Pod::Eventual - read a POD document as a series of trivial events

NAME

Pod::Eventual - read a POD document as a series of trivial events

VERSION

version 0.094000

SYNOPSIS

  package Your::Pod::Parser;
  use base 'Pod::Eventual';
  sub handle_event {
    my ($self, $event) = @_;
    print Dumper($event);
  }

DESCRIPTION

POD is a pretty simple format to write, but it can be a big pain to deal with reading it and doing anything useful with it. Most existing POD parsers care about semantics, like whether a =item occurred after an =over but before a back, figuring out how to link a L<>, and other things like that.

Pod::Eventual is much less ambitious and much more stupid. Fortunately, stupid is often better. (That's what I keep telling myself, anyway.)

Pod::Eventual reads line-based input and produces events describing each POD paragraph or directive it finds. Once complete events are immediately passed to the handle_event method. This method should be implemented by Pod::Eventual subclasses. If it isn't, Pod::Eventual's own handle_event will be called, and will raise an exception.

METHODS

read_handle

  Pod::Eventual->read_handle($io_handle, \%arg);

This method iterates through the lines of a handle, producing events and calling the handle_event method.

The only valid argument in %arg (for now) is in_pod, which indicates whether we should assume that we are parsing pod when we start parsing the file. By default, this is false.

This is useful to behave differently when reading a .pm or .pod file.

Important: the handle is expected to have an encoding layer so that it will return text, not bytes, on reads.

read_file

This behaves just like read_handle, but expects a filename rather than a handle. The file will be assumed to be UTF-8 encoded.

read_string

This behaves just like read_handle, but expects a string containing POD text rather than a handle.

handle_event

This method is called each time Pod::Evental finishes scanning for a new POD event. It must be implemented by a subclass or it will raise an exception.

handle_nonpod

This method is called each time a non-POD segment is seen -- that is, lines after =cut and before another command.

If unimplemented by a subclass, it does nothing by default.

handle_blank

This method is called at the end of a sequence of one or more blank lines.

If unimplemented by a subclass, it does nothing by default.

EVENTS

There are four kinds of events that Pod::Eventual will produce. All are represented as hash references.

Command Events

These events represent commands -- those things that start with an equals sign in the first column. Here are some examples of POD and the event that would be produced.

A simple header:

  =head1 NAME
  { type => 'command', command => 'head1', content => "NAME\n", start_line => 4 }

Notice that the content includes the trailing newline. That's to maintain similarity with this possibly-surprising case:

  =for HTML
  We're actually still in the command event, here.
  {
    type    => 'command',
    command => 'for',
    content => "HTML\nWe're actually still in the command event, here.\n",
    start_line => 8,
  }

Pod::Eventual does not care what the command is. It doesn't keep track of what it's seen or whether you've used a command that isn't defined. The only special case is =cut, which is never more than one line.

  =cut
  We are no longer parsing POD when this line is read.
  {
    type    => 'command',
    command => 'cut',
    content => "\n",
    start_line => 15,
  }

Waiving this special case may be an option in the future.

Text Events

A text event is just a paragraph of text, beginning after one or more empty lines and running until the next empty line (or =cut). In Perl 5's standard usage of Pod, text content that begins with whitespace is a ``verbatim'' paragraph, and text content that begins with non-whitespace is an ``ordinary'' paragraph.

Pod::Eventual doesn't care.

Text events look like this:

  {
    type    => 'text',
    content => "a string of text ending with a\n",
    start_line =>  16,
  }

Blank events

These events represent blank lines (or many blank lines) within a Pod section.

Blank events look like this:

  {
    type    => 'blank',
    content => "\n\n\n\n",
    start_line => 21,
  }

Non-Pod events

These events represent non-Pod segments of the input.

Non-Pod events look like this:

  {
    type    => 'nonpod',
    content => "#!/usr/bin/perl\nuse strict;\n\nuse Acme::ProgressBar\n\n",
    start_line => 1,
  }

AUTHOR

Ricardo SIGNES <rjbs@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2013 by Ricardo SIGNES.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

 Pod::Eventual - read a POD document as a series of trivial events