Message/Field/Structured.pm


=head1 NAME

Message::Field::Structured Perl module

=head1 DESCRIPTION

Perl module for RFC 822/2822 structured C<field>s.

=cut

package Message::Field::Structured;
require 5.6.0;
use strict;
use re 'eval';
use vars qw(%REG $VERSION);
$VERSION = '1.00';

use overload '""' => sub {shift->stringify};

$REG{comment} = qr/\x28(?:\x5C[\x00-\xFF]|[\x00-\x0C\x0E-\x27\x2A-\x5B\x5D-\xFF]|(??{$REG{comment}}))*\x29/;
$REG{quoted_string} = qr/\x22(?:\x5C[\x00-\xFF]|[\x00-\x0C\x0E-\x21\x23-\x5B\x5D-\xFF])*\x22/;
$REG{domain_literal} = qr/\x5B(?:\x5C[\x00-\xFF]|[\x00-\x0C\x0E-\x5A\x5E-\xFF])*\x5D/;

$REG{WSP} = qr/[\x20\x09]+/;
$REG{FWS} = qr/[\x20\x09]*/;
$REG{M_quoted_string} = qr/\x22((?:\x5C[\x00-\xFF]|[\x00-\x0C\x0E-\x21\x23-\x5B\x5D-\xFF])*)\x22/;
$REG{M_comment} = qr/\x28((?:\x5C[\x00-\xFF]|[\x00-\x0C\x0E-\x27\x2A-\x5B\x5D-\xFF]|(??{$REG{comment}}))*)\x29/;

$REG{NON_atom} = qr/[^\x09\x20\x21\x23-\x27\x2A\x2B\x2D\x2F\x30-\x39\x3D\x3F\x41-\x5A\x5E-\x7E]/;

=head2 Message::Field::Structured->new ()

Return empty Message::Field::Structured object.

=cut

sub new ($;%) {
  bless {}, shift;
}

=head2 Message::Field::Structured->parse ($unfolded_field_body)

Parse structured C<field-body>.

=cut

sub parse ($$;%) {
  my $self = bless {}, shift;
  my $field_body = shift;
  $self->{field_body} = $field_body;
  $self;
}

=head2 $self->stringify ()

Returns C<field-body> as a string.

=cut

sub stringify ($) {
  my $self = shift;
  $self->{field_body};
}

=head2 $self->as_plain_string ()

Returns C<field-body> contents as a plain text fragment.
C<quoted-string> and C<quoted-pair> in C<comment> are
unquoted, so return value of this method can be invalid
as a part of the C<field>.

=cut

sub as_plain_string ($) {
  my $self = shift;
  $self->unquote_quoted_string ($self->unquote_comment ($self->{field_body}));
}

sub quote_unsafe_string ($$) {
  my $self = shift;
  my $string = shift;
  if ($string =~ /$REG{NON_atom}/ || $string =~ /$REG{WSP}$REG{WSP}+/) {
    $string =~ s/([\x22\x5C])/\x5C$1/g;
    $string = '"'.$string.'"';
  }
  $string;
}

=head2 $self->unquote_quoted_string ($string)

Unquote C<quoted-string>.  Get rid of C<DQUOTE>s and
C<REVERSED SOLIDUS> included in C<quoted-pair>.
This method is intended for internal use.

=cut

sub unquote_quoted_string ($$) {
  my $self = shift;
  my $quoted_string = shift;
  $quoted_string =~ s{$REG{M_quoted_string}}{
    my $qtext = $1;
    $qtext =~ s/\x5C([\x00-\xFF])/$1/g;
    $qtext;
  }goex;
  $quoted_string;
}

sub unquote_comment ($$) {
  my $self = shift;
  my $quoted_string = shift;
  $quoted_string =~ s{$REG{M_comment}}{
    my $qtext = $1;
    $qtext =~ s/\x5C([\x00-\xFF])/$1/g;
    '('.$qtext.')';
  }goex;
  $quoted_string;
}

=head2 $self->delete_comment ($field_body)

Remove all C<comment> in given strictured C<field-body>.
This method is intended for internal use.

=cut

sub delete_comment ($$) {
  my $self = shift;
  my $body = shift;
  $body =~ s{($REG{quoted_string}|$REG{domain_literal})|$REG{comment}}{
    my $o = $1;  $o? $o : ' ';
  }gex;
  $body;
}

=head1 EXAMPLE

  use Message::Field::Structured;
  
  my $field_body = '"This is an example of <\"> (quotation mark)."
                    (Comment within \q\u\o\t\e\d\-\p\a\i\r\(\s\))';
  my $field = Message::Field::Structured->parse ($field_body);
  
  print $field->as_plain_string;

=head1 LICENSE

Copyright 2002 wakaba E<lt>w@suika.fam.cxE<gt>.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

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.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.

=head1 CHANGE

See F<ChangeLog>.

=cut

1;
1	wakaba	1.1
2			=head1 NAME
3
4			Message::Field::Structured Perl module
5
6			=head1 DESCRIPTION
7
8			Perl module for RFC 822/2822 structured C<field>s.
9
10			=cut
11
12			package Message::Field::Structured;
13			require 5.6.0;
14			use strict;
15			use re 'eval';
16			use vars qw(%REG $VERSION);
17			$VERSION = '1.00';
18
19			use overload '""' => sub {shift->stringify};
20
21			$REG{comment} = qr/\x28(?:\x5C[\x00-\xFF]\|[\x00-\x0C\x0E-\x27\x2A-\x5B\x5D-\xFF]\|(??{$REG{comment}}))*\x29/;
22			$REG{quoted_string} = qr/\x22(?:\x5C[\x00-\xFF]\|[\x00-\x0C\x0E-\x21\x23-\x5B\x5D-\xFF])*\x22/;
23			$REG{domain_literal} = qr/\x5B(?:\x5C[\x00-\xFF]\|[\x00-\x0C\x0E-\x5A\x5E-\xFF])*\x5D/;
24
25			$REG{WSP} = qr/[\x20\x09]+/;
26			$REG{FWS} = qr/[\x20\x09]*/;
27			$REG{M_quoted_string} = qr/\x22((?:\x5C[\x00-\xFF]\|[\x00-\x0C\x0E-\x21\x23-\x5B\x5D-\xFF])*)\x22/;
28			$REG{M_comment} = qr/\x28((?:\x5C[\x00-\xFF]\|[\x00-\x0C\x0E-\x27\x2A-\x5B\x5D-\xFF]\|(??{$REG{comment}}))*)\x29/;
29
30			$REG{NON_atom} = qr/[^\x09\x20\x21\x23-\x27\x2A\x2B\x2D\x2F\x30-\x39\x3D\x3F\x41-\x5A\x5E-\x7E]/;
31
32			=head2 Message::Field::Structured->new ()
33
34			Return empty Message::Field::Structured object.
35
36			=cut
37
38	wakaba	1.2	sub new ($;%) {
39	wakaba	1.1	bless {}, shift;
40			}
41
42			=head2 Message::Field::Structured->parse ($unfolded_field_body)
43
44			Parse structured C<field-body>.
45
46			=cut
47
48	wakaba	1.2	sub parse ($$;%) {
49	wakaba	1.1	my $self = bless {}, shift;
50			my $field_body = shift;
51			$self->{field_body} = $field_body;
52			$self;
53			}
54
55			=head2 $self->stringify ()
56
57			Returns C<field-body> as a string.
58
59			=cut
60
61			sub stringify ($) {
62			my $self = shift;
63			$self->{field_body};
64			}
65
66			=head2 $self->as_plain_string ()
67
68			Returns C<field-body> contents as a plain text fragment.
69			C<quoted-string> and C<quoted-pair> in C<comment> are
70			unquoted, so return value of this method can be invalid
71			as a part of the C<field>.
72
73			=cut
74
75			sub as_plain_string ($) {
76			my $self = shift;
77			$self->unquote_quoted_string ($self->unquote_comment ($self->{field_body}));
78			}
79
80			sub quote_unsafe_string ($$) {
81			my $self = shift;
82			my $string = shift;
83			if ($string =~ /$REG{NON_atom}/ \|\| $string =~ /$REG{WSP}$REG{WSP}+/) {
84			$string =~ s/([\x22\x5C])/\x5C$1/g;
85			$string = '"'.$string.'"';
86			}
87			$string;
88			}
89
90			=head2 $self->unquote_quoted_string ($string)
91
92			Unquote C<quoted-string>. Get rid of C<DQUOTE>s and
93			C<REVERSED SOLIDUS> included in C<quoted-pair>.
94			This method is intended for internal use.
95
96			=cut
97
98			sub unquote_quoted_string ($$) {
99			my $self = shift;
100			my $quoted_string = shift;
101			$quoted_string =~ s{$REG{M_quoted_string}}{
102			my $qtext = $1;
103			$qtext =~ s/\x5C([\x00-\xFF])/$1/g;
104			$qtext;
105			}goex;
106			$quoted_string;
107			}
108
109			sub unquote_comment ($$) {
110			my $self = shift;
111			my $quoted_string = shift;
112			$quoted_string =~ s{$REG{M_comment}}{
113			my $qtext = $1;
114			$qtext =~ s/\x5C([\x00-\xFF])/$1/g;
115			'('.$qtext.')';
116			}goex;
117			$quoted_string;
118			}
119
120			=head2 $self->delete_comment ($field_body)
121
122			Remove all C<comment> in given strictured C<field-body>.
123			This method is intended for internal use.
124
125			=cut
126
127			sub delete_comment ($$) {
128			my $self = shift;
129			my $body = shift;
130			$body =~ s{($REG{quoted_string}\|$REG{domain_literal})\|$REG{comment}}{
131			my $o = $1; $o? $o : ' ';
132			}gex;
133			$body;
134			}
135
136			=head1 EXAMPLE
137
138			use Message::Field::Structured;
139
140			my $field_body = '"This is an example of <\"> (quotation mark)."
141			(Comment within \q\u\o\t\e\d\-\p\a\i\r\(\s\))';
142			my $field = Message::Field::Structured->parse ($field_body);
143
144			print $field->as_plain_string;
145
146			=head1 LICENSE
147
148			Copyright 2002 wakaba E<lt>w@suika.fam.cxE<gt>.
149
150			This program is free software; you can redistribute it and/or modify
151			it under the terms of the GNU General Public License as published by
152			the Free Software Foundation; either version 2 of the License, or
153			(at your option) any later version.
154
155			This program is distributed in the hope that it will be useful,
156			but WITHOUT ANY WARRANTY; without even the implied warranty of
157			MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
158			GNU General Public License for more details.
159
160			You should have received a copy of the GNU General Public License
161			along with this program; see the file COPYING. If not, write to
162			the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
163			Boston, MA 02111-1307, USA.
164
165			=head1 CHANGE
166
167			See F<ChangeLog>.
168
169			=cut
170
171			1;