Perl::Critic::Theme - Construct thematic sets of policies.

Perl-Critic documentation Contained in the Perl-Critic distribution.

Index

Code Index:

NAME

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Perl::Critic::Theme - Construct thematic sets of policies.

DESCRIPTION

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This is a helper class for evaluating theme expressions into sets of Policy objects. There are no user-serviceable parts here.

INTERFACE SUPPORT

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This is considered to be a non-public class. Its interface is subject to change without notice.

METHODS

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new( -rule => $rule_expression )

Returns a reference to a new Perl::Critic::Theme object. -rule is a string expression that evaluates to true or false for each Policy.. See "THEME RULES" for more information.

policy_is_thematic( -policy => $policy )

Given a reference to a Perl::Critic::Policy object, this method returns evaluates the rule against the themes that are associated with the Policy. Returns 1 if the Policy satisfies the rule, 0 otherwise.

rule()

Returns the rule expression that was used to construct this Theme. The rule may have been translated into a normalized expression. See "THEME RULES" for more information.

THEME RULES

A theme rule is a simple boolean expression, where the operands are the names of any of the themes associated with the Perl::Critic::Polices.

Theme names can be combined with logical operators to form arbitrarily complex expressions. Precedence is the same as normal mathematics, but you can use parentheses to enforce precedence as well. Supported operators are:

   Operator    Altertative    Example
   ----------------------------------------------------------------
   &&          and            'pbp && core'
   ||          or             'pbp || (bugs && security)'
   !           not            'pbp && ! (portability || complexity)

See "CONFIGURATION" in Perl::Critic for more information about customizing the themes for each Policy.

SUBROUTINES

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cook_rule( $rule )

Standardize a rule into a almost executable Perl code. The "almost" comes from the fact that theme names are left as is.

CONSTANTS

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$RULE_INVALID_CHARACTER_REGEX

A regular expression that will return the first character in the matched expression that is not valid in a rule.

AUTHOR

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Jeffrey Ryan Thalhammer <jeff@imaginative-software.com>

COPYRIGHT

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Copyright (c) 2006-2011 Imaginative Software Systems

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-Critic documentation Contained in the Perl-Critic distribution. 
##############################################################################
#      $URL: http://perlcritic.tigris.org/svn/perlcritic/trunk/distributions/Perl-Critic/lib/Perl/Critic/Theme.pm $
#     $Date: 2011-05-15 16:34:46 -0500 (Sun, 15 May 2011) $
#   $Author: clonezone $
# $Revision: 4078 $
##############################################################################

package Perl::Critic::Theme;

use 5.006001;
use strict;
use warnings;
use English qw(-no_match_vars);
use Readonly;

use base qw{ Exporter };

use List::MoreUtils qw(any);

use Perl::Critic::Utils qw{ :characters :data_conversion };
use Perl::Critic::Exception::Fatal::Internal qw{ &throw_internal };
use Perl::Critic::Exception::Configuration::Option::Global::ParameterValue
    qw{ &throw_global_value };

#-----------------------------------------------------------------------------

our $VERSION = '1.116';

#-----------------------------------------------------------------------------

Readonly::Array our @EXPORT_OK => qw{
    $RULE_INVALID_CHARACTER_REGEX
    cook_rule
};

#-----------------------------------------------------------------------------

Readonly::Scalar our $RULE_INVALID_CHARACTER_REGEX =>
    qr/ ( [^()\s\w\d+\-*&|!] ) /xms;

#-----------------------------------------------------------------------------

Readonly::Scalar my $CONFIG_KEY => 'theme';

#-----------------------------------------------------------------------------

sub new {

    my ( $class, %args ) = @_;
    my $self = bless {}, $class;
    $self->_init( %args );
    return $self;
}

#-----------------------------------------------------------------------------

sub _init {

    my ($self, %args) = @_;
    my $rule = $args{-rule} || $EMPTY;

    if ( $rule =~ m/$RULE_INVALID_CHARACTER_REGEX/xms ) {
        throw_global_value
            option_name     => $CONFIG_KEY,
            option_value    => $rule,
            message_suffix => qq{contains an invalid character: "$1".};
    }

    $self->{_rule} = cook_rule( $rule );

    return $self;
}

#-----------------------------------------------------------------------------

sub rule {
    my $self = shift;
    return $self->{_rule};
}

#-----------------------------------------------------------------------------

sub policy_is_thematic {

    my ($self, %args) = @_;
    my $policy = $args{-policy}
        || throw_internal 'The -policy argument is required';
    ref $policy
        || throw_internal 'The -policy must be an object';

    my $rule = $self->{_rule} or return 1;
    my %themes = hashify( $policy->get_themes() );

    # This bit of magic turns the rule into a perl expression that can be
    # eval-ed for truth.  Each theme name in the rule is translated to 1 or 0
    # if the $policy belongs in that theme.  For example:
    #
    # 'bugs && (pbp || core)'  ...could become... '1 && (0 || 1)'

    my $as_code = $rule; #Making a copy, so $rule is preserved
    $as_code =~ s/ ( [\w\d]+ ) /exists $themes{$1} || 0/gexms;
    my $is_thematic = eval $as_code;  ## no critic (ProhibitStringyEval)

    if ($EVAL_ERROR) {
        throw_global_value
            option_name     => $CONFIG_KEY,
            option_value    => $rule,
            message_suffix  => q{contains a syntax error.};
    }

    return $is_thematic;
}

#-----------------------------------------------------------------------------

sub cook_rule {
    my ($raw_rule) = @_;
    return if not defined $raw_rule;

    #Translate logical operators
    $raw_rule =~ s{\b not \b}{!}ixmsg;     # "not" -> "!"
    $raw_rule =~ s{\b and \b}{&&}ixmsg;    # "and" -> "&&"
    $raw_rule =~ s{\b or  \b}{||}ixmsg;    # "or"  -> "||"

    #Translate algebra operators (for backward compatibility)
    $raw_rule =~ s{\A [-] }{!}ixmsg;     # "-" -> "!"     e.g. difference
    $raw_rule =~ s{   [-] }{&& !}ixmsg;  # "-" -> "&& !"  e.g. difference
    $raw_rule =~ s{   [*] }{&&}ixmsg;    # "*" -> "&&"    e.g. intersection
    $raw_rule =~ s{   [+] }{||}ixmsg;    # "+" -> "||"    e.g. union

    my $cooked_rule = lc $raw_rule;  #Is now cooked!
    return $cooked_rule;
}


1;

__END__

#-----------------------------------------------------------------------------


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