NAME¶
Pod::Simple - framework for parsing Pod
SYNOPSIS¶
TODO
DESCRIPTION¶
Pod::Simple is a Perl library for parsing text in the Pod ("plain old
documentation") markup language that is typically used for writing
documentation for Perl and for Perl modules. The Pod format is explained
perlpod; the most common formatter is called "perldoc".
Be sure to read "ENCODING" if your Pod contains non-ASCII characters.
Pod formatters can use Pod::Simple to parse Pod documents and render them into
plain text, HTML, or any number of other formats. Typically, such formatters
will be subclasses of Pod::Simple, and so they will inherit its methods, like
"parse_file".
If you're reading this document just because you have a Pod-processing subclass
that you want to use, this document (plus the documentation for the subclass)
is probably all you need to read.
If you're reading this document because you want to write a formatter subclass,
continue reading it and then read Pod::Simple::Subclassing, and then possibly
even read perlpodspec (some of which is for parser-writers, but much of which
is notes to formatter-writers).
MAIN METHODS¶
- "$parser = SomeClass->new();"
- This returns a new parser object, where
"SomeClass" is a subclass of
Pod::Simple.
- "$parser->output_fh( *OUT );"
- This sets the filehandle that $parser's output will be written to. You can
pass *STDOUT, otherwise you should probably do something like this:
my $outfile = "output.txt";
open TXTOUT, ">$outfile" or die "Can't write to $outfile: $!";
$parser->output_fh(*TXTOUT);
...before you call one of the "$parser->parse_ whatever"
methods.
- "$parser->output_string( \$somestring );"
- This sets the string that $parser's output will be sent to, instead of any
filehandle.
- "$parser->parse_file( $some_filename );"
- "$parser->parse_file( *INPUT_FH );"
- This reads the Pod content of the file (or filehandle) that you specify,
and processes it with that $parser object, according to however $parser's
class works, and according to whatever parser options you have set up for
this $parser object.
- "$parser->parse_string_document( $all_content );"
- This works just like "parse_file" except that it reads the Pod
content not from a file, but from a string that you have already in
memory.
- "$parser->parse_lines( ...@lines..., undef );"
- This processes the lines in @lines (where each list item must be a defined
value, and must contain exactly one line of content -- so no items like
"foo\nbar" are allowed). The final "undef" is used to
indicate the end of document being parsed.
The other "parser_ whatever" methods are meant to be called
only once per $parser object; but "parse_lines" can be called as
many times per $parser object as you want, as long as the last call (and
only the last call) ends with an "undef" value.
- "$parser->content_seen"
- This returns true only if there has been any real content seen for this
document. Returns false in cases where the document contains content, but
does not make use of any Pod markup.
- "SomeClass->filter( $filename );"
- "SomeClass->filter( *INPUT_FH );"
- "SomeClass->filter( \$document_content );"
- This is a shortcut method for creating a new parser object, setting the
output handle to STDOUT, and then processing the specified file (or
filehandle, or in-memory document). This is handy for one-liners like
this:
perl -MPod::Simple::Text -e "Pod::Simple::Text->filter('thingy.pod')"
SECONDARY METHODS¶
Some of these methods might be of interest to general users, as well as of
interest to formatter-writers.
Note that the general pattern here is that the accessor-methods read the
attribute's value with "$value = $parser->
attribute" and
set the attribute's value with "$parser->
attribute(
newvalue)". For each accessor, I typically only
mention one syntax or another, based on which I think you are actually most
likely to use.
- "$parser->parse_characters( SOMEVALUE )"
- The Pod parser normally expects to read octets and to convert those octets
to characters based on the "=encoding" declaration in the Pod
source. Set this option to a true value to indicate that the Pod source is
already a Perl character stream. This tells the parser to ignore any
"=encoding" command and to skip all the code paths involving
decoding octets.
- "$parser->no_whining( SOMEVALUE )"
- If you set this attribute to a true value, you will suppress the parser's
complaints about irregularities in the Pod coding. By default, this
attribute's value is false, meaning that irregularities will be reported.
Note that turning this attribute to true won't suppress one or two kinds of
complaints about rarely occurring unrecoverable errors.
- "$parser->no_errata_section( SOMEVALUE )"
- If you set this attribute to a true value, you will stop the parser from
generating a "POD ERRORS" section at the end of the document. By
default, this attribute's value is false, meaning that an errata section
will be generated, as necessary.
- "$parser->complain_stderr( SOMEVALUE )"
- If you set this attribute to a true value, it will send reports of parsing
errors to STDERR. By default, this attribute's value is false, meaning
that no output is sent to STDERR.
Setting "complain_stderr" also sets
"no_errata_section".
- "$parser->source_filename"
- This returns the filename that this parser object was set to read
from.
- "$parser->doc_has_started"
- This returns true if $parser has read from a source, and has seen Pod
content in it.
- "$parser->source_dead"
- This returns true if $parser has read from a source, and come to the end
of that source.
- "$parser->strip_verbatim_indent( SOMEVALUE )"
- The perlpod spec for a Verbatim paragraph is "It should be reproduced
exactly...", which means that the whitespace you've used to indent
your verbatim blocks will be preserved in the output. This can be annoying
for outputs such as HTML, where that whitespace will remain in front of
every line. It's an unfortunate case where syntax is turned into
semantics.
If the POD your parsing adheres to a consistent indentation policy, you can
have such indentation stripped from the beginning of every line of your
verbatim blocks. This method tells Pod::Simple what to strip. For
two-space indents, you'd use:
$parser->strip_verbatim_indent(' ');
For tab indents, you'd use a tab character:
$parser->strip_verbatim_indent("\t");
If the POD is inconsistent about the indentation of verbatim blocks, but you
have figured out a heuristic to determine how much a particular verbatim
block is indented, you can pass a code reference instead. The code
reference will be executed with one argument, an array reference of all
the lines in the verbatim block, and should return the value to be
stripped from each line. For example, if you decide that you're fine to
use the first line of the verbatim block to set the standard for
indentation of the rest of the block, you can look at the first line and
return the appropriate value, like so:
$new->strip_verbatim_indent(sub {
my $lines = shift;
(my $indent = $lines->[0]) =~ s/\S.*//;
return $indent;
});
If you'd rather treat each line individually, you can do that, too, by just
transforming them in-place in the code reference and returning
"undef". Say that you don't want any lines indented. You
can do something like this:
$new->strip_verbatim_indent(sub {
my $lines = shift;
sub { s/^\s+// for @{ $lines },
return undef;
});
TERTIARY METHODS¶
- "$parser->abandon_output_fh()"
- Cancel output to the file handle. Any POD read by the $parser is not
effected.
- "$parser->abandon_output_string()"
- Cancel output to the output string. Any POD read by the $parser is not
effected.
- "$parser->accept_code( @codes )"
- Alias for accept_codes.
- "$parser->accept_codes( @codes )"
- Allows $parser to accept a list of "Formatting Codes" in
perlpod. This can be used to implement user-defined codes.
- "$parser->accept_directive_as_data( @directives )"
- Allows $parser to accept a list of directives for data paragraphs. A
directive is the label of a "Command Paragraph" in perlpod. A
data paragraph is one delimited by "=begin/=for/=end"
directives. This can be used to implement user-defined directives.
- "$parser->accept_directive_as_processed( @directives )"
- Allows $parser to accept a list of directives for processed paragraphs. A
directive is the label of a "Command Paragraph" in perlpod. A
processed paragraph is also known as "Ordinary Paragraph" in
perlpod. This can be used to implement user-defined directives.
- "$parser->accept_directive_as_verbatim( @directives )"
- Allows $parser to accept a list of directives for "Verbatim
Paragraph" in perlpod. A directive is the label of a "Command
Paragraph" in perlpod. This can be used to implement user-defined
directives.
- "$parser->accept_target( @targets )"
- Alias for accept_targets.
- "$parser->accept_target_as_text( @targets )"
- Alias for accept_targets_as_text.
- "$parser->accept_targets( @targets )"
- Accepts targets for "=begin/=for/=end" sections of the POD.
- "$parser->accept_targets_as_text( @targets )"
- Accepts targets for "=begin/=for/=end" sections that should be
parsed as POD. For details, see "About Data Paragraphs" in
perlpodspec.
- "$parser->any_errata_seen()"
- Used to check if any errata was seen.
Example:
die "too many errors\n" if $parser->any_errata_seen();
- "$parser->detected_encoding()"
- Return the encoding corresponding to "=encoding", but only if
the encoding was recognized and handled.
- "$parser->encoding()"
- Return encoding of the document, even if the encoding is not correctly
handled.
- "$parser->parse_from_file( $source, $to )"
- Parses from $source file to $to file. Similar to
"parse_from_file" in Pod::Parser.
- "$parser->scream( @error_messages )"
- Log an error that can't be ignored.
- "$parser->unaccept_code( @codes )"
- Alias for unaccept_codes.
- "$parser->unaccept_codes( @codes )"
- Removes @codes as valid codes for the parse.
- "$parser->unaccept_directive( @directives )"
- Alias for unaccept_directives.
- "$parser->unaccept_directives( @directives )"
- Removes @directives as valid directives for the parse.
- "$parser->unaccept_target( @targets )"
- Alias for unaccept_targets.
- "$parser->unaccept_targets( @targets )"
- Removes @targets as valid targets for the parse.
- "$parser->version_report()"
- Returns a string describing the version.
- "$parser->whine( @error_messages )"
- Log an error unless "$parser->no_whining( TRUE );".
ENCODING¶
The Pod::Simple parser expects to read
octets. The parser will decode the
octets into Perl's internal character string representation using the value of
the "=encoding" declaration in the POD source.
If the POD source does not include an "=encoding" declaration, the
parser will attempt to guess the encoding (selecting one of UTF-8 or Latin-1)
by examining the first non-ASCII bytes and applying the heuristic described in
perlpodspec.
If you set the "parse_characters" option to a true value the parser
will expect characters rather than octets; will ignore any
"=encoding"; and will make no attempt to decode the input.
CAVEATS¶
This is just a beta release -- there are a good number of things still left to
do. Notably, support for EBCDIC platforms is still half-done, an untested.
SEE ALSO¶
Pod::Simple::Subclassing
perlpod
perlpodspec
Pod::Escapes
perldoc
SUPPORT¶
Questions or discussion about POD and Pod::Simple should be sent to the
pod-people@perl.org mail list. Send an empty email to
pod-people-subscribe@perl.org to subscribe.
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
<bug-pod-simple@rt.cpan.org>.
COPYRIGHT AND DISCLAIMERS¶
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 <sburke@cpan.org>. 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"
Documentation has been contributed by:
- •
- Gabor Szabo "szabgab@gmail.com"
- •
- Shawn H Corey "SHCOREY at cpan.org"