# best viewed via "perldoc TODO.pod" =pod =for stopwords LHS RHS REFACTORINGS FH SVN stopwords =head1 NAME Perl::Critic::TODO - Things for Perl::Critic developers to do =head1 SOURCE ####################################################################### # $URL: http://perlcritic.tigris.org/svn/perlcritic/trunk/Perl-Critic/TODO.pod $ # $Date: 2008-07-03 09:36:05 -0500 (Thu, 03 Jul 2008) $ # $Author: clonezone $ # $Revision: 2487 $ ####################################################################### =head1 SEE ALSO Perl-Critic-More is a separate distribution for less-widely-accepted policies. It contains its own TODO.pod. =head1 NEW FEATURES =over =item * Report Safari sections in addition to book page numbers. =item * Add --files-with-violations/-l and --files-without-violations/-L options to F. Just print out file names. I could have used this at work when combined with C<--single-policy>. gvim `perlcritic --single-policy QuotedWordLists -l` =item * Add a file Behavior. =item * Allow values of (at least) string-list Parameters to be specified in a file. For the benefit of PodSpelling, etc. =item * Enhance string-list Behavior to allow specification of delimiters. For things like RequirePodSections. =item * Add queries to --list option to F. List Policies based upon severity, theme, and (what I want this second) applies_to. =item * Add --prohibit-unrestricted-no-critic option to F. Requires C<## no critic> to take an argument: ## no critic (SomePolicyPattern) # ok ## no critic # not ok Can't be done as a regular Policy because any line that violated it would disable it. =item * Support for C<#line 123 "filename"> directives. For code generators and template languages that allow inline Perl code. Yes, somebody has an in-house templating system where they've written a custom test module that extracts the perl code from a template and critiques it. Actually, this would be useful for programs: Module::Build "fixes" shebang lines so that there's the bit about invoking perl if the program is attempted to be run by a Bourne shell, which throws the line numbers off when using Test::P::C on the contents of a C directory. =item * Enhance statistics. - Blank line count - POD line count - Comment line count - Data section count =item * Detect 5.10 source and enable stuff for that. For example, treat C as equivalent to C. =item * Support a means of failing if a Policy isn't installed. For example, the self compliance test now depends upon a Policy in the More distribution. Something like using a "+" sign in front of the Policy name in its configuration block, analogous to the "-" sign used for disabling a policy, e.g. "C<[+Example::Policy]>". =back =head1 BUGS/LIMITATIONS =over =item * NamingConventions::ProhibitAmbiguousNames Don't allow compound names with forbidden words, like "last_record". Allow forbidden words in RHS of variable declarations Also, we should make it easeir to add (or delete) words from the forbbiden list. =item * Subroutines::ProtectPrivateSubs Doesn't forbid C<< $pkg->_foo() >> because it can't tell the difference between that and C<< $self->_foo() >> =item * ErrorHandling::RequireCarping This should not complain about using C or C if it's not in a function, or if it's in main::. Also, should allow C when it is obvious that the "message" is a reference. =item * RegularExpressions::ProhibitCaptureWithoutTest Allow this construct: for ( ... ) { next unless /(....)/; if ( $1 ) { .... } } Right now, P::C thinks that the C<$1> isn't legal to use because it's "outside" of the match. The thing is, we can only get to the C if the regex matched. while ( $str =~ /(expression)/ ) =item * CodeLayout::ProhibitParensWithBuiltins Some builtin functions (particularly those that take a variable number of scalar arguments) should probably get parentheses. This policy should be enhanced to allow the user to specify a list of builtins that are expempt from the policy. =item * ValuesAndExpressions::ProhibitCommaSeparatedStatements Needs to check for C. =item * Variables::ProhibitPunctuationVars Needs to look inside strings. RT #35970. =item * TestingAndDebugging::RequireUseWarnings Check for -w on the shbang line. =item * Change formatting in Violation to eliminate double periods. =back =head1 OTHER PBP POLICIES THAT SEEM FEASIBLE TO IMPLEMENT =over =item * Modules::RequireUseVersion [405-406] =item * Modules::RequireThreePartVersion [405-406] =item * RegularExpressions::RequireDotMatchAnything [240-241] =back =head1 NON-PBP POLICIES WANTED =over =item * Documentation::RequireModuleAbstract Require a C<=head1 NAME> POD section with content that matches C<\A \s* [\w:]+ \s+ - \s+ \S>. The single hyphen is the important bit. Also, must be a single line. =item * Expressions::RequireFatCommasInHashConstructors =item * ErrorHandling::RequireLocalizingEvalErrorInDESTROY Prevent C<$@> from being cleared unexpectedly by DESTROY methods. package Foo; sub DESTROY { die "Died in Foo::DESTROY()"; } package main; eval { my $foo = Foo->new(); die "Died in eval." } print $@; # "Died in Foo::DESTROY()", not "Died in eval.". See L. =item * Expressions::ProhibitDecimalWithBitwiseOperator =item * Expressions::ProhibitStringsWithBitwiseOperator =item * InputOutput::ProhibitMagicDiamond Steal the idea from L. =item * TBD::AllProgramsNeedShebangs Anything that is a program should have a shebang line. This includes .t files. =item * BuiltInFunctions::RequireConstantSprintfFormat =item * BuiltInFunctions::RequireConstantUnpackFormat L =item * Miscellanea::ProhibitObnoxiousComments Forbid excessive hash marks e.g. "#### This is a loud comment ####". Make the obnoxious pattern configurable =item * ValuesAndExpressions::RequireNotOperator Require the use of "not" instead of "!", except when this would contradict ProhibitMixedBooleanOperators. This may be better suited for Perl::Critic::More. =item * Modules::RequireExplicitImporting Require every C statement to have an explicit import list. You could still get around this by calling C directly. =item * Modules::ForbidImporting Require every C to have an explicitly empty import list. This is for folks who like to see fully-qualified function names. Should probably provide a list of exempt modules (like FindBin); =item * ControlStructures::ProhibitIncludeViaDo Forbid C. Not sure about this policy name. =item * Variables::ProhibitUseVars Disallow C and require C instead. This contradicts Miscellanea::Prohibit5006isms. Maybe verify C before applying this policy. Low severity. =item * VariablesAndExpressions::ProhibitQuotedHashKeys Forbid quotes around hash keys, unless they are really needed. This is against what Damian says. Suggested by Adam Kennedy. Low severity. =item * CodeLayout::ProhibitFunctionalNew Good: C<< Foo::Bar->new >>, Bad: C<< new Foo::Bar >> =item * RegularExpressions::ProhibitSWSWSW Require C instead of C. From MJD's Red Flags. =item * VariablesAndExpressions::RequireConstantVersion (low severity) =item * VariablesAndExpressions::ProhibitComplexVersion (medium severity) L =item * Documentation::RequireSynopsis =item * Documentation::RequireLicense These are simplified versions of Documentation::RequirePodSections. =item * Documentation::RequireValidSynopsis The Synopsis section must be all indented and must be syntactically valid Perl (as validated by PPI). =item * Documentation::ProhibitEmptySections Any C<=headN> and C<=over> sections must not be empty. This helps catch boilerplate (althought Test::Pod should catch empty C<=over> blocks). On the other hand, C<=item ...> sections can be empty, since the item label is content. =item * Miscellaneous::ProhibitBoilerplate Complain about copy-and-paste code or docs from h2xs, Module::Starter::*, etc. Here's a non-PPI implementation: L =item * BuiltinFunctions::ProhibitExtraneousScalarCall Recommend that C be rewritten as C. =item * RegularExpressions::ProhibitMixedDelimiters Ban s{foo}(bar) =item * RegularExpressions::ProhibitScalarAsRegexp Ban naked srtings as regexps, like: print 1 if $str =~ $regexp; Instead, it should be: print 1 if $str =~ m/$regexp/; or print 1 if $str =~ m/$regexp/xms; =item * ValuesAndExpressions::RequireInterpolatedStringyEval Ensure that the argument to a stringy eval is not a constant string. That's just wasteful. Real world examples include: eval 'use Optional::Module'; which is better written as eval { require Optional::Module; Optional::Module->import }; for performance gains and compile-time syntax checking. =item * RegularExpressions::ProhibitUnnecessaryEscapes Complain if user puts a backslash escape in front of non-special characters. For example: m/\!/; Make exceptions for C<\">, C<\'> and C<\`> since those are often inserted to workaround bugs in syntax highlighting. Note that this is different inside character classes, where only C<^>, C<]> and C<-> need to be escaped, I think. Caret only needs to be escaped at the beginning, and dash does NOT need to be escaped at the beginning and end. See L. =item * Steal ideas from L. Can someone expand this entry, please? =item * ControlStructures::ProhibitAssigmentInConditional =item * ValuesAndExpressions::RequireConstantBeforeEquals =item * ValuesAndExpressions::RequireConstantBeforeOperator L Just about everyone has been bitten by C when they meant to use C<==>. A safer style is C<10 == $x> because omitting the second C<=> yields a noisy compile-time failure instead of silent runtime error. ProhibitAssigmentInConditional complains if the condition of a while, until, if or unless is solely an assignment. If it's anything more complex (like C or C), there is no warning. RequireConstantBeforeEquals complains if the left side of an C<==> is a variable while the right side is a constant. RequireConstantBeforeOperator complains if the left side of any comparison operator (C<==>, C, C<<>, etc) is a variable while the right side is a constant. =item * InputOutput::ProhibitUTF8IOLayer http://www.perlfoundation.org/perl5/index.cgi?the_utf8_perlio_layer =item * BuiltinFunctions::ProhibitExit(?:InModules)? Forbid C in files that lack a shebang. Inspired by L and an analgous checker in FindBugs. =back =head1 REFACTORINGS and ENHANCEMENTS =over =item * Create constants for the PPI location array elements. =item * MOVE THE LINE-DISABLING INTO P::C::Document All the code that deals with finding all the '##no critic' comments and noting which policies are disabled at each line seems like it would be better placed in Perl::Critic::Document. P::C::Document could then provide methods to indicate if a policy is disabled at a particular line. So the basic algorithm in Perl::Critic might look something like this: foreach $element (@PPI_ELEMENTS) { foreach $policy (@POLICIES) { $line = $element->location->[0]; next if $doc->policy_is_disabled_at_line( $policy, $line ); push @violations, $policy->violates( $elem, $doc ); } } =item * Some means of detecting "runnaway" C<##no critic> Elliot was talking to a couple of users at ETech and one of their major concerns was that they were using C<##no critic> and forgetting to do a C<##use critic> after the problematic section. Perhaps an option to F to scan for such things is in order. =item * Change API to use named parameters Most of the methods on the public classes use named parameters for passing arguments. I'd like to extend that pattern to include all object-methods. Static methods can still use positional parameters. =item * Enhance P::C::critique() to accept files, directories, or code strings Just like F does now. =item * Add C<-cache> flag to F If enabled, this turns on L: require PPI::Cache; my $cache_path = "/tmp/test-perl-critic-cache-$ENV{USER}"; mkdir $cache_path, oct 700 if (! -d $cache_path); PPI::Cache->import(path => $cache_path); This cachedir should perhaps include the PPI version number! At least until PPI incorporates its own version number in the cache. (see F for a more robust implementation) =item * Use hash-lookup instead of C function. In several places, Perl::Critic uses C to see if a string is a member of a list. Instead, I suggest using a named subroutine that does a hash-lookup like this: my %logical_ops = hashify( qw( ! || && ||= &&= and or not ) ); sub is_logical_op { return exists $logical_ops{ $_[0] }; } Why? =item * Allow color output to work through a pipe. http://rt.cpan.org/Ticket/Display.html?id=30140 F now supports this. =back =head1 PPI BUGS We're waiting on the following bugs to get fixed in a CPAN release of PPI: =over =item PPI::Token::descendant_of() Exists in svn. Replace _descendant_of() in RequireCheckingReturnValueOfEval with that, once it is released, because it's faster and native. =item Newlines PPI does not preserve newlines. That makes CodeLayout::RequireConsistentNewlines impossible to implement under PPI. For now, it's implemented by pulling the source out of the file and skipping PPI. It's unlikely that PPI will support mixde newlines anytime soon. =item Operators ValuesAndExpressions::ProhibitMismatchedOperators has two workarounds for PPI bugs with parsing operators. Many of these bugs have been fixed in PPI, so it would be good to check if those workarounds are still needed. =item Regexp methods Not strictly a bug -- the PPI Regexp classes have a dearth of accessor methods as of v1.118, meaning that we have to do messy digging into internals. I wrote Perl::Critic:Utils::PPIRegexp to encapsulate this messiness, but it would be nicer to have an official interface in PPI. =back =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=pod expandtab shiftround :