Perl::...Summary(3pm)

okay bestie, welcome to Perl::...Summary(3pm) from User Contributed Perl Documentation — the master-list page for the Policy modules that ship with Perl::Critic itself. this is the vibe check for your code’s whole personality 💅✨

💖 NAME 💖

Perl::Critic::PolicySummary - Descriptions of the Policy modules included with Perl::Critic itself. 🫶

✨ DESCRIPTION ✨

okay so, the following Policy modules are distributed with Perl::Critic. (There are additional Policies that can be found in add-on distributions.) The Policy modules have been categorized according to the table of contents in Damian Conway’s book Perl Best Practices. Since most coding standards take the form "do this..." or "don't do that...", I have adopted the convention of naming each module "RequireSomething" or "ProhibitSomething". Each Policy is listed here with its default severity. If you don't agree with the default severity, you can change it in your .perlcriticrc file (try perlcritic --profile-proto for a starting version). See the documentation of each module for its specific details. 💖

🎀 POLICIES 🎀

BuiltinFunctions::ProhibitBooleanGrep

Use any from List::Util, List::SomeUtils, or List::MoreUtils instead of grep in boolean context. bestie, this is the slay move. [Default severity 2]

BuiltinFunctions::ProhibitComplexMappings

Map blocks should have a single statement. lowkey keep it simple. [Default severity 3]

BuiltinFunctions::ProhibitLvalueSubstr

Use 4-argument substr instead of writing substr($foo, 2, 6) = $bar. periodt. [Default severity 3]

BuiltinFunctions::ProhibitReverseSortBlock

Forbid $b before $a in sort blocks. [Default severity 1]

BuiltinFunctions::ProhibitShiftRef

Prohibit \shift in code. [Default severity 3]

BuiltinFunctions::ProhibitSleepViaSelect

Use Time::HiRes instead of something like select(undef, undef, undef, .05). [Default severity 5]

BuiltinFunctions::ProhibitStringyEval

Write eval { my $foo; bar($foo) } instead of eval "my $foo; bar($foo);". [Default severity 5]

BuiltinFunctions::ProhibitStringySplit

Write split /-/, $string instead of split '-', $string. [Default severity 2]

BuiltinFunctions::ProhibitUniversalCan

Write eval { $foo->can($name) } instead of UNIVERSAL::can($foo, $name). [Default severity 3]

BuiltinFunctions::ProhibitUniversalIsa

Write eval { $foo->isa($pkg) } instead of UNIVERSAL::isa($foo, $pkg). [Default severity 3]

BuiltinFunctions::ProhibitUselessTopic

Don't pass $_ to built-in functions that assume it, or to most filetest operators. [Default severity 2]

BuiltinFunctions::ProhibitVoidGrep

Don't use grep in void contexts. [Default severity 3]

BuiltinFunctions::ProhibitVoidMap

Don't use map in void contexts. [Default severity 3]

BuiltinFunctions::RequireBlockGrep

Write grep { /$pattern/ } @list instead of grep /$pattern/, @list. [Default severity 4]

BuiltinFunctions::RequireBlockMap

Write map { /$pattern/ } @list instead of map /$pattern/, @list. [Default severity 4]

BuiltinFunctions::RequireGlobFunction

Use glob q{*} instead of <*>, bestie. [Default severity 5]

BuiltinFunctions::RequireSimpleSortBlock

Sort blocks should have a single statement. [Default severity 3]

ClassHierarchies::ProhibitAutoloading

AUTOLOAD methods should be avoided. [Default severity 3]

ClassHierarchies::ProhibitExplicitISA

Employ use parent instead of @ISA. [Default severity 3]

ClassHierarchies::ProhibitOneArgBless

Write bless {}, $class; instead of just bless {};. [Default severity 5]

CodeLayout::ProhibitHardTabs

Use spaces instead of tabs. [Default severity 3]

CodeLayout::ProhibitParensWithBuiltins

Write open $handle, $path instead of open($handle, $path). [Default severity 1]

CodeLayout::ProhibitQuotedWordLists

Write qw(foo bar baz) instead of ('foo', 'bar', 'baz'). [Default severity 2]

CodeLayout::ProhibitTrailingWhitespace

Don't use whitespace at the end of lines. [Default severity 1]

CodeLayout::RequireConsistentNewlines

Use the same newline through the source. [Default severity 4]

CodeLayout::RequireTidyCode

Must run code through perltidy. [Default severity 1]

CodeLayout::RequireTrailingCommas

Put a comma at the end of every multi-line list declaration, including the last one. [Default severity 1]

ControlStructures::ProhibitCStyleForLoops

Write for(0..20) instead of for($i=0; $i<=20; $i++). [Default severity 2]

ControlStructures::ProhibitCascadingIfElse

Don't write long if-elsif-elsif-elsif-elsif...else chains. [Default severity 3]

ControlStructures::ProhibitDeepNests

Don't write deeply nested loops and conditionals. [Default severity 3]

ControlStructures::ProhibitLabelsWithSpecialBlockNames

Don't use labels that are the same as the special block names. [Default severity 4]

ControlStructures::ProhibitMutatingListFunctions

Don't modify $_ in list functions. [Default severity 5]

ControlStructures::ProhibitNegativeExpressionsInUnlessAndUntilConditions

Don't use operators like not, !~, and le within until and unless. [Default severity 3]

ControlStructures::ProhibitPostfixControls

Write if($condition){ do_something() } instead of do_something() if $condition. [Default severity 2]

ControlStructures::ProhibitUnlessBlocks

Write if(! $condition) instead of unless($condition). [Default severity 2]

ControlStructures::ProhibitUnreachableCode

Don't write code after an unconditional die, exit, or next. [Default severity 4]

ControlStructures::ProhibitUntilBlocks

Write while(! $condition) instead of until($condition). [Default severity 2]

ControlStructures::ProhibitYadaOperator

Never use ... in production code. [Default severity 4]

Documentation::PodSpelling

Check your spelling. [Default severity 1]

Documentation::RequirePackageMatchesPodName

The =head1 NAME section should match the package. [Default severity 1]

Documentation::RequirePodAtEnd

All POD should be after __END__. [Default severity 1]

Documentation::RequirePodSections

Organize your POD into the customary sections. [Default severity 2]

ErrorHandling::RequireCarping

Use functions from Carp instead of warn or die. [Default severity 3]

ErrorHandling::RequireCheckingReturnValueOfEval

You can't depend upon the value of $@/$EVAL_ERROR to tell whether an eval failed. [Default severity 3]

InputOutput::ProhibitBacktickOperators

Discourage stuff like this, fr fr:

@files = `ls $directory`

[Default severity 3]

InputOutput::ProhibitBarewordDirHandles

Write opendir my $dh, $dirname; instead of opendir DH, $dirname;. [Default severity 5]

InputOutput::ProhibitBarewordFileHandles

Write open my $fh, q{<}, $filename; instead of open FH, q{<}, $filename;. [Default severity 5]

InputOutput::ProhibitExplicitStdin

Use <> or <ARGV> or a prompting module instead of <STDIN>. [Default severity 4]

InputOutput::ProhibitInteractiveTest

Use prompt() instead of -t. [Default severity 5]

InputOutput::ProhibitJoinedReadline

Use local $/ = undef or Path::Tiny instead of joined readline. [Default severity 3]

InputOutput::ProhibitOneArgSelect

Never write select($fh). [Default severity 4]

InputOutput::ProhibitReadlineInForLoop

Write while( $line = <> ){...} instead of for(<>){...}. [Default severity 4]

InputOutput::ProhibitTwoArgOpen

Write open $fh, q{<}, $filename; instead of open $fh, "<$filename";. [Default severity 5]

InputOutput::RequireBracedFileHandleWithPrint

Write print {$FH} $foo, $bar; instead of print $FH $foo, $bar;. [Default severity 1]

InputOutput::RequireBriefOpen

Close filehandles as soon as possible after opening them. [Default severity 4]

InputOutput::RequireCheckedClose

Write my $error = close $fh; instead of close $fh;. [Default severity 2]

InputOutput::RequireCheckedOpen

Write my $error = open $fh, $mode, $filename; instead of open $fh, $mode, $filename;. [Default severity 3]

InputOutput::RequireCheckedSyscalls

Return value of flagged function ignored. [Default severity 1]

InputOutput::RequireEncodingWithUTF8Layer

Write open $fh, q{<:encoding(UTF-8)}, $filename; instead of open $fh, q{<:utf8}, $filename;. [Default severity 5]

Miscellanea::ProhibitFormats

Do not use format. [Default severity 3]

Miscellanea::ProhibitTies

Do not use tie. [Default severity 2]

Miscellanea::ProhibitUnrestrictedNoCritic

Forbid a bare ## no critic. [Default severity 3]

Miscellanea::ProhibitUselessNoCritic

Remove ineffective ## no critic annotations. [Default severity 2]

Modules::ProhibitAutomaticExportation

Export symbols via @EXPORT_OK or %EXPORT_TAGS instead of @EXPORT. [Default severity 4]

Modules::ProhibitConditionalUseStatements

Avoid putting conditional logic around compile-time includes. [Default severity 3]

Modules::ProhibitEvilModules

Ban modules that aren't blessed by your shop. [Default severity 5]

Modules::ProhibitExcessMainComplexity

Minimize complexity in code that is outside of subroutines. [Default severity 3]

Modules::ProhibitMultiplePackages

Put packages (especially subclasses) in separate files. [Default severity 4]

Modules::RequireBarewordIncludes

Write require Module instead of require 'Module.pm'. [Default severity 5]

Modules::RequireEndWithOne

End each module with an explicitly 1; instead of some funky expression. [Default severity 4]

Modules::RequireExplicitPackage

Always make the package explicit. [Default severity 4]

Modules::RequireFilenameMatchesPackage

Package declaration must match filename. [Default severity 5]

Modules::RequireNoMatchVarsWithUseEnglish

use English must be passed a -no_match_vars argument. [Default severity 2]

Modules::RequireVersionVar

Give every module a $VERSION number. [Default severity 2]

NamingConventions::Capitalization

Distinguish different program components by case. [Default severity 1]

NamingConventions::ProhibitAmbiguousNames

Don't use vague variable or subroutine names like 'last' or 'record'. [Default severity 3]

Objects::ProhibitIndirectSyntax

Prohibit indirect object call syntax. [Default severity 4]

References::ProhibitDoubleSigils

Write @{ $array_ref } instead of @$array_ref. [Default severity 2]

RegularExpressions::ProhibitCaptureWithoutTest

Capture variable used outside conditional. [Default severity 3]

RegularExpressions::ProhibitComplexRegexes

Split long regexps into smaller qr// chunks. [Default severity 3]

RegularExpressions::ProhibitEnumeratedClasses

Use named character classes instead of explicit character lists. [Default severity 1]

RegularExpressions::ProhibitEscapedMetacharacters

Use character classes for literal meta-characters instead of escapes. [Default severity 1]

RegularExpressions::ProhibitFixedStringMatches

Use eq or hash instead of fixed-pattern regexps. [Default severity 2]

RegularExpressions::ProhibitSingleCharAlternation

Use [abc] instead of a|b|c. [Default severity 1]

RegularExpressions::ProhibitUnusedCapture

Only use a capturing group if you plan to use the captured value. [Default severity 3]

Okay, picking the policy list right back up — each entry still keeps its exact [Default severity N] badge, and we’re doing every single one, no skipping, bestie 💖

• RegularExpressions::ProhibitUnusualDelimiters — use only // or {} to delimit regexps, okay? [Default severity 1]
• RegularExpressions::ProhibitUselessTopic — don’t use $_ to match against regexes. [Default severity 2]
• RegularExpressions::RequireBracesForMultiline — use { and } to delimit multi-line regexps. [Default severity 1]
• RegularExpressions::RequireDotMatchAnything — always use the /s modifier with regular expressions. [Default severity 2]
• RegularExpressions::RequireExtendedFormatting — always use the /x modifier with regular expressions. [Default severity 3]
• RegularExpressions::RequireLineBoundaryMatching — always use the /m modifier with regular expressions. [Default severity 2]
• Subroutines::ProhibitAmpersandSigils — don’t call functions with a leading ampersand sigil. [Default severity 2]
• Subroutines::ProhibitBuiltinHomonyms — don’t declare your own open function, bestie. [Default severity 4]
• Subroutines::ProhibitExcessComplexity — minimize complexity by factoring code into smaller subroutines. [Default severity 3]
• Subroutines::ProhibitExplicitReturnUndef — return failure with bare return instead of return undef. [Default severity 5]
• Subroutines::ProhibitManyArgs — too many arguments. [Default severity 3]
• Subroutines::ProhibitNestedSubs — nope to this exact nesting: sub never { sub correct {} }. [Default severity 5]
• Subroutines::ProhibitReturnSort — behavior of sort is not defined if called in scalar context. [Default severity 5]
• Subroutines::ProhibitSubroutinePrototypes — don’t write sub my_function (@@) {}. [Default severity 5]
• Subroutines::ProhibitUnusedPrivateSubroutines — prevent unused private subroutines. [Default severity 3]
• Subroutines::ProtectPrivateSubs — prevent access to private subs in other packages. [Default severity 3]
• Subroutines::RequireArgUnpacking — always unpack @_ first. [Default severity 4]
• Subroutines::RequireFinalReturn — end every path through a subroutine with an explicit return statement. [Default severity 4]
• TestingAndDebugging::ProhibitNoStrict — prohibit various flavors of no strict. [Default severity 5]
• TestingAndDebugging::ProhibitNoWarnings — prohibit various flavors of no warnings. [Default severity 4]
• TestingAndDebugging::ProhibitProlongedStrictureOverride — don’t turn off strict for large blocks of code. [Default severity 4]
• TestingAndDebugging::RequireTestLabels — tests should all have labels. [Default severity 3]
• TestingAndDebugging::RequireUseStrict — always use strict. [Default severity 5]
• TestingAndDebugging::RequireUseWarnings — always use warnings. [Default severity 4]
• ValuesAndExpressions::ProhibitCommaSeparatedStatements — don’t use the comma operator as a statement separator. [Default severity 4]
• ValuesAndExpressions::ProhibitComplexVersion — prohibit version values from outside the module. [Default severity 3]
• ValuesAndExpressions::ProhibitConstantPragma — don’t do use constant FOO => 15. [Default severity 4]
• ValuesAndExpressions::ProhibitEmptyQuotes — write q{} instead of ''. [Default severity 2]
• ValuesAndExpressions::ProhibitEscapedCharacters — write \N{DELETE} instead of \x7F, etc. [Default severity 2]
• ValuesAndExpressions::ProhibitImplicitNewlines — use concatenation or HEREDOCs instead of literal line breaks in strings. [Default severity 3]
• ValuesAndExpressions::ProhibitInterpolationOfLiterals — always use single quotes for literal strings. [Default severity 1]
• ValuesAndExpressions::ProhibitLeadingZeros — write oct(755) instead of 0755. [Default severity 5]
• ValuesAndExpressions::ProhibitLongChainsOfMethodCalls — long chains of method calls indicate tightly coupled code. [Default severity 2]
• ValuesAndExpressions::ProhibitMagicNumbers — don’t use values that don’t explain themselves. [Default severity 2]
• ValuesAndExpressions::ProhibitMismatchedOperators — don’t mix numeric operators with string operands, or vice-versa. [Default severity 3]
• ValuesAndExpressions::ProhibitMixedBooleanOperators — write !$foo && $bar || $baz instead of not $foo && $bar or $baz. [Default severity 4]
• ValuesAndExpressions::ProhibitNoisyQuotes — use q{} or qq{} instead of quotes for awkward-looking strings. [Default severity 2]
• ValuesAndExpressions::ProhibitQuotesAsQuotelikeOperatorDelimiters — don’t use quotes (', ", `) as delimiters for the quote-like operators. [Default severity 3]
• ValuesAndExpressions::ProhibitSpecialLiteralHeredocTerminator — don’t write print <<'__END__'. [Default severity 3]
• ValuesAndExpressions::ProhibitVersionStrings — don’t use strings like v1.4 or 1.4.5 when including other modules. [Default severity 3]
• ValuesAndExpressions::RequireConstantVersion — require $VERSION to be a constant rather than a computed value. [Default severity 2]
• ValuesAndExpressions::RequireInterpolationOfMetachars — warns that you might have used single quotes when you really wanted double-quotes. [Default severity 1]
• ValuesAndExpressions::RequireNumberSeparators — write 141_234_397.0145 instead of 141234397.0145. [Default severity 2]
• ValuesAndExpressions::RequireQuotedHeredocTerminator — write print <<'THE_END' or print <<"THE_END". [Default severity 3]
• ValuesAndExpressions::RequireUpperCaseHeredocTerminator — write <<'THE_END'; instead of <<'theEnd';. [Default severity 2]
• Variables::ProhibitAugmentedAssignmentInDeclaration — do not write my $foo .= 'bar';. [Default severity 4]
• Variables::ProhibitConditionalDeclarations — do not write my $foo = $bar if $baz;. [Default severity 5]
• Variables::ProhibitEvilVariables — ban variables that aren’t blessed by your shop. [Default severity 5]
• Variables::ProhibitLocalVars — use my instead of local, except when you have to. [Default severity 2]
• Variables::ProhibitMatchVars — avoid $`, $&, $' and their English equivalents. [Default severity 4]
• Variables::ProhibitPackageVars — eliminate globals declared with our or use vars. [Default severity 3]
• Variables::ProhibitPerl4PackageNames — use double colon (::) to separate package name components instead of single quotes ('). [Default severity 2]
• Variables::ProhibitPunctuationVars — write $EVAL_ERROR instead of $@. [Default severity 2]
• Variables::ProhibitReusedNames — do not reuse a variable name in a lexical scope. [Default severity 3]
• Variables::ProhibitUnusedVariables — don’t ask for storage you don’t need. [Default severity 3]
• Variables::ProtectPrivateVars — prevent access to private vars in other packages. [Default severity 3]
• Variables::RequireInitializationForLocalVars — write local $foo = $bar; instead of just local $foo;. [Default severity 3]
• Variables::RequireLexicalLoopIterators — write for my $element (@list) {...} instead of for $element (@list) {...}. [Default severity 5]
• Variables::RequireLocalizedPunctuationVars — magic variables should be assigned as local. [Default severity 4]
• Variables::RequireNegativeIndices — negative array index should be used. [Default severity 4]

💖 VERSION 💖

Okay so this whole thing is part of Perl::Critic version 1.126. Periodt. ✨

✨ AUTHOR ✨

Jeffrey Ryan Thalhammer <jeff@imaginative-software.com> — yes, that’s the icon who authored it, bestie 🫶

🎀 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. 🦋

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That’s the whole page, bestie — footer energy says perl v5.42.0 on 2024-10-23, and it’s giving official manual-page realness 💅✨