Commit | Line | Data |
94b19069 |
1 | |
2 | package Class::MOP; |
3 | |
4 | use strict; |
5 | use warnings; |
6 | |
5a2932cf |
7 | use 5.008; |
8 | |
3cf322a0 |
9 | use MRO::Compat; |
10 | |
4c105333 |
11 | use Carp 'confess'; |
b1a46f91 |
12 | use Scalar::Util 'weaken', 'reftype', 'blessed'; |
a8344505 |
13 | use Try::Tiny; |
fc4f8f91 |
14 | |
0531f510 |
15 | use Class::MOP::Class; |
16 | use Class::MOP::Attribute; |
17 | use Class::MOP::Method; |
18 | |
b1f5f41d |
19 | BEGIN { |
c7e28c19 |
20 | *IS_RUNNING_ON_5_10 = ($] < 5.009_005) |
11b56828 |
21 | ? sub () { 0 } |
c7e28c19 |
22 | : sub () { 1 }; |
46b23b44 |
23 | |
3ecd1b25 |
24 | # this is either part of core or set up appropriately by MRO::Compat |
25 | *check_package_cache_flag = \&mro::get_pkg_gen; |
b1f5f41d |
26 | } |
e0e4674a |
27 | |
f6ca0704 |
28 | our $VERSION = '0.94'; |
8a7085c1 |
29 | our $XS_VERSION = $VERSION; |
d519662a |
30 | $VERSION = eval $VERSION; |
c7e28c19 |
31 | our $AUTHORITY = 'cpan:STEVAN'; |
9d655b6d |
32 | |
4bfa5ddb |
33 | require XSLoader; |
34 | XSLoader::load( __PACKAGE__, $XS_VERSION ); |
d7bda114 |
35 | |
36 | |
be7677c7 |
37 | { |
38 | # Metaclasses are singletons, so we cache them here. |
39 | # there is no need to worry about destruction though |
40 | # because they should die only when the program dies. |
41 | # After all, do package definitions even get reaped? |
247d5b3c |
42 | # Anonymous classes manage their own destruction. |
1d68af04 |
43 | my %METAS; |
44 | |
1d68af04 |
45 | sub get_all_metaclasses { %METAS } |
46 | sub get_all_metaclass_instances { values %METAS } |
47 | sub get_all_metaclass_names { keys %METAS } |
be7677c7 |
48 | sub get_metaclass_by_name { $METAS{$_[0]} } |
1d68af04 |
49 | sub store_metaclass_by_name { $METAS{$_[0]} = $_[1] } |
50 | sub weaken_metaclass { weaken($METAS{$_[0]}) } |
be7677c7 |
51 | sub does_metaclass_exist { exists $METAS{$_[0]} && defined $METAS{$_[0]} } |
efc98200 |
52 | sub remove_metaclass_by_name { delete $METAS{$_[0]}; return } |
1d68af04 |
53 | |
86866fb5 |
54 | # This handles instances as well as class names |
55 | sub class_of { |
82999986 |
56 | return unless defined $_[0]; |
86866fb5 |
57 | my $class = blessed($_[0]) || $_[0]; |
58 | return $METAS{$class}; |
59 | } |
60 | |
be7677c7 |
61 | # NOTE: |
1d68af04 |
62 | # We only cache metaclasses, meaning instances of |
63 | # Class::MOP::Class. We do not cache instance of |
be7677c7 |
64 | # Class::MOP::Package or Class::MOP::Module. Mostly |
1d68af04 |
65 | # because I don't yet see a good reason to do so. |
be7677c7 |
66 | } |
67 | |
44da14be |
68 | sub _class_to_pmfile { |
69 | my $class = shift; |
70 | |
71 | my $file = $class . '.pm'; |
72 | $file =~ s{::}{/}g; |
73 | |
74 | return $file; |
75 | } |
76 | |
063ad0c5 |
77 | sub load_first_existing_class { |
f280f05c |
78 | my @classes = @_ |
79 | or return; |
5a24cf8a |
80 | |
81 | foreach my $class (@classes) { |
82 | unless ( _is_valid_class_name($class) ) { |
83 | my $display = defined($class) ? $class : 'undef'; |
84 | confess "Invalid class name ($display)"; |
85 | } |
ab5e2f48 |
86 | } |
87 | |
063ad0c5 |
88 | my $found; |
5a24cf8a |
89 | my %exceptions; |
063ad0c5 |
90 | for my $class (@classes) { |
a8344505 |
91 | my ($fail, $e) = _try_load_one_class($class); |
063ad0c5 |
92 | |
a8344505 |
93 | if ($fail) { |
a3f2cdc0 |
94 | my $pmfile = _class_to_pmfile($class); |
063ad0c5 |
95 | $exceptions{$class} = $e; |
44da14be |
96 | last if $e !~ /^Can't locate \Q$pmfile\E in \@INC/; |
5a24cf8a |
97 | } |
98 | else { |
063ad0c5 |
99 | $found = $class; |
100 | last; |
5a24cf8a |
101 | } |
063ad0c5 |
102 | } |
5a24cf8a |
103 | |
1d8153bd |
104 | return $found if $found; |
07940968 |
105 | |
063ad0c5 |
106 | confess join( |
107 | "\n", |
108 | map { |
109 | sprintf( |
fea44045 |
110 | "Could not load class (%s) because : %s", $_, |
063ad0c5 |
111 | $exceptions{$_} |
112 | ) |
44da14be |
113 | } |
114 | grep { |
115 | exists $exceptions{$_} |
063ad0c5 |
116 | } @classes |
f280f05c |
117 | ); |
5a24cf8a |
118 | } |
119 | |
063ad0c5 |
120 | sub _try_load_one_class { |
121 | my $class = shift; |
122 | |
123 | return if is_class_loaded($class); |
2beec805 |
124 | |
44da14be |
125 | my $file = _class_to_pmfile($class); |
063ad0c5 |
126 | |
a8344505 |
127 | my ($failed, $error); |
128 | try { |
b3813a8c |
129 | local $SIG{__DIE__}; |
a8344505 |
130 | require($file); |
131 | } |
132 | catch { |
133 | $failed = 1; |
134 | $error = $_; |
063ad0c5 |
135 | }; |
a8344505 |
136 | |
137 | return $failed, $error; |
063ad0c5 |
138 | } |
139 | |
5a24cf8a |
140 | sub load_class { |
7716a8f9 |
141 | load_first_existing_class($_[0]); |
142 | |
674d9359 |
143 | # This is done to avoid breaking code which checked the return value. Said |
144 | # code is dumb. The return value was _always_ true, since it dies on |
145 | # failure! |
146 | return 1; |
448b6e55 |
147 | } |
148 | |
2c0fb064 |
149 | sub _is_valid_class_name { |
150 | my $class = shift; |
151 | |
152 | return 0 if ref($class); |
153 | return 0 unless defined($class); |
154 | return 0 unless length($class); |
155 | |
156 | return 1 if $class =~ /^\w+(?:::\w+)*$/; |
157 | |
158 | return 0; |
159 | } |
160 | |
aa448b16 |
161 | ## ---------------------------------------------------------------------------- |
162 | ## Setting up our environment ... |
163 | ## ---------------------------------------------------------------------------- |
1d68af04 |
164 | ## Class::MOP needs to have a few things in the global perl environment so |
aa448b16 |
165 | ## that it can operate effectively. Those things are done here. |
166 | ## ---------------------------------------------------------------------------- |
167 | |
3bf7644b |
168 | # ... nothing yet actually ;) |
8b978dd5 |
169 | |
b51af7f9 |
170 | ## ---------------------------------------------------------------------------- |
1d68af04 |
171 | ## Bootstrapping |
b51af7f9 |
172 | ## ---------------------------------------------------------------------------- |
1d68af04 |
173 | ## The code below here is to bootstrap our MOP with itself. This is also |
b51af7f9 |
174 | ## sometimes called "tying the knot". By doing this, we make it much easier |
175 | ## to extend the MOP through subclassing and such since now you can use the |
1d68af04 |
176 | ## MOP itself to extend itself. |
177 | ## |
b51af7f9 |
178 | ## Yes, I know, thats weird and insane, but it's a good thing, trust me :) |
1d68af04 |
179 | ## ---------------------------------------------------------------------------- |
727919c5 |
180 | |
1d68af04 |
181 | # We need to add in the meta-attributes here so that |
182 | # any subclass of Class::MOP::* will be able to |
c2b256bc |
183 | # inherit them using _construct_instance |
727919c5 |
184 | |
f0480c45 |
185 | ## -------------------------------------------------------- |
6d5355c3 |
186 | ## Class::MOP::Package |
727919c5 |
187 | |
6d5355c3 |
188 | Class::MOP::Package->meta->add_attribute( |
8683db0e |
189 | Class::MOP::Attribute->new('package' => ( |
b880e0de |
190 | reader => { |
1d68af04 |
191 | # NOTE: we need to do this in order |
192 | # for the instance meta-object to |
b880e0de |
193 | # not fall into meta-circular death |
1d68af04 |
194 | # |
ce2ae40f |
195 | # we just alias the original method |
1d68af04 |
196 | # rather than re-produce it here |
ce2ae40f |
197 | 'name' => \&Class::MOP::Package::name |
b880e0de |
198 | }, |
727919c5 |
199 | )) |
200 | ); |
201 | |
a5e51f0b |
202 | Class::MOP::Package->meta->add_attribute( |
8683db0e |
203 | Class::MOP::Attribute->new('namespace' => ( |
a5e51f0b |
204 | reader => { |
56dcfc1a |
205 | # NOTE: |
ce2ae40f |
206 | # we just alias the original method |
207 | # rather than re-produce it here |
208 | 'namespace' => \&Class::MOP::Package::namespace |
a5e51f0b |
209 | }, |
2e877f58 |
210 | init_arg => undef, |
c4260b45 |
211 | default => sub { \undef } |
a5e51f0b |
212 | )) |
213 | ); |
214 | |
b1ff395f |
215 | Class::MOP::Package->meta->add_attribute( |
bcef1f7c |
216 | Class::MOP::Attribute->new('_methods' => ( |
217 | reader => { |
218 | # NOTE: |
219 | # we just alias the original method |
220 | # rather than re-produce it here |
221 | '_full_method_map' => \&Class::MOP::Package::_full_method_map |
222 | }, |
223 | default => sub { {} } |
224 | )) |
225 | ); |
226 | |
227 | Class::MOP::Package->meta->add_attribute( |
b1ff395f |
228 | Class::MOP::Attribute->new('method_metaclass' => ( |
229 | reader => { |
230 | # NOTE: |
231 | # we just alias the original method |
232 | # rather than re-produce it here |
233 | 'method_metaclass' => \&Class::MOP::Package::method_metaclass |
234 | }, |
235 | default => 'Class::MOP::Method', |
236 | )) |
237 | ); |
238 | |
239 | Class::MOP::Package->meta->add_attribute( |
240 | Class::MOP::Attribute->new('wrapped_method_metaclass' => ( |
241 | reader => { |
242 | # NOTE: |
243 | # we just alias the original method |
244 | # rather than re-produce it here |
245 | 'wrapped_method_metaclass' => \&Class::MOP::Package::wrapped_method_metaclass |
246 | }, |
247 | default => 'Class::MOP::Method::Wrapped', |
248 | )) |
249 | ); |
250 | |
f0480c45 |
251 | ## -------------------------------------------------------- |
252 | ## Class::MOP::Module |
253 | |
254 | # NOTE: |
1d68af04 |
255 | # yeah this is kind of stretching things a bit, |
f0480c45 |
256 | # but truthfully the version should be an attribute |
1d68af04 |
257 | # of the Module, the weirdness comes from having to |
258 | # stick to Perl 5 convention and store it in the |
259 | # $VERSION package variable. Basically if you just |
260 | # squint at it, it will look how you want it to look. |
f0480c45 |
261 | # Either as a package variable, or as a attribute of |
262 | # the metaclass, isn't abstraction great :) |
263 | |
264 | Class::MOP::Module->meta->add_attribute( |
8683db0e |
265 | Class::MOP::Attribute->new('version' => ( |
f0480c45 |
266 | reader => { |
ce2ae40f |
267 | # NOTE: |
268 | # we just alias the original method |
1d68af04 |
269 | # rather than re-produce it here |
ce2ae40f |
270 | 'version' => \&Class::MOP::Module::version |
f0480c45 |
271 | }, |
2e877f58 |
272 | init_arg => undef, |
c4260b45 |
273 | default => sub { \undef } |
f0480c45 |
274 | )) |
275 | ); |
276 | |
277 | # NOTE: |
1d68af04 |
278 | # By following the same conventions as version here, |
279 | # we are opening up the possibility that people can |
280 | # use the $AUTHORITY in non-Class::MOP modules as |
281 | # well. |
f0480c45 |
282 | |
283 | Class::MOP::Module->meta->add_attribute( |
8683db0e |
284 | Class::MOP::Attribute->new('authority' => ( |
f0480c45 |
285 | reader => { |
ce2ae40f |
286 | # NOTE: |
287 | # we just alias the original method |
1d68af04 |
288 | # rather than re-produce it here |
ce2ae40f |
289 | 'authority' => \&Class::MOP::Module::authority |
1d68af04 |
290 | }, |
2e877f58 |
291 | init_arg => undef, |
c4260b45 |
292 | default => sub { \undef } |
f0480c45 |
293 | )) |
294 | ); |
295 | |
296 | ## -------------------------------------------------------- |
6d5355c3 |
297 | ## Class::MOP::Class |
298 | |
727919c5 |
299 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
300 | Class::MOP::Attribute->new('attributes' => ( |
f7259199 |
301 | reader => { |
1d68af04 |
302 | # NOTE: we need to do this in order |
303 | # for the instance meta-object to |
304 | # not fall into meta-circular death |
305 | # |
ce2ae40f |
306 | # we just alias the original method |
1d68af04 |
307 | # rather than re-produce it here |
ce2ae40f |
308 | 'get_attribute_map' => \&Class::MOP::Class::get_attribute_map |
f7259199 |
309 | }, |
727919c5 |
310 | default => sub { {} } |
311 | )) |
312 | ); |
313 | |
351bd7d4 |
314 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
315 | Class::MOP::Attribute->new('superclasses' => ( |
c23184fc |
316 | accessor => { |
317 | # NOTE: |
318 | # we just alias the original method |
1d68af04 |
319 | # rather than re-produce it here |
c23184fc |
320 | 'superclasses' => \&Class::MOP::Class::superclasses |
321 | }, |
2e877f58 |
322 | init_arg => undef, |
c23184fc |
323 | default => sub { \undef } |
324 | )) |
325 | ); |
326 | |
327 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
328 | Class::MOP::Attribute->new('attribute_metaclass' => ( |
1d68af04 |
329 | reader => { |
6d2118a4 |
330 | # NOTE: |
331 | # we just alias the original method |
1d68af04 |
332 | # rather than re-produce it here |
6d2118a4 |
333 | 'attribute_metaclass' => \&Class::MOP::Class::attribute_metaclass |
1d68af04 |
334 | }, |
351bd7d4 |
335 | default => 'Class::MOP::Attribute', |
336 | )) |
337 | ); |
338 | |
339 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
340 | Class::MOP::Attribute->new('instance_metaclass' => ( |
b880e0de |
341 | reader => { |
1d68af04 |
342 | # NOTE: we need to do this in order |
343 | # for the instance meta-object to |
344 | # not fall into meta-circular death |
345 | # |
ce2ae40f |
346 | # we just alias the original method |
1d68af04 |
347 | # rather than re-produce it here |
ce2ae40f |
348 | 'instance_metaclass' => \&Class::MOP::Class::instance_metaclass |
b880e0de |
349 | }, |
1d68af04 |
350 | default => 'Class::MOP::Instance', |
2bab2be6 |
351 | )) |
352 | ); |
353 | |
44d6ea77 |
354 | Class::MOP::Class->meta->add_attribute( |
f5d08022 |
355 | Class::MOP::Attribute->new('immutable_trait' => ( |
356 | reader => { |
357 | 'immutable_trait' => \&Class::MOP::Class::immutable_trait |
358 | }, |
359 | default => "Class::MOP::Class::Immutable::Trait", |
360 | )) |
361 | ); |
362 | |
363 | Class::MOP::Class->meta->add_attribute( |
364 | Class::MOP::Attribute->new('constructor_name' => ( |
44d6ea77 |
365 | reader => { |
f5d08022 |
366 | 'constructor_name' => \&Class::MOP::Class::constructor_name, |
44d6ea77 |
367 | }, |
f5d08022 |
368 | default => "new", |
369 | )) |
370 | ); |
371 | |
372 | Class::MOP::Class->meta->add_attribute( |
373 | Class::MOP::Attribute->new('constructor_class' => ( |
44d6ea77 |
374 | reader => { |
f5d08022 |
375 | 'constructor_class' => \&Class::MOP::Class::constructor_class, |
44d6ea77 |
376 | }, |
f5d08022 |
377 | default => "Class::MOP::Method::Constructor", |
378 | )) |
379 | ); |
380 | |
381 | |
382 | Class::MOP::Class->meta->add_attribute( |
383 | Class::MOP::Attribute->new('destructor_class' => ( |
384 | reader => { |
385 | 'destructor_class' => \&Class::MOP::Class::destructor_class, |
44d6ea77 |
386 | }, |
387 | )) |
388 | ); |
389 | |
9d6dce77 |
390 | # NOTE: |
1d68af04 |
391 | # we don't actually need to tie the knot with |
392 | # Class::MOP::Class here, it is actually handled |
393 | # within Class::MOP::Class itself in the |
c2b256bc |
394 | # _construct_class_instance method. |
9d6dce77 |
395 | |
f0480c45 |
396 | ## -------------------------------------------------------- |
727919c5 |
397 | ## Class::MOP::Attribute |
398 | |
7b31baf4 |
399 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
400 | Class::MOP::Attribute->new('name' => ( |
c23184fc |
401 | reader => { |
1d68af04 |
402 | # NOTE: we need to do this in order |
403 | # for the instance meta-object to |
404 | # not fall into meta-circular death |
405 | # |
ce2ae40f |
406 | # we just alias the original method |
1d68af04 |
407 | # rather than re-produce it here |
ce2ae40f |
408 | 'name' => \&Class::MOP::Attribute::name |
b880e0de |
409 | } |
7b31baf4 |
410 | )) |
411 | ); |
412 | |
413 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
414 | Class::MOP::Attribute->new('associated_class' => ( |
c23184fc |
415 | reader => { |
1d68af04 |
416 | # NOTE: we need to do this in order |
417 | # for the instance meta-object to |
418 | # not fall into meta-circular death |
419 | # |
ce2ae40f |
420 | # we just alias the original method |
1d68af04 |
421 | # rather than re-produce it here |
ce2ae40f |
422 | 'associated_class' => \&Class::MOP::Attribute::associated_class |
b880e0de |
423 | } |
7b31baf4 |
424 | )) |
425 | ); |
426 | |
427 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
428 | Class::MOP::Attribute->new('accessor' => ( |
6d2118a4 |
429 | reader => { 'accessor' => \&Class::MOP::Attribute::accessor }, |
430 | predicate => { 'has_accessor' => \&Class::MOP::Attribute::has_accessor }, |
7b31baf4 |
431 | )) |
432 | ); |
433 | |
434 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
435 | Class::MOP::Attribute->new('reader' => ( |
6d2118a4 |
436 | reader => { 'reader' => \&Class::MOP::Attribute::reader }, |
437 | predicate => { 'has_reader' => \&Class::MOP::Attribute::has_reader }, |
7b31baf4 |
438 | )) |
439 | ); |
440 | |
441 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
442 | Class::MOP::Attribute->new('initializer' => ( |
8ee74136 |
443 | reader => { 'initializer' => \&Class::MOP::Attribute::initializer }, |
444 | predicate => { 'has_initializer' => \&Class::MOP::Attribute::has_initializer }, |
0ab65f99 |
445 | )) |
446 | ); |
447 | |
448 | Class::MOP::Attribute->meta->add_attribute( |
d9d99689 |
449 | Class::MOP::Attribute->new('definition_context' => ( |
450 | reader => { 'definition_context' => \&Class::MOP::Attribute::definition_context }, |
451 | )) |
452 | ); |
453 | |
454 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
455 | Class::MOP::Attribute->new('writer' => ( |
6d2118a4 |
456 | reader => { 'writer' => \&Class::MOP::Attribute::writer }, |
457 | predicate => { 'has_writer' => \&Class::MOP::Attribute::has_writer }, |
7b31baf4 |
458 | )) |
459 | ); |
460 | |
461 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
462 | Class::MOP::Attribute->new('predicate' => ( |
6d2118a4 |
463 | reader => { 'predicate' => \&Class::MOP::Attribute::predicate }, |
464 | predicate => { 'has_predicate' => \&Class::MOP::Attribute::has_predicate }, |
7b31baf4 |
465 | )) |
466 | ); |
467 | |
468 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
469 | Class::MOP::Attribute->new('clearer' => ( |
6d2118a4 |
470 | reader => { 'clearer' => \&Class::MOP::Attribute::clearer }, |
471 | predicate => { 'has_clearer' => \&Class::MOP::Attribute::has_clearer }, |
7d28758b |
472 | )) |
473 | ); |
474 | |
475 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
476 | Class::MOP::Attribute->new('builder' => ( |
1d68af04 |
477 | reader => { 'builder' => \&Class::MOP::Attribute::builder }, |
478 | predicate => { 'has_builder' => \&Class::MOP::Attribute::has_builder }, |
479 | )) |
480 | ); |
481 | |
482 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
483 | Class::MOP::Attribute->new('init_arg' => ( |
6d2118a4 |
484 | reader => { 'init_arg' => \&Class::MOP::Attribute::init_arg }, |
485 | predicate => { 'has_init_arg' => \&Class::MOP::Attribute::has_init_arg }, |
7b31baf4 |
486 | )) |
487 | ); |
488 | |
489 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
490 | Class::MOP::Attribute->new('default' => ( |
7b31baf4 |
491 | # default has a custom 'reader' method ... |
1d68af04 |
492 | predicate => { 'has_default' => \&Class::MOP::Attribute::has_default }, |
7b31baf4 |
493 | )) |
494 | ); |
495 | |
3545c727 |
496 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
497 | Class::MOP::Attribute->new('associated_methods' => ( |
c23184fc |
498 | reader => { 'associated_methods' => \&Class::MOP::Attribute::associated_methods }, |
1d68af04 |
499 | default => sub { [] } |
3545c727 |
500 | )) |
501 | ); |
727919c5 |
502 | |
95b67145 |
503 | Class::MOP::Attribute->meta->add_attribute( |
504 | Class::MOP::Attribute->new('insertion_order' => ( |
505 | reader => { 'insertion_order' => \&Class::MOP::Attribute::insertion_order }, |
943cbe2d |
506 | writer => { '_set_insertion_order' => \&Class::MOP::Attribute::_set_insertion_order }, |
95b67145 |
507 | predicate => { 'has_insertion_order' => \&Class::MOP::Attribute::has_insertion_order }, |
508 | )) |
509 | ); |
510 | |
5659d76e |
511 | Class::MOP::Attribute->meta->add_method('clone' => sub { |
a740253a |
512 | my $self = shift; |
1d68af04 |
513 | $self->meta->clone_object($self, @_); |
727919c5 |
514 | }); |
515 | |
f0480c45 |
516 | ## -------------------------------------------------------- |
b6164407 |
517 | ## Class::MOP::Method |
b6164407 |
518 | Class::MOP::Method->meta->add_attribute( |
8683db0e |
519 | Class::MOP::Attribute->new('body' => ( |
c23184fc |
520 | reader => { 'body' => \&Class::MOP::Method::body }, |
b6164407 |
521 | )) |
522 | ); |
523 | |
4c105333 |
524 | Class::MOP::Method->meta->add_attribute( |
5e607260 |
525 | Class::MOP::Attribute->new('associated_metaclass' => ( |
5e607260 |
526 | reader => { 'associated_metaclass' => \&Class::MOP::Method::associated_metaclass }, |
527 | )) |
528 | ); |
529 | |
530 | Class::MOP::Method->meta->add_attribute( |
8683db0e |
531 | Class::MOP::Attribute->new('package_name' => ( |
4c105333 |
532 | reader => { 'package_name' => \&Class::MOP::Method::package_name }, |
533 | )) |
534 | ); |
535 | |
536 | Class::MOP::Method->meta->add_attribute( |
8683db0e |
537 | Class::MOP::Attribute->new('name' => ( |
4c105333 |
538 | reader => { 'name' => \&Class::MOP::Method::name }, |
539 | )) |
540 | ); |
541 | |
2226a8b0 |
542 | Class::MOP::Method->meta->add_attribute( |
543 | Class::MOP::Attribute->new('original_method' => ( |
544 | reader => { 'original_method' => \&Class::MOP::Method::original_method }, |
545 | writer => { '_set_original_method' => \&Class::MOP::Method::_set_original_method }, |
546 | )) |
547 | ); |
548 | |
4c105333 |
549 | Class::MOP::Method->meta->add_method('clone' => sub { |
550 | my $self = shift; |
2226a8b0 |
551 | my $clone = $self->meta->clone_object($self, @_); |
552 | $clone->_set_original_method($self); |
553 | return $clone; |
4c105333 |
554 | }); |
555 | |
b6164407 |
556 | ## -------------------------------------------------------- |
557 | ## Class::MOP::Method::Wrapped |
558 | |
559 | # NOTE: |
1d68af04 |
560 | # the way this item is initialized, this |
561 | # really does not follow the standard |
562 | # practices of attributes, but we put |
b6164407 |
563 | # it here for completeness |
564 | Class::MOP::Method::Wrapped->meta->add_attribute( |
8683db0e |
565 | Class::MOP::Attribute->new('modifier_table') |
b6164407 |
566 | ); |
567 | |
568 | ## -------------------------------------------------------- |
565f0cbb |
569 | ## Class::MOP::Method::Generated |
570 | |
571 | Class::MOP::Method::Generated->meta->add_attribute( |
8683db0e |
572 | Class::MOP::Attribute->new('is_inline' => ( |
565f0cbb |
573 | reader => { 'is_inline' => \&Class::MOP::Method::Generated::is_inline }, |
4c105333 |
574 | default => 0, |
1d68af04 |
575 | )) |
565f0cbb |
576 | ); |
577 | |
d9d99689 |
578 | Class::MOP::Method::Generated->meta->add_attribute( |
579 | Class::MOP::Attribute->new('definition_context' => ( |
580 | reader => { 'definition_context' => \&Class::MOP::Method::Generated::definition_context }, |
581 | )) |
582 | ); |
583 | |
29d4e92a |
584 | |
585 | ## -------------------------------------------------------- |
586 | ## Class::MOP::Method::Inlined |
587 | |
588 | Class::MOP::Method::Inlined->meta->add_attribute( |
589 | Class::MOP::Attribute->new('_expected_method_class' => ( |
590 | reader => { '_expected_method_class' => \&Class::MOP::Method::Inlined::_expected_method_class }, |
591 | )) |
592 | ); |
593 | |
565f0cbb |
594 | ## -------------------------------------------------------- |
d90b42a6 |
595 | ## Class::MOP::Method::Accessor |
596 | |
597 | Class::MOP::Method::Accessor->meta->add_attribute( |
8683db0e |
598 | Class::MOP::Attribute->new('attribute' => ( |
1d68af04 |
599 | reader => { |
600 | 'associated_attribute' => \&Class::MOP::Method::Accessor::associated_attribute |
d90b42a6 |
601 | }, |
1d68af04 |
602 | )) |
d90b42a6 |
603 | ); |
604 | |
605 | Class::MOP::Method::Accessor->meta->add_attribute( |
8683db0e |
606 | Class::MOP::Attribute->new('accessor_type' => ( |
c23184fc |
607 | reader => { 'accessor_type' => \&Class::MOP::Method::Accessor::accessor_type }, |
1d68af04 |
608 | )) |
d90b42a6 |
609 | ); |
610 | |
d90b42a6 |
611 | ## -------------------------------------------------------- |
612 | ## Class::MOP::Method::Constructor |
613 | |
614 | Class::MOP::Method::Constructor->meta->add_attribute( |
8683db0e |
615 | Class::MOP::Attribute->new('options' => ( |
1d68af04 |
616 | reader => { |
617 | 'options' => \&Class::MOP::Method::Constructor::options |
d90b42a6 |
618 | }, |
4c105333 |
619 | default => sub { +{} } |
1d68af04 |
620 | )) |
d90b42a6 |
621 | ); |
622 | |
623 | Class::MOP::Method::Constructor->meta->add_attribute( |
8683db0e |
624 | Class::MOP::Attribute->new('associated_metaclass' => ( |
e8a38403 |
625 | init_arg => "metaclass", # FIXME alias and rename |
1d68af04 |
626 | reader => { |
627 | 'associated_metaclass' => \&Class::MOP::Method::Constructor::associated_metaclass |
628 | }, |
629 | )) |
d90b42a6 |
630 | ); |
631 | |
632 | ## -------------------------------------------------------- |
86482605 |
633 | ## Class::MOP::Instance |
634 | |
635 | # NOTE: |
1d68af04 |
636 | # these don't yet do much of anything, but are just |
86482605 |
637 | # included for completeness |
638 | |
639 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
640 | Class::MOP::Attribute->new('associated_metaclass', |
641 | reader => { associated_metaclass => \&Class::MOP::Instance::associated_metaclass }, |
642 | ), |
86482605 |
643 | ); |
644 | |
645 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
646 | Class::MOP::Attribute->new('_class_name', |
647 | init_arg => undef, |
648 | reader => { _class_name => \&Class::MOP::Instance::_class_name }, |
649 | #lazy => 1, # not yet supported by Class::MOP but out our version does it anyway |
650 | #default => sub { $_[0]->associated_metaclass->name }, |
651 | ), |
652 | ); |
653 | |
654 | Class::MOP::Instance->meta->add_attribute( |
655 | Class::MOP::Attribute->new('attributes', |
0b5d46da |
656 | reader => { attributes => \&Class::MOP::Instance::get_all_attributes }, |
74890687 |
657 | ), |
32bfc810 |
658 | ); |
659 | |
660 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
661 | Class::MOP::Attribute->new('slots', |
662 | reader => { slots => \&Class::MOP::Instance::slots }, |
663 | ), |
86482605 |
664 | ); |
665 | |
63d08a9e |
666 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
667 | Class::MOP::Attribute->new('slot_hash', |
668 | reader => { slot_hash => \&Class::MOP::Instance::slot_hash }, |
669 | ), |
63d08a9e |
670 | ); |
671 | |
30229767 |
672 | require Class::MOP::Deprecated unless our $no_deprecated; |
63d08a9e |
673 | |
caa051fa |
674 | # we need the meta instance of the meta instance to be created now, in order |
675 | # for the constructor to be able to use it |
676 | Class::MOP::Instance->meta->get_meta_instance; |
677 | |
caa051fa |
678 | # pretend the add_method never happenned. it hasn't yet affected anything |
679 | undef Class::MOP::Instance->meta->{_package_cache_flag}; |
680 | |
86482605 |
681 | ## -------------------------------------------------------- |
f0480c45 |
682 | ## Now close all the Class::MOP::* classes |
4d47b77f |
683 | |
1aa13cf4 |
684 | # NOTE: we don't need to inline the the accessors this only lengthens |
685 | # the compile time of the MOP, and gives us no actual benefits. |
0b9372a2 |
686 | |
687 | $_->meta->make_immutable( |
ec9e38e5 |
688 | inline_constructor => 0, |
6c2f6b5c |
689 | constructor_name => "_new", |
45582002 |
690 | inline_accessors => 0, |
0b9372a2 |
691 | ) for qw/ |
1d68af04 |
692 | Class::MOP::Package |
693 | Class::MOP::Module |
694 | Class::MOP::Class |
695 | |
0b9372a2 |
696 | Class::MOP::Attribute |
1d68af04 |
697 | Class::MOP::Method |
698 | Class::MOP::Instance |
699 | |
700 | Class::MOP::Object |
0b9372a2 |
701 | |
565f0cbb |
702 | Class::MOP::Method::Generated |
29d4e92a |
703 | Class::MOP::Method::Inlined |
1d68af04 |
704 | |
ba38bf08 |
705 | Class::MOP::Method::Accessor |
1d68af04 |
706 | Class::MOP::Method::Constructor |
707 | Class::MOP::Method::Wrapped |
0b9372a2 |
708 | /; |
b6164407 |
709 | |
94b19069 |
710 | 1; |
711 | |
712 | __END__ |
713 | |
714 | =pod |
715 | |
1d68af04 |
716 | =head1 NAME |
94b19069 |
717 | |
718 | Class::MOP - A Meta Object Protocol for Perl 5 |
719 | |
5b60bf98 |
720 | =head1 DESCRIPTION |
94b19069 |
721 | |
127d39a7 |
722 | This module is a fully functioning meta object protocol for the |
1d68af04 |
723 | Perl 5 object system. It makes no attempt to change the behavior or |
724 | characteristics of the Perl 5 object system, only to create a |
27e31eaf |
725 | protocol for its manipulation and introspection. |
94b19069 |
726 | |
828ecf13 |
727 | That said, it does attempt to create the tools for building a rich set |
728 | of extensions to the Perl 5 object system. Every attempt has been made |
729 | to abide by the spirit of the Perl 5 object system that we all know |
730 | and love. |
94b19069 |
731 | |
828ecf13 |
732 | This documentation is sparse on conceptual details. We suggest looking |
733 | at the items listed in the L<SEE ALSO> section for more |
734 | information. In particular the book "The Art of the Meta Object |
735 | Protocol" was very influential in the development of this system. |
40483095 |
736 | |
bfe4d0fc |
737 | =head2 What is a Meta Object Protocol? |
738 | |
1d68af04 |
739 | A meta object protocol is an API to an object system. |
bfe4d0fc |
740 | |
828ecf13 |
741 | To be more specific, it abstracts the components of an object system |
742 | (classes, object, methods, object attributes, etc.). These |
743 | abstractions can then be used to inspect and manipulate the object |
744 | system which they describe. |
bfe4d0fc |
745 | |
1d68af04 |
746 | It can be said that there are two MOPs for any object system; the |
828ecf13 |
747 | implicit MOP and the explicit MOP. The implicit MOP handles things |
1d68af04 |
748 | like method dispatch or inheritance, which happen automatically as |
749 | part of how the object system works. The explicit MOP typically |
750 | handles the introspection/reflection features of the object system. |
bfe4d0fc |
751 | |
828ecf13 |
752 | All object systems have implicit MOPs. Without one, they would not |
5b60bf98 |
753 | work. Explicit MOPs are much less common, and depending on the |
754 | language can vary from restrictive (Reflection in Java or C#) to wide |
755 | open (CLOS is a perfect example). |
e16da3e6 |
756 | |
828ecf13 |
757 | =head2 Yet Another Class Builder! Why? |
758 | |
759 | This is B<not> a class builder so much as a I<class builder |
760 | B<builder>>. The intent is that an end user will not use this module |
761 | directly, but instead this module is used by module authors to build |
762 | extensions and features onto the Perl 5 object system. |
763 | |
764 | This system is used by L<Moose>, which supplies a powerful class |
765 | builder system built entirely on top of C<Class::MOP>. |
e16da3e6 |
766 | |
94b19069 |
767 | =head2 Who is this module for? |
768 | |
828ecf13 |
769 | This module is for anyone who has ever created or wanted to create a |
770 | module for the Class:: namespace. The tools which this module provides |
771 | make doing complex Perl 5 wizardry simpler, by removing such barriers |
772 | as the need to hack symbol tables, or understand the fine details of |
773 | method dispatch. |
94b19069 |
774 | |
bfe4d0fc |
775 | =head2 What changes do I have to make to use this module? |
776 | |
828ecf13 |
777 | This module was designed to be as unintrusive as possible. Many of its |
5b60bf98 |
778 | features are accessible without B<any> change to your existing |
828ecf13 |
779 | code. It is meant to be a compliment to your existing code and not an |
780 | intrusion on your code base. Unlike many other B<Class::> modules, |
781 | this module B<does not> require you subclass it, or even that you |
782 | C<use> it in within your module's package. |
bfe4d0fc |
783 | |
1d68af04 |
784 | The only features which requires additions to your code are the |
2eb717d5 |
785 | attribute handling and instance construction features, and these are |
1d68af04 |
786 | both completely optional features. The only reason for this is because |
787 | Perl 5's object system does not actually have these features built |
2eb717d5 |
788 | in. More information about this feature can be found below. |
bfe4d0fc |
789 | |
828ecf13 |
790 | =head2 About Performance |
791 | |
5b60bf98 |
792 | It is a common misconception that explicit MOPs are a performance hit. |
828ecf13 |
793 | This is not a universal truth, it is a side-effect of some specific |
794 | implementations. For instance, using Java reflection is slow because |
795 | the JVM cannot take advantage of any compiler optimizations, and the |
796 | JVM has to deal with much more runtime type information as well. |
bfe4d0fc |
797 | |
828ecf13 |
798 | Reflection in C# is marginally better as it was designed into the |
799 | language and runtime (the CLR). In contrast, CLOS (the Common Lisp |
800 | Object System) was built to support an explicit MOP, and so |
801 | performance is tuned for it. |
1d68af04 |
802 | |
828ecf13 |
803 | This library in particular does its absolute best to avoid putting |
1d68af04 |
804 | B<any> drain at all upon your code's performance. In fact, by itself |
828ecf13 |
805 | it does nothing to affect your existing code. So you only pay for what |
806 | you actually use. |
bfe4d0fc |
807 | |
550d56db |
808 | =head2 About Metaclass compatibility |
809 | |
1d68af04 |
810 | This module makes sure that all metaclasses created are both upwards |
811 | and downwards compatible. The topic of metaclass compatibility is |
812 | highly esoteric and is something only encountered when doing deep and |
813 | involved metaclass hacking. There are two basic kinds of metaclass |
814 | incompatibility; upwards and downwards. |
550d56db |
815 | |
1d68af04 |
816 | Upwards metaclass compatibility means that the metaclass of a |
817 | given class is either the same as (or a subclass of) all of the |
550d56db |
818 | class's ancestors. |
819 | |
1d68af04 |
820 | Downward metaclass compatibility means that the metaclasses of a |
828ecf13 |
821 | given class's ancestors are all either the same as (or a subclass |
550d56db |
822 | of) that metaclass. |
823 | |
1d68af04 |
824 | Here is a diagram showing a set of two classes (C<A> and C<B>) and |
825 | two metaclasses (C<Meta::A> and C<Meta::B>) which have correct |
550d56db |
826 | metaclass compatibility both upwards and downwards. |
827 | |
828 | +---------+ +---------+ |
829 | | Meta::A |<----| Meta::B | <....... (instance of ) |
1d68af04 |
830 | +---------+ +---------+ <------- (inherits from) |
550d56db |
831 | ^ ^ |
832 | : : |
833 | +---------+ +---------+ |
834 | | A |<----| B | |
835 | +---------+ +---------+ |
836 | |
1d68af04 |
837 | As I said this is a highly esoteric topic and one you will only run |
828ecf13 |
838 | into if you do a lot of subclassing of L<Class::MOP::Class>. If you |
839 | are interested in why this is an issue see the paper I<Uniform and |
840 | safe metaclass composition> linked to in the L<SEE ALSO> section of |
841 | this document. |
550d56db |
842 | |
aa448b16 |
843 | =head2 Using custom metaclasses |
844 | |
828ecf13 |
845 | Always use the L<metaclass> pragma when using a custom metaclass, this |
5b60bf98 |
846 | will ensure the proper initialization order and not accidentally |
847 | create an incorrect type of metaclass for you. This is a very rare |
848 | problem, and one which can only occur if you are doing deep metaclass |
aa448b16 |
849 | programming. So in other words, don't worry about it. |
850 | |
828ecf13 |
851 | Note that if you're using L<Moose> we encourage you to I<not> use |
852 | L<metaclass> pragma, and instead use L<Moose::Util::MetaRole> to apply |
853 | roles to a class's metaclasses. This topic is covered at length in |
854 | various L<Moose::Cookbook> recipes. |
855 | |
94b19069 |
856 | =head1 PROTOCOLS |
857 | |
828ecf13 |
858 | The meta-object protocol is divided into 4 main sub-protocols: |
94b19069 |
859 | |
828ecf13 |
860 | =head2 The Class protocol |
94b19069 |
861 | |
1d68af04 |
862 | This provides a means of manipulating and introspecting a Perl 5 |
828ecf13 |
863 | class. It handles symbol table hacking for you, and provides a rich |
864 | set of methods that go beyond simple package introspection. |
94b19069 |
865 | |
552e3d24 |
866 | See L<Class::MOP::Class> for more details. |
867 | |
828ecf13 |
868 | =head2 The Attribute protocol |
94b19069 |
869 | |
828ecf13 |
870 | This provides a consistent representation for an attribute of a Perl 5 |
871 | class. Since there are so many ways to create and handle attributes in |
872 | Perl 5 OO, the Attribute protocol provide as much of a unified |
873 | approach as possible. Of course, you are always free to extend this |
874 | protocol by subclassing the appropriate classes. |
94b19069 |
875 | |
552e3d24 |
876 | See L<Class::MOP::Attribute> for more details. |
877 | |
828ecf13 |
878 | =head2 The Method protocol |
94b19069 |
879 | |
828ecf13 |
880 | This provides a means of manipulating and introspecting methods in the |
881 | Perl 5 object system. As with attributes, there are many ways to |
1d68af04 |
882 | approach this topic, so we try to keep it pretty basic, while still |
94b19069 |
883 | making it possible to extend the system in many ways. |
884 | |
552e3d24 |
885 | See L<Class::MOP::Method> for more details. |
94b19069 |
886 | |
828ecf13 |
887 | =head2 The Instance protocol |
127d39a7 |
888 | |
828ecf13 |
889 | This provides a layer of abstraction for creating object instances. |
890 | Since the other layers use this protocol, it is relatively easy to |
891 | change the type of your instances from the default hash reference to |
892 | some other type of reference. Several examples are provided in the |
893 | F<examples/> directory included in this distribution. |
127d39a7 |
894 | |
895 | See L<Class::MOP::Instance> for more details. |
896 | |
be7677c7 |
897 | =head1 FUNCTIONS |
898 | |
828ecf13 |
899 | Note that this module does not export any constants or functions. |
900 | |
c1d5345a |
901 | =head2 Constants |
902 | |
903 | =over 4 |
904 | |
828ecf13 |
905 | =item I<Class::MOP::IS_RUNNING_ON_5_10> |
c1d5345a |
906 | |
828ecf13 |
907 | We set this constant depending on what version perl we are on, this |
908 | allows us to take advantage of new 5.10 features and stay backwards |
5b60bf98 |
909 | compatible. |
c1d5345a |
910 | |
911 | =back |
912 | |
448b6e55 |
913 | =head2 Utility functions |
914 | |
bd07fbdb |
915 | Note that these are all called as B<functions, not methods>. |
081a927b |
916 | |
448b6e55 |
917 | =over 4 |
918 | |
828ecf13 |
919 | =item B<Class::MOP::load_class($class_name)> |
448b6e55 |
920 | |
9d441c23 |
921 | This will load the specified C<$class_name>, if it is not already |
922 | loaded (as reported by C<is_class_loaded>). This function can be used |
828ecf13 |
923 | in place of tricks like C<eval "use $module"> or using C<require> |
7716a8f9 |
924 | unconditionally. |
448b6e55 |
925 | |
674d9359 |
926 | If the module cannot be loaded, an exception is thrown. |
927 | |
928 | For historical reasons, this function returns explicitly returns a true value. |
929 | |
828ecf13 |
930 | =item B<Class::MOP::is_class_loaded($class_name)> |
448b6e55 |
931 | |
15ab5451 |
932 | Returns a boolean indicating whether or not C<$class_name> has been |
933 | loaded. |
448b6e55 |
934 | |
828ecf13 |
935 | This does a basic check of the symbol table to try and determine as |
936 | best it can if the C<$class_name> is loaded, it is probably correct |
937 | about 99% of the time, but it can be fooled into reporting false |
9d441c23 |
938 | positives. In particular, loading any of the core L<IO> modules will |
939 | cause most of the rest of the core L<IO> modules to falsely report |
940 | having been loaded, due to the way the base L<IO> module works. |
448b6e55 |
941 | |
cdac22cc |
942 | =item B<Class::MOP::get_code_info($code)> |
943 | |
944 | This function returns two values, the name of the package the C<$code> |
945 | is from and the name of the C<$code> itself. This is used by several |
5b60bf98 |
946 | elements of the MOP to determine where a given C<$code> reference is |
cdac22cc |
947 | from. |
948 | |
44ba77a3 |
949 | =item B<Class::MOP::class_of($instance_or_class_name)> |
950 | |
3fa5b3f9 |
951 | This will return the metaclass of the given instance or class name. If the |
952 | class lacks a metaclass, no metaclass will be initialized, and C<undef> will be |
953 | returned. |
44ba77a3 |
954 | |
828ecf13 |
955 | =item B<Class::MOP::check_package_cache_flag($pkg)> |
e0e4674a |
956 | |
bd07fbdb |
957 | B<NOTE: DO NOT USE THIS FUNCTION, IT IS FOR INTERNAL USE ONLY!> |
958 | |
828ecf13 |
959 | This will return an integer that is managed by L<Class::MOP::Class> to |
960 | determine if a module's symbol table has been altered. |
127d39a7 |
961 | |
828ecf13 |
962 | In Perl 5.10 or greater, this flag is package specific. However in |
963 | versions prior to 5.10, this will use the C<PL_sub_generation> |
964 | variable which is not package specific. |
127d39a7 |
965 | |
828ecf13 |
966 | =item B<Class::MOP::load_first_existing_class(@class_names)> |
063ad0c5 |
967 | |
968 | B<NOTE: DO NOT USE THIS FUNCTION, IT IS FOR INTERNAL USE ONLY!> |
969 | |
970 | Given a list of class names, this function will attempt to load each |
971 | one in turn. |
972 | |
828ecf13 |
973 | If it finds a class it can load, it will return that class' name. If |
974 | none of the classes can be loaded, it will throw an exception. |
063ad0c5 |
975 | |
448b6e55 |
976 | =back |
977 | |
978 | =head2 Metaclass cache functions |
979 | |
6c842677 |
980 | Class::MOP holds a cache of metaclasses. The following are functions |
1d68af04 |
981 | (B<not methods>) which can be used to access that cache. It is not |
6c842677 |
982 | recommended that you mess with these. Bad things could happen, but if |
983 | you are brave and willing to risk it: go for it! |
be7677c7 |
984 | |
985 | =over 4 |
986 | |
828ecf13 |
987 | =item B<Class::MOP::get_all_metaclasses> |
be7677c7 |
988 | |
6c842677 |
989 | This will return a hash of all the metaclass instances that have |
828ecf13 |
990 | been cached by L<Class::MOP::Class>, keyed by the package name. |
b9d9fc0b |
991 | |
828ecf13 |
992 | =item B<Class::MOP::get_all_metaclass_instances> |
be7677c7 |
993 | |
6c842677 |
994 | This will return a list of all the metaclass instances that have |
828ecf13 |
995 | been cached by L<Class::MOP::Class>. |
b9d9fc0b |
996 | |
828ecf13 |
997 | =item B<Class::MOP::get_all_metaclass_names> |
be7677c7 |
998 | |
6c842677 |
999 | This will return a list of all the metaclass names that have |
828ecf13 |
1000 | been cached by L<Class::MOP::Class>. |
b9d9fc0b |
1001 | |
828ecf13 |
1002 | =item B<Class::MOP::get_metaclass_by_name($name)> |
be7677c7 |
1003 | |
828ecf13 |
1004 | This will return a cached L<Class::MOP::Class> instance, or nothing |
6c842677 |
1005 | if no metaclass exists with that C<$name>. |
127d39a7 |
1006 | |
828ecf13 |
1007 | =item B<Class::MOP::store_metaclass_by_name($name, $meta)> |
be7677c7 |
1008 | |
127d39a7 |
1009 | This will store a metaclass in the cache at the supplied C<$key>. |
1010 | |
828ecf13 |
1011 | =item B<Class::MOP::weaken_metaclass($name)> |
be7677c7 |
1012 | |
6c842677 |
1013 | In rare cases (e.g. anonymous metaclasses) it is desirable to |
1014 | store a weakened reference in the metaclass cache. This |
1015 | function will weaken the reference to the metaclass stored |
1016 | in C<$name>. |
127d39a7 |
1017 | |
828ecf13 |
1018 | =item B<Class::MOP::does_metaclass_exist($name)> |
be7677c7 |
1019 | |
828ecf13 |
1020 | This will return true of there exists a metaclass stored in the |
6c842677 |
1021 | C<$name> key, and return false otherwise. |
127d39a7 |
1022 | |
828ecf13 |
1023 | =item B<Class::MOP::remove_metaclass_by_name($name)> |
be7677c7 |
1024 | |
6c842677 |
1025 | This will remove the metaclass stored in the C<$name> key. |
127d39a7 |
1026 | |
be7677c7 |
1027 | =back |
1028 | |
552e3d24 |
1029 | =head1 SEE ALSO |
8b978dd5 |
1030 | |
552e3d24 |
1031 | =head2 Books |
8b978dd5 |
1032 | |
1d68af04 |
1033 | There are very few books out on Meta Object Protocols and Metaclasses |
1034 | because it is such an esoteric topic. The following books are really |
1035 | the only ones I have found. If you know of any more, B<I<please>> |
a2e85e6c |
1036 | email me and let me know, I would love to hear about them. |
1037 | |
8b978dd5 |
1038 | =over 4 |
1039 | |
15ab5451 |
1040 | =item I<The Art of the Meta Object Protocol> |
8b978dd5 |
1041 | |
15ab5451 |
1042 | =item I<Advances in Object-Oriented Metalevel Architecture and Reflection> |
8b978dd5 |
1043 | |
15ab5451 |
1044 | =item I<Putting MetaClasses to Work> |
b51af7f9 |
1045 | |
15ab5451 |
1046 | =item I<Smalltalk: The Language> |
a2e85e6c |
1047 | |
94b19069 |
1048 | =back |
1049 | |
550d56db |
1050 | =head2 Papers |
1051 | |
1052 | =over 4 |
1053 | |
15ab5451 |
1054 | =item "Uniform and safe metaclass composition" |
550d56db |
1055 | |
1d68af04 |
1056 | An excellent paper by the people who brought us the original Traits paper. |
1057 | This paper is on how Traits can be used to do safe metaclass composition, |
1058 | and offers an excellent introduction section which delves into the topic of |
550d56db |
1059 | metaclass compatibility. |
1060 | |
1061 | L<http://www.iam.unibe.ch/~scg/Archive/Papers/Duca05ySafeMetaclassTrait.pdf> |
1062 | |
15ab5451 |
1063 | =item "Safe Metaclass Programming" |
550d56db |
1064 | |
1d68af04 |
1065 | This paper seems to precede the above paper, and propose a mix-in based |
1066 | approach as opposed to the Traits based approach. Both papers have similar |
1067 | information on the metaclass compatibility problem space. |
550d56db |
1068 | |
1069 | L<http://citeseer.ist.psu.edu/37617.html> |
1070 | |
1071 | =back |
1072 | |
552e3d24 |
1073 | =head2 Prior Art |
8b978dd5 |
1074 | |
1075 | =over 4 |
1076 | |
7184ca14 |
1077 | =item The Perl 6 MetaModel work in the Pugs project |
8b978dd5 |
1078 | |
1079 | =over 4 |
1080 | |
02615ef0 |
1081 | =item L<http://svn.openfoundry.org/pugs/misc/Perl-MetaModel/> |
8b978dd5 |
1082 | |
552e3d24 |
1083 | =item L<http://svn.openfoundry.org/pugs/perl5/Perl6-ObjectSpace> |
8b978dd5 |
1084 | |
1085 | =back |
1086 | |
94b19069 |
1087 | =back |
1088 | |
1d68af04 |
1089 | =head2 Articles |
f8dfcfb7 |
1090 | |
1091 | =over 4 |
1092 | |
1d68af04 |
1093 | =item CPAN Module Review of Class::MOP |
f8dfcfb7 |
1094 | |
1095 | L<http://www.oreillynet.com/onlamp/blog/2006/06/cpan_module_review_classmop.html> |
1096 | |
1097 | =back |
1098 | |
a2e85e6c |
1099 | =head1 SIMILAR MODULES |
1100 | |
1d68af04 |
1101 | As I have said above, this module is a class-builder-builder, so it is |
1102 | not the same thing as modules like L<Class::Accessor> and |
1103 | L<Class::MethodMaker>. That being said there are very few modules on CPAN |
1104 | with similar goals to this module. The one I have found which is most |
1105 | like this module is L<Class::Meta>, although it's philosophy and the MOP it |
1106 | creates are very different from this modules. |
94b19069 |
1107 | |
a2e85e6c |
1108 | =head1 BUGS |
1109 | |
1d68af04 |
1110 | All complex software has bugs lurking in it, and this module is no |
53702399 |
1111 | exception. |
1112 | |
1113 | Please report any bugs to C<bug-class-mop@rt.cpan.org>, or through the |
1114 | web interface at L<http://rt.cpan.org>. |
1115 | |
1116 | You can also discuss feature requests or possible bugs on the Moose |
1117 | mailing list (moose@perl.org) or on IRC at |
1118 | L<irc://irc.perl.org/#moose>. |
a2e85e6c |
1119 | |
1120 | =head1 ACKNOWLEDGEMENTS |
1121 | |
1122 | =over 4 |
1123 | |
b9d9fc0b |
1124 | =item Rob Kinyon |
a2e85e6c |
1125 | |
1d68af04 |
1126 | Thanks to Rob for actually getting the development of this module kick-started. |
a2e85e6c |
1127 | |
1128 | =back |
1129 | |
1a09d9cc |
1130 | =head1 AUTHORS |
94b19069 |
1131 | |
a2e85e6c |
1132 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
552e3d24 |
1133 | |
9c8cda90 |
1134 | B<with contributions from:> |
1135 | |
1136 | Brandon (blblack) Black |
1137 | |
4f116037 |
1138 | Florian (rafl) Ragwitz |
1139 | |
9c8cda90 |
1140 | Guillermo (groditi) Roditi |
1141 | |
53702399 |
1142 | Dave (autarch) Rolsky |
1143 | |
9195ddff |
1144 | Matt (mst) Trout |
1145 | |
9c8cda90 |
1146 | Rob (robkinyon) Kinyon |
1147 | |
1148 | Yuval (nothingmuch) Kogman |
1a09d9cc |
1149 | |
f430cfa4 |
1150 | Scott (konobi) McWhirter |
1151 | |
20f5ccef |
1152 | Dylan Hardison |
1153 | |
94b19069 |
1154 | =head1 COPYRIGHT AND LICENSE |
1155 | |
070bb6c9 |
1156 | Copyright 2006-2009 by Infinity Interactive, Inc. |
94b19069 |
1157 | |
1158 | L<http://www.iinteractive.com> |
1159 | |
1160 | This library is free software; you can redistribute it and/or modify |
1d68af04 |
1161 | it under the same terms as Perl itself. |
94b19069 |
1162 | |
1163 | =cut |