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############################################################################## Pod/InputObjects.pm -- package which defines objects for input streams# and paragraphs and commands when parsing POD docs.## Copyright (C) 1996-2000 by Bradford Appleton. All rights reserved.# This file is part of "PodParser". PodParser is free software;# you can redistribute it and/or modify it under the same terms# as Perl itself.#############################################################################package Pod::InputObjects;use strict;use vars qw($VERSION);$VERSION = '1.31'; ## Current version of this packagerequire 5.005; ## requires this Perl version or later#############################################################################=head1 NAMEPod::InputObjects - objects representing POD input paragraphs, commands, etc.=head1 SYNOPSISuse Pod::InputObjects;=head1 REQUIRESperl5.004, Carp=head1 EXPORTSNothing.=head1 DESCRIPTIONThis module defines some basic input objects used by B<Pod::Parser> whenreading and parsing POD text from an input source. The following objectsare defined:=over 4=begin __PRIVATE__=item package B<Pod::InputSource>An object corresponding to a source of POD input text. It is mostly awrapper around a filehandle or C<IO::Handle>-type object (or anythingthat implements the C<getline()> method) which keeps track of someadditional information relevant to the parsing of PODs.=end __PRIVATE__=item package B<Pod::Paragraph>An object corresponding to a paragraph of POD input text. It may be aplain paragraph, a verbatim paragraph, or a command paragraph (seeL<perlpod>).=item package B<Pod::InteriorSequence>An object corresponding to an interior sequence command from the PODinput text (see L<perlpod>).=item package B<Pod::ParseTree>An object corresponding to a tree of parsed POD text. Each "node" ina parse-tree (or I<ptree>) is either a text-string or a reference toa B<Pod::InteriorSequence> object. The nodes appear in the parse-treein the order in which they were parsed from left-to-right.=backEach of these input objects are described in further detail in thesections which follow.=cut#############################################################################package Pod::InputSource;##---------------------------------------------------------------------------=begin __PRIVATE__=head1 B<Pod::InputSource>This object corresponds to an input source or stream of PODdocumentation. When parsing PODs, it is necessary to associate and storecertain context information with each input source. All of thisinformation is kept together with the stream itself in one of theseC<Pod::InputSource> objects. Each such object is merely a wrapper aroundan C<IO::Handle> object of some kind (or at least something thatimplements the C<getline()> method). They have the followingmethods/attributes:=end __PRIVATE__=cut##---------------------------------------------------------------------------=begin __PRIVATE__=head2 B<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 C<Pod::InputSource> object andreturns a reference to the new input source object. It takes one or morekeyword arguments in the form of a hash. The keyword C<-handle> isrequired and designates the corresponding input handle. The keywordC<-name> is optional and specifies the name associated with the inputhandle (typically a file name).=end __PRIVATE__=cutsub new {## Determine if we were called via an object-ref or a classnamemy $this = shift;my $class = ref($this) || $this;## Any remaining arguments are treated as initial values for the## hash that is used to represent this object. Note that we default## certain values by specifying them *before* the arguments passed.## If they are in the argument list, they will override the defaults.my $self = { -name => '(unknown)',-handle => undef,-was_cutting => 0,@_ };## Bless ourselves into the desired class and perform any initializationbless $self, $class;return $self;}##---------------------------------------------------------------------------=begin __PRIVATE__=head2 B<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 ofthe input source; otherwise it sets the name of the input source to thecontents of the given argument.=end __PRIVATE__=cutsub name {(@_ > 1) and $_[0]->{'-name'} = $_[1];return $_[0]->{'-name'};}## allow 'filename' as an alias for 'name'*filename = \&name;##---------------------------------------------------------------------------=begin __PRIVATE__=head2 B<handle()>my $handle = $pod_input->handle();Returns a reference to the handle object from which input is read (theone used to contructed this input source object).=end __PRIVATE__=cutsub handle {return $_[0]->{'-handle'};}##---------------------------------------------------------------------------=begin __PRIVATE__=head2 B<was_cutting()>print "Yes.\n" if ($pod_input->was_cutting());The value of the C<cutting> state (that the B<cutting()> method wouldhave returned) immediately before any input was read from this inputstream. After all input from this stream has been read, the C<cutting>state is restored to this value.=end __PRIVATE__=cutsub was_cutting {(@_ > 1) and $_[0]->{-was_cutting} = $_[1];return $_[0]->{-was_cutting};}##---------------------------------------------------------------------------#############################################################################package Pod::Paragraph;##---------------------------------------------------------------------------=head1 B<Pod::Paragraph>An object representing a paragraph of POD input text.It has the following methods/attributes:=cut##---------------------------------------------------------------------------=head2 Pod::Paragraph-E<gt>B<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 C<Pod::Paragraph> object andreturns a reference to the new paragraph object. It may be given one ortwo keyword arguments. The C<-text> keyword indicates the correspondingtext of the POD paragraph. The C<-name> keyword indicates the name ofthe corresponding POD command, such as C<head1> or C<item> (it shouldI<not> contain the C<=> prefix); this is needed only if the PODparagraph corresponds to a command paragraph. The C<-file> and C<-line>keywords indicate the filename and line number corresponding to thebeginning of the paragraph=cutsub new {## Determine if we were called via an object-ref or a classnamemy $this = shift;my $class = ref($this) || $this;## Any remaining arguments are treated as initial values for the## hash that is used to represent this object. Note that we default## certain values by specifying them *before* the arguments passed.## If they are in the argument list, they will override the defaults.my $self = {-name => undef,-text => (@_ == 1) ? shift : undef,-file => '<unknown-file>',-line => 0,-prefix => '=',-separator => ' ',-ptree => [],@_};## Bless ourselves into the desired class and perform any initializationbless $self, $class;return $self;}##---------------------------------------------------------------------------=head2 $pod_para-E<gt>B<cmd_name()>my $para_cmd = $pod_para->cmd_name();If this paragraph is a command paragraph, then this method will returnthe name of the command (I<without> any leading C<=> prefix).=cutsub cmd_name {(@_ > 1) and $_[0]->{'-name'} = $_[1];return $_[0]->{'-name'};}## let name() be an alias for cmd_name()*name = \&cmd_name;##---------------------------------------------------------------------------=head2 $pod_para-E<gt>B<text()>my $para_text = $pod_para->text();This method will return the corresponding text of the paragraph.=cutsub text {(@_ > 1) and $_[0]->{'-text'} = $_[1];return $_[0]->{'-text'};}##---------------------------------------------------------------------------=head2 $pod_para-E<gt>B<raw_text()>my $raw_pod_para = $pod_para->raw_text();This method will return the I<raw> text of the POD paragraph, exactlyas it appeared in the input.=cutsub raw_text {return $_[0]->{'-text'} unless (defined $_[0]->{'-name'});return $_[0]->{'-prefix'} . $_[0]->{'-name'} .$_[0]->{'-separator'} . $_[0]->{'-text'};}##---------------------------------------------------------------------------=head2 $pod_para-E<gt>B<cmd_prefix()>my $prefix = $pod_para->cmd_prefix();If this paragraph is a command paragraph, then this method will returnthe prefix used to denote the command (which should be the string "="or "==").=cutsub cmd_prefix {return $_[0]->{'-prefix'};}##---------------------------------------------------------------------------=head2 $pod_para-E<gt>B<cmd_separator()>my $separator = $pod_para->cmd_separator();If this paragraph is a command paragraph, then this method will returnthe text used to separate the command name from the rest of theparagraph (if any).=cutsub cmd_separator {return $_[0]->{'-separator'};}##---------------------------------------------------------------------------=head2 $pod_para-E<gt>B<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.=cutsub parse_tree {(@_ > 1) and $_[0]->{'-ptree'} = $_[1];return $_[0]->{'-ptree'};}## let ptree() be an alias for parse_tree()*ptree = \&parse_tree;##---------------------------------------------------------------------------=head2 $pod_para-E<gt>B<file_line()>my ($filename, $line_number) = $pod_para->file_line();my $position = $pod_para->file_line();Returns the current filename and line number for the paragraphobject. If called in a list context, it returns a list of twoelements: first the filename, then the line number. If called ina scalar context, it returns a string containing the filename, followedby a colon (':'), followed by the line number.=cutsub file_line {my @loc = ($_[0]->{'-file'} || '<unknown-file>',$_[0]->{'-line'} || 0);return (wantarray) ? @loc : join(':', @loc);}##---------------------------------------------------------------------------#############################################################################package Pod::InteriorSequence;##---------------------------------------------------------------------------=head1 B<Pod::InteriorSequence>An object representing a POD interior sequence command.It has the following methods/attributes:=cut##---------------------------------------------------------------------------=head2 Pod::InteriorSequence-E<gt>B<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);my $pod_seq4 = new Pod::InteriorSequence(-name => $cmd, $ptree);my $pod_seq5 = new Pod::InteriorSequence($cmd, $ptree);This is a class method that constructs a C<Pod::InteriorSequence> objectand returns a reference to the new interior sequence object. It shouldbe given two keyword arguments. The C<-ldelim> keyword indicates thecorresponding left-delimiter of the interior sequence (e.g. 'E<lt>').The C<-name> keyword indicates the name of the corresponding interiorsequence command, such as C<I> or C<B> or C<C>. The C<-file> andC<-line> keywords indicate the filename and line number correspondingto the beginning of the interior sequence. If the C<$ptree> argument isgiven, it must be the last argument, and it must be either string, orelse an array-ref suitable for passing to B<Pod::ParseTree::new> (orit may be a reference to a Pod::ParseTree object).=cutsub new {## Determine if we were called via an object-ref or a classnamemy $this = shift;my $class = ref($this) || $this;## See if first argument has no keywordif (((@_ <= 2) or (@_ % 2)) and $_[0] !~ /^-\w/) {## Yup - need an implicit '-name' before first parameterunshift @_, '-name';}## See if odd number of argsif ((@_ % 2) != 0) {## Yup - need an implicit '-ptree' before the last parametersplice @_, $#_, 0, '-ptree';}## Any remaining arguments are treated as initial values for the## hash that is used to represent this object. Note that we default## certain values by specifying them *before* the arguments passed.## If they are in the argument list, they will override the defaults.my $self = {-name => (@_ == 1) ? $_[0] : undef,-file => '<unknown-file>',-line => 0,-ldelim => '<',-rdelim => '>',@_};## Initialize contents if they havent been alreadymy $ptree = $self->{'-ptree'} || new Pod::ParseTree();if ( ref $ptree =~ /^(ARRAY)?$/ ) {## We have an array-ref, or a normal scalar. Pass it as an## an argument to the ptree-constructor$ptree = new Pod::ParseTree($1 ? [$ptree] : $ptree);}$self->{'-ptree'} = $ptree;## Bless ourselves into the desired class and perform any initializationbless $self, $class;return $self;}##---------------------------------------------------------------------------=head2 $pod_seq-E<gt>B<cmd_name()>my $seq_cmd = $pod_seq->cmd_name();The name of the interior sequence command.=cutsub cmd_name {(@_ > 1) and $_[0]->{'-name'} = $_[1];return $_[0]->{'-name'};}## let name() be an alias for cmd_name()*name = \&cmd_name;##---------------------------------------------------------------------------## Private subroutine to set the parent pointer of all the given## children that are interior-sequences to be $selfsub _set_child2parent_links {my ($self, @children) = @_;## Make sure any sequences know who their parent isfor (@children) {next unless (length and ref and ref ne 'SCALAR');if (UNIVERSAL::isa($_, 'Pod::InteriorSequence') orUNIVERSAL::can($_, 'nested')){$_->nested($self);}}}## Private subroutine to unset child->parent linkssub _unset_child2parent_links {my $self = shift;$self->{'-parent_sequence'} = undef;my $ptree = $self->{'-ptree'};for (@$ptree) {next unless (length and ref and ref ne 'SCALAR');$_->_unset_child2parent_links()if UNIVERSAL::isa($_, 'Pod::InteriorSequence');}}##---------------------------------------------------------------------------=head2 $pod_seq-E<gt>B<prepend()>$pod_seq->prepend($text);$pod_seq1->prepend($pod_seq2);Prepends the given string or parse-tree or sequence object to the parse-treeof this interior sequence.=cutsub prepend {my $self = shift;$self->{'-ptree'}->prepend(@_);_set_child2parent_links($self, @_);return $self;}##---------------------------------------------------------------------------=head2 $pod_seq-E<gt>B<append()>$pod_seq->append($text);$pod_seq1->append($pod_seq2);Appends the given string or parse-tree or sequence object to the parse-treeof this interior sequence.=cutsub append {my $self = shift;$self->{'-ptree'}->append(@_);_set_child2parent_links($self, @_);return $self;}##---------------------------------------------------------------------------=head2 $pod_seq-E<gt>B<nested()>$outer_seq = $pod_seq->nested || print "not nested";If this interior sequence is nested inside of another interiorsequence, then the outer/parent sequence that contains it isreturned. Otherwise C<undef> is returned.=cutsub nested {my $self = shift;(@_ == 1) and $self->{'-parent_sequence'} = shift;return $self->{'-parent_sequence'} || undef;}##---------------------------------------------------------------------------=head2 $pod_seq-E<gt>B<raw_text()>my $seq_raw_text = $pod_seq->raw_text();This method will return the I<raw> text of the POD interior sequence,exactly as it appeared in the input.=cutsub raw_text {my $self = shift;my $text = $self->{'-name'} . $self->{'-ldelim'};for ( $self->{'-ptree'}->children ) {$text .= (ref $_) ? $_->raw_text : $_;}$text .= $self->{'-rdelim'};return $text;}##---------------------------------------------------------------------------=head2 $pod_seq-E<gt>B<left_delimiter()>my $ldelim = $pod_seq->left_delimiter();The leftmost delimiter beginning the argument text to the interiorsequence (should be "<").=cutsub left_delimiter {(@_ > 1) and $_[0]->{'-ldelim'} = $_[1];return $_[0]->{'-ldelim'};}## let ldelim() be an alias for left_delimiter()*ldelim = \&left_delimiter;##---------------------------------------------------------------------------=head2 $pod_seq-E<gt>B<right_delimiter()>The rightmost delimiter beginning the argument text to the interiorsequence (should be ">").=cutsub right_delimiter {(@_ > 1) and $_[0]->{'-rdelim'} = $_[1];return $_[0]->{'-rdelim'};}## let rdelim() be an alias for right_delimiter()*rdelim = \&right_delimiter;##---------------------------------------------------------------------------=head2 $pod_seq-E<gt>B<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 interiorsequence's text.=cutsub parse_tree {(@_ > 1) and $_[0]->{'-ptree'} = $_[1];return $_[0]->{'-ptree'};}## let ptree() be an alias for parse_tree()*ptree = \&parse_tree;##---------------------------------------------------------------------------=head2 $pod_seq-E<gt>B<file_line()>my ($filename, $line_number) = $pod_seq->file_line();my $position = $pod_seq->file_line();Returns the current filename and line number for the interior sequenceobject. If called in a list context, it returns a list of twoelements: first the filename, then the line number. If called ina scalar context, it returns a string containing the filename, followedby a colon (':'), followed by the line number.=cutsub file_line {my @loc = ($_[0]->{'-file'} || '<unknown-file>',$_[0]->{'-line'} || 0);return (wantarray) ? @loc : join(':', @loc);}##---------------------------------------------------------------------------=head2 Pod::InteriorSequence::B<DESTROY()>This method performs any necessary cleanup for the interior-sequence.If you override this method then it is B<imperative> that you invokethe parent method from within your own method, otherwiseI<interior-sequence storage will not be reclaimed upon destruction!>=cutsub DESTROY {## We need to get rid of all child->parent pointers throughout the## tree so their reference counts will go to zero and they can be## garbage-collected_unset_child2parent_links(@_);}##---------------------------------------------------------------------------#############################################################################package Pod::ParseTree;##---------------------------------------------------------------------------=head1 B<Pod::ParseTree>This object corresponds to a tree of parsed POD text. As POD text isscanned from left to right, it is parsed into an ordered list oftext-strings and B<Pod::InteriorSequence> objects (in order ofappearance). A B<Pod::ParseTree> object corresponds to this list ofstrings and sequences. Each interior sequence in the parse-tree mayitself contain a parse-tree (since interior sequences may be nested).=cut##---------------------------------------------------------------------------=head2 Pod::ParseTree-E<gt>B<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 C<Pod::Parse_tree> object andreturns a reference to the new parse-tree. If a single-argument is given,it must be a reference to an array, and is used to initialize the root(top) of the parse tree.=cutsub new {## Determine if we were called via an object-ref or a classnamemy $this = shift;my $class = ref($this) || $this;my $self = (@_ == 1 and ref $_[0]) ? $_[0] : [];## Bless ourselves into the desired class and perform any initializationbless $self, $class;return $self;}##---------------------------------------------------------------------------=head2 $ptree-E<gt>B<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 aregiven, it returns the topmost node in the tree (the root), which is alsoa B<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 ofchildren for the top node.=cutsub top {my $self = shift;if (@_ > 0) {@{ $self } = (@_ == 1 and ref $_[0]) ? ${ @_ } : @_;}return $self;}## let parse_tree() & ptree() be aliases for the 'top' method*parse_tree = *ptree = \⊤##---------------------------------------------------------------------------=head2 $ptree-E<gt>B<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 B<Pod::InteriorSequence>.Otherwise, if arguments are given, they are treated as the new list ofchildren for the top node.=cutsub children {my $self = shift;if (@_ > 0) {@{ $self } = (@_ == 1 and ref $_[0]) ? ${ @_ } : @_;}return @{ $self };}##---------------------------------------------------------------------------=head2 $ptree-E<gt>B<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 I<before>the current one.=cutuse vars qw(@ptree); ## an alias used for performance reasonssub prepend {my $self = shift;local *ptree = $self;for (@_) {next unless length;if (@ptree && !(ref $ptree[0]) && !(ref $_)) {$ptree[0] = $_ . $ptree[0];}else {unshift @ptree, $_;}}}##---------------------------------------------------------------------------=head2 $ptree-E<gt>B<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 I<after>the current one.=cutsub append {my $self = shift;local *ptree = $self;my $can_append = @ptree && !(ref $ptree[-1]);for (@_) {if (ref) {push @ptree, $_;}elsif(!length) {next;}elsif ($can_append) {$ptree[-1] .= $_;}else {push @ptree, $_;}}}=head2 $ptree-E<gt>B<raw_text()>my $ptree_raw_text = $ptree->raw_text();This method will return the I<raw> text of the POD parse-treeexactly as it appeared in the input.=cutsub raw_text {my $self = shift;my $text = '';for ( @$self ) {$text .= (ref $_) ? $_->raw_text : $_;}return $text;}##---------------------------------------------------------------------------## Private routines to set/unset child->parent linkssub _unset_child2parent_links {my $self = shift;local *ptree = $self;for (@ptree) {next unless (defined and length and ref and ref ne 'SCALAR');$_->_unset_child2parent_links()if UNIVERSAL::isa($_, 'Pod::InteriorSequence');}}sub _set_child2parent_links {## nothing to do, Pod::ParseTrees cant have parent pointers}=head2 Pod::ParseTree::B<DESTROY()>This method performs any necessary cleanup for the parse-tree.If you override this method then it is B<imperative>that you invoke the parent method from within your own method,otherwise I<parse-tree storage will not be reclaimed upon destruction!>=cutsub DESTROY {## We need to get rid of all child->parent pointers throughout the## tree so their reference counts will go to zero and they can be## garbage-collected_unset_child2parent_links(@_);}#############################################################################=head1 SEE ALSOSee L<Pod::Parser>, L<Pod::Select>=head1 AUTHORPlease report bugs using L<http://rt.cpan.org>.Brad Appleton E<lt>bradapp@enteract.comE<gt>=cut1;