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1 | # Copyright (C) 2001, 2002, 2007 Sam Vilain. All Rights Reserved. | |
2 | # This module is free software. It may be used, redistributed and/or | |
3 | # modified under the terms of the Perl Artistic License, version 2 or | |
4 | # later, OR the terms of the GNU General Public License, v3 or later. | |
5 | ||
6 | package Pod::Constants; | |
7 | ||
8 | use 5.006002; | |
9 | use strict; | |
10 | use warnings; | |
11 | ||
12 | use base qw(Pod::Parser Exporter); | |
13 | use Carp; | |
14 | ||
15 | our $VERSION = 0.17; | |
16 | ||
17 | # An ugly hack to go from caller() to the relevant parser state | |
18 | # variable | |
19 | my %parsers; | |
20 | ||
21 | sub end_input { | |
22 | #my ($parser, $command, $paragraph, $line_num) = (@_); | |
23 | my $parser = shift; | |
24 | ||
25 | return unless $parser->{active}; | |
26 | ||
27 | print "Found end of $parser->{active}\n" if $parser->{DEBUG}; | |
28 | my $whereto = $parser->{wanted_pod_tags}->{$parser->{active}}; | |
29 | print "\$_ will be set to:\n---\n$parser->{paragraphs}\n---\n" if $parser->{DEBUG}; | |
30 | ||
31 | $parser->{paragraphs} =~ s/^\s*|\s*$//gs if $parser->{trimmed_tags}->{$parser->{active}}; | |
32 | ||
33 | if (ref $whereto eq "CODE") { | |
34 | print "calling sub\n" if $parser->{DEBUG}; | |
35 | local ($_) = $parser->{paragraphs}; | |
36 | $whereto->(); | |
37 | print "done\n" if $parser->{DEBUG}; | |
38 | } elsif (ref $whereto eq "SCALAR") { | |
39 | print "inserting into scalar\n" if $parser->{DEBUG}; | |
40 | $$whereto = $parser->{paragraphs}; | |
41 | } elsif (ref $whereto eq "ARRAY") { | |
42 | print "inserting into array\n" if $parser->{DEBUG}; | |
43 | @$whereto = split /\n/, $parser->{paragraphs}; | |
44 | } elsif (ref $whereto eq "HASH") { | |
45 | print "inserting into hash\n" if $parser->{DEBUG}; | |
46 | # Oh, sorry, should I be in LISP101? | |
47 | %$whereto = ( | |
48 | map { map { s/^\s*|\s*$//g; $_ } split /=>/, $_ } grep m/^ | |
49 | ( (?:[^=]|=[^>])+ ) # scan up to "=>" | |
50 | => | |
51 | ( (?:[^=]|=[^>])+ =? )# don't allow more "=>"'s | |
52 | $/x, split /\n/, $parser->{paragraphs}); | |
53 | } else { die $whereto } | |
54 | $parser->{active} = undef; | |
55 | } | |
56 | ||
57 | # Pod::Parser overloaded command | |
58 | sub command { | |
59 | my ($parser, $command, $paragraph, $line_num) = @_; | |
60 | ||
61 | $paragraph =~ s/(?:\r\n|\n\r)/\n/g; | |
62 | ||
63 | print "Got command =$command, value=$paragraph\n" if $parser->{DEBUG}; | |
64 | ||
65 | $parser->end_input() if $parser->{active}; | |
66 | ||
67 | my ($lookup); | |
68 | # first check for a catch-all for this command type | |
69 | if ( exists $parser->{wanted_pod_tags}->{"*$command"} ) { | |
70 | $parser->{paragraphs} = $paragraph; | |
71 | $parser->{active} = "*$command"; | |
72 | } elsif ($command =~ m/^(head\d+|item|(for|begin))$/) { | |
73 | if ( $2 ) { | |
74 | # if it's a "for" or "begin" section, the title is the | |
75 | # first word only | |
76 | ($lookup, $parser->{paragraphs}) = $paragraph =~ m/^\s*(\S*)\s*(.*)/s; | |
77 | } else { | |
78 | # otherwise, it's up to the end of the line | |
79 | ($lookup, $parser->{paragraphs}) = $paragraph =~ m/^\s*(\S[^\n]*?)\s*\n(.*)$/s; | |
80 | } | |
81 | ||
82 | # Look for a match by name | |
83 | if (defined $lookup && exists $parser->{wanted_pod_tags}->{$lookup}) { | |
84 | print "Found $lookup\n" if ($parser->{DEBUG}); | |
85 | $parser->{active} = $lookup; | |
86 | } elsif ($parser->{DEBUG}) { | |
87 | local $^W = 0; | |
88 | print "Ignoring =$command $paragraph (lookup = $lookup)\n" | |
89 | } | |
90 | ||
91 | } else { | |
92 | # nothing | |
93 | print "Ignoring =$command (not known)\n" if $parser->{DEBUG}; | |
94 | } | |
95 | } | |
96 | ||
97 | # Pod::Parser overloaded verbatim | |
98 | sub verbatim { | |
99 | my ($parser, $paragraph, $line_num) = @_; | |
100 | $paragraph =~ s/(?:\r\n|\n\r)/\n/g; | |
101 | ||
102 | my $status = $parser->{active} ? "using" : "ignoring"; | |
103 | print "Got paragraph: $paragraph ($status)\n" if $parser->{DEBUG}; | |
104 | ||
105 | $parser->{paragraphs} .= $paragraph if defined $parser->{active} | |
106 | } | |
107 | ||
108 | # Pod::Parser overloaded textblock | |
109 | sub textblock { goto \&verbatim } | |
110 | ||
111 | sub import { | |
112 | my $class = shift; | |
113 | ||
114 | # if no args, just return | |
115 | return unless (@_); | |
116 | ||
117 | # try to guess the source file of the caller | |
118 | my $source_file; | |
119 | if (caller ne "main") { | |
120 | (my $module = caller().".pm") =~ s|::|/|g; | |
121 | $source_file = $INC{$module}; | |
122 | } | |
123 | $source_file ||= $0; | |
124 | ||
125 | croak "Cannot find source file (guessed $source_file) for package ".caller unless -f $source_file; | |
126 | ||
127 | # nasty tricks with the stack so we don't have to be silly with | |
128 | # caller() | |
129 | unshift @_, $source_file; | |
130 | goto \&import_from_file; | |
131 | } | |
132 | ||
133 | use IO::Handle; | |
134 | ||
135 | sub import_from_file { | |
136 | my $filename = shift; | |
137 | ||
138 | my $parser = __PACKAGE__->new(); | |
139 | ||
140 | $parser->{wanted_pod_tags} = {}; | |
141 | $parser->{trimmed_tags} = {}; | |
142 | $parser->{trim_next} = 0; | |
143 | $parser->{DEBUG} = 0; | |
144 | $parser->{active} = undef; | |
145 | $parsers{caller()} = $parser; | |
146 | ||
147 | $parser->add_hook(@_); | |
148 | ||
149 | print "Pod::Parser: DEBUG: Opening $filename for reading\n" if $parser->{DEBUG}; | |
150 | my $fh = new IO::Handle; | |
151 | open $fh, "<$filename" or die "cannot open $filename for reading; $!"; | |
152 | ||
153 | $parser->parse_from_filehandle($fh, \*STDOUT); | |
154 | ||
155 | close $fh; | |
156 | } | |
157 | ||
158 | sub add_hook { | |
159 | my $parser; | |
160 | if (UNIVERSAL::isa($_[0], __PACKAGE__)) { | |
161 | $parser = shift; | |
162 | } else { | |
163 | $parser = $parsers{caller()} or die "add_hook called, but don't know what for - caller = ".caller; | |
164 | } | |
165 | while (my ($pod_tag, $var) = splice @_, 0, 2) { | |
166 | #print "$pod_tag: $var\n"; | |
167 | if (lc($pod_tag) eq "-trim") { | |
168 | $parser->{trim_next} = $var; | |
169 | } elsif ( lc($pod_tag) eq "-debug" ) { | |
170 | $parser->{DEBUG} = $var; | |
171 | } elsif (lc($pod_tag) eq "-usage") { | |
172 | # an idea for later - automatic "usage" | |
173 | #%wanted_pod_tags{@tags} | |
174 | } else { | |
175 | if ((ref $var) =~ /^(?:SCALAR|CODE|ARRAY|HASH)$/) { | |
176 | print "Will look for $pod_tag.\n" if $parser->{DEBUG}; | |
177 | $parser->{wanted_pod_tags}->{$pod_tag} = $var; | |
178 | $parser->{trimmed_tags}->{$pod_tag} = 1 if $parser->{trim_next}; | |
179 | } else { | |
180 | die "Sorry - need a reference to import POD sections into, not the scalar value $var" | |
181 | } | |
182 | } | |
183 | } | |
184 | } | |
185 | ||
186 | sub delete_hook { | |
187 | my $parser; | |
188 | if ( UNIVERSAL::isa($_[0], __PACKAGE__) ) { | |
189 | $parser = shift; | |
190 | } else { | |
191 | $parser = $parsers{caller()} or die "delete_hook called, but don't know what for - caller = ".caller; | |
192 | } | |
193 | while ( my $label = shift ) { | |
194 | delete $parser->{wanted_pod_tags}->{$label}; | |
195 | delete $parser->{trimmed_tags}->{$label}; | |
196 | } | |
197 | } | |
198 | ||
199 | 1.4142; | |
200 | __END__ | |
201 | ||
202 | =encoding utf-8 | |
203 | ||
204 | =head1 NAME | |
205 | ||
206 | Pod::Constants - Include constants from POD | |
207 | ||
208 | =head1 SYNOPSIS | |
209 | ||
210 | our ($myvar, $VERSION, @myarray, $html, %myhash); | |
211 | ||
212 | use Pod::Constants -trim => 1, | |
213 | 'Pod Section Name' => \$myvar, | |
214 | 'Version' => sub { eval }, | |
215 | 'Some list' => \@myarray, | |
216 | html => \$html, | |
217 | 'Some hash' => \%myhash; | |
218 | ||
219 | =head2 Pod Section Name | |
220 | ||
221 | This string will be loaded into $myvar | |
222 | ||
223 | =head2 Version | |
224 | ||
225 | # This is an example of using a closure. $_ is set to the | |
226 | # contents of the paragraph. In this example, "eval" is | |
227 | # used to execute this code at run time. | |
228 | $VERSION = 0.17; | |
229 | ||
230 | =head2 Some list | |
231 | ||
232 | Each line from this section of the file | |
233 | will be placed into a separate array element. | |
234 | For example, this is $myarray[2]. | |
235 | ||
236 | =head2 Some hash | |
237 | ||
238 | This text will not go into the hash, because | |
239 | it doesn't look like a definition list. | |
240 | key1 => Some value (this will go into the hash) | |
241 | var2 => Some Other value (so will this) | |
242 | wtf = This won't make it in. | |
243 | ||
244 | =head2 %myhash's value after the above: | |
245 | ||
246 | ( key1 => "Some value (this will go into the hash)", | |
247 | var2 => "Some Other value (so will this)" ) | |
248 | ||
249 | =begin html <p>This text will be in $html</p> | |
250 | ||
251 | =cut | |
252 | ||
253 | =head1 DESCRIPTION | |
254 | ||
255 | This module allows you to specify those constants that should be | |
256 | documented in your POD, and pull them out a run time in a fairly | |
257 | arbitrary fashion. | |
258 | ||
259 | Pod::Constants uses Pod::Parser to do the parsing of the source file. | |
260 | It has to open the source file it is called from, and does so directly | |
261 | either by lookup in %INC or by assuming it is $0 if the caller is | |
262 | "main" (or it can't find %INC{caller()}) | |
263 | ||
264 | =head2 ARBITARY DECISIONS | |
265 | ||
266 | I have made this code only allow the "Pod Section Name" to match | |
267 | `headN', `item', `for' and `begin' POD sections. If you have a good | |
268 | reason why you think it should match other POD sections, drop me a | |
269 | line and if I'm convinced I'll put it in the standard version. | |
270 | ||
271 | For `for' and `begin' sections, only the first word is counted as | |
272 | being a part of the specifier, as opposed to `headN' and `item', where | |
273 | the entire rest of the line counts. | |
274 | ||
275 | =head1 FUNCTIONS | |
276 | ||
277 | =head2 import(@args) | |
278 | ||
279 | This function is called when we are "use"'d. It determines the source | |
280 | file by inspecting the value of caller() or $0. | |
281 | ||
282 | The form of @args is HOOK => $where. | |
283 | ||
284 | $where may be a scalar reference, in which case the contents of the | |
285 | POD section called "HOOK" will be loaded into $where. | |
286 | ||
287 | $where may be an array reference, in which case the contents of the | |
288 | array will be the contents of the POD section called "HOOK", split | |
289 | into lines. | |
290 | ||
291 | $where may be a hash reference, in which case any lines with a "=>" | |
292 | symbol present will have everything on the left have side of the => | |
293 | operator as keys and everything on the right as values. You do not | |
294 | need to quote either, nor have trailing commas at the end of the | |
295 | lines. | |
296 | ||
297 | $where may be a code reference (sub { }), in which case the sub is | |
298 | called when the hook is encountered. $_ is set to the value of the | |
299 | POD paragraph. | |
300 | ||
301 | You may also specify the behaviour of whitespace trimming; by default, | |
302 | no trimming is done except on the HOOK names. Setting "-trim => 1" | |
303 | turns on a package "global" (until the next time import is called) | |
304 | that will trim the $_ sent for processing by the hook processing | |
305 | function (be it a given function, or the built-in array/hash | |
306 | splitters) for leading and trailing whitespace. | |
307 | ||
308 | The name of HOOK is matched against any "=head1", "=head2", "=item", | |
309 | "=for", "=begin" value. If you specify the special hooknames "*item", | |
310 | "*head1", etc, then you will get a function that is run for every | |
311 | ||
312 | Note that the supplied functions for array and hash splitting are | |
313 | exactly equivalent to fairly simple Perl blocks: | |
314 | ||
315 | Array: | |
316 | ||
317 | HOOK => sub { @array = split /\n/, $_ } | |
318 | ||
319 | Hash: | |
320 | ||
321 | HOOK => sub { | |
322 | %hash = | |
323 | (map { map { s/^\s+|\s+$//g; $_ } split /=>/, $_ } | |
324 | (grep m/^ | |
325 | ( (?:[^=]|=[^>])+ ) # scan up to "=>" | |
326 | => | |
327 | ( (?:[^=]|=[^>])+ =? )# don't allow more "=>"'s | |
328 | $/x, split /\n/, $_)); | |
329 | } | |
330 | ||
331 | Well, they're simple if you can grok map, a regular expression like | |
332 | that and a functional programming style. If you can't I'm sure it is | |
333 | probably voodoo to you. | |
334 | ||
335 | Here's the procedural equivalent: | |
336 | ||
337 | HOOK => sub { | |
338 | for my $line (split /\n/, $_) { | |
339 | my ($key, $value, $junk) = split /=>/, $line; | |
340 | next if $junk; | |
341 | $key =~ s/^\s+|\s+$//g | |
342 | $value =~ s/^\s+|\s+$//g | |
343 | $hash{$key} = $value; | |
344 | } | |
345 | }, | |
346 | ||
347 | =head2 import_from_file($filename, @args) | |
348 | ||
349 | Very similar to straight "import", but you specify the source filename | |
350 | explicitly. | |
351 | ||
352 | =head2 add_hook(NAME => value) | |
353 | ||
354 | This function adds another hook, it is useful for dynamic updating of | |
355 | parsing through the document. | |
356 | ||
357 | For an example, please see t/01-constants.t in the source | |
358 | distribution. More detailed examples will be added in a later | |
359 | release. | |
360 | ||
361 | =head2 delete_hook(@list) | |
362 | ||
363 | Deletes the named hooks. Companion function to add_hook | |
364 | ||
365 | =head2 CLOSURES AS DESTINATIONS | |
366 | ||
367 | If the given value is a ref CODE, then that function is called, with | |
368 | $_ set to the value of the paragraph. This can be very useful for | |
369 | applying your own custom mutations to the POD to change it from human | |
370 | readable text into something your program can use. | |
371 | ||
372 | After I added this function, I just kept on thinking of cool uses for | |
373 | it. The nice, succinct code you can make with it is one of | |
374 | Pod::Constant's strongest features. | |
375 | ||
376 | Below are some examples. | |
377 | ||
378 | =head1 EXAMPLES | |
379 | ||
380 | =head2 Module Makefile.PL maintenance | |
381 | ||
382 | Tired of keeping those module Makefile.PL's up to date? Note: This | |
383 | method seems to break dh-make-perl. | |
384 | ||
385 | =head2 Example Makefile.PL | |
386 | ||
387 | eval "use Pod::Constants"; | |
388 | ($Pod::Constants::VERSION >= 0.11) | |
389 | or die <<EOF | |
390 | #### | |
391 | #### ERROR: This module requires Pod::Constants 0.11 or | |
392 | #### higher to be installed. | |
393 | #### | |
394 | EOF | |
395 | ||
396 | my ($VERSION, $NAME, $PREREQ_PM, $ABSTRACT, $AUTHOR); | |
397 | Pod::Constants::import_from_file | |
398 | ( | |
399 | 'MyTestModule.pm', | |
400 | 'MODULE RELEASE' => sub { ($VERSION) = m/(\d+\.\d+)/ }, | |
401 | 'DEPENDENCIES' => ($PREREQ_PM = { }), | |
402 | -trim => 1, | |
403 | 'NAME' => sub { $ABSTRACT=$_; ($NAME) = m/(\S+)/ }, | |
404 | 'AUTHOR' => \$AUTHOR, | |
405 | ); | |
406 | ||
407 | WriteMakefile | |
408 | ( | |
409 | 'NAME' => $NAME, | |
410 | 'PREREQ_PM' => $PREREQ_PM, | |
411 | 'VERSION' => $VERSION, | |
412 | ($] >= 5.005 ? ## Add these new keywords supported since 5.005 | |
413 | (ABSTRACT => $ABSTRACT, | |
414 | AUTHOR => $AUTHOR) : ()), | |
415 | ); | |
416 | ||
417 | =head2 Corresponding Module | |
418 | ||
419 | =head1 NAME | |
420 | ||
421 | MyTestModule - Demonstrate Pod::Constant's Makefile.PL usefulness | |
422 | ||
423 | =head2 MODULE RELEASE | |
424 | ||
425 | This is release 1.05 of this module. | |
426 | ||
427 | =head2 DEPENDENCIES | |
428 | ||
429 | The following modules are required to make this module: | |
430 | ||
431 | Some::Module => 0.02 | |
432 | ||
433 | =head2 AUTHOR | |
434 | ||
435 | Ima Twat <ima@twat.name> | |
436 | ||
437 | =cut | |
438 | ||
439 | our $VERSION; | |
440 | use Pod::Constants -trim => 1, | |
441 | 'MODULE RELEASE' => sub { ($VERSION) = m/(\d+\.\d+) or die }; | |
442 | ||
443 | =head1 AUTHOR | |
444 | ||
445 | Sam Vilain, <samv@cpan.org> | |
446 | ||
447 | =head1 BUGS/TODO | |
448 | ||
449 | I keep thinking it would be nice to be able to import an =item list | |
450 | into an array or something, eg for a program argument list. But I'm | |
451 | not too sure how it would be all that useful in practice; you'd end up | |
452 | putting the function names for callbacks in the pod or something | |
453 | (perhaps not all that bad). | |
454 | ||
455 | Would this be useful? | |
456 | ||
457 | Pod::Constants::import(Foo::SECTION => \$myvar); | |
458 | ||
459 | Debug output is not very readable | |
460 | ||
461 | =head1 PATCHES WELCOME | |
462 | ||
463 | If you have any suggestions for enhancements, they are much more likely | |
464 | to happen if you submit them as a patch to the distribution. | |
465 | ||
466 | Source is kept at | |
467 | ||
468 | git://utsl.gen.nz/Pod-Constants | |
469 | ||
470 | ||
471 | =cut |