path: root/upstream/mageia-cauldron/man3pm/Pod::Simple::PullParser.3pm

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.\" ========================================================================
.\"
.IX Title "Pod::Simple::PullParser 3pm"
.TH Pod::Simple::PullParser 3pm 2023-11-28 "perl v5.38.2" "Perl Programmers Reference Guide"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
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.nh
.SH NAME
Pod::Simple::PullParser \-\- a pull\-parser interface to parsing Pod
.SH SYNOPSIS
.IX Header "SYNOPSIS"
.Vb 3
\& my $parser = SomePodProcessor\->new;
\& $parser\->set_source( "whatever.pod" );
\& $parser\->run;
.Ve
.PP
Or:
.PP
.Vb 3
\& my $parser = SomePodProcessor\->new;
\& $parser\->set_source( $some_filehandle_object );
\& $parser\->run;
.Ve
.PP
Or:
.PP
.Vb 3
\& my $parser = SomePodProcessor\->new;
\& $parser\->set_source( \e$document_source );
\& $parser\->run;
.Ve
.PP
Or:
.PP
.Vb 3
\& my $parser = SomePodProcessor\->new;
\& $parser\->set_source( \e@document_lines );
\& $parser\->run;
.Ve
.PP
And elsewhere:
.PP
.Vb 4
\& require 5;
\& package SomePodProcessor;
\& use strict;
\& use base qw(Pod::Simple::PullParser);
\&
\& sub run {
\&   my $self = shift;
\&  Token:
\&   while(my $token = $self\->get_token) {
\&     ...process each token...
\&   }
\& }
.Ve
.SH DESCRIPTION
.IX Header "DESCRIPTION"
This class is for using Pod::Simple to build a Pod processor \-\- but
one that uses an interface based on a stream of token objects,
instead of based on events.
.PP
This is a subclass of Pod::Simple and inherits all its methods.
.PP
A subclass of Pod::Simple::PullParser should define a \f(CW\*(C`run\*(C'\fR method
that calls \f(CW\*(C`$token = $parser\->get_token\*(C'\fR to pull tokens.
.PP
See the source for Pod::Simple::RTF for an example of a formatter
that uses Pod::Simple::PullParser.
.SH METHODS
.IX Header "METHODS"
.ie n .IP "my $token = $parser\->get_token" 4
.el .IP "my \f(CW$token\fR = \f(CW$parser\fR\->get_token" 4
.IX Item "my $token = $parser->get_token"
This returns the next token object (which will be of a subclass of
Pod::Simple::PullParserToken), or undef if the parser-stream has hit
the end of the document.
.ie n .IP "$parser\->unget_token( $token )" 4
.el .IP "\f(CW$parser\fR\->unget_token( \f(CW$token\fR )" 4
.IX Item "$parser->unget_token( $token )"
.PD 0
.ie n .IP "$parser\->unget_token( $token1, $token2, ... )" 4
.el .IP "\f(CW$parser\fR\->unget_token( \f(CW$token1\fR, \f(CW$token2\fR, ... )" 4
.IX Item "$parser->unget_token( $token1, $token2, ... )"
.PD
This restores the token object(s) to the front of the parser stream.
.PP
The source has to be set before you can parse anything.  The lowest-level
way is to call \f(CW\*(C`set_source\*(C'\fR:
.ie n .IP "$parser\->set_source( $filename )" 4
.el .IP "\f(CW$parser\fR\->set_source( \f(CW$filename\fR )" 4
.IX Item "$parser->set_source( $filename )"
.PD 0
.ie n .IP "$parser\->set_source( $filehandle_object )" 4
.el .IP "\f(CW$parser\fR\->set_source( \f(CW$filehandle_object\fR )" 4
.IX Item "$parser->set_source( $filehandle_object )"
.ie n .IP "$parser\->set_source( \e$document_source )" 4
.el .IP "\f(CW$parser\fR\->set_source( \e$document_source )" 4
.IX Item "$parser->set_source( $document_source )"
.ie n .IP "$parser\->set_source( \e@document_lines )" 4
.el .IP "\f(CW$parser\fR\->set_source( \e@document_lines )" 4
.IX Item "$parser->set_source( @document_lines )"
.PD
.PP
Or you can call these methods, which Pod::Simple::PullParser has defined
to work just like Pod::Simple's same-named methods:
.ie n .IP $parser\->parse_file(...) 4
.el .IP \f(CW$parser\fR\->parse_file(...) 4
.IX Item "$parser->parse_file(...)"
.PD 0
.ie n .IP $parser\->parse_string_document(...) 4
.el .IP \f(CW$parser\fR\->parse_string_document(...) 4
.IX Item "$parser->parse_string_document(...)"
.ie n .IP $parser\->filter(...) 4
.el .IP \f(CW$parser\fR\->filter(...) 4
.IX Item "$parser->filter(...)"
.ie n .IP $parser\->parse_from_file(...) 4
.el .IP \f(CW$parser\fR\->parse_from_file(...) 4
.IX Item "$parser->parse_from_file(...)"
.PD
.PP
For those to work, the Pod-processing subclass of
Pod::Simple::PullParser has to have defined a \f(CW$parser\fR\->run method \-\-
so it is advised that all Pod::Simple::PullParser subclasses do so.
See the Synopsis above, or the source for Pod::Simple::RTF.
.PP
Authors of formatter subclasses might find these methods useful to
call on a parser object that you haven't started pulling tokens
from yet:
.ie n .IP "my $title_string = $parser\->get_title" 4
.el .IP "my \f(CW$title_string\fR = \f(CW$parser\fR\->get_title" 4
.IX Item "my $title_string = $parser->get_title"
This tries to get the title string out of \f(CW$parser\fR, by getting some tokens,
and scanning them for the title, and then ungetting them so that you can
process the token-stream from the beginning.
.Sp
For example, suppose you have a document that starts out:
.Sp
.Vb 1
\&  =head1 NAME
\&
\&  Hoo::Boy::Wowza \-\- Stuff B<wow> yeah!
.Ve
.Sp
\&\f(CW$parser\fR\->get_title on that document will return "Hoo::Boy::Wowza \-\-
Stuff wow yeah!". If the document starts with:
.Sp
.Vb 1
\&  =head1 Name
\&
\&  Hoo::Boy::W00t \-\- Stuff B<w00t> yeah!
.Ve
.Sp
Then you'll need to pass the \f(CW\*(C`nocase\*(C'\fR option in order to recognize "Name":
.Sp
.Vb 1
\&  $parser\->get_title(nocase => 1);
.Ve
.Sp
In cases where get_title can't find the title, it will return empty-string
("").
.ie n .IP "my $title_string = $parser\->get_short_title" 4
.el .IP "my \f(CW$title_string\fR = \f(CW$parser\fR\->get_short_title" 4
.IX Item "my $title_string = $parser->get_short_title"
This is just like get_title, except that it returns just the modulename, if
the title seems to be of the form "SomeModuleName \-\- description".
.Sp
For example, suppose you have a document that starts out:
.Sp
.Vb 1
\&  =head1 NAME
\&
\&  Hoo::Boy::Wowza \-\- Stuff B<wow> yeah!
.Ve
.Sp
then \f(CW$parser\fR\->get_short_title on that document will return
"Hoo::Boy::Wowza".
.Sp
But if the document starts out:
.Sp
.Vb 1
\&  =head1 NAME
\&
\&  Hooboy, stuff B<wow> yeah!
.Ve
.Sp
then \f(CW$parser\fR\->get_short_title on that document will return "Hooboy,
stuff wow yeah!". If the document starts with:
.Sp
.Vb 1
\&  =head1 Name
\&
\&  Hoo::Boy::W00t \-\- Stuff B<w00t> yeah!
.Ve
.Sp
Then you'll need to pass the \f(CW\*(C`nocase\*(C'\fR option in order to recognize "Name":
.Sp
.Vb 1
\&  $parser\->get_short_title(nocase => 1);
.Ve
.Sp
If the title can't be found, then get_short_title returns empty-string
("").
.ie n .IP "$author_name   = $parser\->get_author" 4
.el .IP "\f(CW$author_name\fR   = \f(CW$parser\fR\->get_author" 4
.IX Item "$author_name = $parser->get_author"
This works like get_title except that it returns the contents of the
"=head1 AUTHOR\en\enParagraph...\en" section, assuming that that section
isn't terribly long. To recognize a "=head1 Author\en\enParagraph\en"
section, pass the \f(CW\*(C`nocase\*(C'\fR option:
.Sp
.Vb 1
\&  $parser\->get_author(nocase => 1);
.Ve
.Sp
(This method tolerates "AUTHORS" instead of "AUTHOR" too.)
.ie n .IP "$description_name = $parser\->get_description" 4
.el .IP "\f(CW$description_name\fR = \f(CW$parser\fR\->get_description" 4
.IX Item "$description_name = $parser->get_description"
This works like get_title except that it returns the contents of the
"=head1 DESCRIPTION\en\enParagraph...\en" section, assuming that that section
isn't terribly long. To recognize a "=head1 Description\en\enParagraph\en"
section, pass the \f(CW\*(C`nocase\*(C'\fR option:
.Sp
.Vb 1
\&  $parser\->get_description(nocase => 1);
.Ve
.ie n .IP "$version_block = $parser\->get_version" 4
.el .IP "\f(CW$version_block\fR = \f(CW$parser\fR\->get_version" 4
.IX Item "$version_block = $parser->get_version"
This works like get_title except that it returns the contents of
the "=head1 VERSION\en\en[BIG BLOCK]\en" block.  Note that this does NOT
return the module's \f(CW$VERSION\fR!! To recognize a
"=head1 Version\en\en[BIG BLOCK]\en" section, pass the \f(CW\*(C`nocase\*(C'\fR option:
.Sp
.Vb 1
\&  $parser\->get_version(nocase => 1);
.Ve
.SH NOTE
.IX Header "NOTE"
You don't actually \fIhave\fR to define a \f(CW\*(C`run\*(C'\fR method.  If you're
writing a Pod-formatter class, you should define a \f(CW\*(C`run\*(C'\fR just so
that users can call \f(CW\*(C`parse_file\*(C'\fR etc, but you don't \fIhave\fR to.
.PP
And if you're not writing a formatter class, but are instead just
writing a program that does something simple with a Pod::PullParser
object (and not an object of a subclass), then there's no reason to
bother subclassing to add a \f(CW\*(C`run\*(C'\fR method.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
Pod::Simple
.PP
Pod::Simple::PullParserToken \-\- and its subclasses
Pod::Simple::PullParserStartToken,
Pod::Simple::PullParserTextToken, and
Pod::Simple::PullParserEndToken.
.PP
HTML::TokeParser, which inspired this.
.SH SUPPORT
.IX Header "SUPPORT"
Questions or discussion about POD and Pod::Simple should be sent to the
pod\-people@perl.org mail list. Send an empty email to
pod\-people\-subscribe@perl.org to subscribe.
.PP
This module is managed in an open GitHub repository,
<https://github.com/perl\-pod/pod\-simple/>. Feel free to fork and contribute, or
to clone <git://github.com/perl\-pod/pod\-simple.git> and send patches!
.PP
Patches against Pod::Simple are welcome. Please send bug reports to
<bug\-pod\-simple@rt.cpan.org>.
.SH "COPYRIGHT AND DISCLAIMERS"
.IX Header "COPYRIGHT AND DISCLAIMERS"
Copyright (c) 2002 Sean M. Burke.
.PP
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
.PP
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.
.SH AUTHOR
.IX Header "AUTHOR"
Pod::Simple was created by Sean M. Burke <sburke@cpan.org>.
But don't bother him, he's retired.
.PP
Pod::Simple is maintained by:
.IP \(bu 4
Allison Randal \f(CW\*(C`allison@perl.org\*(C'\fR
.IP \(bu 4
Hans Dieter Pearcey \f(CW\*(C`hdp@cpan.org\*(C'\fR
.IP \(bu 4
David E. Wheeler \f(CW\*(C`dwheeler@cpan.org\*(C'\fR