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
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
|
=head1 NAME
PPIx::Regexp::Token::Quantifier - Represent an atomic quantifier.
=head1 SYNOPSIS
use PPIx::Regexp::Dumper;
PPIx::Regexp::Dumper->new( 'qr{\w+}smx' )
->print();
=head1 INHERITANCE
C<PPIx::Regexp::Token::Quantifier> is a
L<PPIx::Regexp::Token|PPIx::Regexp::Token>.
C<PPIx::Regexp::Token::Quantifier> has no descendants.
=head1 DESCRIPTION
This class represents an atomic quantifier; that is, one of the
characters C<*>, C<+>, or C<?>.
B<Note> that if they occur inside a variable-length look-behind, C<'?'>
implies a minimum Perl version of C<5.29.9>, and C<'+'> and C<'*'> are
regarded as parse errors and reblessed into the unknown token.
=head1 METHODS
This class provides the following public methods. Methods not documented
here are private, and unsupported in the sense that the author reserves
the right to change or remove them without notice.
=cut
package PPIx::Regexp::Token::Quantifier;
use strict;
use warnings;
use base qw{ PPIx::Regexp::Token };
use Carp;
use PPIx::Regexp::Constant qw{
INFINITY
LITERAL_LEFT_CURLY_ALLOWED
MSG_LOOK_BEHIND_TOO_LONG
TOKEN_UNKNOWN
VARIABLE_LENGTH_LOOK_BEHIND_INTRODUCED
@CARP_NOT
};
our $VERSION = '0.087';
# Return true if the token can be quantified, and false otherwise
sub can_be_quantified { return };
# Return true if the token is a quantifier.
sub is_quantifier { return 1 };
my %quantifier = map { $_ => 1 } qw{ * + ? };
=head2 could_be_quantifier
PPIx::Regexp::Token::Quantifier->could_be_quantifier( '*' );
This method returns true if the given string could be a quantifier; that
is, if it is '*', '+', or '?'.
=cut
sub could_be_quantifier {
my ( undef, $string ) = @_; # Invocant unused
return $quantifier{$string};
}
{
my %explanation = (
'*' => 'match zero or more times',
'+' => 'match one or more times',
'?' => 'match zero or one time',
);
sub __explanation {
return \%explanation;
}
}
sub __following_literal_left_curly_disallowed_in {
return LITERAL_LEFT_CURLY_ALLOWED;
}
{
my $variable_look_behind_introduced = {
'*' => undef,
'+' => undef,
'?' => VARIABLE_LENGTH_LOOK_BEHIND_INTRODUCED,
};
sub __PPIX_LEXER__finalize {
my ( $self ) = @_;
if ( $self->__in_look_behind() ) {
$self->{perl_version_introduced} =
$variable_look_behind_introduced->{$self->content()}
and return 0;
TOKEN_UNKNOWN->__PPIX_ELEM__rebless( $self,
error => MSG_LOOK_BEHIND_TOO_LONG,
);
return 1;
}
return 0;
}
}
{
my %width = (
'*' => [ 0, INFINITY ],
'+' => [ 1, INFINITY ],
'?' => [ 0, 1 ],
);
sub __quantified_width {
my ( $self, $raw_min, $raw_max ) = @_;
my $info = $width{$self->content()}
or croak sprintf q<Bug - Quantifier '%s' width unknown>,
$self->content();
my ( $my_min, $my_max ) = @{ $info };
defined $raw_min
and $raw_min *= $my_min;
defined $raw_max
and $raw_max *= $my_max;
return ( $raw_min, $raw_max );
}
}
sub __PPIX_TOKENIZER__regexp {
my ( undef, $tokenizer, $character ) = @_;
$tokenizer->prior_significant_token( 'can_be_quantified' )
or return;
return $quantifier{$character};
}
1;
__END__
=head1 SUPPORT
Support is by the author. Please file bug reports at
L<https://rt.cpan.org/Public/Dist/Display.html?Name=PPIx-Regexp>,
L<https://github.com/trwyant/perl-PPIx-Regexp/issues>, or in
electronic mail to the author.
=head1 AUTHOR
Thomas R. Wyant, III F<wyant at cpan dot org>
=head1 COPYRIGHT AND LICENSE
Copyright (C) 2009-2023 by Thomas R. Wyant, III
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl 5.10.0. For more details, see the full text
of the licenses in the directory LICENSES.
This program is distributed in the hope that it will be useful, but
without any warranty; without even the implied warranty of
merchantability or fitness for a particular purpose.
=cut
# ex: set textwidth=72 :
|
