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1 | ############################################################################# |
2 | # Pod/Select.pm -- function to select portions of 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::Select; |
11 | |
12 | use vars qw($VERSION); |
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13 | $VERSION = 1.13; ## Current version of this package |
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14 | require 5.005; ## requires this Perl version or later |
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15 | |
16 | ############################################################################# |
17 | |
18 | =head1 NAME |
19 | |
20 | Pod::Select, podselect() - extract selected sections of POD from input |
21 | |
22 | =head1 SYNOPSIS |
23 | |
24 | use Pod::Select; |
25 | |
26 | ## Select all the POD sections for each file in @filelist |
27 | ## and print the result on standard output. |
28 | podselect(@filelist); |
29 | |
30 | ## Same as above, but write to tmp.out |
31 | podselect({-output => "tmp.out"}, @filelist): |
32 | |
33 | ## Select from the given filelist, only those POD sections that are |
34 | ## within a 1st level section named any of: NAME, SYNOPSIS, OPTIONS. |
35 | podselect({-sections => ["NAME|SYNOPSIS", "OPTIONS"]}, @filelist): |
36 | |
37 | ## Select the "DESCRIPTION" section of the PODs from STDIN and write |
38 | ## the result to STDERR. |
39 | podselect({-output => ">&STDERR", -sections => ["DESCRIPTION"]}, \*STDIN); |
40 | |
41 | or |
42 | |
43 | use Pod::Select; |
44 | |
45 | ## Create a parser object for selecting POD sections from the input |
46 | $parser = new Pod::Select(); |
47 | |
48 | ## Select all the POD sections for each file in @filelist |
49 | ## and print the result to tmp.out. |
50 | $parser->parse_from_file("<&STDIN", "tmp.out"); |
51 | |
52 | ## Select from the given filelist, only those POD sections that are |
53 | ## within a 1st level section named any of: NAME, SYNOPSIS, OPTIONS. |
54 | $parser->select("NAME|SYNOPSIS", "OPTIONS"); |
55 | for (@filelist) { $parser->parse_from_file($_); } |
56 | |
57 | ## Select the "DESCRIPTION" and "SEE ALSO" sections of the PODs from |
58 | ## STDIN and write the result to STDERR. |
59 | $parser->select("DESCRIPTION"); |
60 | $parser->add_selection("SEE ALSO"); |
61 | $parser->parse_from_filehandle(\*STDIN, \*STDERR); |
62 | |
63 | =head1 REQUIRES |
64 | |
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65 | perl5.005, Pod::Parser, Exporter, Carp |
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66 | |
67 | =head1 EXPORTS |
68 | |
69 | podselect() |
70 | |
71 | =head1 DESCRIPTION |
72 | |
73 | B<podselect()> is a function which will extract specified sections of |
74 | pod documentation from an input stream. This ability is provided by the |
75 | B<Pod::Select> module which is a subclass of B<Pod::Parser>. |
76 | B<Pod::Select> provides a method named B<select()> to specify the set of |
77 | POD sections to select for processing/printing. B<podselect()> merely |
78 | creates a B<Pod::Select> object and then invokes the B<podselect()> |
79 | followed by B<parse_from_file()>. |
80 | |
81 | =head1 SECTION SPECIFICATIONS |
82 | |
83 | B<podselect()> and B<Pod::Select::select()> may be given one or more |
84 | "section specifications" to restrict the text processed to only the |
85 | desired set of sections and their corresponding subsections. A section |
86 | specification is a string containing one or more Perl-style regular |
87 | expressions separated by forward slashes ("/"). If you need to use a |
88 | forward slash literally within a section title you can escape it with a |
89 | backslash ("\/"). |
90 | |
91 | The formal syntax of a section specification is: |
92 | |
93 | =over 4 |
94 | |
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95 | =item * |
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96 | |
97 | I<head1-title-regex>/I<head2-title-regex>/... |
98 | |
99 | =back |
100 | |
101 | Any omitted or empty regular expressions will default to ".*". |
102 | Please note that each regular expression given is implicitly |
103 | anchored by adding "^" and "$" to the beginning and end. Also, if a |
104 | given regular expression starts with a "!" character, then the |
105 | expression is I<negated> (so C<!foo> would match anything I<except> |
106 | C<foo>). |
107 | |
108 | Some example section specifications follow. |
109 | |
110 | =over 4 |
111 | |
112 | =item |
113 | Match the C<NAME> and C<SYNOPSIS> sections and all of their subsections: |
114 | |
115 | C<NAME|SYNOPSIS> |
116 | |
117 | =item |
118 | Match only the C<Question> and C<Answer> subsections of the C<DESCRIPTION> |
119 | section: |
120 | |
121 | C<DESCRIPTION/Question|Answer> |
122 | |
123 | =item |
124 | Match the C<Comments> subsection of I<all> sections: |
125 | |
126 | C</Comments> |
127 | |
128 | =item |
129 | Match all subsections of C<DESCRIPTION> I<except> for C<Comments>: |
130 | |
131 | C<DESCRIPTION/!Comments> |
132 | |
133 | =item |
134 | Match the C<DESCRIPTION> section but do I<not> match any of its subsections: |
135 | |
136 | C<DESCRIPTION/!.+> |
137 | |
138 | =item |
139 | Match all top level sections but none of their subsections: |
140 | |
141 | C</!.+> |
142 | |
143 | =back |
144 | |
145 | =begin _NOT_IMPLEMENTED_ |
146 | |
147 | =head1 RANGE SPECIFICATIONS |
148 | |
149 | B<podselect()> and B<Pod::Select::select()> may be given one or more |
150 | "range specifications" to restrict the text processed to only the |
151 | desired ranges of paragraphs in the desired set of sections. A range |
152 | specification is a string containing a single Perl-style regular |
153 | expression (a regex), or else two Perl-style regular expressions |
154 | (regexs) separated by a ".." (Perl's "range" operator is ".."). |
155 | The regexs in a range specification are delimited by forward slashes |
156 | ("/"). If you need to use a forward slash literally within a regex you |
157 | can escape it with a backslash ("\/"). |
158 | |
159 | The formal syntax of a range specification is: |
160 | |
161 | =over 4 |
162 | |
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163 | =item * |
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164 | |
165 | /I<start-range-regex>/[../I<end-range-regex>/] |
166 | |
167 | =back |
168 | |
169 | Where each the item inside square brackets (the ".." followed by the |
170 | end-range-regex) is optional. Each "range-regex" is of the form: |
171 | |
172 | =cmd-expr text-expr |
173 | |
174 | Where I<cmd-expr> is intended to match the name of one or more POD |
175 | commands, and I<text-expr> is intended to match the paragraph text for |
176 | the command. If a range-regex is supposed to match a POD command, then |
177 | the first character of the regex (the one after the initial '/') |
178 | absolutely I<must> be an single '=' character; it may not be anything |
179 | else (not even a regex meta-character) if it is supposed to match |
180 | against the name of a POD command. |
181 | |
182 | If no I<=cmd-expr> is given then the text-expr will be matched against |
183 | plain textblocks unless it is preceded by a space, in which case it is |
184 | matched against verbatim text-blocks. If no I<text-expr> is given then |
185 | only the command-portion of the paragraph is matched against. |
186 | |
187 | Note that these two expressions are each implicitly anchored. This |
188 | means that when matching against the command-name, there will be an |
189 | implicit '^' and '$' around the given I<=cmd-expr>; and when matching |
190 | against the paragraph text there will be an implicit '\A' and '\Z' |
191 | around the given I<text-expr>. |
192 | |
193 | Unlike with section-specs, the '!' character does I<not> have any special |
194 | meaning (negation or otherwise) at the beginning of a range-spec! |
195 | |
196 | Some example range specifications follow. |
197 | |
198 | =over 4 |
199 | |
200 | =item |
201 | Match all C<=for html> paragraphs: |
202 | |
203 | C</=for html/> |
204 | |
205 | =item |
206 | Match all paragraphs between C<=begin html> and C<=end html> |
207 | (note that this will I<not> work correctly if such sections |
208 | are nested): |
209 | |
210 | C</=begin html/../=end html/> |
211 | |
212 | =item |
213 | Match all paragraphs between the given C<=item> name until the end of the |
214 | current section: |
215 | |
216 | C</=item mine/../=head\d/> |
217 | |
218 | =item |
219 | Match all paragraphs between the given C<=item> until the next item, or |
220 | until the end of the itemized list (note that this will I<not> work as |
221 | desired if the item contains an itemized list nested within it): |
222 | |
223 | C</=item mine/../=(item|back)/> |
224 | |
225 | =back |
226 | |
227 | =end _NOT_IMPLEMENTED_ |
228 | |
229 | =cut |
230 | |
231 | ############################################################################# |
232 | |
233 | use strict; |
234 | #use diagnostics; |
235 | use Carp; |
236 | use Pod::Parser 1.04; |
237 | use vars qw(@ISA @EXPORT $MAX_HEADING_LEVEL); |
238 | |
239 | @ISA = qw(Pod::Parser); |
240 | @EXPORT = qw(&podselect); |
241 | |
242 | ## Maximum number of heading levels supported for '=headN' directives |
243 | *MAX_HEADING_LEVEL = \3; |
244 | |
245 | ############################################################################# |
246 | |
247 | =head1 OBJECT METHODS |
248 | |
249 | The following methods are provided in this module. Each one takes a |
250 | reference to the object itself as an implicit first parameter. |
251 | |
252 | =cut |
253 | |
254 | ##--------------------------------------------------------------------------- |
255 | |
256 | ## =begin _PRIVATE_ |
257 | ## |
258 | ## =head1 B<_init_headings()> |
259 | ## |
260 | ## Initialize the current set of active section headings. |
261 | ## |
262 | ## =cut |
263 | ## |
264 | ## =end _PRIVATE_ |
265 | |
266 | use vars qw(%myData @section_headings); |
267 | |
268 | sub _init_headings { |
269 | my $self = shift; |
270 | local *myData = $self; |
271 | |
272 | ## Initialize current section heading titles if necessary |
273 | unless (defined $myData{_SECTION_HEADINGS}) { |
274 | local *section_headings = $myData{_SECTION_HEADINGS} = []; |
275 | for (my $i = 0; $i < $MAX_HEADING_LEVEL; ++$i) { |
276 | $section_headings[$i] = ''; |
277 | } |
278 | } |
279 | } |
280 | |
281 | ##--------------------------------------------------------------------------- |
282 | |
283 | =head1 B<curr_headings()> |
284 | |
285 | ($head1, $head2, $head3, ...) = $parser->curr_headings(); |
286 | $head1 = $parser->curr_headings(1); |
287 | |
288 | This method returns a list of the currently active section headings and |
289 | subheadings in the document being parsed. The list of headings returned |
290 | corresponds to the most recently parsed paragraph of the input. |
291 | |
292 | If an argument is given, it must correspond to the desired section |
293 | heading number, in which case only the specified section heading is |
294 | returned. If there is no current section heading at the specified |
295 | level, then C<undef> is returned. |
296 | |
297 | =cut |
298 | |
299 | sub curr_headings { |
300 | my $self = shift; |
301 | $self->_init_headings() unless (defined $self->{_SECTION_HEADINGS}); |
302 | my @headings = @{ $self->{_SECTION_HEADINGS} }; |
303 | return (@_ > 0 and $_[0] =~ /^\d+$/) ? $headings[$_[0] - 1] : @headings; |
304 | } |
305 | |
306 | ##--------------------------------------------------------------------------- |
307 | |
308 | =head1 B<select()> |
309 | |
310 | $parser->select($section_spec1,$section_spec2,...); |
311 | |
312 | This method is used to select the particular sections and subsections of |
313 | POD documentation that are to be printed and/or processed. The existing |
314 | set of selected sections is I<replaced> with the given set of sections. |
315 | See B<add_selection()> for adding to the current set of selected |
316 | sections. |
317 | |
318 | Each of the C<$section_spec> arguments should be a section specification |
319 | as described in L<"SECTION SPECIFICATIONS">. The section specifications |
320 | are parsed by this method and the resulting regular expressions are |
321 | stored in the invoking object. |
322 | |
323 | If no C<$section_spec> arguments are given, then the existing set of |
324 | selected sections is cleared out (which means C<all> sections will be |
325 | processed). |
326 | |
327 | This method should I<not> normally be overridden by subclasses. |
328 | |
329 | =cut |
330 | |
331 | use vars qw(@selected_sections); |
332 | |
333 | sub select { |
334 | my $self = shift; |
335 | my @sections = @_; |
336 | local *myData = $self; |
337 | local $_; |
338 | |
339 | ### NEED TO DISCERN A SECTION-SPEC FROM A RANGE-SPEC (look for m{^/.+/$}?) |
340 | |
341 | ##--------------------------------------------------------------------- |
342 | ## The following is a blatant hack for backward compatibility, and for |
343 | ## implementing add_selection(). If the *first* *argument* is the |
344 | ## string "+", then the remaining section specifications are *added* |
345 | ## to the current set of selections; otherwise the given section |
346 | ## specifications will *replace* the current set of selections. |
347 | ## |
348 | ## This should probably be fixed someday, but for the present time, |
349 | ## it seems incredibly unlikely that "+" would ever correspond to |
350 | ## a legitimate section heading |
351 | ##--------------------------------------------------------------------- |
352 | my $add = ($sections[0] eq "+") ? shift(@sections) : ""; |
353 | |
354 | ## Reset the set of sections to use |
355 | unless (@sections > 0) { |
356 | delete $myData{_SELECTED_SECTIONS} unless ($add); |
357 | return; |
358 | } |
359 | $myData{_SELECTED_SECTIONS} = [] |
360 | unless ($add && exists $myData{_SELECTED_SECTIONS}); |
361 | local *selected_sections = $myData{_SELECTED_SECTIONS}; |
362 | |
363 | ## Compile each spec |
364 | my $spec; |
365 | for $spec (@sections) { |
366 | if ( defined($_ = &_compile_section_spec($spec)) ) { |
367 | ## Store them in our sections array |
368 | push(@selected_sections, $_); |
369 | } |
370 | else { |
371 | carp "Ignoring section spec \"$spec\"!\n"; |
372 | } |
373 | } |
374 | } |
375 | |
376 | ##--------------------------------------------------------------------------- |
377 | |
378 | =head1 B<add_selection()> |
379 | |
380 | $parser->add_selection($section_spec1,$section_spec2,...); |
381 | |
382 | This method is used to add to the currently selected sections and |
383 | subsections of POD documentation that are to be printed and/or |
384 | processed. See <select()> for replacing the currently selected sections. |
385 | |
386 | Each of the C<$section_spec> arguments should be a section specification |
387 | as described in L<"SECTION SPECIFICATIONS">. The section specifications |
388 | are parsed by this method and the resulting regular expressions are |
389 | stored in the invoking object. |
390 | |
391 | This method should I<not> normally be overridden by subclasses. |
392 | |
393 | =cut |
394 | |
395 | sub add_selection { |
396 | my $self = shift; |
397 | $self->select("+", @_); |
398 | } |
399 | |
400 | ##--------------------------------------------------------------------------- |
401 | |
402 | =head1 B<clear_selections()> |
403 | |
404 | $parser->clear_selections(); |
405 | |
406 | This method takes no arguments, it has the exact same effect as invoking |
407 | <select()> with no arguments. |
408 | |
409 | =cut |
410 | |
411 | sub clear_selections { |
412 | my $self = shift; |
413 | $self->select(); |
414 | } |
415 | |
416 | ##--------------------------------------------------------------------------- |
417 | |
418 | =head1 B<match_section()> |
419 | |
420 | $boolean = $parser->match_section($heading1,$heading2,...); |
421 | |
422 | Returns a value of true if the given section and subsection heading |
423 | titles match any of the currently selected section specifications in |
424 | effect from prior calls to B<select()> and B<add_selection()> (or if |
425 | there are no explictly selected/deselected sections). |
426 | |
427 | The arguments C<$heading1>, C<$heading2>, etc. are the heading titles of |
428 | the corresponding sections, subsections, etc. to try and match. If |
429 | C<$headingN> is omitted then it defaults to the current corresponding |
430 | section heading title in the input. |
431 | |
432 | This method should I<not> normally be overridden by subclasses. |
433 | |
434 | =cut |
435 | |
436 | sub match_section { |
437 | my $self = shift; |
438 | my (@headings) = @_; |
439 | local *myData = $self; |
440 | |
441 | ## Return true if no restrictions were explicitly specified |
442 | my $selections = (exists $myData{_SELECTED_SECTIONS}) |
443 | ? $myData{_SELECTED_SECTIONS} : undef; |
444 | return 1 unless ((defined $selections) && (@{$selections} > 0)); |
445 | |
446 | ## Default any unspecified sections to the current one |
447 | my @current_headings = $self->curr_headings(); |
448 | for (my $i = 0; $i < $MAX_HEADING_LEVEL; ++$i) { |
449 | (defined $headings[$i]) or $headings[$i] = $current_headings[$i]; |
450 | } |
451 | |
452 | ## Look for a match against the specified section expressions |
453 | my ($section_spec, $regex, $negated, $match); |
454 | for $section_spec ( @{$selections} ) { |
455 | ##------------------------------------------------------ |
456 | ## Each portion of this spec must match in order for |
457 | ## the spec to be matched. So we will start with a |
458 | ## match-value of 'true' and logically 'and' it with |
459 | ## the results of matching a given element of the spec. |
460 | ##------------------------------------------------------ |
461 | $match = 1; |
462 | for (my $i = 0; $i < $MAX_HEADING_LEVEL; ++$i) { |
463 | $regex = $section_spec->[$i]; |
464 | $negated = ($regex =~ s/^\!//); |
465 | $match &= ($negated ? ($headings[$i] !~ /${regex}/) |
466 | : ($headings[$i] =~ /${regex}/)); |
467 | last unless ($match); |
468 | } |
469 | return 1 if ($match); |
470 | } |
471 | return 0; ## no match |
472 | } |
473 | |
474 | ##--------------------------------------------------------------------------- |
475 | |
476 | =head1 B<is_selected()> |
477 | |
478 | $boolean = $parser->is_selected($paragraph); |
479 | |
480 | This method is used to determine if the block of text given in |
481 | C<$paragraph> falls within the currently selected set of POD sections |
482 | and subsections to be printed or processed. This method is also |
483 | responsible for keeping track of the current input section and |
484 | subsections. It is assumed that C<$paragraph> is the most recently read |
485 | (but not yet processed) input paragraph. |
486 | |
487 | The value returned will be true if the C<$paragraph> and the rest of the |
488 | text in the same section as C<$paragraph> should be selected (included) |
489 | for processing; otherwise a false value is returned. |
490 | |
491 | =cut |
492 | |
493 | sub is_selected { |
494 | my ($self, $paragraph) = @_; |
495 | local $_; |
496 | local *myData = $self; |
497 | |
498 | $self->_init_headings() unless (defined $myData{_SECTION_HEADINGS}); |
499 | |
500 | ## Keep track of current sections levels and headings |
501 | $_ = $paragraph; |
502 | if (/^=((?:sub)*)(?:head(?:ing)?|sec(?:tion)?)(\d*)\s+(.*)\s*$/) { |
503 | ## This is a section heading command |
504 | my ($level, $heading) = ($2, $3); |
505 | $level = 1 + (length($1) / 3) if ((! length $level) || (length $1)); |
506 | ## Reset the current section heading at this level |
507 | $myData{_SECTION_HEADINGS}->[$level - 1] = $heading; |
508 | ## Reset subsection headings of this one to empty |
509 | for (my $i = $level; $i < $MAX_HEADING_LEVEL; ++$i) { |
510 | $myData{_SECTION_HEADINGS}->[$i] = ''; |
511 | } |
512 | } |
513 | |
514 | return $self->match_section(); |
515 | } |
516 | |
517 | ############################################################################# |
518 | |
519 | =head1 EXPORTED FUNCTIONS |
520 | |
521 | The following functions are exported by this module. Please note that |
522 | these are functions (not methods) and therefore C<do not> take an |
523 | implicit first argument. |
524 | |
525 | =cut |
526 | |
527 | ##--------------------------------------------------------------------------- |
528 | |
529 | =head1 B<podselect()> |
530 | |
531 | podselect(\%options,@filelist); |
532 | |
533 | B<podselect> will print the raw (untranslated) POD paragraphs of all |
534 | POD sections in the given input files specified by C<@filelist> |
535 | according to the given options. |
536 | |
537 | If any argument to B<podselect> is a reference to a hash |
538 | (associative array) then the values with the following keys are |
539 | processed as follows: |
540 | |
541 | =over 4 |
542 | |
543 | =item B<-output> |
544 | |
545 | A string corresponding to the desired output file (or ">&STDOUT" |
546 | or ">&STDERR"). The default is to use standard output. |
547 | |
548 | =item B<-sections> |
549 | |
550 | A reference to an array of sections specifications (as described in |
551 | L<"SECTION SPECIFICATIONS">) which indicate the desired set of POD |
552 | sections and subsections to be selected from input. If no section |
553 | specifications are given, then all sections of the PODs are used. |
554 | |
555 | =begin _NOT_IMPLEMENTED_ |
556 | |
557 | =item B<-ranges> |
558 | |
559 | A reference to an array of range specifications (as described in |
560 | L<"RANGE SPECIFICATIONS">) which indicate the desired range of POD |
561 | paragraphs to be selected from the desired input sections. If no range |
562 | specifications are given, then all paragraphs of the desired sections |
563 | are used. |
564 | |
565 | =end _NOT_IMPLEMENTED_ |
566 | |
567 | =back |
568 | |
569 | All other arguments should correspond to the names of input files |
570 | containing POD sections. A file name of "-" or "<&STDIN" will |
571 | be interpeted to mean standard input (which is the default if no |
572 | filenames are given). |
573 | |
574 | =cut |
575 | |
576 | sub podselect { |
577 | my(@argv) = @_; |
578 | my %defaults = (); |
579 | my $pod_parser = new Pod::Select(%defaults); |
580 | my $num_inputs = 0; |
581 | my $output = ">&STDOUT"; |
582 | my %opts = (); |
583 | local $_; |
584 | for (@argv) { |
585 | if (ref($_)) { |
586 | next unless (ref($_) eq 'HASH'); |
587 | %opts = (%defaults, %{$_}); |
588 | |
589 | ##------------------------------------------------------------- |
590 | ## Need this for backward compatibility since we formerly used |
591 | ## options that were all uppercase words rather than ones that |
592 | ## looked like Unix command-line options. |
593 | ## to be uppercase keywords) |
594 | ##------------------------------------------------------------- |
595 | %opts = map { |
596 | my ($key, $val) = (lc $_, $opts{$_}); |
597 | $key =~ s/^(?=\w)/-/; |
598 | $key =~ /^-se[cl]/ and $key = '-sections'; |
599 | #! $key eq '-range' and $key .= 's'; |
600 | ($key => $val); |
601 | } (keys %opts); |
602 | |
603 | ## Process the options |
604 | (exists $opts{'-output'}) and $output = $opts{'-output'}; |
605 | |
606 | ## Select the desired sections |
607 | $pod_parser->select(@{ $opts{'-sections'} }) |
608 | if ( (defined $opts{'-sections'}) |
609 | && ((ref $opts{'-sections'}) eq 'ARRAY') ); |
610 | |
611 | #! ## Select the desired paragraph ranges |
612 | #! $pod_parser->select(@{ $opts{'-ranges'} }) |
613 | #! if ( (defined $opts{'-ranges'}) |
614 | #! && ((ref $opts{'-ranges'}) eq 'ARRAY') ); |
615 | } |
616 | else { |
617 | $pod_parser->parse_from_file($_, $output); |
618 | ++$num_inputs; |
619 | } |
620 | } |
621 | $pod_parser->parse_from_file("-") unless ($num_inputs > 0); |
622 | } |
623 | |
624 | ############################################################################# |
625 | |
626 | =head1 PRIVATE METHODS AND DATA |
627 | |
628 | B<Pod::Select> makes uses a number of internal methods and data fields |
629 | which clients should not need to see or use. For the sake of avoiding |
630 | name collisions with client data and methods, these methods and fields |
631 | are briefly discussed here. Determined hackers may obtain further |
632 | information about them by reading the B<Pod::Select> source code. |
633 | |
634 | Private data fields are stored in the hash-object whose reference is |
635 | returned by the B<new()> constructor for this class. The names of all |
636 | private methods and data-fields used by B<Pod::Select> begin with a |
637 | prefix of "_" and match the regular expression C</^_\w+$/>. |
638 | |
639 | =cut |
640 | |
641 | ##--------------------------------------------------------------------------- |
642 | |
643 | =begin _PRIVATE_ |
644 | |
645 | =head1 B<_compile_section_spec()> |
646 | |
647 | $listref = $parser->_compile_section_spec($section_spec); |
648 | |
649 | This function (note it is a function and I<not> a method) takes a |
650 | section specification (as described in L<"SECTION SPECIFICATIONS">) |
651 | given in C<$section_sepc>, and compiles it into a list of regular |
652 | expressions. If C<$section_spec> has no syntax errors, then a reference |
653 | to the list (array) of corresponding regular expressions is returned; |
654 | otherwise C<undef> is returned and an error message is printed (using |
655 | B<carp>) for each invalid regex. |
656 | |
657 | =end _PRIVATE_ |
658 | |
659 | =cut |
660 | |
661 | sub _compile_section_spec { |
662 | my ($section_spec) = @_; |
663 | my (@regexs, $negated); |
664 | |
665 | ## Compile the spec into a list of regexs |
666 | local $_ = $section_spec; |
667 | s|\\\\|\001|g; ## handle escaped backward slashes |
668 | s|\\/|\002|g; ## handle escaped forward slashes |
669 | |
670 | ## Parse the regexs for the heading titles |
671 | @regexs = split('/', $_, $MAX_HEADING_LEVEL); |
672 | |
673 | ## Set default regex for ommitted levels |
674 | for (my $i = 0; $i < $MAX_HEADING_LEVEL; ++$i) { |
675 | $regexs[$i] = '.*' unless ((defined $regexs[$i]) |
676 | && (length $regexs[$i])); |
677 | } |
678 | ## Modify the regexs as needed and validate their syntax |
679 | my $bad_regexs = 0; |
680 | for (@regexs) { |
681 | $_ .= '.+' if ($_ eq '!'); |
682 | s|\001|\\\\|g; ## restore escaped backward slashes |
683 | s|\002|\\/|g; ## restore escaped forward slashes |
684 | $negated = s/^\!//; ## check for negation |
685 | eval "/$_/"; ## check regex syntax |
686 | if ($@) { |
687 | ++$bad_regexs; |
688 | carp "Bad regular expression /$_/ in \"$section_spec\": $@\n"; |
689 | } |
690 | else { |
691 | ## Add the forward and rear anchors (and put the negator back) |
692 | $_ = '^' . $_ unless (/^\^/); |
693 | $_ = $_ . '$' unless (/\$$/); |
694 | $_ = '!' . $_ if ($negated); |
695 | } |
696 | } |
697 | return (! $bad_regexs) ? [ @regexs ] : undef; |
698 | } |
699 | |
700 | ##--------------------------------------------------------------------------- |
701 | |
702 | =begin _PRIVATE_ |
703 | |
704 | =head2 $self->{_SECTION_HEADINGS} |
705 | |
706 | A reference to an array of the current section heading titles for each |
707 | heading level (note that the first heading level title is at index 0). |
708 | |
709 | =end _PRIVATE_ |
710 | |
711 | =cut |
712 | |
713 | ##--------------------------------------------------------------------------- |
714 | |
715 | =begin _PRIVATE_ |
716 | |
717 | =head2 $self->{_SELECTED_SECTIONS} |
718 | |
719 | A reference to an array of references to arrays. Each subarray is a list |
720 | of anchored regular expressions (preceded by a "!" if the expression is to |
721 | be negated). The index of the expression in the subarray should correspond |
722 | to the index of the heading title in C<$self-E<gt>{_SECTION_HEADINGS}> |
723 | that it is to be matched against. |
724 | |
725 | =end _PRIVATE_ |
726 | |
727 | =cut |
728 | |
729 | ############################################################################# |
730 | |
731 | =head1 SEE ALSO |
732 | |
733 | L<Pod::Parser> |
734 | |
735 | =head1 AUTHOR |
736 | |
737 | Brad Appleton E<lt>bradapp@enteract.comE<gt> |
738 | |
739 | Based on code for B<pod2text> written by |
740 | Tom Christiansen E<lt>tchrist@mox.perl.comE<gt> |
741 | |
742 | =cut |
743 | |
744 | 1; |
745 | |