policy will prohibit such uses. [ErrorHandling::RequireCarping] allow_messages_ending_with_newlines = 0 If you give this policy an "allow_in_main_unless_in_subroutine" option in your .perlcriticrc with a true value, then this policy will allow "die" and "warn" in name space main:: unless they appear in a subroutine, even if they do not end in an explicit newline. [ErrorHandling::RequireCarping] allow_in_main_unless_in_subroutine = 1 BUGS
Should allow "die" when it is obvious that the "message" is a reference. SEE ALSO
Carp::Always AUTHOR
Jeffrey Ryan Thalhammer <jeff@imaginative-software.com> COPYRIGHT
Copyright (c) 2005-2011 Imaginative Software Systems. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. The full text of this license can be found in the LICENSE file included with this module. perl v5.14.2 2012-06-07 Perl::Critic::Policy::ErrorHandling::RequireCarping(3pm)
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Perl::Critic::Policy::ControlStructures::ProhibitPostfixUserrContributed PerlPerl::Critic::Policy::ControlStructures::ProhibitPostfixControls(3pm) NAME
Perl::Critic::Policy::ControlStructures::ProhibitPostfixControls - Write "if($condition){ do_something() }" instead of "do_something() if $condition". AFFILIATION
This Policy is part of the core Perl::Critic distribution. DESCRIPTION
Conway discourages using postfix control structures ("if", "for", "unless", "until", "when", "while") because they hide control flow. The "unless" and "until" controls are particularly evil because they lead to double-negatives that are hard to comprehend. The only tolerable usage of a postfix "if"/"when" is when it follows a loop break such as "last", "next", "redo", or "continue". do_something() if $condition; # not ok if ($condition) { do_something() } # ok do_something() while $condition; # not ok while ($condition) { do_something() } # ok do_something() unless $condition; # not ok do_something() unless ! $condition; # really bad if (! $condition) { do_something() } # ok do_something() until $condition; # not ok do_something() until ! $condition; # really bad while (! $condition) { do_something() } # ok do_something($_) for @list; # not ok LOOP: for my $n (0..100) { next if $condition; # ok last LOOP if $other_condition; # also ok next when m< 0 z >xms; # fine too } CONFIGURATION
A set of constructs to be ignored by this policy can specified by giving a value for 'allow' of a string of space-delimited keywords: "if", "for", "unless", "until", "when", and/or "while". An example of specifying allowed flow-control structures in a .perlcriticrc file: [ControlStructures::ProhibitPostfixControls] allow = for if until By default, all postfix control keywords are prohibited. The set of flow-control functions that are exempt from the restriction can also be configured with the 'flowcontrol' directive in your .perlcriticrc file: [ControlStructures::ProhibitPostfixControls] flowcontrol = warn die carp croak cluck confess goto exit This is useful if you're using additional modules that add things like "assert" or "throw". NOTES
The "die", "croak", and "confess" functions are frequently used as flow-controls just like "next" or "last". So this Policy does permit you to use a postfix "if" when the statement begins with one of those functions. It is also pretty common to use "warn", "carp", and "cluck" with a postfix "if", so those are allowed too. The "when" keyword was added to the language after Perl Best Practices was written. This policy treats "when" the same way it does "if", i.e. it's allowed after flow-control constructs. Thanks to brian d foy for the inspiration <http://www.effectiveperlprogramming.com/blog/543>. BUGS
Look for the "do {} while" case and change the explanation to point to page 123 when it is found. RT #37905. AUTHOR
Jeffrey Ryan Thalhammer <jeff@imaginative-software.com> COPYRIGHT
Copyright (c) 2005-2011 Imaginative Software Systems. 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. perl v5.14.2 2012-06-0Perl::Critic::Policy::ControlStructures::ProhibitPostfixControls(3pm)