NAME

Pod::InputObjects - objects representing POD input streams, paragraphs, etc.

SYNOPSIS

    use Pod::InputObjects;

REQUIRES

perl5.004, Exporter, Carp

EXPORTS

Nothing.

DESCRIPTION

This module defines some basic input objects used by Pod::Parser when reading and parsing POD text from an input source. The following objects are defined:

Pod::InputSource

An object corresponding to a source of POD input text. It is mostly a wrapper around a filehandle or IO::Handle-type object (or anything that implements the getline() method) which keeps track of some additional information relevant to the parsing of PODs.

Pod::Paragraph

An object corresponding to a paragraph of POD input text. It may be a plain paragraph, a verbatim paragraph, or a command paragraph (see perlpod).

Pod::InteriorSequence

An object corresponding to an interior sequence command from the POD input text (see perlpod).

Pod::ParseTree

An object corresponding to a tree of parsed POD text. Each "node" in a parse-tree (or ptree) is either a text-string or a reference to a Pod::InteriorSequence object. The nodes appear in the parse-tree in they order in which they were parsed from left-to-right.

Each of these input objects are described in further detail in the sections which follow.

Pod::InputSource

This object corresponds to an input source or stream of POD documentation. When parsing PODs, it is necessary to associate and store certain context information with each input source. All of this information is kept together with the stream itself in one of these Pod::InputSource objects. Each such object is merely a wrapper around an IO::Handle object of some kind (or at least something that implements the getline() method). They have the following methods/attributes:

new()

        my $pod_input1 = Pod::InputSource->new(-handle => $filehandle);
        my $pod_input2 = new Pod::InputSource(-handle => $filehandle,
                                              -name   => $name);
        my $pod_input3 = new Pod::InputSource(-handle => \*STDIN);
        my $pod_input4 = Pod::InputSource->new(-handle => \*STDIN,
                                               -name => "(STDIN)");

This is a class method that constructs a Pod::InputSource object and returns a reference to the new input source object. It takes one or more keyword arguments in the form of a hash. The keyword -handle is required and designates the corresponding input handle. The keyword -name is optional and specifies the name associated with the input handle (typically a file name).

name()

        my $filename = $pod_input->name();
        $pod_input->name($new_filename_to_use);

This method gets/sets the name of the input source (usually a filename). If no argument is given, it returns a string containing the name of the input source; otherwise it sets the name of the input source to the contents of the given argument.

handle()

        my $handle = $pod_input->handle();

Returns a reference to the handle object from which input is read (the one used to contructed this input source object).

was_cutting()

        print "Yes.\n" if ($pod_input->was_cutting());

The value of the cutting state (that the cutting() method would have returned) immediately before any input was read from this input stream. After all input from this stream has been read, the cutting state is restored to this value.

Pod::Paragraph

An object representing a paragraph of POD input text. It has the following methods/attributes:

new()

        my $pod_para1 = Pod::Paragraph->new(-text => $text);
        my $pod_para2 = Pod::Paragraph->new(-name => $cmd,
                                            -text => $text);
        my $pod_para3 = new Pod::Paragraph(-text => $text);
        my $pod_para4 = new Pod::Paragraph(-name => $cmd,
                                           -text => $text);
        my $pod_para5 = Pod::Paragraph->new(-name => $cmd,
                                            -text => $text,
                                            -file => $filename,
                                            -line => $line_number);

This is a class method that constructs a Pod::Paragraph object and returns a reference to the new paragraph object. It may be given one or two keyword arguments. The -text keyword indicates the corresponding text of the POD paragraph. The -name keyword indicates the name of the corresponding POD command, such as head1 or item (it should not contain the = prefix); this is needed only if the POD paragraph corresponds to a command paragraph. The -file and -line keywords indicate the filename and line number corresponding to the beginning of the paragraph

cmd_name()

        my $para_cmd = $pod_para->cmd_name();

If this paragraph is a command paragraph, then this method will return the name of the command (without any leading = prefix).

text()

        my $para_text = $pod_para->text();

This method will return the corresponding text of the paragraph.

raw_text()

        my $raw_pod_para = $pod_para->raw_text();

This method will return the raw text of the POD paragraph, exactly as it appeared in the input.

cmd_prefix()

        my $prefix = $pod_para->cmd_prefix();

If this paragraph is a command paragraph, then this method will return the prefix used to denote the command (which should be the string "=").

cmd_separator()

        my $separator = $pod_para->cmd_separator();

If this paragraph is a command paragraph, then this method will return the text used to separate the command name from the rest of the paragraph (if any).

parse_tree()

        my $ptree = $pod_parser->parse_text( $pod_para->text() );
        $pod_para->parse_tree( $ptree );
        $ptree = $pod_para->parse_tree();

This method will get/set the corresponding parse-tree of the paragraph's text.

file_line()

        my ($filename, $line_number) = $pod_para->file_line();
        my $position = $pod_para->file_line();

Returns the current filename and line number for the paragraph object. If called in an array context, it returns a list of two elements: first the filename, then the line number. If called in a scalar context, it returns a string containing the filename, followed by a colon (':'), followed by the line number.

Pod::InteriorSequence

An object representing a POD interior sequence command. It has the following methods/attributes:

new()

        my $pod_seq1 = Pod::InteriorSequence->new(-name => $cmd
                                                  -ldelim => $delimiter);
        my $pod_seq2 = new Pod::InteriorSequence(-name => $cmd,
                                                 -ldelim => $delimiter);
        my $pod_seq3 = new Pod::InteriorSequence(-name => $cmd,
                                                 -ldelim => $delimiter,
                                                 -file => $filename,
                                                 -line => $line_number);

This is a class method that constructs a Pod::InteriorSequence object and returns a reference to the new interior sequence object. It should be given two keyword arguments. The -ldelim keyword indicates the corresponding left-delimiter of the interior sequence (e.g. '<'). The -name keyword indicates the name of the corresponding interior sequence command, such as I or B or C. The -file and -line keywords indicate the filename and line number corresponding to the beginning of the interior sequence.

cmd_name()

        my $seq_cmd = $pod_seq->cmd_name();

The name of the interior sequence command.

prepend()

        $pod_seq->prepend($text);
        $pod_seq1->prepend($pod_seq2);

Prepends the given string or parse-tree or sequence object to the parse-tree of this interior sequence.

append()

        $pod_seq->append($text);
        $pod_seq1->append($pod_seq2);

Appends the given string or parse-tree or sequence object to the parse-tree of this interior sequence.

nested()

        $outer_seq = $pod_seq->nested || print "not nested";

If this interior sequence is nested inside of another interior sequence, then the outer/parent sequence that contains it is returned. Otherwise undef is returned.

sub nested { my $self = shift; return $self->{'-parent_sequence'} || undef; }

##---------------------------------------------------------------------------

raw_text()

        my $seq_raw_text = $pod_seq->raw_text();

This method will return the raw text of the POD interior sequence, exactly as it appeared in the input.

left_delimiter()

        my $ldelim = $pod_seq->left_delimiter();

The leftmost delimiter beginning the argument text to the interior sequence (should be "<").

right_delimiter()

The rightmost delimiter beginning the argument text to the interior sequence (should be ">").

parse_tree()

        my $ptree = $pod_parser->parse_text($paragraph_text);
        $pod_seq->parse_tree( $ptree );
        $ptree = $pod_seq->parse_tree();

This method will get/set the corresponding parse-tree of the interior sequence's text.

file_line()

        my ($filename, $line_number) = $pod_seq->file_line();
        my $position = $pod_seq->file_line();

Returns the current filename and line number for the interior sequence object. If called in an array context, it returns a list of two elements: first the filename, then the line number. If called in a scalar context, it returns a string containing the filename, followed by a colon (':'), followed by the line number.

DESTROY()

This method performs any necessary cleanup for the interior-sequence. If you override this method then it is imperative that you invoke the parent method from within your own method, otherwise interior-sequence storage will not be reclaimed upon destruction!

Pod::ParseTree

This object corresponds to a tree of parsed POD text. As POD text is scanned from left to right, it is parsed into an ordered list of text-strings and Pod::InteriorSequence objects (in order of appearance). A Pod::ParseTree object corresponds to this list of strings and sequences. Each interior sequence in the parse-tree may itself contain a parse-tree (since interior sequences may be nested).

new()

        my $ptree1 = Pod::ParseTree->new;
        my $ptree2 = new Pod::ParseTree;
        my $ptree4 = Pod::ParseTree->new($array_ref);
        my $ptree3 = new Pod::ParseTree($array_ref);

This is a class method that constructs a Pod::Parse_tree object and returns a reference to the new parse-tree. If a single-argument is given, it mist be a reference to an array, and is used to initialize the root (top) of the parse tree.

top()

        my $top_node = $ptree->top();
        $ptree->top( $top_node );
        $ptree->top( @children );

This method gets/sets the top node of the parse-tree. If no arguments are given, it returns the topmost node in the tree (the root), which is also a Pod::ParseTree. If it is given a single argument that is a reference, then the reference is assumed to a parse-tree and becomes the new top node. Otherwise, if arguments are given, they are treated as the new list of children for the top node.

children()

This method gets/sets the children of the top node in the parse-tree. If no arguments are given, it returns the list (array) of children (each of which should be either a string or a Pod::InteriorSequence. Otherwise, if arguments are given, they are treated as the new list of children for the top node.

prepend()

This method prepends the given text or parse-tree to the current parse-tree. If the first item on the parse-tree is text and the argument is also text, then the text is prepended to the first item (not added as a separate string). Otherwise the argument is added as a new string or parse-tree before the current one.

append()

This method appends the given text or parse-tree to the current parse-tree. If the last item on the parse-tree is text and the argument is also text, then the text is appended to the last item (not added as a separate string). Otherwise the argument is added as a new string or parse-tree after the current one.

DESTROY()

This method performs any necessary cleanup for the parse-tree. If you override this method then it is imperative that you invoke the parent method from within your own method, otherwise parse-tree storage will not be reclaimed upon destruction!

SEE ALSO

See Pod::Parser, Pod::Select, and Pod::Callbacks.

AUTHOR

Brad Appleton <bradapp@enteract.com>