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/Perl 5.26

Pod::Simple::PullParser

NAME

Pod::Simple::PullParser -- a pull-parser interface to parsing Pod

SYNOPSIS

my $parser = SomePodProcessor->new;
$parser->set_source( "whatever.pod" );
$parser->run;

Or:

my $parser = SomePodProcessor->new;
$parser->set_source( $some_filehandle_object );
$parser->run;

Or:

my $parser = SomePodProcessor->new;
$parser->set_source( \$document_source );
$parser->run;

Or:

my $parser = SomePodProcessor->new;
$parser->set_source( \@document_lines );
$parser->run;

And elsewhere:

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...
  }
}

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.

This is a subclass of Pod::Simple and inherits all its methods.

A subclass of Pod::Simple::PullParser should define a run method that calls $token = $parser->get_token to pull tokens.

See the source for Pod::Simple::RTF for an example of a formatter that uses Pod::Simple::PullParser.

METHODS

  • 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.

  • $parser->unget_token( $token )
  • $parser->unget_token( $token1, $token2, ... )

    This restores the token object(s) to the front of the parser stream.

The source has to be set before you can parse anything. The lowest-level way is to call set_source :

  • $parser->set_source( $filename )
  • $parser->set_source( $filehandle_object )
  • $parser->set_source( \$document_source )
  • $parser->set_source( \@document_lines )

Or you can call these methods, which Pod::Simple::PullParser has defined to work just like Pod::Simple's same-named methods:

  • $parser->parse_file(...)
  • $parser->parse_string_document(...)
  • $parser->filter(...)
  • $parser->parse_from_file(...)

For those to work, the Pod-processing subclass of Pod::Simple::PullParser has to have defined a $parser->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.

Authors of formatter subclasses might find these methods useful to call on a parser object that you haven't started pulling tokens from yet:

  • my $title_string = $parser->get_title

    This tries to get the title string out of $parser, 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.

    For example, suppose you have a document that starts out:

    =head1 NAME
    
    Hoo::Boy::Wowza -- Stuff B<wow> yeah!
    

    $parser->get_title on that document will return "Hoo::Boy::Wowza -- Stuff wow yeah!". If the document starts with:

    =head1 Name
    
    Hoo::Boy::W00t -- Stuff B<w00t> yeah!
    

    Then you'll need to pass the nocase option in order to recognize "Name":

    $parser->get_title(nocase => 1);
    

    In cases where get_title can't find the title, it will return empty-string ("").

  • 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".

    For example, suppose you have a document that starts out:

    =head1 NAME
    
    Hoo::Boy::Wowza -- Stuff B<wow> yeah!
    

    then $parser->get_short_title on that document will return "Hoo::Boy::Wowza".

    But if the document starts out:

    =head1 NAME
    
    Hooboy, stuff B<wow> yeah!
    

    then $parser->get_short_title on that document will return "Hooboy, stuff wow yeah!". If the document starts with:

    =head1 Name
    
    Hoo::Boy::W00t -- Stuff B<w00t> yeah!
    

    Then you'll need to pass the nocase option in order to recognize "Name":

    $parser->get_short_title(nocase => 1);
    

    If the title can't be found, then get_short_title returns empty-string ("").

  • $author_name = $parser->get_author

    This works like get_title except that it returns the contents of the "=head1 AUTHOR\n\nParagraph...\n" section, assuming that that section isn't terribly long. To recognize a "=head1 Author\n\nParagraph\n" section, pass the nocase option:

    $parser->get_author(nocase => 1);
    

    (This method tolerates "AUTHORS" instead of "AUTHOR" too.)

  • $description_name = $parser->get_description

    This works like get_title except that it returns the contents of the "=head1 DESCRIPTION\n\nParagraph...\n" section, assuming that that section isn't terribly long. To recognize a "=head1 Description\n\nParagraph\n" section, pass the nocase option:

    $parser->get_description(nocase => 1);
    
  • $version_block = $parser->get_version

    This works like get_title except that it returns the contents of the "=head1 VERSION\n\n[BIG BLOCK]\n" block. Note that this does NOT return the module's $VERSION !! To recognize a "=head1 Version\n\n[BIG BLOCK]\n" section, pass the nocase option:

    $parser->get_version(nocase => 1);
    

NOTE

You don't actually have to define a run method. If you're writing a Pod-formatter class, you should define a run just so that users can call parse_file etc, but you don't have to.

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 run method.

SEE ALSO

Pod::Simple

Pod::Simple::PullParserToken -- and its subclasses Pod::Simple::PullParserStartToken, Pod::Simple::PullParserTextToken, and Pod::Simple::PullParserEndToken.

HTML::TokeParser, which inspired this.

SUPPORT

Questions or discussion about POD and Pod::Simple should be sent to the [email protected] mail list. Send an empty email to [email protected] to subscribe.

This module is managed in an open GitHub repository, https://github.com/theory/pod-simple/. Feel free to fork and contribute, or to clone git://github.com/theory/pod-simple.git and send patches!

Patches against Pod::Simple are welcome. Please send bug reports to <[email protected]>.

Copyright (c) 2002 Sean M. Burke.

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

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.

AUTHOR

Pod::Simple was created by Sean M. Burke <[email protected]>. But don't bother him, he's retired.

Pod::Simple is maintained by:

  • Allison Randal allison@perl.org
  • Hans Dieter Pearcey hdp@cpan.org
  • David E. Wheeler dwheeler@cpan.org

© 1993–2016 Larry Wall and others
Licensed under the GNU General Public License version 1 or later, or the Artistic License.
The Perl logo is a trademark of the Perl Foundation.
https://perldoc.perl.org/5.26.0/Pod/Simple/PullParser.html