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1 | ############################################################################# |
2 | # Pod/Parser.pm -- package which defines a base class for parsing POD docs. |
3 | # |
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4 | # Copyright (C) 1996-2000 by Bradford Appleton. All rights reserved. |
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5 | # This file is part of "PodParser". PodParser is free software; |
6 | # you can redistribute it and/or modify it under the same terms |
7 | # as Perl itself. |
8 | ############################################################################# |
9 | |
10 | package Pod::Parser; |
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11 | use strict; |
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12 | |
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13 | ## These "variables" are used as local "glob aliases" for performance |
14 | use vars qw($VERSION @ISA %myData %myOpts @input_stack); |
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15 | $VERSION = '1.37'; ## Current version of this package |
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16 | require 5.005; ## requires this Perl version or later |
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17 | |
18 | ############################################################################# |
19 | |
20 | =head1 NAME |
21 | |
22 | Pod::Parser - base class for creating POD filters and translators |
23 | |
24 | =head1 SYNOPSIS |
25 | |
26 | use Pod::Parser; |
27 | |
28 | package MyParser; |
29 | @ISA = qw(Pod::Parser); |
30 | |
31 | sub command { |
32 | my ($parser, $command, $paragraph, $line_num) = @_; |
33 | ## Interpret the command and its text; sample actions might be: |
34 | if ($command eq 'head1') { ... } |
35 | elsif ($command eq 'head2') { ... } |
36 | ## ... other commands and their actions |
37 | my $out_fh = $parser->output_handle(); |
38 | my $expansion = $parser->interpolate($paragraph, $line_num); |
39 | print $out_fh $expansion; |
40 | } |
41 | |
42 | sub verbatim { |
43 | my ($parser, $paragraph, $line_num) = @_; |
44 | ## Format verbatim paragraph; sample actions might be: |
45 | my $out_fh = $parser->output_handle(); |
46 | print $out_fh $paragraph; |
47 | } |
48 | |
49 | sub textblock { |
50 | my ($parser, $paragraph, $line_num) = @_; |
51 | ## Translate/Format this block of text; sample actions might be: |
52 | my $out_fh = $parser->output_handle(); |
53 | my $expansion = $parser->interpolate($paragraph, $line_num); |
54 | print $out_fh $expansion; |
55 | } |
56 | |
57 | sub interior_sequence { |
58 | my ($parser, $seq_command, $seq_argument) = @_; |
59 | ## Expand an interior sequence; sample actions might be: |
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60 | return "*$seq_argument*" if ($seq_command eq 'B'); |
61 | return "`$seq_argument'" if ($seq_command eq 'C'); |
62 | return "_${seq_argument}_'" if ($seq_command eq 'I'); |
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63 | ## ... other sequence commands and their resulting text |
64 | } |
65 | |
66 | package main; |
67 | |
68 | ## Create a parser object and have it parse file whose name was |
69 | ## given on the command-line (use STDIN if no files were given). |
70 | $parser = new MyParser(); |
71 | $parser->parse_from_filehandle(\*STDIN) if (@ARGV == 0); |
72 | for (@ARGV) { $parser->parse_from_file($_); } |
73 | |
74 | =head1 REQUIRES |
75 | |
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76 | perl5.005, Pod::InputObjects, Exporter, Symbol, Carp |
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77 | |
78 | =head1 EXPORTS |
79 | |
80 | Nothing. |
81 | |
82 | =head1 DESCRIPTION |
83 | |
84 | B<Pod::Parser> is a base class for creating POD filters and translators. |
85 | It handles most of the effort involved with parsing the POD sections |
86 | from an input stream, leaving subclasses free to be concerned only with |
87 | performing the actual translation of text. |
88 | |
89 | B<Pod::Parser> parses PODs, and makes method calls to handle the various |
90 | components of the POD. Subclasses of B<Pod::Parser> override these methods |
91 | to translate the POD into whatever output format they desire. |
92 | |
93 | =head1 QUICK OVERVIEW |
94 | |
95 | To create a POD filter for translating POD documentation into some other |
96 | format, you create a subclass of B<Pod::Parser> which typically overrides |
97 | just the base class implementation for the following methods: |
98 | |
99 | =over 2 |
100 | |
101 | =item * |
102 | |
103 | B<command()> |
104 | |
105 | =item * |
106 | |
107 | B<verbatim()> |
108 | |
109 | =item * |
110 | |
111 | B<textblock()> |
112 | |
113 | =item * |
114 | |
115 | B<interior_sequence()> |
116 | |
117 | =back |
118 | |
119 | You may also want to override the B<begin_input()> and B<end_input()> |
120 | methods for your subclass (to perform any needed per-file and/or |
121 | per-document initialization or cleanup). |
122 | |
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123 | If you need to perform any preprocessing of input before it is parsed |
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124 | you may want to override one or more of B<preprocess_line()> and/or |
125 | B<preprocess_paragraph()>. |
126 | |
127 | Sometimes it may be necessary to make more than one pass over the input |
128 | files. If this is the case you have several options. You can make the |
129 | first pass using B<Pod::Parser> and override your methods to store the |
130 | intermediate results in memory somewhere for the B<end_pod()> method to |
131 | process. You could use B<Pod::Parser> for several passes with an |
132 | appropriate state variable to control the operation for each pass. If |
133 | your input source can't be reset to start at the beginning, you can |
134 | store it in some other structure as a string or an array and have that |
135 | structure implement a B<getline()> method (which is all that |
136 | B<parse_from_filehandle()> uses to read input). |
137 | |
138 | Feel free to add any member data fields you need to keep track of things |
139 | like current font, indentation, horizontal or vertical position, or |
140 | whatever else you like. Be sure to read L<"PRIVATE METHODS AND DATA"> |
141 | to avoid name collisions. |
142 | |
143 | For the most part, the B<Pod::Parser> base class should be able to |
144 | do most of the input parsing for you and leave you free to worry about |
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145 | how to interpret the commands and translate the result. |
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146 | |
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147 | Note that all we have described here in this quick overview is the |
148 | simplest most straightforward use of B<Pod::Parser> to do stream-based |
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149 | parsing. It is also possible to use the B<Pod::Parser::parse_text> function |
150 | to do more sophisticated tree-based parsing. See L<"TREE-BASED PARSING">. |
151 | |
152 | =head1 PARSING OPTIONS |
153 | |
154 | A I<parse-option> is simply a named option of B<Pod::Parser> with a |
155 | value that corresponds to a certain specified behavior. These various |
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156 | behaviors of B<Pod::Parser> may be enabled/disabled by setting |
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157 | or unsetting one or more I<parse-options> using the B<parseopts()> method. |
158 | The set of currently accepted parse-options is as follows: |
159 | |
160 | =over 3 |
161 | |
162 | =item B<-want_nonPODs> (default: unset) |
163 | |
164 | Normally (by default) B<Pod::Parser> will only provide access to |
165 | the POD sections of the input. Input paragraphs that are not part |
166 | of the POD-format documentation are not made available to the caller |
167 | (not even using B<preprocess_paragraph()>). Setting this option to a |
168 | non-empty, non-zero value will allow B<preprocess_paragraph()> to see |
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169 | non-POD sections of the input as well as POD sections. The B<cutting()> |
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170 | method can be used to determine if the corresponding paragraph is a POD |
171 | paragraph, or some other input paragraph. |
172 | |
173 | =item B<-process_cut_cmd> (default: unset) |
174 | |
175 | Normally (by default) B<Pod::Parser> handles the C<=cut> POD directive |
176 | by itself and does not pass it on to the caller for processing. Setting |
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177 | this option to a non-empty, non-zero value will cause B<Pod::Parser> to |
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178 | pass the C<=cut> directive to the caller just like any other POD command |
179 | (and hence it may be processed by the B<command()> method). |
180 | |
181 | B<Pod::Parser> will still interpret the C<=cut> directive to mean that |
182 | "cutting mode" has been (re)entered, but the caller will get a chance |
183 | to capture the actual C<=cut> paragraph itself for whatever purpose |
184 | it desires. |
185 | |
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186 | =item B<-warnings> (default: unset) |
187 | |
188 | Normally (by default) B<Pod::Parser> recognizes a bare minimum of |
189 | pod syntax errors and warnings and issues diagnostic messages |
190 | for errors, but not for warnings. (Use B<Pod::Checker> to do more |
191 | thorough checking of POD syntax.) Setting this option to a non-empty, |
192 | non-zero value will cause B<Pod::Parser> to issue diagnostics for |
193 | the few warnings it recognizes as well as the errors. |
194 | |
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195 | =back |
196 | |
197 | Please see L<"parseopts()"> for a complete description of the interface |
198 | for the setting and unsetting of parse-options. |
199 | |
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200 | =cut |
201 | |
202 | ############################################################################# |
203 | |
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204 | #use diagnostics; |
205 | use Pod::InputObjects; |
206 | use Carp; |
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207 | use Exporter; |
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208 | BEGIN { |
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209 | if ($] < 5.006) { |
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210 | require Symbol; |
211 | import Symbol; |
212 | } |
213 | } |
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214 | @ISA = qw(Exporter); |
215 | |
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216 | ############################################################################# |
217 | |
218 | =head1 RECOMMENDED SUBROUTINE/METHOD OVERRIDES |
219 | |
220 | B<Pod::Parser> provides several methods which most subclasses will probably |
221 | want to override. These methods are as follows: |
222 | |
223 | =cut |
224 | |
225 | ##--------------------------------------------------------------------------- |
226 | |
227 | =head1 B<command()> |
228 | |
229 | $parser->command($cmd,$text,$line_num,$pod_para); |
230 | |
231 | This method should be overridden by subclasses to take the appropriate |
232 | action when a POD command paragraph (denoted by a line beginning with |
233 | "=") is encountered. When such a POD directive is seen in the input, |
234 | this method is called and is passed: |
235 | |
236 | =over 3 |
237 | |
238 | =item C<$cmd> |
239 | |
240 | the name of the command for this POD paragraph |
241 | |
242 | =item C<$text> |
243 | |
244 | the paragraph text for the given POD paragraph command. |
245 | |
246 | =item C<$line_num> |
247 | |
248 | the line-number of the beginning of the paragraph |
249 | |
250 | =item C<$pod_para> |
251 | |
252 | a reference to a C<Pod::Paragraph> object which contains further |
253 | information about the paragraph command (see L<Pod::InputObjects> |
254 | for details). |
255 | |
256 | =back |
257 | |
258 | B<Note> that this method I<is> called for C<=pod> paragraphs. |
259 | |
260 | The base class implementation of this method simply treats the raw POD |
261 | command as normal block of paragraph text (invoking the B<textblock()> |
262 | method with the command paragraph). |
263 | |
264 | =cut |
265 | |
266 | sub command { |
267 | my ($self, $cmd, $text, $line_num, $pod_para) = @_; |
268 | ## Just treat this like a textblock |
269 | $self->textblock($pod_para->raw_text(), $line_num, $pod_para); |
270 | } |
271 | |
272 | ##--------------------------------------------------------------------------- |
273 | |
274 | =head1 B<verbatim()> |
275 | |
276 | $parser->verbatim($text,$line_num,$pod_para); |
277 | |
278 | This method may be overridden by subclasses to take the appropriate |
279 | action when a block of verbatim text is encountered. It is passed the |
280 | following parameters: |
281 | |
282 | =over 3 |
283 | |
284 | =item C<$text> |
285 | |
286 | the block of text for the verbatim paragraph |
287 | |
288 | =item C<$line_num> |
289 | |
290 | the line-number of the beginning of the paragraph |
291 | |
292 | =item C<$pod_para> |
293 | |
294 | a reference to a C<Pod::Paragraph> object which contains further |
295 | information about the paragraph (see L<Pod::InputObjects> |
296 | for details). |
297 | |
298 | =back |
299 | |
300 | The base class implementation of this method simply prints the textblock |
301 | (unmodified) to the output filehandle. |
302 | |
303 | =cut |
304 | |
305 | sub verbatim { |
306 | my ($self, $text, $line_num, $pod_para) = @_; |
307 | my $out_fh = $self->{_OUTPUT}; |
308 | print $out_fh $text; |
309 | } |
310 | |
311 | ##--------------------------------------------------------------------------- |
312 | |
313 | =head1 B<textblock()> |
314 | |
315 | $parser->textblock($text,$line_num,$pod_para); |
316 | |
317 | This method may be overridden by subclasses to take the appropriate |
318 | action when a normal block of POD text is encountered (although the base |
319 | class method will usually do what you want). It is passed the following |
320 | parameters: |
321 | |
322 | =over 3 |
323 | |
324 | =item C<$text> |
325 | |
326 | the block of text for the a POD paragraph |
327 | |
328 | =item C<$line_num> |
329 | |
330 | the line-number of the beginning of the paragraph |
331 | |
332 | =item C<$pod_para> |
333 | |
334 | a reference to a C<Pod::Paragraph> object which contains further |
335 | information about the paragraph (see L<Pod::InputObjects> |
336 | for details). |
337 | |
338 | =back |
339 | |
340 | In order to process interior sequences, subclasses implementations of |
341 | this method will probably want to invoke either B<interpolate()> or |
342 | B<parse_text()>, passing it the text block C<$text>, and the corresponding |
343 | line number in C<$line_num>, and then perform any desired processing upon |
344 | the returned result. |
345 | |
346 | The base class implementation of this method simply prints the text block |
347 | as it occurred in the input stream). |
348 | |
349 | =cut |
350 | |
351 | sub textblock { |
352 | my ($self, $text, $line_num, $pod_para) = @_; |
353 | my $out_fh = $self->{_OUTPUT}; |
354 | print $out_fh $self->interpolate($text, $line_num); |
355 | } |
356 | |
357 | ##--------------------------------------------------------------------------- |
358 | |
359 | =head1 B<interior_sequence()> |
360 | |
361 | $parser->interior_sequence($seq_cmd,$seq_arg,$pod_seq); |
362 | |
363 | This method should be overridden by subclasses to take the appropriate |
364 | action when an interior sequence is encountered. An interior sequence is |
365 | an embedded command within a block of text which appears as a command |
366 | name (usually a single uppercase character) followed immediately by a |
367 | string of text which is enclosed in angle brackets. This method is |
368 | passed the sequence command C<$seq_cmd> and the corresponding text |
369 | C<$seq_arg>. It is invoked by the B<interpolate()> method for each interior |
370 | sequence that occurs in the string that it is passed. It should return |
371 | the desired text string to be used in place of the interior sequence. |
372 | The C<$pod_seq> argument is a reference to a C<Pod::InteriorSequence> |
373 | object which contains further information about the interior sequence. |
374 | Please see L<Pod::InputObjects> for details if you need to access this |
375 | additional information. |
376 | |
377 | Subclass implementations of this method may wish to invoke the |
378 | B<nested()> method of C<$pod_seq> to see if it is nested inside |
379 | some other interior-sequence (and if so, which kind). |
380 | |
381 | The base class implementation of the B<interior_sequence()> method |
382 | simply returns the raw text of the interior sequence (as it occurred |
383 | in the input) to the caller. |
384 | |
385 | =cut |
386 | |
387 | sub interior_sequence { |
388 | my ($self, $seq_cmd, $seq_arg, $pod_seq) = @_; |
389 | ## Just return the raw text of the interior sequence |
390 | return $pod_seq->raw_text(); |
391 | } |
392 | |
393 | ############################################################################# |
394 | |
395 | =head1 OPTIONAL SUBROUTINE/METHOD OVERRIDES |
396 | |
397 | B<Pod::Parser> provides several methods which subclasses may want to override |
398 | to perform any special pre/post-processing. These methods do I<not> have to |
399 | be overridden, but it may be useful for subclasses to take advantage of them. |
400 | |
401 | =cut |
402 | |
403 | ##--------------------------------------------------------------------------- |
404 | |
405 | =head1 B<new()> |
406 | |
407 | my $parser = Pod::Parser->new(); |
408 | |
409 | This is the constructor for B<Pod::Parser> and its subclasses. You |
410 | I<do not> need to override this method! It is capable of constructing |
411 | subclass objects as well as base class objects, provided you use |
412 | any of the following constructor invocation styles: |
413 | |
414 | my $parser1 = MyParser->new(); |
415 | my $parser2 = new MyParser(); |
416 | my $parser3 = $parser2->new(); |
417 | |
418 | where C<MyParser> is some subclass of B<Pod::Parser>. |
419 | |
420 | Using the syntax C<MyParser::new()> to invoke the constructor is I<not> |
421 | recommended, but if you insist on being able to do this, then the |
422 | subclass I<will> need to override the B<new()> constructor method. If |
423 | you do override the constructor, you I<must> be sure to invoke the |
424 | B<initialize()> method of the newly blessed object. |
425 | |
426 | Using any of the above invocations, the first argument to the |
427 | constructor is always the corresponding package name (or object |
428 | reference). No other arguments are required, but if desired, an |
429 | associative array (or hash-table) my be passed to the B<new()> |
430 | constructor, as in: |
431 | |
432 | my $parser1 = MyParser->new( MYDATA => $value1, MOREDATA => $value2 ); |
433 | my $parser2 = new MyParser( -myflag => 1 ); |
434 | |
435 | All arguments passed to the B<new()> constructor will be treated as |
436 | key/value pairs in a hash-table. The newly constructed object will be |
437 | initialized by copying the contents of the given hash-table (which may |
438 | have been empty). The B<new()> constructor for this class and all of its |
439 | subclasses returns a blessed reference to the initialized object (hash-table). |
440 | |
441 | =cut |
442 | |
443 | sub new { |
444 | ## Determine if we were called via an object-ref or a classname |
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445 | my ($this,%params) = @_; |
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446 | my $class = ref($this) || $this; |
447 | ## Any remaining arguments are treated as initial values for the |
448 | ## hash that is used to represent this object. |
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449 | my $self = { %params }; |
450 | ## Bless ourselves into the desired class and perform any initialization |
451 | bless $self, $class; |
452 | $self->initialize(); |
453 | return $self; |
454 | } |
455 | |
456 | ##--------------------------------------------------------------------------- |
457 | |
458 | =head1 B<initialize()> |
459 | |
460 | $parser->initialize(); |
461 | |
462 | This method performs any necessary object initialization. It takes no |
463 | arguments (other than the object instance of course, which is typically |
464 | copied to a local variable named C<$self>). If subclasses override this |
465 | method then they I<must> be sure to invoke C<$self-E<gt>SUPER::initialize()>. |
466 | |
467 | =cut |
468 | |
469 | sub initialize { |
470 | #my $self = shift; |
471 | #return; |
472 | } |
473 | |
474 | ##--------------------------------------------------------------------------- |
475 | |
476 | =head1 B<begin_pod()> |
477 | |
478 | $parser->begin_pod(); |
479 | |
480 | This method is invoked at the beginning of processing for each POD |
481 | document that is encountered in the input. Subclasses should override |
482 | this method to perform any per-document initialization. |
483 | |
484 | =cut |
485 | |
486 | sub begin_pod { |
487 | #my $self = shift; |
488 | #return; |
489 | } |
490 | |
491 | ##--------------------------------------------------------------------------- |
492 | |
493 | =head1 B<begin_input()> |
494 | |
495 | $parser->begin_input(); |
496 | |
497 | This method is invoked by B<parse_from_filehandle()> immediately I<before> |
498 | processing input from a filehandle. The base class implementation does |
499 | nothing, however, subclasses may override it to perform any per-file |
500 | initializations. |
501 | |
502 | Note that if multiple files are parsed for a single POD document |
503 | (perhaps the result of some future C<=include> directive) this method |
504 | is invoked for every file that is parsed. If you wish to perform certain |
505 | initializations once per document, then you should use B<begin_pod()>. |
506 | |
507 | =cut |
508 | |
509 | sub begin_input { |
510 | #my $self = shift; |
511 | #return; |
512 | } |
513 | |
514 | ##--------------------------------------------------------------------------- |
515 | |
516 | =head1 B<end_input()> |
517 | |
518 | $parser->end_input(); |
519 | |
520 | This method is invoked by B<parse_from_filehandle()> immediately I<after> |
521 | processing input from a filehandle. The base class implementation does |
522 | nothing, however, subclasses may override it to perform any per-file |
523 | cleanup actions. |
524 | |
525 | Please note that if multiple files are parsed for a single POD document |
526 | (perhaps the result of some kind of C<=include> directive) this method |
527 | is invoked for every file that is parsed. If you wish to perform certain |
528 | cleanup actions once per document, then you should use B<end_pod()>. |
529 | |
530 | =cut |
531 | |
532 | sub end_input { |
533 | #my $self = shift; |
534 | #return; |
535 | } |
536 | |
537 | ##--------------------------------------------------------------------------- |
538 | |
539 | =head1 B<end_pod()> |
540 | |
541 | $parser->end_pod(); |
542 | |
543 | This method is invoked at the end of processing for each POD document |
544 | that is encountered in the input. Subclasses should override this method |
545 | to perform any per-document finalization. |
546 | |
547 | =cut |
548 | |
549 | sub end_pod { |
550 | #my $self = shift; |
551 | #return; |
552 | } |
553 | |
554 | ##--------------------------------------------------------------------------- |
555 | |
556 | =head1 B<preprocess_line()> |
557 | |
558 | $textline = $parser->preprocess_line($text, $line_num); |
559 | |
560 | This method should be overridden by subclasses that wish to perform |
561 | any kind of preprocessing for each I<line> of input (I<before> it has |
562 | been determined whether or not it is part of a POD paragraph). The |
563 | parameter C<$text> is the input line; and the parameter C<$line_num> is |
564 | the line number of the corresponding text line. |
565 | |
566 | The value returned should correspond to the new text to use in its |
567 | place. If the empty string or an undefined value is returned then no |
568 | further processing will be performed for this line. |
569 | |
570 | Please note that the B<preprocess_line()> method is invoked I<before> |
571 | the B<preprocess_paragraph()> method. After all (possibly preprocessed) |
572 | lines in a paragraph have been assembled together and it has been |
573 | determined that the paragraph is part of the POD documentation from one |
574 | of the selected sections, then B<preprocess_paragraph()> is invoked. |
575 | |
576 | The base class implementation of this method returns the given text. |
577 | |
578 | =cut |
579 | |
580 | sub preprocess_line { |
581 | my ($self, $text, $line_num) = @_; |
582 | return $text; |
583 | } |
584 | |
585 | ##--------------------------------------------------------------------------- |
586 | |
587 | =head1 B<preprocess_paragraph()> |
588 | |
589 | $textblock = $parser->preprocess_paragraph($text, $line_num); |
590 | |
591 | This method should be overridden by subclasses that wish to perform any |
592 | kind of preprocessing for each block (paragraph) of POD documentation |
593 | that appears in the input stream. The parameter C<$text> is the POD |
594 | paragraph from the input file; and the parameter C<$line_num> is the |
595 | line number for the beginning of the corresponding paragraph. |
596 | |
597 | The value returned should correspond to the new text to use in its |
598 | place If the empty string is returned or an undefined value is |
599 | returned, then the given C<$text> is ignored (not processed). |
600 | |
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601 | This method is invoked after gathering up all the lines in a paragraph |
602 | and after determining the cutting state of the paragraph, |
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603 | but before trying to further parse or interpret them. After |
604 | B<preprocess_paragraph()> returns, the current cutting state (which |
605 | is returned by C<$self-E<gt>cutting()>) is examined. If it evaluates |
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606 | to true then input text (including the given C<$text>) is cut (not |
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607 | processed) until the next POD directive is encountered. |
608 | |
609 | Please note that the B<preprocess_line()> method is invoked I<before> |
610 | the B<preprocess_paragraph()> method. After all (possibly preprocessed) |
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611 | lines in a paragraph have been assembled together and either it has been |
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612 | determined that the paragraph is part of the POD documentation from one |
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613 | of the selected sections or the C<-want_nonPODs> option is true, |
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614 | then B<preprocess_paragraph()> is invoked. |
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615 | |
616 | The base class implementation of this method returns the given text. |
617 | |
618 | =cut |
619 | |
620 | sub preprocess_paragraph { |
621 | my ($self, $text, $line_num) = @_; |
622 | return $text; |
623 | } |
624 | |
625 | ############################################################################# |
626 | |
627 | =head1 METHODS FOR PARSING AND PROCESSING |
628 | |
629 | B<Pod::Parser> provides several methods to process input text. These |
664bb207 |
630 | methods typically won't need to be overridden (and in some cases they |
631 | can't be overridden), but subclasses may want to invoke them to exploit |
632 | their functionality. |
360aca43 |
633 | |
634 | =cut |
635 | |
636 | ##--------------------------------------------------------------------------- |
637 | |
638 | =head1 B<parse_text()> |
639 | |
640 | $ptree1 = $parser->parse_text($text, $line_num); |
641 | $ptree2 = $parser->parse_text({%opts}, $text, $line_num); |
642 | $ptree3 = $parser->parse_text(\%opts, $text, $line_num); |
643 | |
644 | This method is useful if you need to perform your own interpolation |
645 | of interior sequences and can't rely upon B<interpolate> to expand |
d1be9408 |
646 | them in simple bottom-up order. |
360aca43 |
647 | |
648 | The parameter C<$text> is a string or block of text to be parsed |
649 | for interior sequences; and the parameter C<$line_num> is the |
267d5541 |
650 | line number corresponding to the beginning of C<$text>. |
360aca43 |
651 | |
652 | B<parse_text()> will parse the given text into a parse-tree of "nodes." |
653 | and interior-sequences. Each "node" in the parse tree is either a |
654 | text-string, or a B<Pod::InteriorSequence>. The result returned is a |
655 | parse-tree of type B<Pod::ParseTree>. Please see L<Pod::InputObjects> |
656 | for more information about B<Pod::InteriorSequence> and B<Pod::ParseTree>. |
657 | |
658 | If desired, an optional hash-ref may be specified as the first argument |
659 | to customize certain aspects of the parse-tree that is created and |
660 | returned. The set of recognized option keywords are: |
661 | |
662 | =over 3 |
663 | |
664 | =item B<-expand_seq> =E<gt> I<code-ref>|I<method-name> |
665 | |
666 | Normally, the parse-tree returned by B<parse_text()> will contain an |
667 | unexpanded C<Pod::InteriorSequence> object for each interior-sequence |
668 | encountered. Specifying B<-expand_seq> tells B<parse_text()> to "expand" |
669 | every interior-sequence it sees by invoking the referenced function |
670 | (or named method of the parser object) and using the return value as the |
671 | expanded result. |
672 | |
673 | If a subroutine reference was given, it is invoked as: |
674 | |
675 | &$code_ref( $parser, $sequence ) |
676 | |
677 | and if a method-name was given, it is invoked as: |
678 | |
679 | $parser->method_name( $sequence ) |
680 | |
681 | where C<$parser> is a reference to the parser object, and C<$sequence> |
682 | is a reference to the interior-sequence object. |
683 | [I<NOTE>: If the B<interior_sequence()> method is specified, then it is |
684 | invoked according to the interface specified in L<"interior_sequence()">]. |
685 | |
664bb207 |
686 | =item B<-expand_text> =E<gt> I<code-ref>|I<method-name> |
687 | |
688 | Normally, the parse-tree returned by B<parse_text()> will contain a |
689 | text-string for each contiguous sequence of characters outside of an |
690 | interior-sequence. Specifying B<-expand_text> tells B<parse_text()> to |
691 | "preprocess" every such text-string it sees by invoking the referenced |
692 | function (or named method of the parser object) and using the return value |
693 | as the preprocessed (or "expanded") result. [Note that if the result is |
694 | an interior-sequence, then it will I<not> be expanded as specified by the |
695 | B<-expand_seq> option; Any such recursive expansion needs to be handled by |
696 | the specified callback routine.] |
697 | |
698 | If a subroutine reference was given, it is invoked as: |
699 | |
700 | &$code_ref( $parser, $text, $ptree_node ) |
701 | |
702 | and if a method-name was given, it is invoked as: |
703 | |
704 | $parser->method_name( $text, $ptree_node ) |
705 | |
706 | where C<$parser> is a reference to the parser object, C<$text> is the |
707 | text-string encountered, and C<$ptree_node> is a reference to the current |
708 | node in the parse-tree (usually an interior-sequence object or else the |
709 | top-level node of the parse-tree). |
710 | |
360aca43 |
711 | =item B<-expand_ptree> =E<gt> I<code-ref>|I<method-name> |
712 | |
713 | Rather than returning a C<Pod::ParseTree>, pass the parse-tree as an |
714 | argument to the referenced subroutine (or named method of the parser |
715 | object) and return the result instead of the parse-tree object. |
716 | |
717 | If a subroutine reference was given, it is invoked as: |
718 | |
719 | &$code_ref( $parser, $ptree ) |
720 | |
721 | and if a method-name was given, it is invoked as: |
722 | |
723 | $parser->method_name( $ptree ) |
724 | |
725 | where C<$parser> is a reference to the parser object, and C<$ptree> |
726 | is a reference to the parse-tree object. |
727 | |
728 | =back |
729 | |
730 | =cut |
731 | |
360aca43 |
732 | sub parse_text { |
733 | my $self = shift; |
734 | local $_ = ''; |
735 | |
736 | ## Get options and set any defaults |
737 | my %opts = (ref $_[0]) ? %{ shift() } : (); |
738 | my $expand_seq = $opts{'-expand_seq'} || undef; |
664bb207 |
739 | my $expand_text = $opts{'-expand_text'} || undef; |
360aca43 |
740 | my $expand_ptree = $opts{'-expand_ptree'} || undef; |
741 | |
742 | my $text = shift; |
743 | my $line = shift; |
744 | my $file = $self->input_file(); |
66aff6dd |
745 | my $cmd = ""; |
360aca43 |
746 | |
747 | ## Convert method calls into closures, for our convenience |
748 | my $xseq_sub = $expand_seq; |
664bb207 |
749 | my $xtext_sub = $expand_text; |
360aca43 |
750 | my $xptree_sub = $expand_ptree; |
e9fdc7d2 |
751 | if (defined $expand_seq and $expand_seq eq 'interior_sequence') { |
360aca43 |
752 | ## If 'interior_sequence' is the method to use, we have to pass |
753 | ## more than just the sequence object, we also need to pass the |
754 | ## sequence name and text. |
755 | $xseq_sub = sub { |
1bc4b319 |
756 | my ($sself, $iseq) = @_; |
757 | my $args = join('', $iseq->parse_tree->children); |
758 | return $sself->interior_sequence($iseq->name, $args, $iseq); |
360aca43 |
759 | }; |
760 | } |
761 | ref $xseq_sub or $xseq_sub = sub { shift()->$expand_seq(@_) }; |
664bb207 |
762 | ref $xtext_sub or $xtext_sub = sub { shift()->$expand_text(@_) }; |
360aca43 |
763 | ref $xptree_sub or $xptree_sub = sub { shift()->$expand_ptree(@_) }; |
66aff6dd |
764 | |
360aca43 |
765 | ## Keep track of the "current" interior sequence, and maintain a stack |
766 | ## of "in progress" sequences. |
767 | ## |
768 | ## NOTE that we push our own "accumulator" at the very beginning of the |
769 | ## stack. It's really a parse-tree, not a sequence; but it implements |
770 | ## the methods we need so we can use it to gather-up all the sequences |
771 | ## and strings we parse. Thus, by the end of our parsing, it should be |
772 | ## the only thing left on our stack and all we have to do is return it! |
773 | ## |
774 | my $seq = Pod::ParseTree->new(); |
775 | my @seq_stack = ($seq); |
66aff6dd |
776 | my ($ldelim, $rdelim) = ('', ''); |
360aca43 |
777 | |
faee740f |
778 | ## Iterate over all sequence starts text (NOTE: split with |
779 | ## capturing parens keeps the delimiters) |
360aca43 |
780 | $_ = $text; |
39a52d2c |
781 | my @tokens = split /([A-Z]<(?:<+\s)?)/; |
66aff6dd |
782 | while ( @tokens ) { |
783 | $_ = shift @tokens; |
faee740f |
784 | ## Look for the beginning of a sequence |
39a52d2c |
785 | if ( /^([A-Z])(<(?:<+\s)?)$/ ) { |
e9fdc7d2 |
786 | ## Push a new sequence onto the stack of those "in-progress" |
c23d1eb0 |
787 | my $ldelim_orig; |
788 | ($cmd, $ldelim_orig) = ($1, $2); |
789 | ($ldelim = $ldelim_orig) =~ s/\s+$//; |
790 | ($rdelim = $ldelim) =~ tr/</>/; |
360aca43 |
791 | $seq = Pod::InteriorSequence->new( |
66aff6dd |
792 | -name => $cmd, |
c23d1eb0 |
793 | -ldelim => $ldelim_orig, -rdelim => $rdelim, |
66aff6dd |
794 | -file => $file, -line => $line |
360aca43 |
795 | ); |
796 | (@seq_stack > 1) and $seq->nested($seq_stack[-1]); |
797 | push @seq_stack, $seq; |
798 | } |
66aff6dd |
799 | ## Look for sequence ending |
800 | elsif ( @seq_stack > 1 ) { |
801 | ## Make sure we match the right kind of closing delimiter |
1bc4b319 |
802 | my ($seq_end, $post_seq) = ('', ''); |
66aff6dd |
803 | if ( ($ldelim eq '<' and /\A(.*?)(>)/s) |
804 | or /\A(.*?)(\s+$rdelim)/s ) |
805 | { |
806 | ## Found end-of-sequence, capture the interior and the |
807 | ## closing the delimiter, and put the rest back on the |
808 | ## token-list |
809 | $post_seq = substr($_, length($1) + length($2)); |
810 | ($_, $seq_end) = ($1, $2); |
811 | (length $post_seq) and unshift @tokens, $post_seq; |
812 | } |
813 | if (length) { |
814 | ## In the middle of a sequence, append this text to it, and |
815 | ## dont forget to "expand" it if that's what the caller wanted |
816 | $seq->append($expand_text ? &$xtext_sub($self,$_,$seq) : $_); |
817 | $_ .= $seq_end; |
818 | } |
819 | if (length $seq_end) { |
820 | ## End of current sequence, record terminating delimiter |
821 | $seq->rdelim($seq_end); |
822 | ## Pop it off the stack of "in progress" sequences |
823 | pop @seq_stack; |
824 | ## Append result to its parent in current parse tree |
825 | $seq_stack[-1]->append($expand_seq ? &$xseq_sub($self,$seq) |
826 | : $seq); |
827 | ## Remember the current cmd-name and left-delimiter |
c23d1eb0 |
828 | if(@seq_stack > 1) { |
829 | $cmd = $seq_stack[-1]->name; |
830 | $ldelim = $seq_stack[-1]->ldelim; |
831 | $rdelim = $seq_stack[-1]->rdelim; |
832 | } else { |
833 | $cmd = $ldelim = $rdelim = ''; |
834 | } |
66aff6dd |
835 | } |
360aca43 |
836 | } |
664bb207 |
837 | elsif (length) { |
838 | ## In the middle of a sequence, append this text to it, and |
839 | ## dont forget to "expand" it if that's what the caller wanted |
840 | $seq->append($expand_text ? &$xtext_sub($self,$_,$seq) : $_); |
360aca43 |
841 | } |
66aff6dd |
842 | ## Keep track of line count |
267d5541 |
843 | $line += s/\r*\n//; |
66aff6dd |
844 | ## Remember the "current" sequence |
845 | $seq = $seq_stack[-1]; |
360aca43 |
846 | } |
847 | |
848 | ## Handle unterminated sequences |
664bb207 |
849 | my $errorsub = (@seq_stack > 1) ? $self->errorsub() : undef; |
360aca43 |
850 | while (@seq_stack > 1) { |
851 | ($cmd, $file, $line) = ($seq->name, $seq->file_line); |
66aff6dd |
852 | $ldelim = $seq->ldelim; |
853 | ($rdelim = $ldelim) =~ tr/</>/; |
854 | $rdelim =~ s/^(\S+)(\s*)$/$2$1/; |
360aca43 |
855 | pop @seq_stack; |
a5317591 |
856 | my $errmsg = "*** ERROR: unterminated ${cmd}${ldelim}...${rdelim}". |
66aff6dd |
857 | " at line $line in file $file\n"; |
664bb207 |
858 | (ref $errorsub) and &{$errorsub}($errmsg) |
f5daac4a |
859 | or (defined $errorsub) and $self->$errorsub($errmsg) |
1bc4b319 |
860 | or carp($errmsg); |
360aca43 |
861 | $seq_stack[-1]->append($expand_seq ? &$xseq_sub($self,$seq) : $seq); |
862 | $seq = $seq_stack[-1]; |
863 | } |
864 | |
865 | ## Return the resulting parse-tree |
866 | my $ptree = (pop @seq_stack)->parse_tree; |
867 | return $expand_ptree ? &$xptree_sub($self, $ptree) : $ptree; |
868 | } |
869 | |
870 | ##--------------------------------------------------------------------------- |
871 | |
872 | =head1 B<interpolate()> |
873 | |
874 | $textblock = $parser->interpolate($text, $line_num); |
875 | |
876 | This method translates all text (including any embedded interior sequences) |
877 | in the given text string C<$text> and returns the interpolated result. The |
878 | parameter C<$line_num> is the line number corresponding to the beginning |
879 | of C<$text>. |
880 | |
881 | B<interpolate()> merely invokes a private method to recursively expand |
882 | nested interior sequences in bottom-up order (innermost sequences are |
883 | expanded first). If there is a need to expand nested sequences in |
884 | some alternate order, use B<parse_text> instead. |
885 | |
886 | =cut |
887 | |
888 | sub interpolate { |
889 | my($self, $text, $line_num) = @_; |
890 | my %parse_opts = ( -expand_seq => 'interior_sequence' ); |
891 | my $ptree = $self->parse_text( \%parse_opts, $text, $line_num ); |
1bc4b319 |
892 | return join '', $ptree->children(); |
360aca43 |
893 | } |
894 | |
895 | ##--------------------------------------------------------------------------- |
896 | |
897 | =begin __PRIVATE__ |
898 | |
899 | =head1 B<parse_paragraph()> |
900 | |
901 | $parser->parse_paragraph($text, $line_num); |
902 | |
903 | This method takes the text of a POD paragraph to be processed, along |
904 | with its corresponding line number, and invokes the appropriate method |
905 | (one of B<command()>, B<verbatim()>, or B<textblock()>). |
906 | |
664bb207 |
907 | For performance reasons, this method is invoked directly without any |
908 | dynamic lookup; Hence subclasses may I<not> override it! |
360aca43 |
909 | |
910 | =end __PRIVATE__ |
911 | |
912 | =cut |
913 | |
914 | sub parse_paragraph { |
915 | my ($self, $text, $line_num) = @_; |
664bb207 |
916 | local *myData = $self; ## alias to avoid deref-ing overhead |
917 | local *myOpts = ($myData{_PARSEOPTS} ||= {}); ## get parse-options |
360aca43 |
918 | local $_; |
919 | |
664bb207 |
920 | ## See if we want to preprocess nonPOD paragraphs as well as POD ones. |
e3237417 |
921 | my $wantNonPods = $myOpts{'-want_nonPODs'}; |
922 | |
923 | ## Update cutting status |
924 | $myData{_CUTTING} = 0 if $text =~ /^={1,2}\S/; |
664bb207 |
925 | |
926 | ## Perform any desired preprocessing if we wanted it this early |
927 | $wantNonPods and $text = $self->preprocess_paragraph($text, $line_num); |
928 | |
360aca43 |
929 | ## Ignore up until next POD directive if we are cutting |
e3237417 |
930 | return if $myData{_CUTTING}; |
360aca43 |
931 | |
932 | ## Now we know this is block of text in a POD section! |
933 | |
934 | ##----------------------------------------------------------------- |
935 | ## This is a hook (hack ;-) for Pod::Select to do its thing without |
936 | ## having to override methods, but also without Pod::Parser assuming |
937 | ## $self is an instance of Pod::Select (if the _SELECTED_SECTIONS |
938 | ## field exists then we assume there is an is_selected() method for |
939 | ## us to invoke (calling $self->can('is_selected') could verify this |
940 | ## but that is more overhead than I want to incur) |
941 | ##----------------------------------------------------------------- |
942 | |
943 | ## Ignore this block if it isnt in one of the selected sections |
944 | if (exists $myData{_SELECTED_SECTIONS}) { |
945 | $self->is_selected($text) or return ($myData{_CUTTING} = 1); |
946 | } |
947 | |
664bb207 |
948 | ## If we havent already, perform any desired preprocessing and |
949 | ## then re-check the "cutting" state |
950 | unless ($wantNonPods) { |
951 | $text = $self->preprocess_paragraph($text, $line_num); |
952 | return 1 unless ((defined $text) and (length $text)); |
953 | return 1 if ($myData{_CUTTING}); |
954 | } |
360aca43 |
955 | |
956 | ## Look for one of the three types of paragraphs |
957 | my ($pfx, $cmd, $arg, $sep) = ('', '', '', ''); |
958 | my $pod_para = undef; |
959 | if ($text =~ /^(={1,2})(?=\S)/) { |
960 | ## Looks like a command paragraph. Capture the command prefix used |
961 | ## ("=" or "=="), as well as the command-name, its paragraph text, |
962 | ## and whatever sequence of characters was used to separate them |
963 | $pfx = $1; |
964 | $_ = substr($text, length $pfx); |
1bc4b319 |
965 | ($cmd, $sep, $text) = split /(\s+)/, $_, 2; |
360aca43 |
966 | ## If this is a "cut" directive then we dont need to do anything |
967 | ## except return to "cutting" mode. |
968 | if ($cmd eq 'cut') { |
969 | $myData{_CUTTING} = 1; |
664bb207 |
970 | return unless $myOpts{'-process_cut_cmd'}; |
360aca43 |
971 | } |
972 | } |
973 | ## Save the attributes indicating how the command was specified. |
974 | $pod_para = new Pod::Paragraph( |
975 | -name => $cmd, |
976 | -text => $text, |
977 | -prefix => $pfx, |
978 | -separator => $sep, |
979 | -file => $myData{_INFILE}, |
980 | -line => $line_num |
981 | ); |
982 | # ## Invoke appropriate callbacks |
983 | # if (exists $myData{_CALLBACKS}) { |
984 | # ## Look through the callback list, invoke callbacks, |
985 | # ## then see if we need to do the default actions |
986 | # ## (invoke_callbacks will return true if we do). |
987 | # return 1 unless $self->invoke_callbacks($cmd, $text, $line_num, $pod_para); |
988 | # } |
caa547d4 |
989 | |
990 | # If the last paragraph ended in whitespace, and we're not between verbatim blocks, carp |
991 | if ($myData{_WHITESPACE} and $myOpts{'-warnings'} |
992 | and not ($text =~ /^\s+/ and ($myData{_PREVIOUS}||"") eq "verbatim")) { |
993 | my $errorsub = $self->errorsub(); |
994 | my $line = $line_num - 1; |
995 | my $errmsg = "*** WARNING: line containing nothing but whitespace". |
996 | " in paragraph at line $line in file $myData{_INFILE}\n"; |
997 | (ref $errorsub) and &{$errorsub}($errmsg) |
998 | or (defined $errorsub) and $self->$errorsub($errmsg) |
8b2bdce6 |
999 | or carp($errmsg); |
caa547d4 |
1000 | } |
1001 | |
360aca43 |
1002 | if (length $cmd) { |
1003 | ## A command paragraph |
1004 | $self->command($cmd, $text, $line_num, $pod_para); |
caa547d4 |
1005 | $myData{_PREVIOUS} = $cmd; |
360aca43 |
1006 | } |
1007 | elsif ($text =~ /^\s+/) { |
1008 | ## Indented text - must be a verbatim paragraph |
1009 | $self->verbatim($text, $line_num, $pod_para); |
caa547d4 |
1010 | $myData{_PREVIOUS} = "verbatim"; |
360aca43 |
1011 | } |
1012 | else { |
1013 | ## Looks like an ordinary block of text |
1014 | $self->textblock($text, $line_num, $pod_para); |
caa547d4 |
1015 | $myData{_PREVIOUS} = "textblock"; |
360aca43 |
1016 | } |
caa547d4 |
1017 | |
1018 | # Update the whitespace for the next time around |
1019 | $myData{_WHITESPACE} = $text =~ /^[^\S\r\n]+\Z/m ? 1 : 0; |
1020 | |
360aca43 |
1021 | return 1; |
1022 | } |
1023 | |
1024 | ##--------------------------------------------------------------------------- |
1025 | |
1026 | =head1 B<parse_from_filehandle()> |
1027 | |
1028 | $parser->parse_from_filehandle($in_fh,$out_fh); |
1029 | |
1030 | This method takes an input filehandle (which is assumed to already be |
1031 | opened for reading) and reads the entire input stream looking for blocks |
1032 | (paragraphs) of POD documentation to be processed. If no first argument |
1033 | is given the default input filehandle C<STDIN> is used. |
1034 | |
1035 | The C<$in_fh> parameter may be any object that provides a B<getline()> |
1036 | method to retrieve a single line of input text (hence, an appropriate |
1037 | wrapper object could be used to parse PODs from a single string or an |
1038 | array of strings). |
1039 | |
1040 | Using C<$in_fh-E<gt>getline()>, input is read line-by-line and assembled |
1041 | into paragraphs or "blocks" (which are separated by lines containing |
1042 | nothing but whitespace). For each block of POD documentation |
1043 | encountered it will invoke a method to parse the given paragraph. |
1044 | |
1045 | If a second argument is given then it should correspond to a filehandle where |
1046 | output should be sent (otherwise the default output filehandle is |
1047 | C<STDOUT> if no output filehandle is currently in use). |
1048 | |
1049 | B<NOTE:> For performance reasons, this method caches the input stream at |
1050 | the top of the stack in a local variable. Any attempts by clients to |
1051 | change the stack contents during processing when in the midst executing |
1052 | of this method I<will not affect> the input stream used by the current |
1053 | invocation of this method. |
1054 | |
1055 | This method does I<not> usually need to be overridden by subclasses. |
1056 | |
1057 | =cut |
1058 | |
1059 | sub parse_from_filehandle { |
1060 | my $self = shift; |
1061 | my %opts = (ref $_[0] eq 'HASH') ? %{ shift() } : (); |
1062 | my ($in_fh, $out_fh) = @_; |
22641bdf |
1063 | $in_fh = \*STDIN unless ($in_fh); |
a5317591 |
1064 | local *myData = $self; ## alias to avoid deref-ing overhead |
1065 | local *myOpts = ($myData{_PARSEOPTS} ||= {}); ## get parse-options |
360aca43 |
1066 | local $_; |
1067 | |
1068 | ## Put this stream at the top of the stack and do beginning-of-input |
1069 | ## processing. NOTE that $in_fh might be reset during this process. |
1070 | my $topstream = $self->_push_input_stream($in_fh, $out_fh); |
1071 | (exists $opts{-cutting}) and $self->cutting( $opts{-cutting} ); |
1072 | |
1073 | ## Initialize line/paragraph |
1074 | my ($textline, $paragraph) = ('', ''); |
1075 | my ($nlines, $plines) = (0, 0); |
1076 | |
1077 | ## Use <$fh> instead of $fh->getline where possible (for speed) |
1078 | $_ = ref $in_fh; |
1079 | my $tied_fh = (/^(?:GLOB|FileHandle|IO::\w+)$/ or tied $in_fh); |
1080 | |
1081 | ## Read paragraphs line-by-line |
1082 | while (defined ($textline = $tied_fh ? <$in_fh> : $in_fh->getline)) { |
1083 | $textline = $self->preprocess_line($textline, ++$nlines); |
1084 | next unless ((defined $textline) && (length $textline)); |
360aca43 |
1085 | |
1086 | if ((! length $paragraph) && ($textline =~ /^==/)) { |
1087 | ## '==' denotes a one-line command paragraph |
1088 | $paragraph = $textline; |
1089 | $plines = 1; |
1090 | $textline = ''; |
1091 | } else { |
1092 | ## Append this line to the current paragraph |
1093 | $paragraph .= $textline; |
1094 | ++$plines; |
1095 | } |
1096 | |
66aff6dd |
1097 | ## See if this line is blank and ends the current paragraph. |
360aca43 |
1098 | ## If it isnt, then keep iterating until it is. |
a5317591 |
1099 | next unless (($textline =~ /^([^\S\r\n]*)[\r\n]*$/) |
1100 | && (length $paragraph)); |
66aff6dd |
1101 | |
360aca43 |
1102 | ## Now process the paragraph |
1103 | parse_paragraph($self, $paragraph, ($nlines - $plines) + 1); |
1104 | $paragraph = ''; |
1105 | $plines = 0; |
1106 | } |
1107 | ## Dont forget about the last paragraph in the file |
1108 | if (length $paragraph) { |
1109 | parse_paragraph($self, $paragraph, ($nlines - $plines) + 1) |
1110 | } |
1111 | |
1112 | ## Now pop the input stream off the top of the input stack. |
1113 | $self->_pop_input_stream(); |
1114 | } |
1115 | |
1116 | ##--------------------------------------------------------------------------- |
1117 | |
1118 | =head1 B<parse_from_file()> |
1119 | |
1120 | $parser->parse_from_file($filename,$outfile); |
1121 | |
1122 | This method takes a filename and does the following: |
1123 | |
1124 | =over 2 |
1125 | |
1126 | =item * |
1127 | |
1128 | opens the input and output files for reading |
1129 | (creating the appropriate filehandles) |
1130 | |
1131 | =item * |
1132 | |
1133 | invokes the B<parse_from_filehandle()> method passing it the |
1134 | corresponding input and output filehandles. |
1135 | |
1136 | =item * |
1137 | |
1138 | closes the input and output files. |
1139 | |
1140 | =back |
1141 | |
1142 | If the special input filename "-" or "<&STDIN" is given then the STDIN |
1143 | filehandle is used for input (and no open or close is performed). If no |
1bc4b319 |
1144 | input filename is specified then "-" is implied. Filehandle references, |
1145 | or objects that support the regular IO operations (like C<E<lt>$fhE<gt>> |
1146 | or C<$fh-<Egt>getline>) are also accepted; the handles must already be |
1147 | opened. |
360aca43 |
1148 | |
1149 | If a second argument is given then it should be the name of the desired |
1150 | output file. If the special output filename "-" or ">&STDOUT" is given |
1151 | then the STDOUT filehandle is used for output (and no open or close is |
1152 | performed). If the special output filename ">&STDERR" is given then the |
1153 | STDERR filehandle is used for output (and no open or close is |
1154 | performed). If no output filehandle is currently in use and no output |
1155 | filename is specified, then "-" is implied. |
1bc4b319 |
1156 | Alternatively, filehandle references or objects that support the regular |
1157 | IO operations (like C<print>, e.g. L<IO::String>) are also accepted; |
1158 | the object must already be opened. |
360aca43 |
1159 | |
1160 | This method does I<not> usually need to be overridden by subclasses. |
1161 | |
1162 | =cut |
1163 | |
1164 | sub parse_from_file { |
1165 | my $self = shift; |
1166 | my %opts = (ref $_[0] eq 'HASH') ? %{ shift() } : (); |
1167 | my ($infile, $outfile) = @_; |
267d5541 |
1168 | my ($in_fh, $out_fh); |
1169 | if ($] < 5.006) { |
1170 | ($in_fh, $out_fh) = (gensym(), gensym()); |
1171 | } |
360aca43 |
1172 | my ($close_input, $close_output) = (0, 0); |
1173 | local *myData = $self; |
d5c61f7c |
1174 | local *_; |
360aca43 |
1175 | |
1176 | ## Is $infile a filename or a (possibly implied) filehandle |
7b47f8ec |
1177 | if (defined $infile && ref $infile) { |
d5c61f7c |
1178 | if (ref($infile) =~ /^(SCALAR|ARRAY|HASH|CODE|REF)$/) { |
1179 | croak "Input from $1 reference not supported!\n"; |
1180 | } |
360aca43 |
1181 | ## Must be a filehandle-ref (or else assume its a ref to an object |
1182 | ## that supports the common IO read operations). |
1183 | $myData{_INFILE} = ${$infile}; |
1184 | $in_fh = $infile; |
1185 | } |
7b47f8ec |
1186 | elsif (!defined($infile) || !length($infile) || ($infile eq '-') |
1187 | || ($infile =~ /^<&(?:STDIN|0)$/i)) |
1188 | { |
1189 | ## Not a filename, just a string implying STDIN |
1190 | $infile ||= '-'; |
1bc4b319 |
1191 | $myData{_INFILE} = '<standard input>'; |
7b47f8ec |
1192 | $in_fh = \*STDIN; |
1193 | } |
360aca43 |
1194 | else { |
1195 | ## We have a filename, open it for reading |
1196 | $myData{_INFILE} = $infile; |
475d79b5 |
1197 | open($in_fh, "< $infile") or |
360aca43 |
1198 | croak "Can't open $infile for reading: $!\n"; |
1199 | $close_input = 1; |
1200 | } |
1201 | |
1202 | ## NOTE: we need to be *very* careful when "defaulting" the output |
1203 | ## file. We only want to use a default if this is the beginning of |
1204 | ## the entire document (but *not* if this is an included file). We |
1205 | ## determine this by seeing if the input stream stack has been set-up |
1206 | ## already |
d5c61f7c |
1207 | |
1208 | ## Is $outfile a filename, a (possibly implied) filehandle, maybe a ref? |
7b47f8ec |
1209 | if (ref $outfile) { |
d5c61f7c |
1210 | ## we need to check for ref() first, as other checks involve reading |
1211 | if (ref($outfile) =~ /^(ARRAY|HASH|CODE)$/) { |
1212 | croak "Output to $1 reference not supported!\n"; |
1213 | } |
1214 | elsif (ref($outfile) eq 'SCALAR') { |
1215 | # # NOTE: IO::String isn't a part of the perl distribution, |
1216 | # # so probably we shouldn't support this case... |
1217 | # require IO::String; |
1218 | # $myData{_OUTFILE} = "$outfile"; |
1219 | # $out_fh = IO::String->new($outfile); |
1220 | croak "Output to SCALAR reference not supported!\n"; |
360aca43 |
1221 | } |
d5c61f7c |
1222 | else { |
360aca43 |
1223 | ## Must be a filehandle-ref (or else assume its a ref to an |
1224 | ## object that supports the common IO write operations). |
828c4421 |
1225 | $myData{_OUTFILE} = ${$outfile}; |
360aca43 |
1226 | $out_fh = $outfile; |
1227 | } |
d5c61f7c |
1228 | } |
7b47f8ec |
1229 | elsif (!defined($outfile) || !length($outfile) || ($outfile eq '-') |
1230 | || ($outfile =~ /^>&?(?:STDOUT|1)$/i)) |
1231 | { |
1232 | if (defined $myData{_TOP_STREAM}) { |
1233 | $out_fh = $myData{_OUTPUT}; |
1234 | } |
1235 | else { |
1236 | ## Not a filename, just a string implying STDOUT |
1237 | $outfile ||= '-'; |
1bc4b319 |
1238 | $myData{_OUTFILE} = '<standard output>'; |
7b47f8ec |
1239 | $out_fh = \*STDOUT; |
1240 | } |
1241 | } |
d5c61f7c |
1242 | elsif ($outfile =~ /^>&(STDERR|2)$/i) { |
1243 | ## Not a filename, just a string implying STDERR |
1bc4b319 |
1244 | $myData{_OUTFILE} = '<standard error>'; |
d5c61f7c |
1245 | $out_fh = \*STDERR; |
1246 | } |
1247 | else { |
1248 | ## We have a filename, open it for writing |
1249 | $myData{_OUTFILE} = $outfile; |
1250 | (-d $outfile) and croak "$outfile is a directory, not POD input!\n"; |
1251 | open($out_fh, "> $outfile") or |
1252 | croak "Can't open $outfile for writing: $!\n"; |
1253 | $close_output = 1; |
360aca43 |
1254 | } |
1255 | |
1256 | ## Whew! That was a lot of work to set up reasonably/robust behavior |
1257 | ## in the case of a non-filename for reading and writing. Now we just |
1258 | ## have to parse the input and close the handles when we're finished. |
1259 | $self->parse_from_filehandle(\%opts, $in_fh, $out_fh); |
1260 | |
1bc4b319 |
1261 | $close_input and |
360aca43 |
1262 | close($in_fh) || croak "Can't close $infile after reading: $!\n"; |
1263 | $close_output and |
1264 | close($out_fh) || croak "Can't close $outfile after writing: $!\n"; |
1265 | } |
1266 | |
1267 | ############################################################################# |
1268 | |
1269 | =head1 ACCESSOR METHODS |
1270 | |
1271 | Clients of B<Pod::Parser> should use the following methods to access |
1272 | instance data fields: |
1273 | |
1274 | =cut |
1275 | |
1276 | ##--------------------------------------------------------------------------- |
1277 | |
664bb207 |
1278 | =head1 B<errorsub()> |
1279 | |
1280 | $parser->errorsub("method_name"); |
1281 | $parser->errorsub(\&warn_user); |
1282 | $parser->errorsub(sub { print STDERR, @_ }); |
1283 | |
1284 | Specifies the method or subroutine to use when printing error messages |
1285 | about POD syntax. The supplied method/subroutine I<must> return TRUE upon |
1bc4b319 |
1286 | successful printing of the message. If C<undef> is given, then the B<carp> |
664bb207 |
1287 | builtin is used to issue error messages (this is the default behavior). |
1288 | |
1289 | my $errorsub = $parser->errorsub() |
1290 | my $errmsg = "This is an error message!\n" |
1291 | (ref $errorsub) and &{$errorsub}($errmsg) |
e3237417 |
1292 | or (defined $errorsub) and $parser->$errorsub($errmsg) |
1bc4b319 |
1293 | or carp($errmsg); |
664bb207 |
1294 | |
1295 | Returns a method name, or else a reference to the user-supplied subroutine |
1bc4b319 |
1296 | used to print error messages. Returns C<undef> if the B<carp> builtin |
664bb207 |
1297 | is used to issue error messages (this is the default behavior). |
1298 | |
1299 | =cut |
1300 | |
1301 | sub errorsub { |
1302 | return (@_ > 1) ? ($_[0]->{_ERRORSUB} = $_[1]) : $_[0]->{_ERRORSUB}; |
1303 | } |
1304 | |
1305 | ##--------------------------------------------------------------------------- |
1306 | |
360aca43 |
1307 | =head1 B<cutting()> |
1308 | |
1309 | $boolean = $parser->cutting(); |
1310 | |
1311 | Returns the current C<cutting> state: a boolean-valued scalar which |
1312 | evaluates to true if text from the input file is currently being "cut" |
1313 | (meaning it is I<not> considered part of the POD document). |
1314 | |
1315 | $parser->cutting($boolean); |
1316 | |
1317 | Sets the current C<cutting> state to the given value and returns the |
1318 | result. |
1319 | |
1320 | =cut |
1321 | |
1322 | sub cutting { |
1323 | return (@_ > 1) ? ($_[0]->{_CUTTING} = $_[1]) : $_[0]->{_CUTTING}; |
1324 | } |
1325 | |
1326 | ##--------------------------------------------------------------------------- |
1327 | |
664bb207 |
1328 | ##--------------------------------------------------------------------------- |
1329 | |
1330 | =head1 B<parseopts()> |
1331 | |
1332 | When invoked with no additional arguments, B<parseopts> returns a hashtable |
1333 | of all the current parsing options. |
1334 | |
1335 | ## See if we are parsing non-POD sections as well as POD ones |
1336 | my %opts = $parser->parseopts(); |
1337 | $opts{'-want_nonPODs}' and print "-want_nonPODs\n"; |
1338 | |
1339 | When invoked using a single string, B<parseopts> treats the string as the |
1340 | name of a parse-option and returns its corresponding value if it exists |
1341 | (returns C<undef> if it doesn't). |
1342 | |
1343 | ## Did we ask to see '=cut' paragraphs? |
1344 | my $want_cut = $parser->parseopts('-process_cut_cmd'); |
1345 | $want_cut and print "-process_cut_cmd\n"; |
1346 | |
1347 | When invoked with multiple arguments, B<parseopts> treats them as |
1348 | key/value pairs and the specified parse-option names are set to the |
1349 | given values. Any unspecified parse-options are unaffected. |
1350 | |
1351 | ## Set them back to the default |
a5317591 |
1352 | $parser->parseopts(-warnings => 0); |
664bb207 |
1353 | |
1354 | When passed a single hash-ref, B<parseopts> uses that hash to completely |
1355 | reset the existing parse-options, all previous parse-option values |
1356 | are lost. |
1357 | |
1358 | ## Reset all options to default |
1359 | $parser->parseopts( { } ); |
1360 | |
a5317591 |
1361 | See L<"PARSING OPTIONS"> for more information on the name and meaning of each |
664bb207 |
1362 | parse-option currently recognized. |
1363 | |
1364 | =cut |
1365 | |
1366 | sub parseopts { |
1367 | local *myData = shift; |
1368 | local *myOpts = ($myData{_PARSEOPTS} ||= {}); |
1369 | return %myOpts if (@_ == 0); |
1370 | if (@_ == 1) { |
1371 | local $_ = shift; |
1372 | return ref($_) ? $myData{_PARSEOPTS} = $_ : $myOpts{$_}; |
1373 | } |
1374 | my @newOpts = (%myOpts, @_); |
1375 | $myData{_PARSEOPTS} = { @newOpts }; |
1376 | } |
1377 | |
1378 | ##--------------------------------------------------------------------------- |
1379 | |
360aca43 |
1380 | =head1 B<output_file()> |
1381 | |
1382 | $fname = $parser->output_file(); |
1383 | |
1384 | Returns the name of the output file being written. |
1385 | |
1386 | =cut |
1387 | |
1388 | sub output_file { |
1389 | return $_[0]->{_OUTFILE}; |
1390 | } |
1391 | |
1392 | ##--------------------------------------------------------------------------- |
1393 | |
1394 | =head1 B<output_handle()> |
1395 | |
1396 | $fhandle = $parser->output_handle(); |
1397 | |
1398 | Returns the output filehandle object. |
1399 | |
1400 | =cut |
1401 | |
1402 | sub output_handle { |
1403 | return $_[0]->{_OUTPUT}; |
1404 | } |
1405 | |
1406 | ##--------------------------------------------------------------------------- |
1407 | |
1408 | =head1 B<input_file()> |
1409 | |
1410 | $fname = $parser->input_file(); |
1411 | |
1412 | Returns the name of the input file being read. |
1413 | |
1414 | =cut |
1415 | |
1416 | sub input_file { |
1417 | return $_[0]->{_INFILE}; |
1418 | } |
1419 | |
1420 | ##--------------------------------------------------------------------------- |
1421 | |
1422 | =head1 B<input_handle()> |
1423 | |
1424 | $fhandle = $parser->input_handle(); |
1425 | |
1426 | Returns the current input filehandle object. |
1427 | |
1428 | =cut |
1429 | |
1430 | sub input_handle { |
1431 | return $_[0]->{_INPUT}; |
1432 | } |
1433 | |
1434 | ##--------------------------------------------------------------------------- |
1435 | |
1436 | =begin __PRIVATE__ |
1437 | |
1438 | =head1 B<input_streams()> |
1439 | |
1440 | $listref = $parser->input_streams(); |
1441 | |
1442 | Returns a reference to an array which corresponds to the stack of all |
1443 | the input streams that are currently in the middle of being parsed. |
1444 | |
1445 | While parsing an input stream, it is possible to invoke |
1446 | B<parse_from_file()> or B<parse_from_filehandle()> to parse a new input |
1447 | stream and then return to parsing the previous input stream. Each input |
1448 | stream to be parsed is pushed onto the end of this input stack |
1449 | before any of its input is read. The input stream that is currently |
1450 | being parsed is always at the end (or top) of the input stack. When an |
1451 | input stream has been exhausted, it is popped off the end of the |
1452 | input stack. |
1453 | |
1454 | Each element on this input stack is a reference to C<Pod::InputSource> |
1455 | object. Please see L<Pod::InputObjects> for more details. |
1456 | |
1457 | This method might be invoked when printing diagnostic messages, for example, |
1458 | to obtain the name and line number of the all input files that are currently |
1459 | being processed. |
1460 | |
1461 | =end __PRIVATE__ |
1462 | |
1463 | =cut |
1464 | |
1465 | sub input_streams { |
1466 | return $_[0]->{_INPUT_STREAMS}; |
1467 | } |
1468 | |
1469 | ##--------------------------------------------------------------------------- |
1470 | |
1471 | =begin __PRIVATE__ |
1472 | |
1473 | =head1 B<top_stream()> |
1474 | |
1475 | $hashref = $parser->top_stream(); |
1476 | |
1477 | Returns a reference to the hash-table that represents the element |
1478 | that is currently at the top (end) of the input stream stack |
1479 | (see L<"input_streams()">). The return value will be the C<undef> |
1480 | if the input stack is empty. |
1481 | |
1482 | This method might be used when printing diagnostic messages, for example, |
1483 | to obtain the name and line number of the current input file. |
1484 | |
1485 | =end __PRIVATE__ |
1486 | |
1487 | =cut |
1488 | |
1489 | sub top_stream { |
1490 | return $_[0]->{_TOP_STREAM} || undef; |
1491 | } |
1492 | |
1493 | ############################################################################# |
1494 | |
1495 | =head1 PRIVATE METHODS AND DATA |
1496 | |
1497 | B<Pod::Parser> makes use of several internal methods and data fields |
1498 | which clients should not need to see or use. For the sake of avoiding |
1499 | name collisions for client data and methods, these methods and fields |
1500 | are briefly discussed here. Determined hackers may obtain further |
1501 | information about them by reading the B<Pod::Parser> source code. |
1502 | |
1503 | Private data fields are stored in the hash-object whose reference is |
1504 | returned by the B<new()> constructor for this class. The names of all |
1505 | private methods and data-fields used by B<Pod::Parser> begin with a |
1506 | prefix of "_" and match the regular expression C</^_\w+$/>. |
1507 | |
1508 | =cut |
1509 | |
1510 | ##--------------------------------------------------------------------------- |
1511 | |
1512 | =begin _PRIVATE_ |
1513 | |
1514 | =head1 B<_push_input_stream()> |
1515 | |
1516 | $hashref = $parser->_push_input_stream($in_fh,$out_fh); |
1517 | |
1518 | This method will push the given input stream on the input stack and |
1519 | perform any necessary beginning-of-document or beginning-of-file |
1520 | processing. The argument C<$in_fh> is the input stream filehandle to |
1521 | push, and C<$out_fh> is the corresponding output filehandle to use (if |
1522 | it is not given or is undefined, then the current output stream is used, |
1523 | which defaults to standard output if it doesnt exist yet). |
1524 | |
1525 | The value returned will be reference to the hash-table that represents |
1526 | the new top of the input stream stack. I<Please Note> that it is |
1527 | possible for this method to use default values for the input and output |
1528 | file handles. If this happens, you will need to look at the C<INPUT> |
1529 | and C<OUTPUT> instance data members to determine their new values. |
1530 | |
1531 | =end _PRIVATE_ |
1532 | |
1533 | =cut |
1534 | |
1535 | sub _push_input_stream { |
1536 | my ($self, $in_fh, $out_fh) = @_; |
1537 | local *myData = $self; |
1538 | |
1539 | ## Initialize stuff for the entire document if this is *not* |
1540 | ## an included file. |
1541 | ## |
1542 | ## NOTE: we need to be *very* careful when "defaulting" the output |
1543 | ## filehandle. We only want to use a default value if this is the |
1544 | ## beginning of the entire document (but *not* if this is an included |
1545 | ## file). |
1546 | unless (defined $myData{_TOP_STREAM}) { |
1547 | $out_fh = \*STDOUT unless (defined $out_fh); |
1548 | $myData{_CUTTING} = 1; ## current "cutting" state |
1549 | $myData{_INPUT_STREAMS} = []; ## stack of all input streams |
1550 | } |
1551 | |
1552 | ## Initialize input indicators |
1553 | $myData{_OUTFILE} = '(unknown)' unless (defined $myData{_OUTFILE}); |
1554 | $myData{_OUTPUT} = $out_fh if (defined $out_fh); |
1555 | $in_fh = \*STDIN unless (defined $in_fh); |
1556 | $myData{_INFILE} = '(unknown)' unless (defined $myData{_INFILE}); |
1557 | $myData{_INPUT} = $in_fh; |
1558 | my $input_top = $myData{_TOP_STREAM} |
1559 | = new Pod::InputSource( |
1560 | -name => $myData{_INFILE}, |
1561 | -handle => $in_fh, |
1562 | -was_cutting => $myData{_CUTTING} |
1563 | ); |
1564 | local *input_stack = $myData{_INPUT_STREAMS}; |
1565 | push(@input_stack, $input_top); |
1566 | |
1567 | ## Perform beginning-of-document and/or beginning-of-input processing |
1568 | $self->begin_pod() if (@input_stack == 1); |
1569 | $self->begin_input(); |
1570 | |
1571 | return $input_top; |
1572 | } |
1573 | |
1574 | ##--------------------------------------------------------------------------- |
1575 | |
1576 | =begin _PRIVATE_ |
1577 | |
1578 | =head1 B<_pop_input_stream()> |
1579 | |
1580 | $hashref = $parser->_pop_input_stream(); |
1581 | |
1582 | This takes no arguments. It will perform any necessary end-of-file or |
1583 | end-of-document processing and then pop the current input stream from |
1584 | the top of the input stack. |
1585 | |
1586 | The value returned will be reference to the hash-table that represents |
1587 | the new top of the input stream stack. |
1588 | |
1589 | =end _PRIVATE_ |
1590 | |
1591 | =cut |
1592 | |
1593 | sub _pop_input_stream { |
1594 | my ($self) = @_; |
1595 | local *myData = $self; |
1596 | local *input_stack = $myData{_INPUT_STREAMS}; |
1597 | |
1598 | ## Perform end-of-input and/or end-of-document processing |
1599 | $self->end_input() if (@input_stack > 0); |
1600 | $self->end_pod() if (@input_stack == 1); |
1601 | |
1602 | ## Restore cutting state to whatever it was before we started |
1603 | ## parsing this file. |
1604 | my $old_top = pop(@input_stack); |
1605 | $myData{_CUTTING} = $old_top->was_cutting(); |
1606 | |
1607 | ## Dont forget to reset the input indicators |
1608 | my $input_top = undef; |
1609 | if (@input_stack > 0) { |
1610 | $input_top = $myData{_TOP_STREAM} = $input_stack[-1]; |
1611 | $myData{_INFILE} = $input_top->name(); |
1612 | $myData{_INPUT} = $input_top->handle(); |
1613 | } else { |
1614 | delete $myData{_TOP_STREAM}; |
1615 | delete $myData{_INPUT_STREAMS}; |
1616 | } |
1617 | |
1618 | return $input_top; |
1619 | } |
1620 | |
1621 | ############################################################################# |
1622 | |
664bb207 |
1623 | =head1 TREE-BASED PARSING |
1624 | |
1625 | If straightforward stream-based parsing wont meet your needs (as is |
1626 | likely the case for tasks such as translating PODs into structured |
1627 | markup languages like HTML and XML) then you may need to take the |
1628 | tree-based approach. Rather than doing everything in one pass and |
1629 | calling the B<interpolate()> method to expand sequences into text, it |
1630 | may be desirable to instead create a parse-tree using the B<parse_text()> |
d1be9408 |
1631 | method to return a tree-like structure which may contain an ordered |
664bb207 |
1632 | list of children (each of which may be a text-string, or a similar |
1633 | tree-like structure). |
1634 | |
1635 | Pay special attention to L<"METHODS FOR PARSING AND PROCESSING"> and |
1636 | to the objects described in L<Pod::InputObjects>. The former describes |
1637 | the gory details and parameters for how to customize and extend the |
1638 | parsing behavior of B<Pod::Parser>. B<Pod::InputObjects> provides |
1639 | several objects that may all be used interchangeably as parse-trees. The |
1640 | most obvious one is the B<Pod::ParseTree> object. It defines the basic |
1641 | interface and functionality that all things trying to be a POD parse-tree |
1642 | should do. A B<Pod::ParseTree> is defined such that each "node" may be a |
1643 | text-string, or a reference to another parse-tree. Each B<Pod::Paragraph> |
1644 | object and each B<Pod::InteriorSequence> object also supports the basic |
1645 | parse-tree interface. |
1646 | |
1647 | The B<parse_text()> method takes a given paragraph of text, and |
1648 | returns a parse-tree that contains one or more children, each of which |
1649 | may be a text-string, or an InteriorSequence object. There are also |
1650 | callback-options that may be passed to B<parse_text()> to customize |
1651 | the way it expands or transforms interior-sequences, as well as the |
1652 | returned result. These callbacks can be used to create a parse-tree |
1653 | with custom-made objects (which may or may not support the parse-tree |
1654 | interface, depending on how you choose to do it). |
1655 | |
1656 | If you wish to turn an entire POD document into a parse-tree, that process |
1657 | is fairly straightforward. The B<parse_text()> method is the key to doing |
1658 | this successfully. Every paragraph-callback (i.e. the polymorphic methods |
1659 | for B<command()>, B<verbatim()>, and B<textblock()> paragraphs) takes |
1660 | a B<Pod::Paragraph> object as an argument. Each paragraph object has a |
1661 | B<parse_tree()> method that can be used to get or set a corresponding |
1662 | parse-tree. So for each of those paragraph-callback methods, simply call |
1663 | B<parse_text()> with the options you desire, and then use the returned |
1664 | parse-tree to assign to the given paragraph object. |
1665 | |
1666 | That gives you a parse-tree for each paragraph - so now all you need is |
1667 | an ordered list of paragraphs. You can maintain that yourself as a data |
1668 | element in the object/hash. The most straightforward way would be simply |
1669 | to use an array-ref, with the desired set of custom "options" for each |
1670 | invocation of B<parse_text>. Let's assume the desired option-set is |
1671 | given by the hash C<%options>. Then we might do something like the |
1672 | following: |
1673 | |
1674 | package MyPodParserTree; |
1675 | |
1676 | @ISA = qw( Pod::Parser ); |
1677 | |
1678 | ... |
1679 | |
1680 | sub begin_pod { |
1681 | my $self = shift; |
1682 | $self->{'-paragraphs'} = []; ## initialize paragraph list |
1683 | } |
1684 | |
1685 | sub command { |
1686 | my ($parser, $command, $paragraph, $line_num, $pod_para) = @_; |
1687 | my $ptree = $parser->parse_text({%options}, $paragraph, ...); |
1688 | $pod_para->parse_tree( $ptree ); |
1689 | push @{ $self->{'-paragraphs'} }, $pod_para; |
1690 | } |
1691 | |
1692 | sub verbatim { |
1693 | my ($parser, $paragraph, $line_num, $pod_para) = @_; |
1694 | push @{ $self->{'-paragraphs'} }, $pod_para; |
1695 | } |
1696 | |
1697 | sub textblock { |
1698 | my ($parser, $paragraph, $line_num, $pod_para) = @_; |
1699 | my $ptree = $parser->parse_text({%options}, $paragraph, ...); |
1700 | $pod_para->parse_tree( $ptree ); |
1701 | push @{ $self->{'-paragraphs'} }, $pod_para; |
1702 | } |
1703 | |
1704 | ... |
1705 | |
1706 | package main; |
1707 | ... |
1708 | my $parser = new MyPodParserTree(...); |
1709 | $parser->parse_from_file(...); |
1710 | my $paragraphs_ref = $parser->{'-paragraphs'}; |
1711 | |
1712 | Of course, in this module-author's humble opinion, I'd be more inclined to |
1713 | use the existing B<Pod::ParseTree> object than a simple array. That way |
1714 | everything in it, paragraphs and sequences, all respond to the same core |
1715 | interface for all parse-tree nodes. The result would look something like: |
1716 | |
1717 | package MyPodParserTree2; |
1718 | |
1719 | ... |
1720 | |
1721 | sub begin_pod { |
1722 | my $self = shift; |
1723 | $self->{'-ptree'} = new Pod::ParseTree; ## initialize parse-tree |
1724 | } |
1725 | |
1726 | sub parse_tree { |
1727 | ## convenience method to get/set the parse-tree for the entire POD |
1728 | (@_ > 1) and $_[0]->{'-ptree'} = $_[1]; |
1729 | return $_[0]->{'-ptree'}; |
1730 | } |
1731 | |
1732 | sub command { |
1733 | my ($parser, $command, $paragraph, $line_num, $pod_para) = @_; |
1734 | my $ptree = $parser->parse_text({<<options>>}, $paragraph, ...); |
1735 | $pod_para->parse_tree( $ptree ); |
1736 | $parser->parse_tree()->append( $pod_para ); |
1737 | } |
1738 | |
1739 | sub verbatim { |
1740 | my ($parser, $paragraph, $line_num, $pod_para) = @_; |
1741 | $parser->parse_tree()->append( $pod_para ); |
1742 | } |
1743 | |
1744 | sub textblock { |
1745 | my ($parser, $paragraph, $line_num, $pod_para) = @_; |
1746 | my $ptree = $parser->parse_text({<<options>>}, $paragraph, ...); |
1747 | $pod_para->parse_tree( $ptree ); |
1748 | $parser->parse_tree()->append( $pod_para ); |
1749 | } |
1750 | |
1751 | ... |
1752 | |
1753 | package main; |
1754 | ... |
1755 | my $parser = new MyPodParserTree2(...); |
1756 | $parser->parse_from_file(...); |
1757 | my $ptree = $parser->parse_tree; |
1758 | ... |
1759 | |
1760 | Now you have the entire POD document as one great big parse-tree. You |
1761 | can even use the B<-expand_seq> option to B<parse_text> to insert |
1762 | whole different kinds of objects. Just don't expect B<Pod::Parser> |
1763 | to know what to do with them after that. That will need to be in your |
1764 | code. Or, alternatively, you can insert any object you like so long as |
1765 | it conforms to the B<Pod::ParseTree> interface. |
1766 | |
1767 | One could use this to create subclasses of B<Pod::Paragraphs> and |
1768 | B<Pod::InteriorSequences> for specific commands (or to create your own |
1769 | custom node-types in the parse-tree) and add some kind of B<emit()> |
1770 | method to each custom node/subclass object in the tree. Then all you'd |
1771 | need to do is recursively walk the tree in the desired order, processing |
1772 | the children (most likely from left to right) by formatting them if |
1773 | they are text-strings, or by calling their B<emit()> method if they |
1774 | are objects/references. |
1775 | |
267d5541 |
1776 | =head1 CAVEATS |
1777 | |
1778 | Please note that POD has the notion of "paragraphs": this is something |
1779 | starting I<after> a blank (read: empty) line, with the single exception |
1780 | of the file start, which is also starting a paragraph. That means that |
1781 | especially a command (e.g. C<=head1>) I<must> be preceded with a blank |
1782 | line; C<__END__> is I<not> a blank line. |
1783 | |
360aca43 |
1784 | =head1 SEE ALSO |
1785 | |
1786 | L<Pod::InputObjects>, L<Pod::Select> |
1787 | |
1788 | B<Pod::InputObjects> defines POD input objects corresponding to |
1789 | command paragraphs, parse-trees, and interior-sequences. |
1790 | |
1791 | B<Pod::Select> is a subclass of B<Pod::Parser> which provides the ability |
1792 | to selectively include and/or exclude sections of a POD document from being |
1793 | translated based upon the current heading, subheading, subsubheading, etc. |
1794 | |
1795 | =for __PRIVATE__ |
1796 | B<Pod::Callbacks> is a subclass of B<Pod::Parser> which gives its users |
1797 | the ability the employ I<callback functions> instead of, or in addition |
1798 | to, overriding methods of the base class. |
1799 | |
1800 | =for __PRIVATE__ |
1801 | B<Pod::Select> and B<Pod::Callbacks> do not override any |
1802 | methods nor do they define any new methods with the same name. Because |
1803 | of this, they may I<both> be used (in combination) as a base class of |
1804 | the same subclass in order to combine their functionality without |
1805 | causing any namespace clashes due to multiple inheritance. |
1806 | |
1807 | =head1 AUTHOR |
1808 | |
aaa799f9 |
1809 | Please report bugs using L<http://rt.cpan.org>. |
1810 | |
360aca43 |
1811 | Brad Appleton E<lt>bradapp@enteract.comE<gt> |
1812 | |
1813 | Based on code for B<Pod::Text> written by |
1814 | Tom Christiansen E<lt>tchrist@mox.perl.comE<gt> |
1815 | |
1bc4b319 |
1816 | =head1 LICENSE |
1817 | |
1818 | Pod-Parser is free software; you can redistribute it and/or modify it |
1819 | under the terms of the Artistic License distributed with Perl version |
1820 | 5.000 or (at your option) any later version. Please refer to the |
1821 | Artistic License that came with your Perl distribution for more |
1822 | details. If your version of Perl was not distributed under the |
1823 | terms of the Artistic License, than you may distribute PodParser |
1824 | under the same terms as Perl itself. |
1825 | |
360aca43 |
1826 | =cut |
1827 | |
1828 | 1; |
d5c61f7c |
1829 | # vim: ts=4 sw=4 et |