1Perl::Critic::PolicySumUmsaerry(C3o)ntributed Perl DocumPeenrtla:t:iCornitic::PolicySummary(3)
2
6 Perl::Critic::PolicySummary - Descriptions of the Policy modules
7 included with Perl::Critic itself.
8
10 The following Policy modules are distributed with Perl::Critic. (There
11 are additional Policies that can be found in add-on distributions.)
12 The Policy modules have been categorized according to the table of
13 contents in Damian Conway's book Perl Best Practices. Since most
14 coding standards take the form "do this..." or "don't do that...", I
15 have adopted the convention of naming each module "RequireSomething" or
16 "ProhibitSomething". Each Policy is listed here with its default
17 severity. If you don't agree with the default severity, you can change
18 it in your .perlcriticrc file. See the documentation of each module
19 for its specific details.
20
22 Perl::Critic::Policy::BuiltinFunctions::ProhibitBooleanGrep
23 Use "List::MoreUtils::any" instead of "grep" in boolean context.
24 [Severity 2]
25 Perl::Critic::Policy::BuiltinFunctions::ProhibitComplexMappings
27 Map blocks should have a single statement. [Severity 3]
28 Perl::Critic::Policy::BuiltinFunctions::ProhibitLvalueSubstr
30 Use 4-argument "substr" instead of writing "substr($foo, 2, 6) = $bar".
31 [Severity 3]
32 Perl::Critic::Policy::BuiltinFunctions::ProhibitReverseSortBlock
34 Forbid $b before $a in sort blocks. [Severity 1]
35 Perl::Critic::Policy::BuiltinFunctions::ProhibitSleepViaSelect
37 Use Time::HiRes instead of something like "select(undef, undef, undef,
38 .05)". [Severity 5]
39 Perl::Critic::Policy::BuiltinFunctions::ProhibitStringyEval
41 Write "eval { my $foo; bar($foo) }" instead of "eval "my $foo;
42 bar($foo);"". [Severity 5]
43 Perl::Critic::Policy::BuiltinFunctions::ProhibitStringySplit
45 Write "split /-/, $string" instead of "split '-', $string". [Severity
46 2]
47 Perl::Critic::Policy::BuiltinFunctions::ProhibitUniversalCan
49 Write "eval { $foo->can($name) }" instead of "UNIVERSAL::can($foo,
50 $name)". [Severity 3]
51 Perl::Critic::Policy::BuiltinFunctions::ProhibitUniversalIsa
53 Write "eval { $foo->isa($pkg) }" instead of "UNIVERSAL::isa($foo,
54 $pkg)". [Severity 3]
55 Perl::Critic::Policy::BuiltinFunctions::ProhibitVoidGrep
57 Don't use "grep" in void contexts. [Severity 3]
58 Perl::Critic::Policy::BuiltinFunctions::ProhibitVoidMap
60 Don't use "map" in void contexts. [Severity 3]
61 Perl::Critic::Policy::BuiltinFunctions::RequireBlockGrep
63 Write "grep { $_ =~ /$pattern/ } @list" instead of "grep /$pattern/,
64 @list". [Severity 4]
65 Perl::Critic::Policy::BuiltinFunctions::RequireBlockMap
67 Write "map { $_ =~ /$pattern/ } @list" instead of "map /$pattern/,
68 @list". [Severity 4]
69 Perl::Critic::Policy::BuiltinFunctions::RequireGlobFunction
71 Use "glob q{*}" instead of <*>. [Severity 5]
72 Perl::Critic::Policy::BuiltinFunctions::RequireSimpleSortBlock
74 Sort blocks should have a single statement. [Severity 3]
75 Perl::Critic::Policy::ClassHierarchies::ProhibitAutoloading
77 AUTOLOAD methods should be avoided. [Severity 3]
78 Perl::Critic::Policy::ClassHierarchies::ProhibitExplicitISA
80 Employ "use base" instead of @ISA. [Severity 3]
81 Perl::Critic::Policy::ClassHierarchies::ProhibitOneArgBless
83 Write "bless {}, $class;" instead of just "bless {};". [Severity 5]
84 Perl::Critic::Policy::CodeLayout::ProhibitHardTabs
86 Use spaces instead of tabs. [Severity 3]
87 Perl::Critic::Policy::CodeLayout::ProhibitParensWithBuiltins
89 Write "open $handle, $path" instead of "open($handle, $path)".
90 [Severity 1]
91 Perl::Critic::Policy::CodeLayout::ProhibitQuotedWordLists
93 Write "qw(foo bar baz)" instead of "('foo', 'bar', 'baz')". [Severity
94 2]
95 Perl::Critic::Policy::CodeLayout::ProhibitTrailingWhitespace
97 Don't use whitespace at the end of lines. [Severity 1]
98 Perl::Critic::Policy::CodeLayout::RequireConsistentNewlines
100 Use the same newline through the source. [Severity 4]
101 Perl::Critic::Policy::CodeLayout::RequireTidyCode
103 Must run code through perltidy. [Severity 1]
104 Perl::Critic::Policy::CodeLayout::RequireTrailingCommas
106 Put a comma at the end of every multi-line list declaration, including
107 the last one. [Severity 1]
108 Perl::Critic::Policy::ControlStructures::ProhibitCStyleForLoops
110 Write "for(0..20)" instead of "for($i=0; $i<=20; $i++)". [Severity 2]
111 Perl::Critic::Policy::ControlStructures::ProhibitCascadingIfElse
113 Don't write long "if-elsif-elsif-elsif-elsif...else" chains. [Severity
114 3]
115 Perl::Critic::Policy::ControlStructures::ProhibitDeepNests
117 Don't write deeply nested loops and conditionals. [Severity 3]
118 Perl::Critic::Policy::ControlStructures::ProhibitLabelsWithSpecialBlockNames
120 Don't use labels that are the same as the special block names.
121 [Severity 4]
122 Perl::Critic::Policy::ControlStructures::ProhibitMutatingListFunctions
124 Don't modify $_ in list functions. [Severity 5]
125 Perl::Critic::Policy::ControlStructures::ProhibitNegativeExpressionsInUnlessAndUntilConditions
127 Don't use operators like "not", "!~", and "le" within "until" and
128 "unless". [Severity 3]
129 Perl::Critic::Policy::ControlStructures::ProhibitPostfixControls
131 Write "if($condition){ do_something() }" instead of "do_something() if
132 $condition". [Severity 2]
133 Perl::Critic::Policy::ControlStructures::ProhibitUnlessBlocks
135 Write "if(! $condition)" instead of "unless($condition)". [Severity 2]
136 Perl::Critic::Policy::ControlStructures::ProhibitUnreachableCode
138 Don't write code after an unconditional "die, exit, or next". [Severity
139 4]
140 Perl::Critic::Policy::ControlStructures::ProhibitUntilBlocks
142 Write "while(! $condition)" instead of "until($condition)". [Severity
143 2]
144 Perl::Critic::Policy::Documentation::PodSpelling
146 Check your spelling. [Severity 1]
147 Perl::Critic::Policy::Documentation::RequirePackageMatchesPodName
149 The "=head1 NAME" section should match the package. [Severity 1]
150 Perl::Critic::Policy::Documentation::RequirePodAtEnd
152 All POD should be after "__END__". [Severity 1]
153 Perl::Critic::Policy::Documentation::RequirePodSections
155 Organize your POD into the customary sections. [Severity 2]
156 Perl::Critic::Policy::ErrorHandling::RequireCarping
158 Use functions from Carp instead of "warn" or "die". [Severity 3]
159 Perl::Critic::Policy::ErrorHandling::RequireCheckingReturnValueOfEval
161 You can't depend upon the value of $@/$EVAL_ERROR to tell whether an
162 "eval" failed. [Severity 3]
163 Perl::Critic::Policy::InputOutput::ProhibitBacktickOperators
165 Discourage stuff like "@files = `ls $directory`". [Severity 3]
166 Perl::Critic::Policy::InputOutput::ProhibitBarewordFileHandles
168 Write "open my $fh, q{<}, $filename;" instead of "open FH, q{<},
169 $filename;". [Severity 5]
170 Perl::Critic::Policy::InputOutput::ProhibitExplicitStdin
172 Use "<>" or "<ARGV>" or a prompting module instead of "<STDIN>".
173 [Severity 4]
174 Perl::Critic::Policy::InputOutput::ProhibitInteractiveTest
176 Use prompt() instead of -t. [Severity 5]
177 Perl::Critic::Policy::InputOutput::ProhibitJoinedReadline
179 Use "local $/ = undef" or File::Slurp instead of joined readline.
180 [Severity 3]
181 Perl::Critic::Policy::InputOutput::ProhibitOneArgSelect
183 Never write "select($fh)". [Severity 4]
184 Perl::Critic::Policy::InputOutput::ProhibitReadlineInForLoop
186 Write "while( $line = <> ){...}" instead of "for(<>){...}". [Severity
187 4]
188 Perl::Critic::Policy::InputOutput::ProhibitTwoArgOpen
190 Write "open $fh, q{<}, $filename;" instead of "open $fh,
191 "<$filename";". [Severity 5]
192 Perl::Critic::Policy::InputOutput::RequireBracedFileHandleWithPrint
194 Write "print {$FH} $foo, $bar;" instead of "print $FH $foo, $bar;".
195 [Severity 1]
196 Perl::Critic::Policy::InputOutput::RequireBriefOpen
198 Close filehandles as soon as possible after opening them. [Severity 4]
199 Perl::Critic::Policy::InputOutput::RequireCheckedClose
201 Write "my $error = close $fh;" instead of "close $fh;". [Severity 2]
202 Perl::Critic::Policy::InputOutput::RequireCheckedOpen
204 Write "my $error = open $fh, $mode, $filename;" instead of "open $fh,
205 $mode, $filename;". [Severity 3]
206 Perl::Critic::Policy::InputOutput::RequireCheckedSyscalls
208 Return value of flagged function ignored. [Severity 1]
209 Perl::Critic::Policy::Miscellanea::ProhibitFormats
211 Do not use "format". [Severity 3]
212 Perl::Critic::Policy::Miscellanea::ProhibitTies
214 Do not use "tie". [Severity 2]
215 Perl::Critic::Policy::Miscellanea::ProhibitUnrestrictedNoCritic
217 Forbid a bare "## no critic" [Severity 3]
218 Perl::Critic::Policy::Miscellanea::ProhibitUselessNoCritic
220 Remove ineffective "## no critic" annotations. [Severity 2]
221 Perl::Critic::Policy::Miscellanea::RequireRcsKeywords
223 Put source-control keywords in every file. [Severity 2]
224 Perl::Critic::Policy::Modules::ProhibitAutomaticExportation
226 Export symbols via @EXPORT_OK or %EXPORT_TAGS instead of @EXPORT.
227 [Severity 4]
228 Perl::Critic::Policy::Modules::ProhibitEvilModules
230 Ban modules that aren't blessed by your shop. [Severity 5]
231 Perl::Critic::Policy::Modules::ProhibitExcessMainComplexity
233 Minimize complexity in code that is outside of subroutines. [Severity
234 3]
235 Perl::Critic::Policy::Modules::ProhibitMultiplePackages
237 Put packages (especially subclasses) in separate files. [Severity 4]
238 Perl::Critic::Policy::Modules::RequireBarewordIncludes
240 Write "require Module" instead of "require 'Module.pm'". [Severity 5]
241 Perl::Critic::Policy::Modules::RequireEndWithOne
243 End each module with an explicitly "1;" instead of some funky
244 expression. [Severity 4]
245 Perl::Critic::Policy::Modules::RequireExplicitPackage
247 Always make the "package" explicit. [Severity 4]
248 Perl::Critic::Policy::Modules::RequireFilenameMatchesPackage
250 Package declaration must match filename. [Severity 5]
251 Perl::Critic::Policy::Modules::RequireNoMatchVarsWithUseEnglish
253 "use English" must be passed a "-no_match_vars" argument. [Severity 2]
254 Perl::Critic::Policy::Modules::RequireVersionVar
256 Give every module a $VERSION number. [Severity 2]
257 Perl::Critic::Policy::NamingConventions::Capitalization
259 Distinguish different program components by case. [Severity 1]
260 Perl::Critic::Policy::NamingConventions::ProhibitAmbiguousNames
262 Don't use vague variable or subroutine names like 'last' or 'record'.
263 [Severity 3]
264 Perl::Critic::Policy::Objects::ProhibitIndirectSyntax
266 Prohibit indirect object call syntax. [Severity 4]
267 Perl::Critic::Policy::References::ProhibitDoubleSigils
269 Write "@{ $array_ref }" instead of @$array_ref. [Severity 2]
270 Perl::Critic::Policy::RegularExpressions::ProhibitCaptureWithoutTest
272 Capture variable used outside conditional. [Severity 3]
273 Perl::Critic::Policy::RegularExpressions::ProhibitComplexRegexes
275 Split long regexps into smaller "qr//" chunks. [Severity 3]
276 Perl::Critic::Policy::RegularExpressions::ProhibitEnumeratedClasses
278 Use named character classes instead of explicit character lists.
279 [Severity 1]
280 Perl::Critic::Policy::RegularExpressions::ProhibitEscapedMetacharacters
282 Use character classes for literal meta-characters instead of escapes.
283 [Severity 1]
284 Perl::Critic::Policy::RegularExpressions::ProhibitFixedStringMatches
286 Use "eq" or hash instead of fixed-pattern regexps. [Severity 2]
287 Perl::Critic::Policy::RegularExpressions::ProhibitSingleCharAlternation
289 Use "[abc]" instead of "a|b|c". [Severity 1]
290 Perl::Critic::Policy::RegularExpressions::ProhibitUnusedCapture
292 Only use a capturing group if you plan to use the captured value.
293 [Severity 3]
294 Perl::Critic::Policy::RegularExpressions::ProhibitUnusualDelimiters
296 Use only "//" or "{}" to delimit regexps. [Severity 1]
297 Perl::Critic::Policy::RegularExpressions::RequireBracesForMultiline
299 Use "{" and "}" to delimit multi-line regexps. [Severity 1]
300 Perl::Critic::Policy::RegularExpressions::RequireDotMatchAnything
302 Always use the "/s" modifier with regular expressions. [Severity 2]
303 Perl::Critic::Policy::RegularExpressions::RequireExtendedFormatting
305 Always use the "/x" modifier with regular expressions. [Severity 3]
306 Perl::Critic::Policy::RegularExpressions::RequireLineBoundaryMatching
308 Always use the "/m" modifier with regular expressions. [Severity 2]
309 Perl::Critic::Policy::Subroutines::ProhibitAmpersandSigils
311 Don't call functions with a leading ampersand sigil. [Severity 2]
312 Perl::Critic::Policy::Subroutines::ProhibitBuiltinHomonyms
314 Don't declare your own "open" function. [Severity 4]
315 Perl::Critic::Policy::Subroutines::ProhibitExcessComplexity
317 Minimize complexity by factoring code into smaller subroutines.
318 [Severity 3]
319 Perl::Critic::Policy::Subroutines::ProhibitExplicitReturnUndef
321 Return failure with bare "return" instead of "return undef". [Severity
322 5]
323 Perl::Critic::Policy::Subroutines::ProhibitManyArgs
325 Too many arguments. [Severity 3]
326 Perl::Critic::Policy::Subroutines::ProhibitNestedSubs
328 "sub never { sub correct {} }". [Severity 5]
329 Perl::Critic::Policy::Subroutines::ProhibitReturnSort
331 Behavior of "sort" is not defined if called in scalar context.
332 [Severity 5]
333 Perl::Critic::Policy::Subroutines::ProhibitSubroutinePrototypes
335 Don't write "sub my_function (@@) {}". [Severity 5]
336 Perl::Critic::Policy::Subroutines::ProtectPrivateSubs
338 Prevent access to private subs in other packages. [Severity 3]
339 Perl::Critic::Policy::Subroutines::RequireArgUnpacking
341 Always unpack @_ first. [Severity 4]
342 Perl::Critic::Policy::Subroutines::RequireFinalReturn
344 End every path through a subroutine with an explicit "return"
345 statement. [Severity 4]
346 Perl::Critic::Policy::TestingAndDebugging::ProhibitNoStrict
348 Prohibit various flavors of "no strict". [Severity 5]
349 Perl::Critic::Policy::TestingAndDebugging::ProhibitNoWarnings
351 Prohibit various flavors of "no warnings". [Severity 4]
352 Perl::Critic::Policy::TestingAndDebugging::ProhibitProlongedStrictureOverride
354 Don't turn off strict for large blocks of code. [Severity 4]
355 Perl::Critic::Policy::TestingAndDebugging::RequireTestLabels
357 Tests should all have labels. [Severity 3]
358 Perl::Critic::Policy::TestingAndDebugging::RequireUseStrict
360 Always "use strict". [Severity 5]
361 Perl::Critic::Policy::TestingAndDebugging::RequireUseWarnings
363 Always "use warnings". [Severity 4]
364 Perl::Critic::Policy::ValuesAndExpressions::ProhibitCommaSeparatedStatements
366 Don't use the comma operator as a statement separator. [Severity 4]
367 Perl::Critic::Policy::ValuesAndExpressions::ProhibitComplexVersion
369 Prohibit version values from outside the module. [Severity 3]
370 Perl::Critic::Policy::ValuesAndExpressions::ProhibitConstantPragma
372 Don't "use constant FOO => 15". [Severity 4]
373 Perl::Critic::Policy::ValuesAndExpressions::ProhibitEmptyQuotes
375 Write "q{}" instead of ''. [Severity 2]
376 Perl::Critic::Policy::ValuesAndExpressions::ProhibitEscapedCharacters
378 Write "\N{DELETE}" instead of "\x7F", etc. [Severity 2]
379 Perl::Critic::Policy::ValuesAndExpressions::ProhibitImplicitNewlines
381 Use concatenation or HEREDOCs instead of literal line breaks in
382 strings. [Severity 3]
383 Perl::Critic::Policy::ValuesAndExpressions::ProhibitInterpolationOfLiterals
385 Always use single quotes for literal strings. [Severity 1]
386 Perl::Critic::Policy::ValuesAndExpressions::ProhibitLeadingZeros
388 Write "oct(755)" instead of 0755. [Severity 5]
389 Perl::Critic::Policy::ValuesAndExpressions::ProhibitLongChainsOfMethodCalls
391 Long chains of method calls indicate tightly coupled code. [Severity 2]
392 Perl::Critic::Policy::ValuesAndExpressions::ProhibitMagicNumbers
394 Don't use values that don't explain themselves. [Severity 2]
395 Perl::Critic::Policy::ValuesAndExpressions::ProhibitMismatchedOperators
397 Don't mix numeric operators with string operands, or vice-versa.
398 [Severity 3]
399 Perl::Critic::Policy::ValuesAndExpressions::ProhibitMixedBooleanOperators
401 Write " !$foo && $bar || $baz " instead of " not $foo && $bar or $baz".
402 [Severity 4]
403 Perl::Critic::Policy::ValuesAndExpressions::ProhibitNoisyQuotes
405 Use "q{}" or "qq{}" instead of quotes for awkward-looking strings.
406 [Severity 2]
407 Perl::Critic::Policy::ValuesAndExpressions::ProhibitQuotesAsQuotelikeOperatorDelimiters
409 Don't use quotes ("'", """, "`") as delimiters for the quote-like
410 operators. [Severity 3]
411 Perl::Critic::Policy::ValuesAndExpressions::ProhibitSpecialLiteralHeredocTerminator
413 Don't write " print <<'__END__' ". [Severity 3]
414 Perl::Critic::Policy::ValuesAndExpressions::ProhibitVersionStrings
416 Don't use strings like "v1.4" or 1.4.5 when including other modules.
417 [Severity 3]
418 Perl::Critic::Policy::ValuesAndExpressions::RequireConstantVersion
420 Require $VERSION to be a constant rather than a computed value.
421 [Severity 2]
422 Perl::Critic::Policy::ValuesAndExpressions::RequireInterpolationOfMetachars
424 Warns that you might have used single quotes when you really wanted
425 double-quotes. [Severity 1]
426 Perl::Critic::Policy::ValuesAndExpressions::RequireNumberSeparators
428 Write " 141_234_397.0145 " instead of 141234397.0145 . [Severity 2]
429 Perl::Critic::Policy::ValuesAndExpressions::RequireQuotedHeredocTerminator
431 Write " print <<'THE_END' " or " print <<"THE_END" ". [Severity 3]
432 Perl::Critic::Policy::ValuesAndExpressions::RequireUpperCaseHeredocTerminator
434 Write " <<'THE_END'; " instead of " <<'theEnd'; ". [Severity 2]
435 Perl::Critic::Policy::Variables::ProhibitConditionalDeclarations
437 Do not write " my $foo = $bar if $baz; ". [Severity 5]
438 Perl::Critic::Policy::Variables::ProhibitLocalVars
440 Use "my" instead of "local", except when you have to. [Severity 2]
441 Perl::Critic::Policy::Variables::ProhibitMatchVars
443 Avoid "$`", $&, "$'" and their English equivalents. [Severity 4]
444 Perl::Critic::Policy::Variables::ProhibitPackageVars
446 Eliminate globals declared with "our" or "use vars". [Severity 3]
447 Perl::Critic::Policy::Variables::ProhibitPerl4PackageNames
449 Use double colon (::) to separate package name components instead of
450 single quotes ('). [Severity 2]
451 Perl::Critic::Policy::Variables::ProhibitPunctuationVars
453 Write $EVAL_ERROR instead of $@. [Severity 2]
454 Perl::Critic::Policy::Variables::ProhibitReusedNames
456 Do not reuse a variable name in a lexical scope [Severity 3]
457 Perl::Critic::Policy::Variables::ProhibitUnusedVariables
459 Don't ask for storage you don't need. [Severity 3]
460 Perl::Critic::Policy::Variables::ProtectPrivateVars
462 Prevent access to private vars in other packages. [Severity 3]
463 Perl::Critic::Policy::Variables::RequireInitializationForLocalVars
465 Write "local $foo = $bar;" instead of just "local $foo;". [Severity 3]
466 Perl::Critic::Policy::Variables::RequireLexicalLoopIterators
468 Write "for my $element (@list) {...}" instead of "for $element (@list)
469 {...}". [Severity 5]
470 Perl::Critic::Policy::Variables::RequireLocalizedPunctuationVars
472 Magic variables should be assigned as "local". [Severity 4]
473 Perl::Critic::Policy::Variables::RequireNegativeIndices
475 Negative array index should be used. [Severity 4]
476
478 This is part of Perl::Critic version 1.106.
479
481 Jeffrey Ryan Thalhammer <thaljef@cpan.org>
482
484 Copyright (c) 2005-2009 Jeffrey Ryan Thalhammer. All rights reserved.
485 This program is free software; you can redistribute it and/or modify it
487 under the same terms as Perl itself. The full text of this license can
488 be found in the LICENSE file included with this module.
489perl v5.12.1 2010-09-08 Perl::Critic::PolicySummary(3)