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package Perl::Critic::Policy::RegularExpressions::RequireExtendedFormatting;
use 5.010001;
use strict;
use warnings;
use Readonly;
use Perl::Critic::Utils qw{ :severities };
use parent 'Perl::Critic::Policy';
our $VERSION = '1.156';
#-----------------------------------------------------------------------------
Readonly::Scalar my $DESC => q{Regular expression without "/x" flag};
Readonly::Scalar my $EXPL => [ 236 ];
#-----------------------------------------------------------------------------
sub supported_parameters {
return (
{
name => 'minimum_regex_length_to_complain_about',
description =>
q<The number of characters that a regular expression must contain before this policy will complain.>,
behavior => 'integer',
default_string => '0',
integer_minimum => 0,
},
{
name => 'strict',
description =>
q<Should regexes that only contain whitespace and word characters be complained about?>,
behavior => 'boolean',
default_string => '0',
},
);
}
sub default_severity { return $SEVERITY_MEDIUM }
sub default_themes { return qw< core pbp maintenance > }
sub applies_to {
return qw<
PPI::Token::Regexp::Match
PPI::Token::Regexp::Substitute
PPI::Token::QuoteLike::Regexp
>;
}
#-----------------------------------------------------------------------------
sub violates {
my ( $self, $elem, $doc ) = @_;
my $match = $elem->get_match_string();
return if length $match <= $self->{_minimum_regex_length_to_complain_about};
return if not $self->{_strict} and $match =~ m< \A [\s\w]* \z >xms;
my $re = $doc->ppix_regexp_from_element( $elem )
or return;
$re->modifier_asserted( 'x' )
or return $self->violation( $DESC, $EXPL, $elem );
return; # ok!;
}
1;
__END__
#-----------------------------------------------------------------------------
=pod
=head1 NAME
Perl::Critic::Policy::RegularExpressions::RequireExtendedFormatting - Always use the C</x> modifier with regular expressions.
=head1 AFFILIATION
This Policy is part of the core L<Perl::Critic|Perl::Critic>
distribution.
=head1 DESCRIPTION
Extended regular expression formatting allows you mix whitespace and
comments into the pattern, thus making them much more readable.
# Match a single-quoted string efficiently...
m{'[^\\']*(?:\\.[^\\']*)*'}; #Huh?
# Same thing with extended format...
m{
' # an opening single quote
[^\\'] # any non-special chars (i.e. not backslash or single quote)
(?: # then all of...
\\ . # any explicitly backslashed char
[^\\']* # followed by a non-special char
)* # ...repeated zero or more times
' # a closing single quote
}x;
=head1 CONFIGURATION
You might find that putting a C</x> on short regular expressions to be
excessive. An exception can be made for them by setting
C<minimum_regex_length_to_complain_about> to the minimum match length
you'll allow without a C</x>. The length only counts the regular
expression, not the braces or operators.
[RegularExpressions::RequireExtendedFormatting]
minimum_regex_length_to_complain_about = 5
$num =~ m<(\d+)>; # ok, only 5 characters
$num =~ m<\d\.(\d+)>; # not ok, 9 characters
This option defaults to 0.
Because using C</x> on a regex which has whitespace in it can make it
harder to read (you have to escape all that innocent whitespace), by
default, you can have a regular expression that only contains
whitespace and word characters without the modifier. If you want to
restrict this, turn on the C<strict> option.
[RegularExpressions::RequireExtendedFormatting]
strict = 1
$string =~ m/Basset hounds got long ears/; # no longer ok
This option defaults to false.
=head1 NOTES
For common regular expressions like e-mail addresses, phone numbers,
dates, etc., have a look at the L<Regexp::Common|Regexp::Common> module.
Also, be cautions about slapping modifier flags onto existing regular
expressions, as they can drastically alter their meaning. See
L<http://www.perlmonks.org/?node_id=484238> for an interesting
discussion on the effects of blindly modifying regular expression
flags.
=head1 TO DO
Add an exemption for regular expressions that contain C<\Q> at the
front and don't use C<\E> until the very end, if at all.
=head1 AUTHOR
Jeffrey Ryan Thalhammer <jeff@imaginative-software.com>
=head1 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.
=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=perl expandtab shiftround :
|
