Pod/Text/Overstrike.pm

# Pod::Text::Overstrike -- Convert POD data to formatted overstrike text
# $Id: Overstrike.pm,v 1.10 2002/08/04 03:35:01 eagle Exp $
#
# Created by Joe Smith <Joe.Smith@inwap.com> 30-Nov-2000
#   (based on Pod::Text::Color by Russ Allbery <rra@stanford.edu>)
#
# This program is free software; you may redistribute it and/or modify it
# under the same terms as Perl itself.
#
# This was written because the output from:
#
#     pod2text Text.pm > plain.txt; less plain.txt
#
# is not as rich as the output from
#
#     pod2man Text.pm | nroff -man > fancy.txt; less fancy.txt
#
# and because both Pod::Text::Color and Pod::Text::Termcap are not device
# independent.

##############################################################################
# Modules and declarations
##############################################################################

package Pod::Text::Overstrike;

require 5.004;

use Pod::Text ();

use strict;
use vars qw(@ISA $VERSION);

@ISA = qw(Pod::Text);

# Don't use the CVS revision as the version, since this module is also in Perl
# core and too many things could munge CVS magic revision strings.  This
# number should ideally be the same as the CVS revision in podlators, however.
$VERSION = 1.10;


##############################################################################
# Overrides
##############################################################################

# Make level one headings bold, overridding any existing formatting.
sub cmd_head1 {
    my ($self, $text, $line) = @_;
    $text =~ s/\s+$//;
    $text = $self->strip_format ($self->interpolate ($text, $line));
    $text =~ s/(.)/$1\b$1/g;
    $self->SUPER::cmd_head1 ($text);
}

# Make level two headings bold, overriding any existing formatting.
sub cmd_head2 {
    my ($self, $text, $line) = @_;
    $text =~ s/\s+$//;
    $text = $self->strip_format ($self->interpolate ($text, $line));
    $text =~ s/(.)/$1\b$1/g;
    $self->SUPER::cmd_head2 ($text);
}

# Make level three headings underscored, overriding any existing formatting.
sub cmd_head3 {
    my ($self, $text, $line) = @_;
    $text =~ s/\s+$//;
    $text = $self->strip_format ($self->interpolate ($text, $line));
    $text =~ s/(.)/_\b$1/g;
    $self->SUPER::cmd_head3 ($text);
}

# Level four headings look like level three headings.
sub cmd_head4 {
    my ($self, $text, $line) = @_;
    $text =~ s/\s+$//;
    $text = $self->strip_format ($self->interpolate ($text, $line));
    $text =~ s/(.)/_\b$1/g;
    $self->SUPER::cmd_head4 ($text);
}

# The common code for handling all headers.  We have to override to avoid
# interpolating twice and because we don't want to honor alt.
sub heading {
    my ($self, $text, $line, $indent, $marker) = @_;
    $self->item ("\n\n") if defined $$self{ITEM};
    $text .= "\n" if $$self{loose};
    my $margin = ' ' x ($$self{margin} + $indent);
    $self->output ($margin . $text . "\n");
}

# Fix the various formatting codes.
sub seq_b { local $_ = strip_format (@_); s/(.)/$1\b$1/g; $_ }
sub seq_f { local $_ = strip_format (@_); s/(.)/_\b$1/g; $_ }
sub seq_i { local $_ = strip_format (@_); s/(.)/_\b$1/g; $_ }

# Output any included code in bold.
sub output_code {
    my ($self, $code) = @_;
    $code =~ s/(.)/$1\b$1/g;
    $self->output ($code);
}

# We unfortunately have to override the wrapping code here, since the normal
# wrapping code gets really confused by all the backspaces.
sub wrap {
    my $self = shift;
    local $_ = shift;
    my $output = '';
    my $spaces = ' ' x $$self{MARGIN};
    my $width = $$self{width} - $$self{MARGIN};
    while (length > $width) {
        # This regex represents a single character, that's possibly underlined
        # or in bold (in which case, it's three characters; the character, a
        # backspace, and a character).  Use [^\n] rather than . to protect
        # against odd settings of $*.
        my $char = '(?:[^\n][\b])?[^\n]';
        if (s/^((?>$char){0,$width})(?:\Z|\s+)//) {
            $output .= $spaces . $1 . "\n";
        } else {
            last;
        }
    }
    $output .= $spaces . $_;
    $output =~ s/\s+$/\n\n/;
    $output;
}

##############################################################################
# Utility functions
##############################################################################

# Strip all of the formatting from a provided string, returning the stripped
# version.
sub strip_format {
    my ($self, $text) = @_;
    $text =~ s/(.)[\b]\1/$1/g;
    $text =~ s/_[\b]//g;
    return $text;
}

##############################################################################
# Module return value and documentation
##############################################################################

1;
__END__

=head1 NAME

Pod::Text::Overstrike - Convert POD data to formatted overstrike text

=head1 SYNOPSIS

    use Pod::Text::Overstrike;
    my $parser = Pod::Text::Overstrike->new (sentence => 0, width => 78);

    # Read POD from STDIN and write to STDOUT.
    $parser->parse_from_filehandle;

    # Read POD from file.pod and write to file.txt.
    $parser->parse_from_file ('file.pod', 'file.txt');

=head1 DESCRIPTION

Pod::Text::Overstrike is a simple subclass of Pod::Text that highlights
output text using overstrike sequences, in a manner similar to nroff.
Characters in bold text are overstruck (character, backspace, character) and
characters in underlined text are converted to overstruck underscores
(underscore, backspace, character).  This format was originally designed for
hardcopy terminals and/or lineprinters, yet is readable on softcopy (CRT)
terminals.

Overstruck text is best viewed by page-at-a-time programs that take
advantage of the terminal's B<stand-out> and I<underline> capabilities, such
as the less program on Unix.

Apart from the overstrike, it in all ways functions like Pod::Text.  See
L<Pod::Text> for details and available options.

=head1 BUGS

Currently, the outermost formatting instruction wins, so for example
underlined text inside a region of bold text is displayed as simply bold.
There may be some better approach possible.

=head1 SEE ALSO

L<Pod::Text>, L<Pod::Parser>

The current version of this module is always available from its web site at
L<http://www.eyrie.org/~eagle/software/podlators/>.  It is also part of the
Perl core distribution as of 5.6.0.

=head1 AUTHOR

Joe Smith <Joe.Smith@inwap.com>, using the framework created by Russ Allbery
<rra@stanford.edu>.

=head1 COPYRIGHT AND LICENSE

Copyright 2000 by Joe Smith <Joe.Smith@inwap.com>.
Copyright 2001 by Russ Allbery <rra@stanford.edu>.

This program is free software; you may redistribute it and/or modify it
under the same terms as Perl itself.

=cut
Revision:	1.1
Committed:	Thu Jun 30 14:27:15 2005 UTC (21 years, 4 months ago) by root
Branch:	MAIN
CVS Tags:	HEAD
Branch point for:	PERL
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	# Pod::Text::Overstrike -- Convert POD data to formatted overstrike text
2			# $Id: Overstrike.pm,v 1.10 2002/08/04 03:35:01 eagle Exp $
3			#
4			# Created by Joe Smith <Joe.Smith@inwap.com> 30-Nov-2000
5			# (based on Pod::Text::Color by Russ Allbery <rra@stanford.edu>)
6			#
7			# This program is free software; you may redistribute it and/or modify it
8			# under the same terms as Perl itself.
9			#
10			# This was written because the output from:
11			#
12			# pod2text Text.pm > plain.txt; less plain.txt
13			#
14			# is not as rich as the output from
15			#
16			# pod2man Text.pm \| nroff -man > fancy.txt; less fancy.txt
17			#
18			# and because both Pod::Text::Color and Pod::Text::Termcap are not device
19			# independent.
20
21			##############################################################################
22			# Modules and declarations
23			##############################################################################
24
25			package Pod::Text::Overstrike;
26
27			require 5.004;
28
29			use Pod::Text ();
30
31			use strict;
32			use vars qw(@ISA $VERSION);
33
34			@ISA = qw(Pod::Text);
35
36			# Don't use the CVS revision as the version, since this module is also in Perl
37			# core and too many things could munge CVS magic revision strings. This
38			# number should ideally be the same as the CVS revision in podlators, however.
39			$VERSION = 1.10;
40
41
42			##############################################################################
43			# Overrides
44			##############################################################################
45
46			# Make level one headings bold, overridding any existing formatting.
47			sub cmd_head1 {
48			my ($self, $text, $line) = @_;
49			$text =~ s/\s+$//;
50			$text = $self->strip_format ($self->interpolate ($text, $line));
51			$text =~ s/(.)/$1\b$1/g;
52			$self->SUPER::cmd_head1 ($text);
53			}
54
55			# Make level two headings bold, overriding any existing formatting.
56			sub cmd_head2 {
57			my ($self, $text, $line) = @_;
58			$text =~ s/\s+$//;
59			$text = $self->strip_format ($self->interpolate ($text, $line));
60			$text =~ s/(.)/$1\b$1/g;
61			$self->SUPER::cmd_head2 ($text);
62			}
63
64			# Make level three headings underscored, overriding any existing formatting.
65			sub cmd_head3 {
66			my ($self, $text, $line) = @_;
67			$text =~ s/\s+$//;
68			$text = $self->strip_format ($self->interpolate ($text, $line));
69			$text =~ s/(.)/_\b$1/g;
70			$self->SUPER::cmd_head3 ($text);
71			}
72
73			# Level four headings look like level three headings.
74			sub cmd_head4 {
75			my ($self, $text, $line) = @_;
76			$text =~ s/\s+$//;
77			$text = $self->strip_format ($self->interpolate ($text, $line));
78			$text =~ s/(.)/_\b$1/g;
79			$self->SUPER::cmd_head4 ($text);
80			}
81
82			# The common code for handling all headers. We have to override to avoid
83			# interpolating twice and because we don't want to honor alt.
84			sub heading {
85			my ($self, $text, $line, $indent, $marker) = @_;
86			$self->item ("\n\n") if defined $$self{ITEM};
87			$text .= "\n" if $$self{loose};
88			my $margin = ' ' x ($$self{margin} + $indent);
89			$self->output ($margin . $text . "\n");
90			}
91
92			# Fix the various formatting codes.
93			sub seq_b { local $_ = strip_format (@_); s/(.)/$1\b$1/g; $_ }
94			sub seq_f { local $_ = strip_format (@_); s/(.)/_\b$1/g; $_ }
95			sub seq_i { local $_ = strip_format (@_); s/(.)/_\b$1/g; $_ }
96
97			# Output any included code in bold.
98			sub output_code {
99			my ($self, $code) = @_;
100			$code =~ s/(.)/$1\b$1/g;
101			$self->output ($code);
102			}
103
104			# We unfortunately have to override the wrapping code here, since the normal
105			# wrapping code gets really confused by all the backspaces.
106			sub wrap {
107			my $self = shift;
108			local $_ = shift;
109			my $output = '';
110			my $spaces = ' ' x $$self{MARGIN};
111			my $width = $$self{width} - $$self{MARGIN};
112			while (length > $width) {
113			# This regex represents a single character, that's possibly underlined
114			# or in bold (in which case, it's three characters; the character, a
115			# backspace, and a character). Use [^\n] rather than . to protect
116			# against odd settings of $*.
117			my $char = '(?:[^\n][\b])?[^\n]';
118			if (s/^((?>$char){0,$width})(?:\Z\|\s+)//) {
119			$output .= $spaces . $1 . "\n";
120			} else {
121			last;
122			}
123			}
124			$output .= $spaces . $_;
125			$output =~ s/\s+$/\n\n/;
126			$output;
127			}
128
129			##############################################################################
130			# Utility functions
131			##############################################################################
132
133			# Strip all of the formatting from a provided string, returning the stripped
134			# version.
135			sub strip_format {
136			my ($self, $text) = @_;
137			$text =~ s/(.)[\b]\1/$1/g;
138			$text =~ s/_[\b]//g;
139			return $text;
140			}
141
142			##############################################################################
143			# Module return value and documentation
144			##############################################################################
145
146			1;
147			__END__
148
149			=head1 NAME
150
151			Pod::Text::Overstrike - Convert POD data to formatted overstrike text
152
153			=head1 SYNOPSIS
154
155			use Pod::Text::Overstrike;
156			my $parser = Pod::Text::Overstrike->new (sentence => 0, width => 78);
157
158			# Read POD from STDIN and write to STDOUT.
159			$parser->parse_from_filehandle;
160
161			# Read POD from file.pod and write to file.txt.
162			$parser->parse_from_file ('file.pod', 'file.txt');
163
164			=head1 DESCRIPTION
165
166			Pod::Text::Overstrike is a simple subclass of Pod::Text that highlights
167			output text using overstrike sequences, in a manner similar to nroff.
168			Characters in bold text are overstruck (character, backspace, character) and
169			characters in underlined text are converted to overstruck underscores
170			(underscore, backspace, character). This format was originally designed for
171			hardcopy terminals and/or lineprinters, yet is readable on softcopy (CRT)
172			terminals.
173
174			Overstruck text is best viewed by page-at-a-time programs that take
175			advantage of the terminal's B<stand-out> and I<underline> capabilities, such
176			as the less program on Unix.
177
178			Apart from the overstrike, it in all ways functions like Pod::Text. See
179			L<Pod::Text> for details and available options.
180
181			=head1 BUGS
182
183			Currently, the outermost formatting instruction wins, so for example
184			underlined text inside a region of bold text is displayed as simply bold.
185			There may be some better approach possible.
186
187			=head1 SEE ALSO
188
189			L<Pod::Text>, L<Pod::Parser>
190
191			The current version of this module is always available from its web site at
192			L<http://www.eyrie.org/~eagle/software/podlators/>. It is also part of the
193			Perl core distribution as of 5.6.0.
194
195			=head1 AUTHOR
196
197			Joe Smith <Joe.Smith@inwap.com>, using the framework created by Russ Allbery
198			<rra@stanford.edu>.
199
200			=head1 COPYRIGHT AND LICENSE
201
202			Copyright 2000 by Joe Smith <Joe.Smith@inwap.com>.
203			Copyright 2001 by Russ Allbery <rra@stanford.edu>.
204
205			This program is free software; you may redistribute it and/or modify it
206			under the same terms as Perl itself.
207
208			=cut