1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
|
package Perl::Critic::Policy::RegularExpressions::ProhibitSingleCharAlternation;
use 5.010001;
use strict;
use warnings;
use Readonly;
use Perl::Critic::Utils qw( :characters :severities );
use parent 'Perl::Critic::Policy';
our $VERSION = '1.156';
#-----------------------------------------------------------------------------
Readonly::Scalar my $EXPL => [265];
#-----------------------------------------------------------------------------
sub supported_parameters { return qw() }
sub default_severity { return $SEVERITY_LOWEST }
sub default_themes { return qw( core pbp performance ) }
sub applies_to { return qw(PPI::Token::Regexp::Match
PPI::Token::Regexp::Substitute
PPI::Token::QuoteLike::Regexp) }
#-----------------------------------------------------------------------------
sub violates {
my ( $self, $elem, $document ) = @_;
# optimization: don't bother parsing the regexp if there are no pipes
return if $elem !~ m/[|]/xms;
my $re = $document->ppix_regexp_from_element( $elem ) or return;
$re->failures() and return;
my @violations;
foreach my $node ( @{ $re->find_parents( sub {
return $_[1]->isa( 'PPIx::Regexp::Token::Operator' )
&& $_[1]->content() eq q<|>;
} ) || [] } ) {
my @singles;
my @alternative;
foreach my $kid ( $node->children() ) {
if ( $kid->isa( 'PPIx::Regexp::Token::Operator' )
&& $kid->content() eq q<|>
) {
@alternative == 1
and $alternative[0]->isa( 'PPIx::Regexp::Token::Literal' )
and push @singles, map { $_->content() } @alternative;
@alternative = ();
} elsif ( $kid->significant() ) {
push @alternative, $kid;
}
}
@alternative == 1
and $alternative[0]->isa( 'PPIx::Regexp::Token::Literal' )
and push @singles, map { $_->content() } @alternative;
if ( 1 < @singles ) {
my $description =
'Use ['
. join( $EMPTY, @singles )
. '] instead of '
. join q<|>, @singles;
push @violations, $self->violation( $description, $EXPL, $elem );
}
}
return @violations;
}
1;
__END__
#-----------------------------------------------------------------------------
=pod
=head1 NAME
Perl::Critic::Policy::RegularExpressions::ProhibitSingleCharAlternation - Use C<[abc]> instead of C<a|b|c>.
=head1 AFFILIATION
This Policy is part of the core L<Perl::Critic|Perl::Critic>
distribution.
=head1 DESCRIPTION
Character classes (like C<[abc]>) are significantly faster than single
character alternations (like C<(?:a|b|c)>). This policy complains if
you have more than one instance of a single character in an
alternation. So C<(?:a|the)> is allowed, but C<(?:a|e|i|o|u)> is not.
=head1 CONFIGURATION
This Policy is not configurable except for the standard options.
=head1 CREDITS
Initial development of this policy was supported by a grant from the
Perl Foundation.
=head1 AUTHOR
Chris Dolan <cdolan@cpan.org>
=head1 COPYRIGHT
Copyright (c) 2007-2023 Chris Dolan
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 :
|
