1772 lines
62 KiB
Perl
1772 lines
62 KiB
Perl
#############################################################################
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# Pod/Parser.pm -- package which defines a base class for parsing POD docs.
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#
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# Copyright (C) 1996-2000 by Bradford Appleton. All rights reserved.
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# This file is part of "PodParser". PodParser is free software;
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# you can redistribute it and/or modify it under the same terms
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# as Perl itself.
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#############################################################################
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package Pod::Parser;
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use vars qw($VERSION);
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$VERSION = 1.12; ## Current version of this package
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require 5.005; ## requires this Perl version or later
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#############################################################################
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=head1 NAME
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Pod::Parser - base class for creating POD filters and translators
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=head1 SYNOPSIS
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use Pod::Parser;
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package MyParser;
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@ISA = qw(Pod::Parser);
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sub command {
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my ($parser, $command, $paragraph, $line_num) = @_;
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## Interpret the command and its text; sample actions might be:
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if ($command eq 'head1') { ... }
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elsif ($command eq 'head2') { ... }
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## ... other commands and their actions
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my $out_fh = $parser->output_handle();
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my $expansion = $parser->interpolate($paragraph, $line_num);
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print $out_fh $expansion;
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}
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sub verbatim {
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my ($parser, $paragraph, $line_num) = @_;
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## Format verbatim paragraph; sample actions might be:
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my $out_fh = $parser->output_handle();
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print $out_fh $paragraph;
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}
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sub textblock {
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my ($parser, $paragraph, $line_num) = @_;
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## Translate/Format this block of text; sample actions might be:
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my $out_fh = $parser->output_handle();
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my $expansion = $parser->interpolate($paragraph, $line_num);
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print $out_fh $expansion;
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}
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sub interior_sequence {
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my ($parser, $seq_command, $seq_argument) = @_;
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## Expand an interior sequence; sample actions might be:
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return "*$seq_argument*" if ($seq_command eq 'B');
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return "`$seq_argument'" if ($seq_command eq 'C');
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return "_${seq_argument}_'" if ($seq_command eq 'I');
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## ... other sequence commands and their resulting text
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}
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package main;
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## Create a parser object and have it parse file whose name was
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## given on the command-line (use STDIN if no files were given).
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$parser = new MyParser();
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$parser->parse_from_filehandle(\*STDIN) if (@ARGV == 0);
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for (@ARGV) { $parser->parse_from_file($_); }
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=head1 REQUIRES
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perl5.005, Pod::InputObjects, Exporter, Symbol, Carp
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=head1 EXPORTS
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Nothing.
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=head1 DESCRIPTION
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B<Pod::Parser> is a base class for creating POD filters and translators.
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It handles most of the effort involved with parsing the POD sections
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from an input stream, leaving subclasses free to be concerned only with
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performing the actual translation of text.
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B<Pod::Parser> parses PODs, and makes method calls to handle the various
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components of the POD. Subclasses of B<Pod::Parser> override these methods
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to translate the POD into whatever output format they desire.
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=head1 QUICK OVERVIEW
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To create a POD filter for translating POD documentation into some other
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format, you create a subclass of B<Pod::Parser> which typically overrides
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just the base class implementation for the following methods:
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=over 2
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=item *
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B<command()>
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=item *
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B<verbatim()>
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=item *
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B<textblock()>
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=item *
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B<interior_sequence()>
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=back
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You may also want to override the B<begin_input()> and B<end_input()>
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methods for your subclass (to perform any needed per-file and/or
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per-document initialization or cleanup).
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If you need to perform any preprocesssing of input before it is parsed
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you may want to override one or more of B<preprocess_line()> and/or
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B<preprocess_paragraph()>.
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Sometimes it may be necessary to make more than one pass over the input
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files. If this is the case you have several options. You can make the
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first pass using B<Pod::Parser> and override your methods to store the
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intermediate results in memory somewhere for the B<end_pod()> method to
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process. You could use B<Pod::Parser> for several passes with an
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appropriate state variable to control the operation for each pass. If
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your input source can't be reset to start at the beginning, you can
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store it in some other structure as a string or an array and have that
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structure implement a B<getline()> method (which is all that
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B<parse_from_filehandle()> uses to read input).
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Feel free to add any member data fields you need to keep track of things
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like current font, indentation, horizontal or vertical position, or
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whatever else you like. Be sure to read L<"PRIVATE METHODS AND DATA">
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to avoid name collisions.
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For the most part, the B<Pod::Parser> base class should be able to
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do most of the input parsing for you and leave you free to worry about
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how to intepret the commands and translate the result.
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Note that all we have described here in this quick overview is the
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simplest most straightforward use of B<Pod::Parser> to do stream-based
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parsing. It is also possible to use the B<Pod::Parser::parse_text> function
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to do more sophisticated tree-based parsing. See L<"TREE-BASED PARSING">.
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=head1 PARSING OPTIONS
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A I<parse-option> is simply a named option of B<Pod::Parser> with a
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value that corresponds to a certain specified behavior. These various
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behaviors of B<Pod::Parser> may be enabled/disabled by setting or
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or unsetting one or more I<parse-options> using the B<parseopts()> method.
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The set of currently accepted parse-options is as follows:
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=over 3
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=item B<-want_nonPODs> (default: unset)
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Normally (by default) B<Pod::Parser> will only provide access to
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the POD sections of the input. Input paragraphs that are not part
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of the POD-format documentation are not made available to the caller
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(not even using B<preprocess_paragraph()>). Setting this option to a
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non-empty, non-zero value will allow B<preprocess_paragraph()> to see
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non-POD sections of the input as well as POD sections. The B<cutting()>
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method can be used to determine if the corresponding paragraph is a POD
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paragraph, or some other input paragraph.
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=item B<-process_cut_cmd> (default: unset)
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Normally (by default) B<Pod::Parser> handles the C<=cut> POD directive
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by itself and does not pass it on to the caller for processing. Setting
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this option to a non-empty, non-zero value will cause B<Pod::Parser> to
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pass the C<=cut> directive to the caller just like any other POD command
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(and hence it may be processed by the B<command()> method).
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B<Pod::Parser> will still interpret the C<=cut> directive to mean that
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"cutting mode" has been (re)entered, but the caller will get a chance
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to capture the actual C<=cut> paragraph itself for whatever purpose
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it desires.
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=item B<-warnings> (default: unset)
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Normally (by default) B<Pod::Parser> recognizes a bare minimum of
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pod syntax errors and warnings and issues diagnostic messages
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for errors, but not for warnings. (Use B<Pod::Checker> to do more
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thorough checking of POD syntax.) Setting this option to a non-empty,
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non-zero value will cause B<Pod::Parser> to issue diagnostics for
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the few warnings it recognizes as well as the errors.
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=back
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Please see L<"parseopts()"> for a complete description of the interface
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for the setting and unsetting of parse-options.
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=cut
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#############################################################################
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use vars qw(@ISA);
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use strict;
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#use diagnostics;
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use Pod::InputObjects;
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use Carp;
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use Exporter;
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require VMS::Filespec if $^O eq 'VMS';
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BEGIN {
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if ($] < 5.6) {
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require Symbol;
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import Symbol;
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}
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}
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@ISA = qw(Exporter);
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## These "variables" are used as local "glob aliases" for performance
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use vars qw(%myData %myOpts @input_stack);
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#############################################################################
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=head1 RECOMMENDED SUBROUTINE/METHOD OVERRIDES
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B<Pod::Parser> provides several methods which most subclasses will probably
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want to override. These methods are as follows:
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=cut
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##---------------------------------------------------------------------------
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=head1 B<command()>
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$parser->command($cmd,$text,$line_num,$pod_para);
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This method should be overridden by subclasses to take the appropriate
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action when a POD command paragraph (denoted by a line beginning with
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"=") is encountered. When such a POD directive is seen in the input,
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this method is called and is passed:
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=over 3
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=item C<$cmd>
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the name of the command for this POD paragraph
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=item C<$text>
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the paragraph text for the given POD paragraph command.
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=item C<$line_num>
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the line-number of the beginning of the paragraph
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=item C<$pod_para>
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a reference to a C<Pod::Paragraph> object which contains further
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information about the paragraph command (see L<Pod::InputObjects>
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for details).
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=back
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B<Note> that this method I<is> called for C<=pod> paragraphs.
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The base class implementation of this method simply treats the raw POD
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command as normal block of paragraph text (invoking the B<textblock()>
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method with the command paragraph).
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=cut
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sub command {
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my ($self, $cmd, $text, $line_num, $pod_para) = @_;
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## Just treat this like a textblock
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$self->textblock($pod_para->raw_text(), $line_num, $pod_para);
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}
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##---------------------------------------------------------------------------
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=head1 B<verbatim()>
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$parser->verbatim($text,$line_num,$pod_para);
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This method may be overridden by subclasses to take the appropriate
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action when a block of verbatim text is encountered. It is passed the
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following parameters:
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=over 3
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=item C<$text>
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the block of text for the verbatim paragraph
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=item C<$line_num>
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the line-number of the beginning of the paragraph
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=item C<$pod_para>
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a reference to a C<Pod::Paragraph> object which contains further
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information about the paragraph (see L<Pod::InputObjects>
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for details).
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=back
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The base class implementation of this method simply prints the textblock
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(unmodified) to the output filehandle.
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=cut
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sub verbatim {
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my ($self, $text, $line_num, $pod_para) = @_;
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my $out_fh = $self->{_OUTPUT};
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print $out_fh $text;
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}
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##---------------------------------------------------------------------------
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=head1 B<textblock()>
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$parser->textblock($text,$line_num,$pod_para);
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This method may be overridden by subclasses to take the appropriate
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action when a normal block of POD text is encountered (although the base
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class method will usually do what you want). It is passed the following
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parameters:
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=over 3
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=item C<$text>
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the block of text for the a POD paragraph
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=item C<$line_num>
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the line-number of the beginning of the paragraph
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=item C<$pod_para>
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a reference to a C<Pod::Paragraph> object which contains further
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information about the paragraph (see L<Pod::InputObjects>
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for details).
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=back
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In order to process interior sequences, subclasses implementations of
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this method will probably want to invoke either B<interpolate()> or
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B<parse_text()>, passing it the text block C<$text>, and the corresponding
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line number in C<$line_num>, and then perform any desired processing upon
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the returned result.
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The base class implementation of this method simply prints the text block
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as it occurred in the input stream).
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=cut
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sub textblock {
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my ($self, $text, $line_num, $pod_para) = @_;
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my $out_fh = $self->{_OUTPUT};
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print $out_fh $self->interpolate($text, $line_num);
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}
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##---------------------------------------------------------------------------
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=head1 B<interior_sequence()>
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$parser->interior_sequence($seq_cmd,$seq_arg,$pod_seq);
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This method should be overridden by subclasses to take the appropriate
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action when an interior sequence is encountered. An interior sequence is
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an embedded command within a block of text which appears as a command
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name (usually a single uppercase character) followed immediately by a
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string of text which is enclosed in angle brackets. This method is
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passed the sequence command C<$seq_cmd> and the corresponding text
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C<$seq_arg>. It is invoked by the B<interpolate()> method for each interior
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sequence that occurs in the string that it is passed. It should return
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the desired text string to be used in place of the interior sequence.
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The C<$pod_seq> argument is a reference to a C<Pod::InteriorSequence>
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object which contains further information about the interior sequence.
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Please see L<Pod::InputObjects> for details if you need to access this
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additional information.
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Subclass implementations of this method may wish to invoke the
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B<nested()> method of C<$pod_seq> to see if it is nested inside
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some other interior-sequence (and if so, which kind).
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The base class implementation of the B<interior_sequence()> method
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simply returns the raw text of the interior sequence (as it occurred
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in the input) to the caller.
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=cut
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sub interior_sequence {
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my ($self, $seq_cmd, $seq_arg, $pod_seq) = @_;
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## Just return the raw text of the interior sequence
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return $pod_seq->raw_text();
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}
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#############################################################################
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=head1 OPTIONAL SUBROUTINE/METHOD OVERRIDES
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B<Pod::Parser> provides several methods which subclasses may want to override
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to perform any special pre/post-processing. These methods do I<not> have to
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be overridden, but it may be useful for subclasses to take advantage of them.
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=cut
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##---------------------------------------------------------------------------
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=head1 B<new()>
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my $parser = Pod::Parser->new();
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This is the constructor for B<Pod::Parser> and its subclasses. You
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I<do not> need to override this method! It is capable of constructing
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subclass objects as well as base class objects, provided you use
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any of the following constructor invocation styles:
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my $parser1 = MyParser->new();
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my $parser2 = new MyParser();
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my $parser3 = $parser2->new();
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where C<MyParser> is some subclass of B<Pod::Parser>.
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Using the syntax C<MyParser::new()> to invoke the constructor is I<not>
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recommended, but if you insist on being able to do this, then the
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subclass I<will> need to override the B<new()> constructor method. If
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you do override the constructor, you I<must> be sure to invoke the
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B<initialize()> method of the newly blessed object.
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Using any of the above invocations, the first argument to the
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constructor is always the corresponding package name (or object
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reference). No other arguments are required, but if desired, an
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associative array (or hash-table) my be passed to the B<new()>
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constructor, as in:
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my $parser1 = MyParser->new( MYDATA => $value1, MOREDATA => $value2 );
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my $parser2 = new MyParser( -myflag => 1 );
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All arguments passed to the B<new()> constructor will be treated as
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key/value pairs in a hash-table. The newly constructed object will be
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initialized by copying the contents of the given hash-table (which may
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have been empty). The B<new()> constructor for this class and all of its
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subclasses returns a blessed reference to the initialized object (hash-table).
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=cut
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sub new {
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## Determine if we were called via an object-ref or a classname
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my $this = shift;
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my $class = ref($this) || $this;
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## Any remaining arguments are treated as initial values for the
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## hash that is used to represent this object.
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my %params = @_;
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my $self = { %params };
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## Bless ourselves into the desired class and perform any initialization
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bless $self, $class;
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$self->initialize();
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return $self;
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}
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##---------------------------------------------------------------------------
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=head1 B<initialize()>
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$parser->initialize();
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This method performs any necessary object initialization. It takes no
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arguments (other than the object instance of course, which is typically
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copied to a local variable named C<$self>). If subclasses override this
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method then they I<must> be sure to invoke C<$self-E<gt>SUPER::initialize()>.
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=cut
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sub initialize {
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#my $self = shift;
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#return;
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}
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##---------------------------------------------------------------------------
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=head1 B<begin_pod()>
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$parser->begin_pod();
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This method is invoked at the beginning of processing for each POD
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document that is encountered in the input. Subclasses should override
|
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this method to perform any per-document initialization.
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=cut
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sub begin_pod {
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#my $self = shift;
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#return;
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}
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##---------------------------------------------------------------------------
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=head1 B<begin_input()>
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$parser->begin_input();
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This method is invoked by B<parse_from_filehandle()> immediately I<before>
|
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processing input from a filehandle. The base class implementation does
|
|
nothing, however, subclasses may override it to perform any per-file
|
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initializations.
|
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Note that if multiple files are parsed for a single POD document
|
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(perhaps the result of some future C<=include> directive) this method
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is invoked for every file that is parsed. If you wish to perform certain
|
|
initializations once per document, then you should use B<begin_pod()>.
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=cut
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sub begin_input {
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#my $self = shift;
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#return;
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}
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##---------------------------------------------------------------------------
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=head1 B<end_input()>
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$parser->end_input();
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This method is invoked by B<parse_from_filehandle()> immediately I<after>
|
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processing input from a filehandle. The base class implementation does
|
|
nothing, however, subclasses may override it to perform any per-file
|
|
cleanup actions.
|
|
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|
Please note that if multiple files are parsed for a single POD document
|
|
(perhaps the result of some kind of C<=include> directive) this method
|
|
is invoked for every file that is parsed. If you wish to perform certain
|
|
cleanup actions once per document, then you should use B<end_pod()>.
|
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=cut
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sub end_input {
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#my $self = shift;
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#return;
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}
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##---------------------------------------------------------------------------
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=head1 B<end_pod()>
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$parser->end_pod();
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|
|
This method is invoked at the end of processing for each POD document
|
|
that is encountered in the input. Subclasses should override this method
|
|
to perform any per-document finalization.
|
|
|
|
=cut
|
|
|
|
sub end_pod {
|
|
#my $self = shift;
|
|
#return;
|
|
}
|
|
|
|
##---------------------------------------------------------------------------
|
|
|
|
=head1 B<preprocess_line()>
|
|
|
|
$textline = $parser->preprocess_line($text, $line_num);
|
|
|
|
This method should be overridden by subclasses that wish to perform
|
|
any kind of preprocessing for each I<line> of input (I<before> it has
|
|
been determined whether or not it is part of a POD paragraph). The
|
|
parameter C<$text> is the input line; and the parameter C<$line_num> is
|
|
the line number of the corresponding text line.
|
|
|
|
The value returned should correspond to the new text to use in its
|
|
place. If the empty string or an undefined value is returned then no
|
|
further processing will be performed for this line.
|
|
|
|
Please note that the B<preprocess_line()> method is invoked I<before>
|
|
the B<preprocess_paragraph()> method. After all (possibly preprocessed)
|
|
lines in a paragraph have been assembled together and it has been
|
|
determined that the paragraph is part of the POD documentation from one
|
|
of the selected sections, then B<preprocess_paragraph()> is invoked.
|
|
|
|
The base class implementation of this method returns the given text.
|
|
|
|
=cut
|
|
|
|
sub preprocess_line {
|
|
my ($self, $text, $line_num) = @_;
|
|
return $text;
|
|
}
|
|
|
|
##---------------------------------------------------------------------------
|
|
|
|
=head1 B<preprocess_paragraph()>
|
|
|
|
$textblock = $parser->preprocess_paragraph($text, $line_num);
|
|
|
|
This method should be overridden by subclasses that wish to perform any
|
|
kind of preprocessing for each block (paragraph) of POD documentation
|
|
that appears in the input stream. The parameter C<$text> is the POD
|
|
paragraph from the input file; and the parameter C<$line_num> is the
|
|
line number for the beginning of the corresponding paragraph.
|
|
|
|
The value returned should correspond to the new text to use in its
|
|
place If the empty string is returned or an undefined value is
|
|
returned, then the given C<$text> is ignored (not processed).
|
|
|
|
This method is invoked after gathering up all the lines in a paragraph
|
|
and after determining the cutting state of the paragraph,
|
|
but before trying to further parse or interpret them. After
|
|
B<preprocess_paragraph()> returns, the current cutting state (which
|
|
is returned by C<$self-E<gt>cutting()>) is examined. If it evaluates
|
|
to true then input text (including the given C<$text>) is cut (not
|
|
processed) until the next POD directive is encountered.
|
|
|
|
Please note that the B<preprocess_line()> method is invoked I<before>
|
|
the B<preprocess_paragraph()> method. After all (possibly preprocessed)
|
|
lines in a paragraph have been assembled together and either it has been
|
|
determined that the paragraph is part of the POD documentation from one
|
|
of the selected sections or the C<-want_nonPODs> option is true,
|
|
then B<preprocess_paragraph()> is invoked.
|
|
|
|
The base class implementation of this method returns the given text.
|
|
|
|
=cut
|
|
|
|
sub preprocess_paragraph {
|
|
my ($self, $text, $line_num) = @_;
|
|
return $text;
|
|
}
|
|
|
|
#############################################################################
|
|
|
|
=head1 METHODS FOR PARSING AND PROCESSING
|
|
|
|
B<Pod::Parser> provides several methods to process input text. These
|
|
methods typically won't need to be overridden (and in some cases they
|
|
can't be overridden), but subclasses may want to invoke them to exploit
|
|
their functionality.
|
|
|
|
=cut
|
|
|
|
##---------------------------------------------------------------------------
|
|
|
|
=head1 B<parse_text()>
|
|
|
|
$ptree1 = $parser->parse_text($text, $line_num);
|
|
$ptree2 = $parser->parse_text({%opts}, $text, $line_num);
|
|
$ptree3 = $parser->parse_text(\%opts, $text, $line_num);
|
|
|
|
This method is useful if you need to perform your own interpolation
|
|
of interior sequences and can't rely upon B<interpolate> to expand
|
|
them in simple bottom-up order order.
|
|
|
|
The parameter C<$text> is a string or block of text to be parsed
|
|
for interior sequences; and the parameter C<$line_num> is the
|
|
line number curresponding to the beginning of C<$text>.
|
|
|
|
B<parse_text()> will parse the given text into a parse-tree of "nodes."
|
|
and interior-sequences. Each "node" in the parse tree is either a
|
|
text-string, or a B<Pod::InteriorSequence>. The result returned is a
|
|
parse-tree of type B<Pod::ParseTree>. Please see L<Pod::InputObjects>
|
|
for more information about B<Pod::InteriorSequence> and B<Pod::ParseTree>.
|
|
|
|
If desired, an optional hash-ref may be specified as the first argument
|
|
to customize certain aspects of the parse-tree that is created and
|
|
returned. The set of recognized option keywords are:
|
|
|
|
=over 3
|
|
|
|
=item B<-expand_seq> =E<gt> I<code-ref>|I<method-name>
|
|
|
|
Normally, the parse-tree returned by B<parse_text()> will contain an
|
|
unexpanded C<Pod::InteriorSequence> object for each interior-sequence
|
|
encountered. Specifying B<-expand_seq> tells B<parse_text()> to "expand"
|
|
every interior-sequence it sees by invoking the referenced function
|
|
(or named method of the parser object) and using the return value as the
|
|
expanded result.
|
|
|
|
If a subroutine reference was given, it is invoked as:
|
|
|
|
&$code_ref( $parser, $sequence )
|
|
|
|
and if a method-name was given, it is invoked as:
|
|
|
|
$parser->method_name( $sequence )
|
|
|
|
where C<$parser> is a reference to the parser object, and C<$sequence>
|
|
is a reference to the interior-sequence object.
|
|
[I<NOTE>: If the B<interior_sequence()> method is specified, then it is
|
|
invoked according to the interface specified in L<"interior_sequence()">].
|
|
|
|
=item B<-expand_text> =E<gt> I<code-ref>|I<method-name>
|
|
|
|
Normally, the parse-tree returned by B<parse_text()> will contain a
|
|
text-string for each contiguous sequence of characters outside of an
|
|
interior-sequence. Specifying B<-expand_text> tells B<parse_text()> to
|
|
"preprocess" every such text-string it sees by invoking the referenced
|
|
function (or named method of the parser object) and using the return value
|
|
as the preprocessed (or "expanded") result. [Note that if the result is
|
|
an interior-sequence, then it will I<not> be expanded as specified by the
|
|
B<-expand_seq> option; Any such recursive expansion needs to be handled by
|
|
the specified callback routine.]
|
|
|
|
If a subroutine reference was given, it is invoked as:
|
|
|
|
&$code_ref( $parser, $text, $ptree_node )
|
|
|
|
and if a method-name was given, it is invoked as:
|
|
|
|
$parser->method_name( $text, $ptree_node )
|
|
|
|
where C<$parser> is a reference to the parser object, C<$text> is the
|
|
text-string encountered, and C<$ptree_node> is a reference to the current
|
|
node in the parse-tree (usually an interior-sequence object or else the
|
|
top-level node of the parse-tree).
|
|
|
|
=item B<-expand_ptree> =E<gt> I<code-ref>|I<method-name>
|
|
|
|
Rather than returning a C<Pod::ParseTree>, pass the parse-tree as an
|
|
argument to the referenced subroutine (or named method of the parser
|
|
object) and return the result instead of the parse-tree object.
|
|
|
|
If a subroutine reference was given, it is invoked as:
|
|
|
|
&$code_ref( $parser, $ptree )
|
|
|
|
and if a method-name was given, it is invoked as:
|
|
|
|
$parser->method_name( $ptree )
|
|
|
|
where C<$parser> is a reference to the parser object, and C<$ptree>
|
|
is a reference to the parse-tree object.
|
|
|
|
=back
|
|
|
|
=cut
|
|
|
|
sub parse_text {
|
|
my $self = shift;
|
|
local $_ = '';
|
|
|
|
## Get options and set any defaults
|
|
my %opts = (ref $_[0]) ? %{ shift() } : ();
|
|
my $expand_seq = $opts{'-expand_seq'} || undef;
|
|
my $expand_text = $opts{'-expand_text'} || undef;
|
|
my $expand_ptree = $opts{'-expand_ptree'} || undef;
|
|
|
|
my $text = shift;
|
|
my $line = shift;
|
|
my $file = $self->input_file();
|
|
my $cmd = "";
|
|
|
|
## Convert method calls into closures, for our convenience
|
|
my $xseq_sub = $expand_seq;
|
|
my $xtext_sub = $expand_text;
|
|
my $xptree_sub = $expand_ptree;
|
|
if (defined $expand_seq and $expand_seq eq 'interior_sequence') {
|
|
## If 'interior_sequence' is the method to use, we have to pass
|
|
## more than just the sequence object, we also need to pass the
|
|
## sequence name and text.
|
|
$xseq_sub = sub {
|
|
my ($self, $iseq) = @_;
|
|
my $args = join("", $iseq->parse_tree->children);
|
|
return $self->interior_sequence($iseq->name, $args, $iseq);
|
|
};
|
|
}
|
|
ref $xseq_sub or $xseq_sub = sub { shift()->$expand_seq(@_) };
|
|
ref $xtext_sub or $xtext_sub = sub { shift()->$expand_text(@_) };
|
|
ref $xptree_sub or $xptree_sub = sub { shift()->$expand_ptree(@_) };
|
|
|
|
## Keep track of the "current" interior sequence, and maintain a stack
|
|
## of "in progress" sequences.
|
|
##
|
|
## NOTE that we push our own "accumulator" at the very beginning of the
|
|
## stack. It's really a parse-tree, not a sequence; but it implements
|
|
## the methods we need so we can use it to gather-up all the sequences
|
|
## and strings we parse. Thus, by the end of our parsing, it should be
|
|
## the only thing left on our stack and all we have to do is return it!
|
|
##
|
|
my $seq = Pod::ParseTree->new();
|
|
my @seq_stack = ($seq);
|
|
my ($ldelim, $rdelim) = ('', '');
|
|
|
|
## Iterate over all sequence starts text (NOTE: split with
|
|
## capturing parens keeps the delimiters)
|
|
$_ = $text;
|
|
my @tokens = split /([A-Z]<(?:<+\s+)?)/;
|
|
while ( @tokens ) {
|
|
$_ = shift @tokens;
|
|
## Look for the beginning of a sequence
|
|
if ( /^([A-Z])(<(?:<+\s+)?)$/ ) {
|
|
## Push a new sequence onto the stack of those "in-progress"
|
|
($cmd, $ldelim) = ($1, $2);
|
|
$seq = Pod::InteriorSequence->new(
|
|
-name => $cmd,
|
|
-ldelim => $ldelim, -rdelim => '',
|
|
-file => $file, -line => $line
|
|
);
|
|
$ldelim =~ s/\s+$//, ($rdelim = $ldelim) =~ tr/</>/;
|
|
(@seq_stack > 1) and $seq->nested($seq_stack[-1]);
|
|
push @seq_stack, $seq;
|
|
}
|
|
## Look for sequence ending
|
|
elsif ( @seq_stack > 1 ) {
|
|
## Make sure we match the right kind of closing delimiter
|
|
my ($seq_end, $post_seq) = ("", "");
|
|
if ( ($ldelim eq '<' and /\A(.*?)(>)/s)
|
|
or /\A(.*?)(\s+$rdelim)/s )
|
|
{
|
|
## Found end-of-sequence, capture the interior and the
|
|
## closing the delimiter, and put the rest back on the
|
|
## token-list
|
|
$post_seq = substr($_, length($1) + length($2));
|
|
($_, $seq_end) = ($1, $2);
|
|
(length $post_seq) and unshift @tokens, $post_seq;
|
|
}
|
|
if (length) {
|
|
## In the middle of a sequence, append this text to it, and
|
|
## dont forget to "expand" it if that's what the caller wanted
|
|
$seq->append($expand_text ? &$xtext_sub($self,$_,$seq) : $_);
|
|
$_ .= $seq_end;
|
|
}
|
|
if (length $seq_end) {
|
|
## End of current sequence, record terminating delimiter
|
|
$seq->rdelim($seq_end);
|
|
## Pop it off the stack of "in progress" sequences
|
|
pop @seq_stack;
|
|
## Append result to its parent in current parse tree
|
|
$seq_stack[-1]->append($expand_seq ? &$xseq_sub($self,$seq)
|
|
: $seq);
|
|
## Remember the current cmd-name and left-delimiter
|
|
$cmd = (@seq_stack > 1) ? $seq_stack[-1]->name : '';
|
|
$ldelim = (@seq_stack > 1) ? $seq_stack[-1]->ldelim : '';
|
|
$ldelim =~ s/\s+$//, ($rdelim = $ldelim) =~ tr/</>/;
|
|
}
|
|
}
|
|
elsif (length) {
|
|
## In the middle of a sequence, append this text to it, and
|
|
## dont forget to "expand" it if that's what the caller wanted
|
|
$seq->append($expand_text ? &$xtext_sub($self,$_,$seq) : $_);
|
|
}
|
|
## Keep track of line count
|
|
$line += tr/\n//;
|
|
## Remember the "current" sequence
|
|
$seq = $seq_stack[-1];
|
|
}
|
|
|
|
## Handle unterminated sequences
|
|
my $errorsub = (@seq_stack > 1) ? $self->errorsub() : undef;
|
|
while (@seq_stack > 1) {
|
|
($cmd, $file, $line) = ($seq->name, $seq->file_line);
|
|
$file = VMS::Filespec::unixify($file) if $^O eq 'VMS';
|
|
$ldelim = $seq->ldelim;
|
|
($rdelim = $ldelim) =~ tr/</>/;
|
|
$rdelim =~ s/^(\S+)(\s*)$/$2$1/;
|
|
pop @seq_stack;
|
|
my $errmsg = "*** ERROR: unterminated ${cmd}${ldelim}...${rdelim}".
|
|
" at line $line in file $file\n";
|
|
(ref $errorsub) and &{$errorsub}($errmsg)
|
|
or (defined $errorsub) and $self->$errorsub($errmsg)
|
|
or warn($errmsg);
|
|
$seq_stack[-1]->append($expand_seq ? &$xseq_sub($self,$seq) : $seq);
|
|
$seq = $seq_stack[-1];
|
|
}
|
|
|
|
## Return the resulting parse-tree
|
|
my $ptree = (pop @seq_stack)->parse_tree;
|
|
return $expand_ptree ? &$xptree_sub($self, $ptree) : $ptree;
|
|
}
|
|
|
|
##---------------------------------------------------------------------------
|
|
|
|
=head1 B<interpolate()>
|
|
|
|
$textblock = $parser->interpolate($text, $line_num);
|
|
|
|
This method translates all text (including any embedded interior sequences)
|
|
in the given text string C<$text> and returns the interpolated result. The
|
|
parameter C<$line_num> is the line number corresponding to the beginning
|
|
of C<$text>.
|
|
|
|
B<interpolate()> merely invokes a private method to recursively expand
|
|
nested interior sequences in bottom-up order (innermost sequences are
|
|
expanded first). If there is a need to expand nested sequences in
|
|
some alternate order, use B<parse_text> instead.
|
|
|
|
=cut
|
|
|
|
sub interpolate {
|
|
my($self, $text, $line_num) = @_;
|
|
my %parse_opts = ( -expand_seq => 'interior_sequence' );
|
|
my $ptree = $self->parse_text( \%parse_opts, $text, $line_num );
|
|
return join "", $ptree->children();
|
|
}
|
|
|
|
##---------------------------------------------------------------------------
|
|
|
|
=begin __PRIVATE__
|
|
|
|
=head1 B<parse_paragraph()>
|
|
|
|
$parser->parse_paragraph($text, $line_num);
|
|
|
|
This method takes the text of a POD paragraph to be processed, along
|
|
with its corresponding line number, and invokes the appropriate method
|
|
(one of B<command()>, B<verbatim()>, or B<textblock()>).
|
|
|
|
For performance reasons, this method is invoked directly without any
|
|
dynamic lookup; Hence subclasses may I<not> override it!
|
|
|
|
=end __PRIVATE__
|
|
|
|
=cut
|
|
|
|
sub parse_paragraph {
|
|
my ($self, $text, $line_num) = @_;
|
|
local *myData = $self; ## alias to avoid deref-ing overhead
|
|
local *myOpts = ($myData{_PARSEOPTS} ||= {}); ## get parse-options
|
|
local $_;
|
|
|
|
## See if we want to preprocess nonPOD paragraphs as well as POD ones.
|
|
my $wantNonPods = $myOpts{'-want_nonPODs'};
|
|
|
|
## Update cutting status
|
|
$myData{_CUTTING} = 0 if $text =~ /^={1,2}\S/;
|
|
|
|
## Perform any desired preprocessing if we wanted it this early
|
|
$wantNonPods and $text = $self->preprocess_paragraph($text, $line_num);
|
|
|
|
## Ignore up until next POD directive if we are cutting
|
|
return if $myData{_CUTTING};
|
|
|
|
## Now we know this is block of text in a POD section!
|
|
|
|
##-----------------------------------------------------------------
|
|
## This is a hook (hack ;-) for Pod::Select to do its thing without
|
|
## having to override methods, but also without Pod::Parser assuming
|
|
## $self is an instance of Pod::Select (if the _SELECTED_SECTIONS
|
|
## field exists then we assume there is an is_selected() method for
|
|
## us to invoke (calling $self->can('is_selected') could verify this
|
|
## but that is more overhead than I want to incur)
|
|
##-----------------------------------------------------------------
|
|
|
|
## Ignore this block if it isnt in one of the selected sections
|
|
if (exists $myData{_SELECTED_SECTIONS}) {
|
|
$self->is_selected($text) or return ($myData{_CUTTING} = 1);
|
|
}
|
|
|
|
## If we havent already, perform any desired preprocessing and
|
|
## then re-check the "cutting" state
|
|
unless ($wantNonPods) {
|
|
$text = $self->preprocess_paragraph($text, $line_num);
|
|
return 1 unless ((defined $text) and (length $text));
|
|
return 1 if ($myData{_CUTTING});
|
|
}
|
|
|
|
## Look for one of the three types of paragraphs
|
|
my ($pfx, $cmd, $arg, $sep) = ('', '', '', '');
|
|
my $pod_para = undef;
|
|
if ($text =~ /^(={1,2})(?=\S)/) {
|
|
## Looks like a command paragraph. Capture the command prefix used
|
|
## ("=" or "=="), as well as the command-name, its paragraph text,
|
|
## and whatever sequence of characters was used to separate them
|
|
$pfx = $1;
|
|
$_ = substr($text, length $pfx);
|
|
($cmd, $sep, $text) = split /(\s+)/, $_, 2;
|
|
## If this is a "cut" directive then we dont need to do anything
|
|
## except return to "cutting" mode.
|
|
if ($cmd eq 'cut') {
|
|
$myData{_CUTTING} = 1;
|
|
return unless $myOpts{'-process_cut_cmd'};
|
|
}
|
|
}
|
|
## Save the attributes indicating how the command was specified.
|
|
$pod_para = new Pod::Paragraph(
|
|
-name => $cmd,
|
|
-text => $text,
|
|
-prefix => $pfx,
|
|
-separator => $sep,
|
|
-file => $myData{_INFILE},
|
|
-line => $line_num
|
|
);
|
|
# ## Invoke appropriate callbacks
|
|
# if (exists $myData{_CALLBACKS}) {
|
|
# ## Look through the callback list, invoke callbacks,
|
|
# ## then see if we need to do the default actions
|
|
# ## (invoke_callbacks will return true if we do).
|
|
# return 1 unless $self->invoke_callbacks($cmd, $text, $line_num, $pod_para);
|
|
# }
|
|
if (length $cmd) {
|
|
## A command paragraph
|
|
$self->command($cmd, $text, $line_num, $pod_para);
|
|
}
|
|
elsif ($text =~ /^\s+/) {
|
|
## Indented text - must be a verbatim paragraph
|
|
$self->verbatim($text, $line_num, $pod_para);
|
|
}
|
|
else {
|
|
## Looks like an ordinary block of text
|
|
$self->textblock($text, $line_num, $pod_para);
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
##---------------------------------------------------------------------------
|
|
|
|
=head1 B<parse_from_filehandle()>
|
|
|
|
$parser->parse_from_filehandle($in_fh,$out_fh);
|
|
|
|
This method takes an input filehandle (which is assumed to already be
|
|
opened for reading) and reads the entire input stream looking for blocks
|
|
(paragraphs) of POD documentation to be processed. If no first argument
|
|
is given the default input filehandle C<STDIN> is used.
|
|
|
|
The C<$in_fh> parameter may be any object that provides a B<getline()>
|
|
method to retrieve a single line of input text (hence, an appropriate
|
|
wrapper object could be used to parse PODs from a single string or an
|
|
array of strings).
|
|
|
|
Using C<$in_fh-E<gt>getline()>, input is read line-by-line and assembled
|
|
into paragraphs or "blocks" (which are separated by lines containing
|
|
nothing but whitespace). For each block of POD documentation
|
|
encountered it will invoke a method to parse the given paragraph.
|
|
|
|
If a second argument is given then it should correspond to a filehandle where
|
|
output should be sent (otherwise the default output filehandle is
|
|
C<STDOUT> if no output filehandle is currently in use).
|
|
|
|
B<NOTE:> For performance reasons, this method caches the input stream at
|
|
the top of the stack in a local variable. Any attempts by clients to
|
|
change the stack contents during processing when in the midst executing
|
|
of this method I<will not affect> the input stream used by the current
|
|
invocation of this method.
|
|
|
|
This method does I<not> usually need to be overridden by subclasses.
|
|
|
|
=cut
|
|
|
|
sub parse_from_filehandle {
|
|
my $self = shift;
|
|
my %opts = (ref $_[0] eq 'HASH') ? %{ shift() } : ();
|
|
my ($in_fh, $out_fh) = @_;
|
|
$in_fh = \*STDIN unless ($in_fh);
|
|
local *myData = $self; ## alias to avoid deref-ing overhead
|
|
local *myOpts = ($myData{_PARSEOPTS} ||= {}); ## get parse-options
|
|
local $_;
|
|
|
|
## Put this stream at the top of the stack and do beginning-of-input
|
|
## processing. NOTE that $in_fh might be reset during this process.
|
|
my $topstream = $self->_push_input_stream($in_fh, $out_fh);
|
|
(exists $opts{-cutting}) and $self->cutting( $opts{-cutting} );
|
|
|
|
## Initialize line/paragraph
|
|
my ($textline, $paragraph) = ('', '');
|
|
my ($nlines, $plines) = (0, 0);
|
|
|
|
## Use <$fh> instead of $fh->getline where possible (for speed)
|
|
$_ = ref $in_fh;
|
|
my $tied_fh = (/^(?:GLOB|FileHandle|IO::\w+)$/ or tied $in_fh);
|
|
|
|
## Read paragraphs line-by-line
|
|
while (defined ($textline = $tied_fh ? <$in_fh> : $in_fh->getline)) {
|
|
$textline = $self->preprocess_line($textline, ++$nlines);
|
|
next unless ((defined $textline) && (length $textline));
|
|
$_ = $paragraph; ## save previous contents
|
|
|
|
if ((! length $paragraph) && ($textline =~ /^==/)) {
|
|
## '==' denotes a one-line command paragraph
|
|
$paragraph = $textline;
|
|
$plines = 1;
|
|
$textline = '';
|
|
} else {
|
|
## Append this line to the current paragraph
|
|
$paragraph .= $textline;
|
|
++$plines;
|
|
}
|
|
|
|
## See if this line is blank and ends the current paragraph.
|
|
## If it isnt, then keep iterating until it is.
|
|
next unless (($textline =~ /^([^\S\r\n]*)[\r\n]*$/)
|
|
&& (length $paragraph));
|
|
|
|
## Issue a warning about any non-empty blank lines
|
|
if (length($1) > 1 and $myOpts{'-warnings'} and ! $myData{_CUTTING}) {
|
|
my $errorsub = $self->errorsub();
|
|
my $file = $self->input_file();
|
|
$file = VMS::Filespec::unixify($file) if $^O eq 'VMS';
|
|
my $errmsg = "*** WARNING: line containing nothing but whitespace".
|
|
" in paragraph at line $nlines in file $file\n";
|
|
(ref $errorsub) and &{$errorsub}($errmsg)
|
|
or (defined $errorsub) and $self->$errorsub($errmsg)
|
|
or warn($errmsg);
|
|
}
|
|
|
|
## Now process the paragraph
|
|
parse_paragraph($self, $paragraph, ($nlines - $plines) + 1);
|
|
$paragraph = '';
|
|
$plines = 0;
|
|
}
|
|
## Dont forget about the last paragraph in the file
|
|
if (length $paragraph) {
|
|
parse_paragraph($self, $paragraph, ($nlines - $plines) + 1)
|
|
}
|
|
|
|
## Now pop the input stream off the top of the input stack.
|
|
$self->_pop_input_stream();
|
|
}
|
|
|
|
##---------------------------------------------------------------------------
|
|
|
|
=head1 B<parse_from_file()>
|
|
|
|
$parser->parse_from_file($filename,$outfile);
|
|
|
|
This method takes a filename and does the following:
|
|
|
|
=over 2
|
|
|
|
=item *
|
|
|
|
opens the input and output files for reading
|
|
(creating the appropriate filehandles)
|
|
|
|
=item *
|
|
|
|
invokes the B<parse_from_filehandle()> method passing it the
|
|
corresponding input and output filehandles.
|
|
|
|
=item *
|
|
|
|
closes the input and output files.
|
|
|
|
=back
|
|
|
|
If the special input filename "-" or "<&STDIN" is given then the STDIN
|
|
filehandle is used for input (and no open or close is performed). If no
|
|
input filename is specified then "-" is implied.
|
|
|
|
If a second argument is given then it should be the name of the desired
|
|
output file. If the special output filename "-" or ">&STDOUT" is given
|
|
then the STDOUT filehandle is used for output (and no open or close is
|
|
performed). If the special output filename ">&STDERR" is given then the
|
|
STDERR filehandle is used for output (and no open or close is
|
|
performed). If no output filehandle is currently in use and no output
|
|
filename is specified, then "-" is implied.
|
|
|
|
This method does I<not> usually need to be overridden by subclasses.
|
|
|
|
=cut
|
|
|
|
sub parse_from_file {
|
|
my $self = shift;
|
|
my %opts = (ref $_[0] eq 'HASH') ? %{ shift() } : ();
|
|
my ($infile, $outfile) = @_;
|
|
my ($in_fh, $out_fh) = (gensym, gensym) if ($] < 5.6);
|
|
my ($close_input, $close_output) = (0, 0);
|
|
local *myData = $self;
|
|
local $_;
|
|
|
|
## Is $infile a filename or a (possibly implied) filehandle
|
|
$infile = '-' unless ((defined $infile) && (length $infile));
|
|
if (($infile eq '-') || ($infile =~ /^<&(STDIN|0)$/i)) {
|
|
## Not a filename, just a string implying STDIN
|
|
$myData{_INFILE} = "<standard input>";
|
|
$in_fh = \*STDIN;
|
|
}
|
|
elsif (ref $infile) {
|
|
## Must be a filehandle-ref (or else assume its a ref to an object
|
|
## that supports the common IO read operations).
|
|
$myData{_INFILE} = ${$infile};
|
|
$in_fh = $infile;
|
|
}
|
|
else {
|
|
## We have a filename, open it for reading
|
|
$myData{_INFILE} = $infile;
|
|
open($in_fh, "< $infile") or
|
|
croak "Can't open $infile for reading: $!\n";
|
|
$close_input = 1;
|
|
}
|
|
|
|
## NOTE: we need to be *very* careful when "defaulting" the output
|
|
## file. We only want to use a default if this is the beginning of
|
|
## the entire document (but *not* if this is an included file). We
|
|
## determine this by seeing if the input stream stack has been set-up
|
|
## already
|
|
##
|
|
unless ((defined $outfile) && (length $outfile)) {
|
|
(defined $myData{_TOP_STREAM}) && ($out_fh = $myData{_OUTPUT})
|
|
|| ($outfile = '-');
|
|
}
|
|
## Is $outfile a filename or a (possibly implied) filehandle
|
|
if ((defined $outfile) && (length $outfile)) {
|
|
if (($outfile eq '-') || ($outfile =~ /^>&?(?:STDOUT|1)$/i)) {
|
|
## Not a filename, just a string implying STDOUT
|
|
$myData{_OUTFILE} = "<standard output>";
|
|
$out_fh = \*STDOUT;
|
|
}
|
|
elsif ($outfile =~ /^>&(STDERR|2)$/i) {
|
|
## Not a filename, just a string implying STDERR
|
|
$myData{_OUTFILE} = "<standard error>";
|
|
$out_fh = \*STDERR;
|
|
}
|
|
elsif (ref $outfile) {
|
|
## Must be a filehandle-ref (or else assume its a ref to an
|
|
## object that supports the common IO write operations).
|
|
$myData{_OUTFILE} = ${$outfile};
|
|
$out_fh = $outfile;
|
|
}
|
|
else {
|
|
## We have a filename, open it for writing
|
|
$myData{_OUTFILE} = $outfile;
|
|
(-d $outfile) and croak "$outfile is a directory, not POD input!\n";
|
|
open($out_fh, "> $outfile") or
|
|
croak "Can't open $outfile for writing: $!\n";
|
|
$close_output = 1;
|
|
}
|
|
}
|
|
|
|
## Whew! That was a lot of work to set up reasonably/robust behavior
|
|
## in the case of a non-filename for reading and writing. Now we just
|
|
## have to parse the input and close the handles when we're finished.
|
|
$self->parse_from_filehandle(\%opts, $in_fh, $out_fh);
|
|
|
|
$close_input and
|
|
close($in_fh) || croak "Can't close $infile after reading: $!\n";
|
|
$close_output and
|
|
close($out_fh) || croak "Can't close $outfile after writing: $!\n";
|
|
}
|
|
|
|
#############################################################################
|
|
|
|
=head1 ACCESSOR METHODS
|
|
|
|
Clients of B<Pod::Parser> should use the following methods to access
|
|
instance data fields:
|
|
|
|
=cut
|
|
|
|
##---------------------------------------------------------------------------
|
|
|
|
=head1 B<errorsub()>
|
|
|
|
$parser->errorsub("method_name");
|
|
$parser->errorsub(\&warn_user);
|
|
$parser->errorsub(sub { print STDERR, @_ });
|
|
|
|
Specifies the method or subroutine to use when printing error messages
|
|
about POD syntax. The supplied method/subroutine I<must> return TRUE upon
|
|
successful printing of the message. If C<undef> is given, then the B<warn>
|
|
builtin is used to issue error messages (this is the default behavior).
|
|
|
|
my $errorsub = $parser->errorsub()
|
|
my $errmsg = "This is an error message!\n"
|
|
(ref $errorsub) and &{$errorsub}($errmsg)
|
|
or (defined $errorsub) and $parser->$errorsub($errmsg)
|
|
or warn($errmsg);
|
|
|
|
Returns a method name, or else a reference to the user-supplied subroutine
|
|
used to print error messages. Returns C<undef> if the B<warn> builtin
|
|
is used to issue error messages (this is the default behavior).
|
|
|
|
=cut
|
|
|
|
sub errorsub {
|
|
return (@_ > 1) ? ($_[0]->{_ERRORSUB} = $_[1]) : $_[0]->{_ERRORSUB};
|
|
}
|
|
|
|
##---------------------------------------------------------------------------
|
|
|
|
=head1 B<cutting()>
|
|
|
|
$boolean = $parser->cutting();
|
|
|
|
Returns the current C<cutting> state: a boolean-valued scalar which
|
|
evaluates to true if text from the input file is currently being "cut"
|
|
(meaning it is I<not> considered part of the POD document).
|
|
|
|
$parser->cutting($boolean);
|
|
|
|
Sets the current C<cutting> state to the given value and returns the
|
|
result.
|
|
|
|
=cut
|
|
|
|
sub cutting {
|
|
return (@_ > 1) ? ($_[0]->{_CUTTING} = $_[1]) : $_[0]->{_CUTTING};
|
|
}
|
|
|
|
##---------------------------------------------------------------------------
|
|
|
|
##---------------------------------------------------------------------------
|
|
|
|
=head1 B<parseopts()>
|
|
|
|
When invoked with no additional arguments, B<parseopts> returns a hashtable
|
|
of all the current parsing options.
|
|
|
|
## See if we are parsing non-POD sections as well as POD ones
|
|
my %opts = $parser->parseopts();
|
|
$opts{'-want_nonPODs}' and print "-want_nonPODs\n";
|
|
|
|
When invoked using a single string, B<parseopts> treats the string as the
|
|
name of a parse-option and returns its corresponding value if it exists
|
|
(returns C<undef> if it doesn't).
|
|
|
|
## Did we ask to see '=cut' paragraphs?
|
|
my $want_cut = $parser->parseopts('-process_cut_cmd');
|
|
$want_cut and print "-process_cut_cmd\n";
|
|
|
|
When invoked with multiple arguments, B<parseopts> treats them as
|
|
key/value pairs and the specified parse-option names are set to the
|
|
given values. Any unspecified parse-options are unaffected.
|
|
|
|
## Set them back to the default
|
|
$parser->parseopts(-warnings => 0);
|
|
|
|
When passed a single hash-ref, B<parseopts> uses that hash to completely
|
|
reset the existing parse-options, all previous parse-option values
|
|
are lost.
|
|
|
|
## Reset all options to default
|
|
$parser->parseopts( { } );
|
|
|
|
See L<"PARSING OPTIONS"> for more information on the name and meaning of each
|
|
parse-option currently recognized.
|
|
|
|
=cut
|
|
|
|
sub parseopts {
|
|
local *myData = shift;
|
|
local *myOpts = ($myData{_PARSEOPTS} ||= {});
|
|
return %myOpts if (@_ == 0);
|
|
if (@_ == 1) {
|
|
local $_ = shift;
|
|
return ref($_) ? $myData{_PARSEOPTS} = $_ : $myOpts{$_};
|
|
}
|
|
my @newOpts = (%myOpts, @_);
|
|
$myData{_PARSEOPTS} = { @newOpts };
|
|
}
|
|
|
|
##---------------------------------------------------------------------------
|
|
|
|
=head1 B<output_file()>
|
|
|
|
$fname = $parser->output_file();
|
|
|
|
Returns the name of the output file being written.
|
|
|
|
=cut
|
|
|
|
sub output_file {
|
|
return $_[0]->{_OUTFILE};
|
|
}
|
|
|
|
##---------------------------------------------------------------------------
|
|
|
|
=head1 B<output_handle()>
|
|
|
|
$fhandle = $parser->output_handle();
|
|
|
|
Returns the output filehandle object.
|
|
|
|
=cut
|
|
|
|
sub output_handle {
|
|
return $_[0]->{_OUTPUT};
|
|
}
|
|
|
|
##---------------------------------------------------------------------------
|
|
|
|
=head1 B<input_file()>
|
|
|
|
$fname = $parser->input_file();
|
|
|
|
Returns the name of the input file being read.
|
|
|
|
=cut
|
|
|
|
sub input_file {
|
|
return $_[0]->{_INFILE};
|
|
}
|
|
|
|
##---------------------------------------------------------------------------
|
|
|
|
=head1 B<input_handle()>
|
|
|
|
$fhandle = $parser->input_handle();
|
|
|
|
Returns the current input filehandle object.
|
|
|
|
=cut
|
|
|
|
sub input_handle {
|
|
return $_[0]->{_INPUT};
|
|
}
|
|
|
|
##---------------------------------------------------------------------------
|
|
|
|
=begin __PRIVATE__
|
|
|
|
=head1 B<input_streams()>
|
|
|
|
$listref = $parser->input_streams();
|
|
|
|
Returns a reference to an array which corresponds to the stack of all
|
|
the input streams that are currently in the middle of being parsed.
|
|
|
|
While parsing an input stream, it is possible to invoke
|
|
B<parse_from_file()> or B<parse_from_filehandle()> to parse a new input
|
|
stream and then return to parsing the previous input stream. Each input
|
|
stream to be parsed is pushed onto the end of this input stack
|
|
before any of its input is read. The input stream that is currently
|
|
being parsed is always at the end (or top) of the input stack. When an
|
|
input stream has been exhausted, it is popped off the end of the
|
|
input stack.
|
|
|
|
Each element on this input stack is a reference to C<Pod::InputSource>
|
|
object. Please see L<Pod::InputObjects> for more details.
|
|
|
|
This method might be invoked when printing diagnostic messages, for example,
|
|
to obtain the name and line number of the all input files that are currently
|
|
being processed.
|
|
|
|
=end __PRIVATE__
|
|
|
|
=cut
|
|
|
|
sub input_streams {
|
|
return $_[0]->{_INPUT_STREAMS};
|
|
}
|
|
|
|
##---------------------------------------------------------------------------
|
|
|
|
=begin __PRIVATE__
|
|
|
|
=head1 B<top_stream()>
|
|
|
|
$hashref = $parser->top_stream();
|
|
|
|
Returns a reference to the hash-table that represents the element
|
|
that is currently at the top (end) of the input stream stack
|
|
(see L<"input_streams()">). The return value will be the C<undef>
|
|
if the input stack is empty.
|
|
|
|
This method might be used when printing diagnostic messages, for example,
|
|
to obtain the name and line number of the current input file.
|
|
|
|
=end __PRIVATE__
|
|
|
|
=cut
|
|
|
|
sub top_stream {
|
|
return $_[0]->{_TOP_STREAM} || undef;
|
|
}
|
|
|
|
#############################################################################
|
|
|
|
=head1 PRIVATE METHODS AND DATA
|
|
|
|
B<Pod::Parser> makes use of several internal methods and data fields
|
|
which clients should not need to see or use. For the sake of avoiding
|
|
name collisions for client data and methods, these methods and fields
|
|
are briefly discussed here. Determined hackers may obtain further
|
|
information about them by reading the B<Pod::Parser> source code.
|
|
|
|
Private data fields are stored in the hash-object whose reference is
|
|
returned by the B<new()> constructor for this class. The names of all
|
|
private methods and data-fields used by B<Pod::Parser> begin with a
|
|
prefix of "_" and match the regular expression C</^_\w+$/>.
|
|
|
|
=cut
|
|
|
|
##---------------------------------------------------------------------------
|
|
|
|
=begin _PRIVATE_
|
|
|
|
=head1 B<_push_input_stream()>
|
|
|
|
$hashref = $parser->_push_input_stream($in_fh,$out_fh);
|
|
|
|
This method will push the given input stream on the input stack and
|
|
perform any necessary beginning-of-document or beginning-of-file
|
|
processing. The argument C<$in_fh> is the input stream filehandle to
|
|
push, and C<$out_fh> is the corresponding output filehandle to use (if
|
|
it is not given or is undefined, then the current output stream is used,
|
|
which defaults to standard output if it doesnt exist yet).
|
|
|
|
The value returned will be reference to the hash-table that represents
|
|
the new top of the input stream stack. I<Please Note> that it is
|
|
possible for this method to use default values for the input and output
|
|
file handles. If this happens, you will need to look at the C<INPUT>
|
|
and C<OUTPUT> instance data members to determine their new values.
|
|
|
|
=end _PRIVATE_
|
|
|
|
=cut
|
|
|
|
sub _push_input_stream {
|
|
my ($self, $in_fh, $out_fh) = @_;
|
|
local *myData = $self;
|
|
|
|
## Initialize stuff for the entire document if this is *not*
|
|
## an included file.
|
|
##
|
|
## NOTE: we need to be *very* careful when "defaulting" the output
|
|
## filehandle. We only want to use a default value if this is the
|
|
## beginning of the entire document (but *not* if this is an included
|
|
## file).
|
|
unless (defined $myData{_TOP_STREAM}) {
|
|
$out_fh = \*STDOUT unless (defined $out_fh);
|
|
$myData{_CUTTING} = 1; ## current "cutting" state
|
|
$myData{_INPUT_STREAMS} = []; ## stack of all input streams
|
|
}
|
|
|
|
## Initialize input indicators
|
|
$myData{_OUTFILE} = '(unknown)' unless (defined $myData{_OUTFILE});
|
|
$myData{_OUTPUT} = $out_fh if (defined $out_fh);
|
|
$in_fh = \*STDIN unless (defined $in_fh);
|
|
$myData{_INFILE} = '(unknown)' unless (defined $myData{_INFILE});
|
|
$myData{_INPUT} = $in_fh;
|
|
my $input_top = $myData{_TOP_STREAM}
|
|
= new Pod::InputSource(
|
|
-name => $myData{_INFILE},
|
|
-handle => $in_fh,
|
|
-was_cutting => $myData{_CUTTING}
|
|
);
|
|
local *input_stack = $myData{_INPUT_STREAMS};
|
|
push(@input_stack, $input_top);
|
|
|
|
## Perform beginning-of-document and/or beginning-of-input processing
|
|
$self->begin_pod() if (@input_stack == 1);
|
|
$self->begin_input();
|
|
|
|
return $input_top;
|
|
}
|
|
|
|
##---------------------------------------------------------------------------
|
|
|
|
=begin _PRIVATE_
|
|
|
|
=head1 B<_pop_input_stream()>
|
|
|
|
$hashref = $parser->_pop_input_stream();
|
|
|
|
This takes no arguments. It will perform any necessary end-of-file or
|
|
end-of-document processing and then pop the current input stream from
|
|
the top of the input stack.
|
|
|
|
The value returned will be reference to the hash-table that represents
|
|
the new top of the input stream stack.
|
|
|
|
=end _PRIVATE_
|
|
|
|
=cut
|
|
|
|
sub _pop_input_stream {
|
|
my ($self) = @_;
|
|
local *myData = $self;
|
|
local *input_stack = $myData{_INPUT_STREAMS};
|
|
|
|
## Perform end-of-input and/or end-of-document processing
|
|
$self->end_input() if (@input_stack > 0);
|
|
$self->end_pod() if (@input_stack == 1);
|
|
|
|
## Restore cutting state to whatever it was before we started
|
|
## parsing this file.
|
|
my $old_top = pop(@input_stack);
|
|
$myData{_CUTTING} = $old_top->was_cutting();
|
|
|
|
## Dont forget to reset the input indicators
|
|
my $input_top = undef;
|
|
if (@input_stack > 0) {
|
|
$input_top = $myData{_TOP_STREAM} = $input_stack[-1];
|
|
$myData{_INFILE} = $input_top->name();
|
|
$myData{_INPUT} = $input_top->handle();
|
|
} else {
|
|
delete $myData{_TOP_STREAM};
|
|
delete $myData{_INPUT_STREAMS};
|
|
}
|
|
|
|
return $input_top;
|
|
}
|
|
|
|
#############################################################################
|
|
|
|
=head1 TREE-BASED PARSING
|
|
|
|
If straightforward stream-based parsing wont meet your needs (as is
|
|
likely the case for tasks such as translating PODs into structured
|
|
markup languages like HTML and XML) then you may need to take the
|
|
tree-based approach. Rather than doing everything in one pass and
|
|
calling the B<interpolate()> method to expand sequences into text, it
|
|
may be desirable to instead create a parse-tree using the B<parse_text()>
|
|
method to return a tree-like structure which may contain an ordered list
|
|
list of children (each of which may be a text-string, or a similar
|
|
tree-like structure).
|
|
|
|
Pay special attention to L<"METHODS FOR PARSING AND PROCESSING"> and
|
|
to the objects described in L<Pod::InputObjects>. The former describes
|
|
the gory details and parameters for how to customize and extend the
|
|
parsing behavior of B<Pod::Parser>. B<Pod::InputObjects> provides
|
|
several objects that may all be used interchangeably as parse-trees. The
|
|
most obvious one is the B<Pod::ParseTree> object. It defines the basic
|
|
interface and functionality that all things trying to be a POD parse-tree
|
|
should do. A B<Pod::ParseTree> is defined such that each "node" may be a
|
|
text-string, or a reference to another parse-tree. Each B<Pod::Paragraph>
|
|
object and each B<Pod::InteriorSequence> object also supports the basic
|
|
parse-tree interface.
|
|
|
|
The B<parse_text()> method takes a given paragraph of text, and
|
|
returns a parse-tree that contains one or more children, each of which
|
|
may be a text-string, or an InteriorSequence object. There are also
|
|
callback-options that may be passed to B<parse_text()> to customize
|
|
the way it expands or transforms interior-sequences, as well as the
|
|
returned result. These callbacks can be used to create a parse-tree
|
|
with custom-made objects (which may or may not support the parse-tree
|
|
interface, depending on how you choose to do it).
|
|
|
|
If you wish to turn an entire POD document into a parse-tree, that process
|
|
is fairly straightforward. The B<parse_text()> method is the key to doing
|
|
this successfully. Every paragraph-callback (i.e. the polymorphic methods
|
|
for B<command()>, B<verbatim()>, and B<textblock()> paragraphs) takes
|
|
a B<Pod::Paragraph> object as an argument. Each paragraph object has a
|
|
B<parse_tree()> method that can be used to get or set a corresponding
|
|
parse-tree. So for each of those paragraph-callback methods, simply call
|
|
B<parse_text()> with the options you desire, and then use the returned
|
|
parse-tree to assign to the given paragraph object.
|
|
|
|
That gives you a parse-tree for each paragraph - so now all you need is
|
|
an ordered list of paragraphs. You can maintain that yourself as a data
|
|
element in the object/hash. The most straightforward way would be simply
|
|
to use an array-ref, with the desired set of custom "options" for each
|
|
invocation of B<parse_text>. Let's assume the desired option-set is
|
|
given by the hash C<%options>. Then we might do something like the
|
|
following:
|
|
|
|
package MyPodParserTree;
|
|
|
|
@ISA = qw( Pod::Parser );
|
|
|
|
...
|
|
|
|
sub begin_pod {
|
|
my $self = shift;
|
|
$self->{'-paragraphs'} = []; ## initialize paragraph list
|
|
}
|
|
|
|
sub command {
|
|
my ($parser, $command, $paragraph, $line_num, $pod_para) = @_;
|
|
my $ptree = $parser->parse_text({%options}, $paragraph, ...);
|
|
$pod_para->parse_tree( $ptree );
|
|
push @{ $self->{'-paragraphs'} }, $pod_para;
|
|
}
|
|
|
|
sub verbatim {
|
|
my ($parser, $paragraph, $line_num, $pod_para) = @_;
|
|
push @{ $self->{'-paragraphs'} }, $pod_para;
|
|
}
|
|
|
|
sub textblock {
|
|
my ($parser, $paragraph, $line_num, $pod_para) = @_;
|
|
my $ptree = $parser->parse_text({%options}, $paragraph, ...);
|
|
$pod_para->parse_tree( $ptree );
|
|
push @{ $self->{'-paragraphs'} }, $pod_para;
|
|
}
|
|
|
|
...
|
|
|
|
package main;
|
|
...
|
|
my $parser = new MyPodParserTree(...);
|
|
$parser->parse_from_file(...);
|
|
my $paragraphs_ref = $parser->{'-paragraphs'};
|
|
|
|
Of course, in this module-author's humble opinion, I'd be more inclined to
|
|
use the existing B<Pod::ParseTree> object than a simple array. That way
|
|
everything in it, paragraphs and sequences, all respond to the same core
|
|
interface for all parse-tree nodes. The result would look something like:
|
|
|
|
package MyPodParserTree2;
|
|
|
|
...
|
|
|
|
sub begin_pod {
|
|
my $self = shift;
|
|
$self->{'-ptree'} = new Pod::ParseTree; ## initialize parse-tree
|
|
}
|
|
|
|
sub parse_tree {
|
|
## convenience method to get/set the parse-tree for the entire POD
|
|
(@_ > 1) and $_[0]->{'-ptree'} = $_[1];
|
|
return $_[0]->{'-ptree'};
|
|
}
|
|
|
|
sub command {
|
|
my ($parser, $command, $paragraph, $line_num, $pod_para) = @_;
|
|
my $ptree = $parser->parse_text({<<options>>}, $paragraph, ...);
|
|
$pod_para->parse_tree( $ptree );
|
|
$parser->parse_tree()->append( $pod_para );
|
|
}
|
|
|
|
sub verbatim {
|
|
my ($parser, $paragraph, $line_num, $pod_para) = @_;
|
|
$parser->parse_tree()->append( $pod_para );
|
|
}
|
|
|
|
sub textblock {
|
|
my ($parser, $paragraph, $line_num, $pod_para) = @_;
|
|
my $ptree = $parser->parse_text({<<options>>}, $paragraph, ...);
|
|
$pod_para->parse_tree( $ptree );
|
|
$parser->parse_tree()->append( $pod_para );
|
|
}
|
|
|
|
...
|
|
|
|
package main;
|
|
...
|
|
my $parser = new MyPodParserTree2(...);
|
|
$parser->parse_from_file(...);
|
|
my $ptree = $parser->parse_tree;
|
|
...
|
|
|
|
Now you have the entire POD document as one great big parse-tree. You
|
|
can even use the B<-expand_seq> option to B<parse_text> to insert
|
|
whole different kinds of objects. Just don't expect B<Pod::Parser>
|
|
to know what to do with them after that. That will need to be in your
|
|
code. Or, alternatively, you can insert any object you like so long as
|
|
it conforms to the B<Pod::ParseTree> interface.
|
|
|
|
One could use this to create subclasses of B<Pod::Paragraphs> and
|
|
B<Pod::InteriorSequences> for specific commands (or to create your own
|
|
custom node-types in the parse-tree) and add some kind of B<emit()>
|
|
method to each custom node/subclass object in the tree. Then all you'd
|
|
need to do is recursively walk the tree in the desired order, processing
|
|
the children (most likely from left to right) by formatting them if
|
|
they are text-strings, or by calling their B<emit()> method if they
|
|
are objects/references.
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<Pod::InputObjects>, L<Pod::Select>
|
|
|
|
B<Pod::InputObjects> defines POD input objects corresponding to
|
|
command paragraphs, parse-trees, and interior-sequences.
|
|
|
|
B<Pod::Select> is a subclass of B<Pod::Parser> which provides the ability
|
|
to selectively include and/or exclude sections of a POD document from being
|
|
translated based upon the current heading, subheading, subsubheading, etc.
|
|
|
|
=for __PRIVATE__
|
|
B<Pod::Callbacks> is a subclass of B<Pod::Parser> which gives its users
|
|
the ability the employ I<callback functions> instead of, or in addition
|
|
to, overriding methods of the base class.
|
|
|
|
=for __PRIVATE__
|
|
B<Pod::Select> and B<Pod::Callbacks> do not override any
|
|
methods nor do they define any new methods with the same name. Because
|
|
of this, they may I<both> be used (in combination) as a base class of
|
|
the same subclass in order to combine their functionality without
|
|
causing any namespace clashes due to multiple inheritance.
|
|
|
|
=head1 AUTHOR
|
|
|
|
Brad Appleton E<lt>bradapp@enteract.comE<gt>
|
|
|
|
Based on code for B<Pod::Text> written by
|
|
Tom Christiansen E<lt>tchrist@mox.perl.comE<gt>
|
|
|
|
=cut
|
|
|
|
1;
|