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'; |
fc4f8f91 |
13 | |
0531f510 |
14 | use Class::MOP::Class; |
15 | use Class::MOP::Attribute; |
16 | use Class::MOP::Method; |
17 | |
b1f5f41d |
18 | BEGIN { |
c7e28c19 |
19 | *IS_RUNNING_ON_5_10 = ($] < 5.009_005) |
11b56828 |
20 | ? sub () { 0 } |
c7e28c19 |
21 | : sub () { 1 }; |
46b23b44 |
22 | |
f9bd8fe2 |
23 | sub HAVE_ISAREV () { |
c7e28c19 |
24 | Carp::cluck("Class::MOP::HAVE_ISAREV is deprecated and will be removed in a future release. It has always returned 1 anyway."); |
f9bd8fe2 |
25 | return 1; |
26 | } |
3ecd1b25 |
27 | |
28 | # this is either part of core or set up appropriately by MRO::Compat |
29 | *check_package_cache_flag = \&mro::get_pkg_gen; |
b1f5f41d |
30 | } |
e0e4674a |
31 | |
074ec38f |
32 | our $VERSION = '0.89'; |
8a7085c1 |
33 | our $XS_VERSION = $VERSION; |
d519662a |
34 | $VERSION = eval $VERSION; |
c7e28c19 |
35 | our $AUTHORITY = 'cpan:STEVAN'; |
9d655b6d |
36 | |
4bfa5ddb |
37 | require XSLoader; |
38 | XSLoader::load( __PACKAGE__, $XS_VERSION ); |
d7bda114 |
39 | |
40 | |
be7677c7 |
41 | { |
42 | # Metaclasses are singletons, so we cache them here. |
43 | # there is no need to worry about destruction though |
44 | # because they should die only when the program dies. |
45 | # After all, do package definitions even get reaped? |
247d5b3c |
46 | # Anonymous classes manage their own destruction. |
1d68af04 |
47 | my %METAS; |
48 | |
1d68af04 |
49 | sub get_all_metaclasses { %METAS } |
50 | sub get_all_metaclass_instances { values %METAS } |
51 | sub get_all_metaclass_names { keys %METAS } |
be7677c7 |
52 | sub get_metaclass_by_name { $METAS{$_[0]} } |
1d68af04 |
53 | sub store_metaclass_by_name { $METAS{$_[0]} = $_[1] } |
54 | sub weaken_metaclass { weaken($METAS{$_[0]}) } |
be7677c7 |
55 | sub does_metaclass_exist { exists $METAS{$_[0]} && defined $METAS{$_[0]} } |
efc98200 |
56 | sub remove_metaclass_by_name { delete $METAS{$_[0]}; return } |
1d68af04 |
57 | |
86866fb5 |
58 | # This handles instances as well as class names |
59 | sub class_of { |
82999986 |
60 | return unless defined $_[0]; |
86866fb5 |
61 | my $class = blessed($_[0]) || $_[0]; |
62 | return $METAS{$class}; |
63 | } |
64 | |
be7677c7 |
65 | # NOTE: |
1d68af04 |
66 | # We only cache metaclasses, meaning instances of |
67 | # Class::MOP::Class. We do not cache instance of |
be7677c7 |
68 | # Class::MOP::Package or Class::MOP::Module. Mostly |
1d68af04 |
69 | # because I don't yet see a good reason to do so. |
be7677c7 |
70 | } |
71 | |
44da14be |
72 | sub _class_to_pmfile { |
73 | my $class = shift; |
74 | |
75 | my $file = $class . '.pm'; |
76 | $file =~ s{::}{/}g; |
77 | |
78 | return $file; |
79 | } |
80 | |
063ad0c5 |
81 | sub load_first_existing_class { |
f280f05c |
82 | my @classes = @_ |
83 | or return; |
5a24cf8a |
84 | |
85 | foreach my $class (@classes) { |
86 | unless ( _is_valid_class_name($class) ) { |
87 | my $display = defined($class) ? $class : 'undef'; |
88 | confess "Invalid class name ($display)"; |
89 | } |
ab5e2f48 |
90 | } |
91 | |
063ad0c5 |
92 | my $found; |
5a24cf8a |
93 | my %exceptions; |
063ad0c5 |
94 | for my $class (@classes) { |
44da14be |
95 | my $pmfile = _class_to_pmfile($class); |
063ad0c5 |
96 | my $e = _try_load_one_class($class); |
97 | |
5a24cf8a |
98 | if ($e) { |
063ad0c5 |
99 | $exceptions{$class} = $e; |
44da14be |
100 | last if $e !~ /^Can't locate \Q$pmfile\E in \@INC/; |
5a24cf8a |
101 | } |
102 | else { |
063ad0c5 |
103 | $found = $class; |
104 | last; |
5a24cf8a |
105 | } |
063ad0c5 |
106 | } |
5a24cf8a |
107 | |
1d8153bd |
108 | return $found if $found; |
07940968 |
109 | |
063ad0c5 |
110 | confess join( |
111 | "\n", |
112 | map { |
113 | sprintf( |
fea44045 |
114 | "Could not load class (%s) because : %s", $_, |
063ad0c5 |
115 | $exceptions{$_} |
116 | ) |
44da14be |
117 | } |
118 | grep { |
119 | exists $exceptions{$_} |
063ad0c5 |
120 | } @classes |
f280f05c |
121 | ); |
5a24cf8a |
122 | } |
123 | |
063ad0c5 |
124 | sub _try_load_one_class { |
125 | my $class = shift; |
126 | |
127 | return if is_class_loaded($class); |
2beec805 |
128 | |
44da14be |
129 | my $file = _class_to_pmfile($class); |
063ad0c5 |
130 | |
131 | return do { |
132 | local $@; |
b3813a8c |
133 | local $SIG{__DIE__}; |
063ad0c5 |
134 | eval { require($file) }; |
135 | $@; |
136 | }; |
137 | } |
138 | |
5a24cf8a |
139 | sub load_class { |
1d8153bd |
140 | my $class = load_first_existing_class($_[0]); |
141 | return get_metaclass_by_name($class) || $class; |
448b6e55 |
142 | } |
143 | |
2c0fb064 |
144 | sub _is_valid_class_name { |
145 | my $class = shift; |
146 | |
147 | return 0 if ref($class); |
148 | return 0 unless defined($class); |
149 | return 0 unless length($class); |
150 | |
151 | return 1 if $class =~ /^\w+(?:::\w+)*$/; |
152 | |
153 | return 0; |
154 | } |
155 | |
d5ed91ad |
156 | sub subname { |
157 | require Sub::Name; |
158 | Carp::carp("Class::MOP::subname is deprecated. Please use Sub::Name directly."); |
159 | goto \&Sub::Name::subname; |
160 | } |
161 | |
162 | sub in_global_destruction { |
163 | require Devel::GlobalDestruction; |
164 | Carp::carp("Class::MOP::in_global_destruction is deprecated. Please use Devel::GlobalDestruction directly."); |
165 | goto \&Devel::GlobalDestruction::in_global_destruction; |
166 | } |
167 | |
aa448b16 |
168 | ## ---------------------------------------------------------------------------- |
169 | ## Setting up our environment ... |
170 | ## ---------------------------------------------------------------------------- |
1d68af04 |
171 | ## Class::MOP needs to have a few things in the global perl environment so |
aa448b16 |
172 | ## that it can operate effectively. Those things are done here. |
173 | ## ---------------------------------------------------------------------------- |
174 | |
3bf7644b |
175 | # ... nothing yet actually ;) |
8b978dd5 |
176 | |
b51af7f9 |
177 | ## ---------------------------------------------------------------------------- |
1d68af04 |
178 | ## Bootstrapping |
b51af7f9 |
179 | ## ---------------------------------------------------------------------------- |
1d68af04 |
180 | ## The code below here is to bootstrap our MOP with itself. This is also |
b51af7f9 |
181 | ## sometimes called "tying the knot". By doing this, we make it much easier |
182 | ## to extend the MOP through subclassing and such since now you can use the |
1d68af04 |
183 | ## MOP itself to extend itself. |
184 | ## |
b51af7f9 |
185 | ## Yes, I know, thats weird and insane, but it's a good thing, trust me :) |
1d68af04 |
186 | ## ---------------------------------------------------------------------------- |
727919c5 |
187 | |
1d68af04 |
188 | # We need to add in the meta-attributes here so that |
189 | # any subclass of Class::MOP::* will be able to |
c2b256bc |
190 | # inherit them using _construct_instance |
727919c5 |
191 | |
f0480c45 |
192 | ## -------------------------------------------------------- |
6d5355c3 |
193 | ## Class::MOP::Package |
727919c5 |
194 | |
6d5355c3 |
195 | Class::MOP::Package->meta->add_attribute( |
8683db0e |
196 | Class::MOP::Attribute->new('package' => ( |
b880e0de |
197 | reader => { |
1d68af04 |
198 | # NOTE: we need to do this in order |
199 | # for the instance meta-object to |
b880e0de |
200 | # not fall into meta-circular death |
1d68af04 |
201 | # |
ce2ae40f |
202 | # we just alias the original method |
1d68af04 |
203 | # rather than re-produce it here |
ce2ae40f |
204 | 'name' => \&Class::MOP::Package::name |
b880e0de |
205 | }, |
727919c5 |
206 | )) |
207 | ); |
208 | |
a5e51f0b |
209 | Class::MOP::Package->meta->add_attribute( |
8683db0e |
210 | Class::MOP::Attribute->new('namespace' => ( |
a5e51f0b |
211 | reader => { |
56dcfc1a |
212 | # NOTE: |
ce2ae40f |
213 | # we just alias the original method |
214 | # rather than re-produce it here |
215 | 'namespace' => \&Class::MOP::Package::namespace |
a5e51f0b |
216 | }, |
2e877f58 |
217 | init_arg => undef, |
c4260b45 |
218 | default => sub { \undef } |
a5e51f0b |
219 | )) |
220 | ); |
221 | |
f0480c45 |
222 | ## -------------------------------------------------------- |
223 | ## Class::MOP::Module |
224 | |
225 | # NOTE: |
1d68af04 |
226 | # yeah this is kind of stretching things a bit, |
f0480c45 |
227 | # but truthfully the version should be an attribute |
1d68af04 |
228 | # of the Module, the weirdness comes from having to |
229 | # stick to Perl 5 convention and store it in the |
230 | # $VERSION package variable. Basically if you just |
231 | # squint at it, it will look how you want it to look. |
f0480c45 |
232 | # Either as a package variable, or as a attribute of |
233 | # the metaclass, isn't abstraction great :) |
234 | |
235 | Class::MOP::Module->meta->add_attribute( |
8683db0e |
236 | Class::MOP::Attribute->new('version' => ( |
f0480c45 |
237 | reader => { |
ce2ae40f |
238 | # NOTE: |
239 | # we just alias the original method |
1d68af04 |
240 | # rather than re-produce it here |
ce2ae40f |
241 | 'version' => \&Class::MOP::Module::version |
f0480c45 |
242 | }, |
2e877f58 |
243 | init_arg => undef, |
c4260b45 |
244 | default => sub { \undef } |
f0480c45 |
245 | )) |
246 | ); |
247 | |
248 | # NOTE: |
1d68af04 |
249 | # By following the same conventions as version here, |
250 | # we are opening up the possibility that people can |
251 | # use the $AUTHORITY in non-Class::MOP modules as |
252 | # well. |
f0480c45 |
253 | |
254 | Class::MOP::Module->meta->add_attribute( |
8683db0e |
255 | Class::MOP::Attribute->new('authority' => ( |
f0480c45 |
256 | reader => { |
ce2ae40f |
257 | # NOTE: |
258 | # we just alias the original method |
1d68af04 |
259 | # rather than re-produce it here |
ce2ae40f |
260 | 'authority' => \&Class::MOP::Module::authority |
1d68af04 |
261 | }, |
2e877f58 |
262 | init_arg => undef, |
c4260b45 |
263 | default => sub { \undef } |
f0480c45 |
264 | )) |
265 | ); |
266 | |
267 | ## -------------------------------------------------------- |
6d5355c3 |
268 | ## Class::MOP::Class |
269 | |
727919c5 |
270 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
271 | Class::MOP::Attribute->new('attributes' => ( |
f7259199 |
272 | reader => { |
1d68af04 |
273 | # NOTE: we need to do this in order |
274 | # for the instance meta-object to |
275 | # not fall into meta-circular death |
276 | # |
ce2ae40f |
277 | # we just alias the original method |
1d68af04 |
278 | # rather than re-produce it here |
ce2ae40f |
279 | 'get_attribute_map' => \&Class::MOP::Class::get_attribute_map |
f7259199 |
280 | }, |
727919c5 |
281 | default => sub { {} } |
282 | )) |
283 | ); |
284 | |
351bd7d4 |
285 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
286 | Class::MOP::Attribute->new('methods' => ( |
1d68af04 |
287 | reader => { |
ce2ae40f |
288 | # NOTE: |
289 | # we just alias the original method |
1d68af04 |
290 | # rather than re-produce it here |
ce2ae40f |
291 | 'get_method_map' => \&Class::MOP::Class::get_method_map |
92330ee2 |
292 | }, |
7855ddba |
293 | default => sub { {} } |
c4260b45 |
294 | )) |
295 | ); |
296 | |
297 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
298 | Class::MOP::Attribute->new('superclasses' => ( |
c23184fc |
299 | accessor => { |
300 | # NOTE: |
301 | # we just alias the original method |
1d68af04 |
302 | # rather than re-produce it here |
c23184fc |
303 | 'superclasses' => \&Class::MOP::Class::superclasses |
304 | }, |
2e877f58 |
305 | init_arg => undef, |
c23184fc |
306 | default => sub { \undef } |
307 | )) |
308 | ); |
309 | |
310 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
311 | Class::MOP::Attribute->new('attribute_metaclass' => ( |
1d68af04 |
312 | reader => { |
6d2118a4 |
313 | # NOTE: |
314 | # we just alias the original method |
1d68af04 |
315 | # rather than re-produce it here |
6d2118a4 |
316 | 'attribute_metaclass' => \&Class::MOP::Class::attribute_metaclass |
1d68af04 |
317 | }, |
351bd7d4 |
318 | default => 'Class::MOP::Attribute', |
319 | )) |
320 | ); |
321 | |
322 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
323 | Class::MOP::Attribute->new('method_metaclass' => ( |
1d68af04 |
324 | reader => { |
6d2118a4 |
325 | # NOTE: |
326 | # we just alias the original method |
1d68af04 |
327 | # rather than re-produce it here |
6d2118a4 |
328 | 'method_metaclass' => \&Class::MOP::Class::method_metaclass |
329 | }, |
1d68af04 |
330 | default => 'Class::MOP::Method', |
351bd7d4 |
331 | )) |
332 | ); |
333 | |
2bab2be6 |
334 | Class::MOP::Class->meta->add_attribute( |
77373da8 |
335 | Class::MOP::Attribute->new('wrapped_method_metaclass' => ( |
336 | reader => { |
337 | # NOTE: |
338 | # we just alias the original method |
339 | # rather than re-produce it here |
340 | 'wrapped_method_metaclass' => \&Class::MOP::Class::wrapped_method_metaclass |
341 | }, |
342 | default => 'Class::MOP::Method::Wrapped', |
343 | )) |
344 | ); |
345 | |
346 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
347 | Class::MOP::Attribute->new('instance_metaclass' => ( |
b880e0de |
348 | reader => { |
1d68af04 |
349 | # NOTE: we need to do this in order |
350 | # for the instance meta-object to |
351 | # not fall into meta-circular death |
352 | # |
ce2ae40f |
353 | # we just alias the original method |
1d68af04 |
354 | # rather than re-produce it here |
ce2ae40f |
355 | 'instance_metaclass' => \&Class::MOP::Class::instance_metaclass |
b880e0de |
356 | }, |
1d68af04 |
357 | default => 'Class::MOP::Instance', |
2bab2be6 |
358 | )) |
359 | ); |
360 | |
44d6ea77 |
361 | Class::MOP::Class->meta->add_attribute( |
f5d08022 |
362 | Class::MOP::Attribute->new('immutable_trait' => ( |
363 | reader => { |
364 | 'immutable_trait' => \&Class::MOP::Class::immutable_trait |
365 | }, |
366 | default => "Class::MOP::Class::Immutable::Trait", |
367 | )) |
368 | ); |
369 | |
370 | Class::MOP::Class->meta->add_attribute( |
371 | Class::MOP::Attribute->new('constructor_name' => ( |
44d6ea77 |
372 | reader => { |
f5d08022 |
373 | 'constructor_name' => \&Class::MOP::Class::constructor_name, |
44d6ea77 |
374 | }, |
f5d08022 |
375 | default => "new", |
376 | )) |
377 | ); |
378 | |
379 | Class::MOP::Class->meta->add_attribute( |
380 | Class::MOP::Attribute->new('constructor_class' => ( |
44d6ea77 |
381 | reader => { |
f5d08022 |
382 | 'constructor_class' => \&Class::MOP::Class::constructor_class, |
44d6ea77 |
383 | }, |
f5d08022 |
384 | default => "Class::MOP::Method::Constructor", |
385 | )) |
386 | ); |
387 | |
388 | |
389 | Class::MOP::Class->meta->add_attribute( |
390 | Class::MOP::Attribute->new('destructor_class' => ( |
391 | reader => { |
392 | 'destructor_class' => \&Class::MOP::Class::destructor_class, |
44d6ea77 |
393 | }, |
394 | )) |
395 | ); |
396 | |
9d6dce77 |
397 | # NOTE: |
1d68af04 |
398 | # we don't actually need to tie the knot with |
399 | # Class::MOP::Class here, it is actually handled |
400 | # within Class::MOP::Class itself in the |
c2b256bc |
401 | # _construct_class_instance method. |
9d6dce77 |
402 | |
f0480c45 |
403 | ## -------------------------------------------------------- |
727919c5 |
404 | ## Class::MOP::Attribute |
405 | |
7b31baf4 |
406 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
407 | Class::MOP::Attribute->new('name' => ( |
c23184fc |
408 | reader => { |
1d68af04 |
409 | # NOTE: we need to do this in order |
410 | # for the instance meta-object to |
411 | # not fall into meta-circular death |
412 | # |
ce2ae40f |
413 | # we just alias the original method |
1d68af04 |
414 | # rather than re-produce it here |
ce2ae40f |
415 | 'name' => \&Class::MOP::Attribute::name |
b880e0de |
416 | } |
7b31baf4 |
417 | )) |
418 | ); |
419 | |
420 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
421 | Class::MOP::Attribute->new('associated_class' => ( |
c23184fc |
422 | reader => { |
1d68af04 |
423 | # NOTE: we need to do this in order |
424 | # for the instance meta-object to |
425 | # not fall into meta-circular death |
426 | # |
ce2ae40f |
427 | # we just alias the original method |
1d68af04 |
428 | # rather than re-produce it here |
ce2ae40f |
429 | 'associated_class' => \&Class::MOP::Attribute::associated_class |
b880e0de |
430 | } |
7b31baf4 |
431 | )) |
432 | ); |
433 | |
434 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
435 | Class::MOP::Attribute->new('accessor' => ( |
6d2118a4 |
436 | reader => { 'accessor' => \&Class::MOP::Attribute::accessor }, |
437 | predicate => { 'has_accessor' => \&Class::MOP::Attribute::has_accessor }, |
7b31baf4 |
438 | )) |
439 | ); |
440 | |
441 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
442 | Class::MOP::Attribute->new('reader' => ( |
6d2118a4 |
443 | reader => { 'reader' => \&Class::MOP::Attribute::reader }, |
444 | predicate => { 'has_reader' => \&Class::MOP::Attribute::has_reader }, |
7b31baf4 |
445 | )) |
446 | ); |
447 | |
448 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
449 | Class::MOP::Attribute->new('initializer' => ( |
8ee74136 |
450 | reader => { 'initializer' => \&Class::MOP::Attribute::initializer }, |
451 | predicate => { 'has_initializer' => \&Class::MOP::Attribute::has_initializer }, |
0ab65f99 |
452 | )) |
453 | ); |
454 | |
455 | Class::MOP::Attribute->meta->add_attribute( |
d9d99689 |
456 | Class::MOP::Attribute->new('definition_context' => ( |
457 | reader => { 'definition_context' => \&Class::MOP::Attribute::definition_context }, |
458 | )) |
459 | ); |
460 | |
461 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
462 | Class::MOP::Attribute->new('writer' => ( |
6d2118a4 |
463 | reader => { 'writer' => \&Class::MOP::Attribute::writer }, |
464 | predicate => { 'has_writer' => \&Class::MOP::Attribute::has_writer }, |
7b31baf4 |
465 | )) |
466 | ); |
467 | |
468 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
469 | Class::MOP::Attribute->new('predicate' => ( |
6d2118a4 |
470 | reader => { 'predicate' => \&Class::MOP::Attribute::predicate }, |
471 | predicate => { 'has_predicate' => \&Class::MOP::Attribute::has_predicate }, |
7b31baf4 |
472 | )) |
473 | ); |
474 | |
475 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
476 | Class::MOP::Attribute->new('clearer' => ( |
6d2118a4 |
477 | reader => { 'clearer' => \&Class::MOP::Attribute::clearer }, |
478 | predicate => { 'has_clearer' => \&Class::MOP::Attribute::has_clearer }, |
7d28758b |
479 | )) |
480 | ); |
481 | |
482 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
483 | Class::MOP::Attribute->new('builder' => ( |
1d68af04 |
484 | reader => { 'builder' => \&Class::MOP::Attribute::builder }, |
485 | predicate => { 'has_builder' => \&Class::MOP::Attribute::has_builder }, |
486 | )) |
487 | ); |
488 | |
489 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
490 | Class::MOP::Attribute->new('init_arg' => ( |
6d2118a4 |
491 | reader => { 'init_arg' => \&Class::MOP::Attribute::init_arg }, |
492 | predicate => { 'has_init_arg' => \&Class::MOP::Attribute::has_init_arg }, |
7b31baf4 |
493 | )) |
494 | ); |
495 | |
496 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
497 | Class::MOP::Attribute->new('default' => ( |
7b31baf4 |
498 | # default has a custom 'reader' method ... |
1d68af04 |
499 | predicate => { 'has_default' => \&Class::MOP::Attribute::has_default }, |
7b31baf4 |
500 | )) |
501 | ); |
502 | |
3545c727 |
503 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
504 | Class::MOP::Attribute->new('associated_methods' => ( |
c23184fc |
505 | reader => { 'associated_methods' => \&Class::MOP::Attribute::associated_methods }, |
1d68af04 |
506 | default => sub { [] } |
3545c727 |
507 | )) |
508 | ); |
727919c5 |
509 | |
95b67145 |
510 | Class::MOP::Attribute->meta->add_attribute( |
511 | Class::MOP::Attribute->new('insertion_order' => ( |
512 | reader => { 'insertion_order' => \&Class::MOP::Attribute::insertion_order }, |
943cbe2d |
513 | writer => { '_set_insertion_order' => \&Class::MOP::Attribute::_set_insertion_order }, |
95b67145 |
514 | predicate => { 'has_insertion_order' => \&Class::MOP::Attribute::has_insertion_order }, |
515 | )) |
516 | ); |
517 | |
5659d76e |
518 | Class::MOP::Attribute->meta->add_method('clone' => sub { |
a740253a |
519 | my $self = shift; |
1d68af04 |
520 | $self->meta->clone_object($self, @_); |
727919c5 |
521 | }); |
522 | |
f0480c45 |
523 | ## -------------------------------------------------------- |
b6164407 |
524 | ## Class::MOP::Method |
b6164407 |
525 | Class::MOP::Method->meta->add_attribute( |
8683db0e |
526 | Class::MOP::Attribute->new('body' => ( |
c23184fc |
527 | reader => { 'body' => \&Class::MOP::Method::body }, |
b6164407 |
528 | )) |
529 | ); |
530 | |
4c105333 |
531 | Class::MOP::Method->meta->add_attribute( |
5e607260 |
532 | Class::MOP::Attribute->new('associated_metaclass' => ( |
5e607260 |
533 | reader => { 'associated_metaclass' => \&Class::MOP::Method::associated_metaclass }, |
534 | )) |
535 | ); |
536 | |
537 | Class::MOP::Method->meta->add_attribute( |
8683db0e |
538 | Class::MOP::Attribute->new('package_name' => ( |
4c105333 |
539 | reader => { 'package_name' => \&Class::MOP::Method::package_name }, |
540 | )) |
541 | ); |
542 | |
543 | Class::MOP::Method->meta->add_attribute( |
8683db0e |
544 | Class::MOP::Attribute->new('name' => ( |
4c105333 |
545 | reader => { 'name' => \&Class::MOP::Method::name }, |
546 | )) |
547 | ); |
548 | |
2226a8b0 |
549 | Class::MOP::Method->meta->add_attribute( |
550 | Class::MOP::Attribute->new('original_method' => ( |
551 | reader => { 'original_method' => \&Class::MOP::Method::original_method }, |
552 | writer => { '_set_original_method' => \&Class::MOP::Method::_set_original_method }, |
553 | )) |
554 | ); |
555 | |
4c105333 |
556 | Class::MOP::Method->meta->add_method('clone' => sub { |
557 | my $self = shift; |
2226a8b0 |
558 | my $clone = $self->meta->clone_object($self, @_); |
559 | $clone->_set_original_method($self); |
560 | return $clone; |
4c105333 |
561 | }); |
562 | |
b6164407 |
563 | ## -------------------------------------------------------- |
564 | ## Class::MOP::Method::Wrapped |
565 | |
566 | # NOTE: |
1d68af04 |
567 | # the way this item is initialized, this |
568 | # really does not follow the standard |
569 | # practices of attributes, but we put |
b6164407 |
570 | # it here for completeness |
571 | Class::MOP::Method::Wrapped->meta->add_attribute( |
8683db0e |
572 | Class::MOP::Attribute->new('modifier_table') |
b6164407 |
573 | ); |
574 | |
575 | ## -------------------------------------------------------- |
565f0cbb |
576 | ## Class::MOP::Method::Generated |
577 | |
578 | Class::MOP::Method::Generated->meta->add_attribute( |
8683db0e |
579 | Class::MOP::Attribute->new('is_inline' => ( |
565f0cbb |
580 | reader => { 'is_inline' => \&Class::MOP::Method::Generated::is_inline }, |
4c105333 |
581 | default => 0, |
1d68af04 |
582 | )) |
565f0cbb |
583 | ); |
584 | |
d9d99689 |
585 | Class::MOP::Method::Generated->meta->add_attribute( |
586 | Class::MOP::Attribute->new('definition_context' => ( |
587 | reader => { 'definition_context' => \&Class::MOP::Method::Generated::definition_context }, |
588 | )) |
589 | ); |
590 | |
29d4e92a |
591 | |
592 | ## -------------------------------------------------------- |
593 | ## Class::MOP::Method::Inlined |
594 | |
595 | Class::MOP::Method::Inlined->meta->add_attribute( |
596 | Class::MOP::Attribute->new('_expected_method_class' => ( |
597 | reader => { '_expected_method_class' => \&Class::MOP::Method::Inlined::_expected_method_class }, |
598 | )) |
599 | ); |
600 | |
565f0cbb |
601 | ## -------------------------------------------------------- |
d90b42a6 |
602 | ## Class::MOP::Method::Accessor |
603 | |
604 | Class::MOP::Method::Accessor->meta->add_attribute( |
8683db0e |
605 | Class::MOP::Attribute->new('attribute' => ( |
1d68af04 |
606 | reader => { |
607 | 'associated_attribute' => \&Class::MOP::Method::Accessor::associated_attribute |
d90b42a6 |
608 | }, |
1d68af04 |
609 | )) |
d90b42a6 |
610 | ); |
611 | |
612 | Class::MOP::Method::Accessor->meta->add_attribute( |
8683db0e |
613 | Class::MOP::Attribute->new('accessor_type' => ( |
c23184fc |
614 | reader => { 'accessor_type' => \&Class::MOP::Method::Accessor::accessor_type }, |
1d68af04 |
615 | )) |
d90b42a6 |
616 | ); |
617 | |
d90b42a6 |
618 | ## -------------------------------------------------------- |
619 | ## Class::MOP::Method::Constructor |
620 | |
621 | Class::MOP::Method::Constructor->meta->add_attribute( |
8683db0e |
622 | Class::MOP::Attribute->new('options' => ( |
1d68af04 |
623 | reader => { |
624 | 'options' => \&Class::MOP::Method::Constructor::options |
d90b42a6 |
625 | }, |
4c105333 |
626 | default => sub { +{} } |
1d68af04 |
627 | )) |
d90b42a6 |
628 | ); |
629 | |
630 | Class::MOP::Method::Constructor->meta->add_attribute( |
8683db0e |
631 | Class::MOP::Attribute->new('associated_metaclass' => ( |
e8a38403 |
632 | init_arg => "metaclass", # FIXME alias and rename |
1d68af04 |
633 | reader => { |
634 | 'associated_metaclass' => \&Class::MOP::Method::Constructor::associated_metaclass |
635 | }, |
636 | )) |
d90b42a6 |
637 | ); |
638 | |
639 | ## -------------------------------------------------------- |
86482605 |
640 | ## Class::MOP::Instance |
641 | |
642 | # NOTE: |
1d68af04 |
643 | # these don't yet do much of anything, but are just |
86482605 |
644 | # included for completeness |
645 | |
646 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
647 | Class::MOP::Attribute->new('associated_metaclass', |
648 | reader => { associated_metaclass => \&Class::MOP::Instance::associated_metaclass }, |
649 | ), |
86482605 |
650 | ); |
651 | |
652 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
653 | Class::MOP::Attribute->new('_class_name', |
654 | init_arg => undef, |
655 | reader => { _class_name => \&Class::MOP::Instance::_class_name }, |
656 | #lazy => 1, # not yet supported by Class::MOP but out our version does it anyway |
657 | #default => sub { $_[0]->associated_metaclass->name }, |
658 | ), |
659 | ); |
660 | |
661 | Class::MOP::Instance->meta->add_attribute( |
662 | Class::MOP::Attribute->new('attributes', |
0b5d46da |
663 | reader => { attributes => \&Class::MOP::Instance::get_all_attributes }, |
74890687 |
664 | ), |
32bfc810 |
665 | ); |
666 | |
667 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
668 | Class::MOP::Attribute->new('slots', |
669 | reader => { slots => \&Class::MOP::Instance::slots }, |
670 | ), |
86482605 |
671 | ); |
672 | |
63d08a9e |
673 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
674 | Class::MOP::Attribute->new('slot_hash', |
675 | reader => { slot_hash => \&Class::MOP::Instance::slot_hash }, |
676 | ), |
63d08a9e |
677 | ); |
678 | |
679 | |
caa051fa |
680 | # we need the meta instance of the meta instance to be created now, in order |
681 | # for the constructor to be able to use it |
682 | Class::MOP::Instance->meta->get_meta_instance; |
683 | |
caa051fa |
684 | # pretend the add_method never happenned. it hasn't yet affected anything |
685 | undef Class::MOP::Instance->meta->{_package_cache_flag}; |
686 | |
86482605 |
687 | ## -------------------------------------------------------- |
f0480c45 |
688 | ## Now close all the Class::MOP::* classes |
4d47b77f |
689 | |
1aa13cf4 |
690 | # NOTE: we don't need to inline the the accessors this only lengthens |
691 | # the compile time of the MOP, and gives us no actual benefits. |
0b9372a2 |
692 | |
693 | $_->meta->make_immutable( |
ec9e38e5 |
694 | inline_constructor => 0, |
6c2f6b5c |
695 | constructor_name => "_new", |
45582002 |
696 | inline_accessors => 0, |
0b9372a2 |
697 | ) for qw/ |
1d68af04 |
698 | Class::MOP::Package |
699 | Class::MOP::Module |
700 | Class::MOP::Class |
701 | |
0b9372a2 |
702 | Class::MOP::Attribute |
1d68af04 |
703 | Class::MOP::Method |
704 | Class::MOP::Instance |
705 | |
706 | Class::MOP::Object |
0b9372a2 |
707 | |
565f0cbb |
708 | Class::MOP::Method::Generated |
29d4e92a |
709 | Class::MOP::Method::Inlined |
1d68af04 |
710 | |
ba38bf08 |
711 | Class::MOP::Method::Accessor |
1d68af04 |
712 | Class::MOP::Method::Constructor |
713 | Class::MOP::Method::Wrapped |
0b9372a2 |
714 | /; |
b6164407 |
715 | |
94b19069 |
716 | 1; |
717 | |
718 | __END__ |
719 | |
720 | =pod |
721 | |
1d68af04 |
722 | =head1 NAME |
94b19069 |
723 | |
724 | Class::MOP - A Meta Object Protocol for Perl 5 |
725 | |
5b60bf98 |
726 | =head1 DESCRIPTION |
94b19069 |
727 | |
127d39a7 |
728 | This module is a fully functioning meta object protocol for the |
1d68af04 |
729 | Perl 5 object system. It makes no attempt to change the behavior or |
730 | characteristics of the Perl 5 object system, only to create a |
27e31eaf |
731 | protocol for its manipulation and introspection. |
94b19069 |
732 | |
828ecf13 |
733 | That said, it does attempt to create the tools for building a rich set |
734 | of extensions to the Perl 5 object system. Every attempt has been made |
735 | to abide by the spirit of the Perl 5 object system that we all know |
736 | and love. |
94b19069 |
737 | |
828ecf13 |
738 | This documentation is sparse on conceptual details. We suggest looking |
739 | at the items listed in the L<SEE ALSO> section for more |
740 | information. In particular the book "The Art of the Meta Object |
741 | Protocol" was very influential in the development of this system. |
40483095 |
742 | |
bfe4d0fc |
743 | =head2 What is a Meta Object Protocol? |
744 | |
1d68af04 |
745 | A meta object protocol is an API to an object system. |
bfe4d0fc |
746 | |
828ecf13 |
747 | To be more specific, it abstracts the components of an object system |
748 | (classes, object, methods, object attributes, etc.). These |
749 | abstractions can then be used to inspect and manipulate the object |
750 | system which they describe. |
bfe4d0fc |
751 | |
1d68af04 |
752 | It can be said that there are two MOPs for any object system; the |
828ecf13 |
753 | implicit MOP and the explicit MOP. The implicit MOP handles things |
1d68af04 |
754 | like method dispatch or inheritance, which happen automatically as |
755 | part of how the object system works. The explicit MOP typically |
756 | handles the introspection/reflection features of the object system. |
bfe4d0fc |
757 | |
828ecf13 |
758 | All object systems have implicit MOPs. Without one, they would not |
5b60bf98 |
759 | work. Explicit MOPs are much less common, and depending on the |
760 | language can vary from restrictive (Reflection in Java or C#) to wide |
761 | open (CLOS is a perfect example). |
e16da3e6 |
762 | |
828ecf13 |
763 | =head2 Yet Another Class Builder! Why? |
764 | |
765 | This is B<not> a class builder so much as a I<class builder |
766 | B<builder>>. The intent is that an end user will not use this module |
767 | directly, but instead this module is used by module authors to build |
768 | extensions and features onto the Perl 5 object system. |
769 | |
770 | This system is used by L<Moose>, which supplies a powerful class |
771 | builder system built entirely on top of C<Class::MOP>. |
e16da3e6 |
772 | |
94b19069 |
773 | =head2 Who is this module for? |
774 | |
828ecf13 |
775 | This module is for anyone who has ever created or wanted to create a |
776 | module for the Class:: namespace. The tools which this module provides |
777 | make doing complex Perl 5 wizardry simpler, by removing such barriers |
778 | as the need to hack symbol tables, or understand the fine details of |
779 | method dispatch. |
94b19069 |
780 | |
bfe4d0fc |
781 | =head2 What changes do I have to make to use this module? |
782 | |
828ecf13 |
783 | This module was designed to be as unintrusive as possible. Many of its |
5b60bf98 |
784 | features are accessible without B<any> change to your existing |
828ecf13 |
785 | code. It is meant to be a compliment to your existing code and not an |
786 | intrusion on your code base. Unlike many other B<Class::> modules, |
787 | this module B<does not> require you subclass it, or even that you |
788 | C<use> it in within your module's package. |
bfe4d0fc |
789 | |
1d68af04 |
790 | The only features which requires additions to your code are the |
2eb717d5 |
791 | attribute handling and instance construction features, and these are |
1d68af04 |
792 | both completely optional features. The only reason for this is because |
793 | Perl 5's object system does not actually have these features built |
2eb717d5 |
794 | in. More information about this feature can be found below. |
bfe4d0fc |
795 | |
828ecf13 |
796 | =head2 About Performance |
797 | |
5b60bf98 |
798 | It is a common misconception that explicit MOPs are a performance hit. |
828ecf13 |
799 | This is not a universal truth, it is a side-effect of some specific |
800 | implementations. For instance, using Java reflection is slow because |
801 | the JVM cannot take advantage of any compiler optimizations, and the |
802 | JVM has to deal with much more runtime type information as well. |
bfe4d0fc |
803 | |
828ecf13 |
804 | Reflection in C# is marginally better as it was designed into the |
805 | language and runtime (the CLR). In contrast, CLOS (the Common Lisp |
806 | Object System) was built to support an explicit MOP, and so |
807 | performance is tuned for it. |
1d68af04 |
808 | |
828ecf13 |
809 | This library in particular does its absolute best to avoid putting |
1d68af04 |
810 | B<any> drain at all upon your code's performance. In fact, by itself |
828ecf13 |
811 | it does nothing to affect your existing code. So you only pay for what |
812 | you actually use. |
bfe4d0fc |
813 | |
550d56db |
814 | =head2 About Metaclass compatibility |
815 | |
1d68af04 |
816 | This module makes sure that all metaclasses created are both upwards |
817 | and downwards compatible. The topic of metaclass compatibility is |
818 | highly esoteric and is something only encountered when doing deep and |
819 | involved metaclass hacking. There are two basic kinds of metaclass |
820 | incompatibility; upwards and downwards. |
550d56db |
821 | |
1d68af04 |
822 | Upwards metaclass compatibility means that the metaclass of a |
823 | given class is either the same as (or a subclass of) all of the |
550d56db |
824 | class's ancestors. |
825 | |
1d68af04 |
826 | Downward metaclass compatibility means that the metaclasses of a |
828ecf13 |
827 | given class's ancestors are all either the same as (or a subclass |
550d56db |
828 | of) that metaclass. |
829 | |
1d68af04 |
830 | Here is a diagram showing a set of two classes (C<A> and C<B>) and |
831 | two metaclasses (C<Meta::A> and C<Meta::B>) which have correct |
550d56db |
832 | metaclass compatibility both upwards and downwards. |
833 | |
834 | +---------+ +---------+ |
835 | | Meta::A |<----| Meta::B | <....... (instance of ) |
1d68af04 |
836 | +---------+ +---------+ <------- (inherits from) |
550d56db |
837 | ^ ^ |
838 | : : |
839 | +---------+ +---------+ |
840 | | A |<----| B | |
841 | +---------+ +---------+ |
842 | |
1d68af04 |
843 | As I said this is a highly esoteric topic and one you will only run |
828ecf13 |
844 | into if you do a lot of subclassing of L<Class::MOP::Class>. If you |
845 | are interested in why this is an issue see the paper I<Uniform and |
846 | safe metaclass composition> linked to in the L<SEE ALSO> section of |
847 | this document. |
550d56db |
848 | |
aa448b16 |
849 | =head2 Using custom metaclasses |
850 | |
828ecf13 |
851 | Always use the L<metaclass> pragma when using a custom metaclass, this |
5b60bf98 |
852 | will ensure the proper initialization order and not accidentally |
853 | create an incorrect type of metaclass for you. This is a very rare |
854 | problem, and one which can only occur if you are doing deep metaclass |
aa448b16 |
855 | programming. So in other words, don't worry about it. |
856 | |
828ecf13 |
857 | Note that if you're using L<Moose> we encourage you to I<not> use |
858 | L<metaclass> pragma, and instead use L<Moose::Util::MetaRole> to apply |
859 | roles to a class's metaclasses. This topic is covered at length in |
860 | various L<Moose::Cookbook> recipes. |
861 | |
94b19069 |
862 | =head1 PROTOCOLS |
863 | |
828ecf13 |
864 | The meta-object protocol is divided into 4 main sub-protocols: |
94b19069 |
865 | |
828ecf13 |
866 | =head2 The Class protocol |
94b19069 |
867 | |
1d68af04 |
868 | This provides a means of manipulating and introspecting a Perl 5 |
828ecf13 |
869 | class. It handles symbol table hacking for you, and provides a rich |
870 | set of methods that go beyond simple package introspection. |
94b19069 |
871 | |
552e3d24 |
872 | See L<Class::MOP::Class> for more details. |
873 | |
828ecf13 |
874 | =head2 The Attribute protocol |
94b19069 |
875 | |
828ecf13 |
876 | This provides a consistent representation for an attribute of a Perl 5 |
877 | class. Since there are so many ways to create and handle attributes in |
878 | Perl 5 OO, the Attribute protocol provide as much of a unified |
879 | approach as possible. Of course, you are always free to extend this |
880 | protocol by subclassing the appropriate classes. |
94b19069 |
881 | |
552e3d24 |
882 | See L<Class::MOP::Attribute> for more details. |
883 | |
828ecf13 |
884 | =head2 The Method protocol |
94b19069 |
885 | |
828ecf13 |
886 | This provides a means of manipulating and introspecting methods in the |
887 | Perl 5 object system. As with attributes, there are many ways to |
1d68af04 |
888 | approach this topic, so we try to keep it pretty basic, while still |
94b19069 |
889 | making it possible to extend the system in many ways. |
890 | |
552e3d24 |
891 | See L<Class::MOP::Method> for more details. |
94b19069 |
892 | |
828ecf13 |
893 | =head2 The Instance protocol |
127d39a7 |
894 | |
828ecf13 |
895 | This provides a layer of abstraction for creating object instances. |
896 | Since the other layers use this protocol, it is relatively easy to |
897 | change the type of your instances from the default hash reference to |
898 | some other type of reference. Several examples are provided in the |
899 | F<examples/> directory included in this distribution. |
127d39a7 |
900 | |
901 | See L<Class::MOP::Instance> for more details. |
902 | |
be7677c7 |
903 | =head1 FUNCTIONS |
904 | |
828ecf13 |
905 | Note that this module does not export any constants or functions. |
906 | |
c1d5345a |
907 | =head2 Constants |
908 | |
909 | =over 4 |
910 | |
828ecf13 |
911 | =item I<Class::MOP::IS_RUNNING_ON_5_10> |
c1d5345a |
912 | |
828ecf13 |
913 | We set this constant depending on what version perl we are on, this |
914 | allows us to take advantage of new 5.10 features and stay backwards |
5b60bf98 |
915 | compatible. |
c1d5345a |
916 | |
917 | =back |
918 | |
448b6e55 |
919 | =head2 Utility functions |
920 | |
bd07fbdb |
921 | Note that these are all called as B<functions, not methods>. |
081a927b |
922 | |
448b6e55 |
923 | =over 4 |
924 | |
828ecf13 |
925 | =item B<Class::MOP::load_class($class_name)> |
448b6e55 |
926 | |
9d441c23 |
927 | This will load the specified C<$class_name>, if it is not already |
928 | loaded (as reported by C<is_class_loaded>). This function can be used |
828ecf13 |
929 | in place of tricks like C<eval "use $module"> or using C<require> |
828de8f4 |
930 | unconditionally. This will return the metaclass of C<$class_name> if |
931 | one exists, otherwise it will return C<$class_name>. |
448b6e55 |
932 | |
828ecf13 |
933 | =item B<Class::MOP::is_class_loaded($class_name)> |
448b6e55 |
934 | |
15ab5451 |
935 | Returns a boolean indicating whether or not C<$class_name> has been |
936 | loaded. |
448b6e55 |
937 | |
828ecf13 |
938 | This does a basic check of the symbol table to try and determine as |
939 | best it can if the C<$class_name> is loaded, it is probably correct |
940 | about 99% of the time, but it can be fooled into reporting false |
9d441c23 |
941 | positives. In particular, loading any of the core L<IO> modules will |
942 | cause most of the rest of the core L<IO> modules to falsely report |
943 | having been loaded, due to the way the base L<IO> module works. |
448b6e55 |
944 | |
cdac22cc |
945 | =item B<Class::MOP::get_code_info($code)> |
946 | |
947 | This function returns two values, the name of the package the C<$code> |
948 | is from and the name of the C<$code> itself. This is used by several |
5b60bf98 |
949 | elements of the MOP to determine where a given C<$code> reference is |
cdac22cc |
950 | from. |
951 | |
44ba77a3 |
952 | =item B<Class::MOP::class_of($instance_or_class_name)> |
953 | |
3fa5b3f9 |
954 | This will return the metaclass of the given instance or class name. If the |
955 | class lacks a metaclass, no metaclass will be initialized, and C<undef> will be |
956 | returned. |
44ba77a3 |
957 | |
828ecf13 |
958 | =item B<Class::MOP::check_package_cache_flag($pkg)> |
e0e4674a |
959 | |
bd07fbdb |
960 | B<NOTE: DO NOT USE THIS FUNCTION, IT IS FOR INTERNAL USE ONLY!> |
961 | |
828ecf13 |
962 | This will return an integer that is managed by L<Class::MOP::Class> to |
963 | determine if a module's symbol table has been altered. |
127d39a7 |
964 | |
828ecf13 |
965 | In Perl 5.10 or greater, this flag is package specific. However in |
966 | versions prior to 5.10, this will use the C<PL_sub_generation> |
967 | variable which is not package specific. |
127d39a7 |
968 | |
828ecf13 |
969 | =item B<Class::MOP::load_first_existing_class(@class_names)> |
063ad0c5 |
970 | |
971 | B<NOTE: DO NOT USE THIS FUNCTION, IT IS FOR INTERNAL USE ONLY!> |
972 | |
973 | Given a list of class names, this function will attempt to load each |
974 | one in turn. |
975 | |
828ecf13 |
976 | If it finds a class it can load, it will return that class' name. If |
977 | none of the classes can be loaded, it will throw an exception. |
063ad0c5 |
978 | |
448b6e55 |
979 | =back |
980 | |
981 | =head2 Metaclass cache functions |
982 | |
6c842677 |
983 | Class::MOP holds a cache of metaclasses. The following are functions |
1d68af04 |
984 | (B<not methods>) which can be used to access that cache. It is not |
6c842677 |
985 | recommended that you mess with these. Bad things could happen, but if |
986 | you are brave and willing to risk it: go for it! |
be7677c7 |
987 | |
988 | =over 4 |
989 | |
828ecf13 |
990 | =item B<Class::MOP::get_all_metaclasses> |
be7677c7 |
991 | |
6c842677 |
992 | This will return a hash of all the metaclass instances that have |
828ecf13 |
993 | been cached by L<Class::MOP::Class>, keyed by the package name. |
b9d9fc0b |
994 | |
828ecf13 |
995 | =item B<Class::MOP::get_all_metaclass_instances> |
be7677c7 |
996 | |
6c842677 |
997 | This will return a list of all the metaclass instances that have |
828ecf13 |
998 | been cached by L<Class::MOP::Class>. |
b9d9fc0b |
999 | |
828ecf13 |
1000 | =item B<Class::MOP::get_all_metaclass_names> |
be7677c7 |
1001 | |
6c842677 |
1002 | This will return a list of all the metaclass names that have |
828ecf13 |
1003 | been cached by L<Class::MOP::Class>. |
b9d9fc0b |
1004 | |
828ecf13 |
1005 | =item B<Class::MOP::get_metaclass_by_name($name)> |
be7677c7 |
1006 | |
828ecf13 |
1007 | This will return a cached L<Class::MOP::Class> instance, or nothing |
6c842677 |
1008 | if no metaclass exists with that C<$name>. |
127d39a7 |
1009 | |
828ecf13 |
1010 | =item B<Class::MOP::store_metaclass_by_name($name, $meta)> |
be7677c7 |
1011 | |
127d39a7 |
1012 | This will store a metaclass in the cache at the supplied C<$key>. |
1013 | |
828ecf13 |
1014 | =item B<Class::MOP::weaken_metaclass($name)> |
be7677c7 |
1015 | |
6c842677 |
1016 | In rare cases (e.g. anonymous metaclasses) it is desirable to |
1017 | store a weakened reference in the metaclass cache. This |
1018 | function will weaken the reference to the metaclass stored |
1019 | in C<$name>. |
127d39a7 |
1020 | |
828ecf13 |
1021 | =item B<Class::MOP::does_metaclass_exist($name)> |
be7677c7 |
1022 | |
828ecf13 |
1023 | This will return true of there exists a metaclass stored in the |
6c842677 |
1024 | C<$name> key, and return false otherwise. |
127d39a7 |
1025 | |
828ecf13 |
1026 | =item B<Class::MOP::remove_metaclass_by_name($name)> |
be7677c7 |
1027 | |
6c842677 |
1028 | This will remove the metaclass stored in the C<$name> key. |
127d39a7 |
1029 | |
be7677c7 |
1030 | =back |
1031 | |
552e3d24 |
1032 | =head1 SEE ALSO |
8b978dd5 |
1033 | |
552e3d24 |
1034 | =head2 Books |
8b978dd5 |
1035 | |
1d68af04 |
1036 | There are very few books out on Meta Object Protocols and Metaclasses |
1037 | because it is such an esoteric topic. The following books are really |
1038 | the only ones I have found. If you know of any more, B<I<please>> |
a2e85e6c |
1039 | email me and let me know, I would love to hear about them. |
1040 | |
8b978dd5 |
1041 | =over 4 |
1042 | |
15ab5451 |
1043 | =item I<The Art of the Meta Object Protocol> |
8b978dd5 |
1044 | |
15ab5451 |
1045 | =item I<Advances in Object-Oriented Metalevel Architecture and Reflection> |
8b978dd5 |
1046 | |
15ab5451 |
1047 | =item I<Putting MetaClasses to Work> |
b51af7f9 |
1048 | |
15ab5451 |
1049 | =item I<Smalltalk: The Language> |
a2e85e6c |
1050 | |
94b19069 |
1051 | =back |
1052 | |
550d56db |
1053 | =head2 Papers |
1054 | |
1055 | =over 4 |
1056 | |
15ab5451 |
1057 | =item "Uniform and safe metaclass composition" |
550d56db |
1058 | |
1d68af04 |
1059 | An excellent paper by the people who brought us the original Traits paper. |
1060 | This paper is on how Traits can be used to do safe metaclass composition, |
1061 | and offers an excellent introduction section which delves into the topic of |
550d56db |
1062 | metaclass compatibility. |
1063 | |
1064 | L<http://www.iam.unibe.ch/~scg/Archive/Papers/Duca05ySafeMetaclassTrait.pdf> |
1065 | |
15ab5451 |
1066 | =item "Safe Metaclass Programming" |
550d56db |
1067 | |
1d68af04 |
1068 | This paper seems to precede the above paper, and propose a mix-in based |
1069 | approach as opposed to the Traits based approach. Both papers have similar |
1070 | information on the metaclass compatibility problem space. |
550d56db |
1071 | |
1072 | L<http://citeseer.ist.psu.edu/37617.html> |
1073 | |
1074 | =back |
1075 | |
552e3d24 |
1076 | =head2 Prior Art |
8b978dd5 |
1077 | |
1078 | =over 4 |
1079 | |
7184ca14 |
1080 | =item The Perl 6 MetaModel work in the Pugs project |
8b978dd5 |
1081 | |
1082 | =over 4 |
1083 | |
552e3d24 |
1084 | =item L<http://svn.openfoundry.org/pugs/perl5/Perl6-MetaModel> |
8b978dd5 |
1085 | |
552e3d24 |
1086 | =item L<http://svn.openfoundry.org/pugs/perl5/Perl6-ObjectSpace> |
8b978dd5 |
1087 | |
1088 | =back |
1089 | |
94b19069 |
1090 | =back |
1091 | |
1d68af04 |
1092 | =head2 Articles |
f8dfcfb7 |
1093 | |
1094 | =over 4 |
1095 | |
1d68af04 |
1096 | =item CPAN Module Review of Class::MOP |
f8dfcfb7 |
1097 | |
1098 | L<http://www.oreillynet.com/onlamp/blog/2006/06/cpan_module_review_classmop.html> |
1099 | |
1100 | =back |
1101 | |
a2e85e6c |
1102 | =head1 SIMILAR MODULES |
1103 | |
1d68af04 |
1104 | As I have said above, this module is a class-builder-builder, so it is |
1105 | not the same thing as modules like L<Class::Accessor> and |
1106 | L<Class::MethodMaker>. That being said there are very few modules on CPAN |
1107 | with similar goals to this module. The one I have found which is most |
1108 | like this module is L<Class::Meta>, although it's philosophy and the MOP it |
1109 | creates are very different from this modules. |
94b19069 |
1110 | |
a2e85e6c |
1111 | =head1 BUGS |
1112 | |
1d68af04 |
1113 | All complex software has bugs lurking in it, and this module is no |
53702399 |
1114 | exception. |
1115 | |
1116 | Please report any bugs to C<bug-class-mop@rt.cpan.org>, or through the |
1117 | web interface at L<http://rt.cpan.org>. |
1118 | |
1119 | You can also discuss feature requests or possible bugs on the Moose |
1120 | mailing list (moose@perl.org) or on IRC at |
1121 | L<irc://irc.perl.org/#moose>. |
a2e85e6c |
1122 | |
1123 | =head1 ACKNOWLEDGEMENTS |
1124 | |
1125 | =over 4 |
1126 | |
b9d9fc0b |
1127 | =item Rob Kinyon |
a2e85e6c |
1128 | |
1d68af04 |
1129 | Thanks to Rob for actually getting the development of this module kick-started. |
a2e85e6c |
1130 | |
1131 | =back |
1132 | |
1a09d9cc |
1133 | =head1 AUTHORS |
94b19069 |
1134 | |
a2e85e6c |
1135 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
552e3d24 |
1136 | |
9c8cda90 |
1137 | B<with contributions from:> |
1138 | |
1139 | Brandon (blblack) Black |
1140 | |
4f116037 |
1141 | Florian (rafl) Ragwitz |
1142 | |
9c8cda90 |
1143 | Guillermo (groditi) Roditi |
1144 | |
53702399 |
1145 | Dave (autarch) Rolsky |
1146 | |
9195ddff |
1147 | Matt (mst) Trout |
1148 | |
9c8cda90 |
1149 | Rob (robkinyon) Kinyon |
1150 | |
1151 | Yuval (nothingmuch) Kogman |
1a09d9cc |
1152 | |
f430cfa4 |
1153 | Scott (konobi) McWhirter |
1154 | |
20f5ccef |
1155 | Dylan Hardison |
1156 | |
94b19069 |
1157 | =head1 COPYRIGHT AND LICENSE |
1158 | |
070bb6c9 |
1159 | Copyright 2006-2009 by Infinity Interactive, Inc. |
94b19069 |
1160 | |
1161 | L<http://www.iinteractive.com> |
1162 | |
1163 | This library is free software; you can redistribute it and/or modify |
1d68af04 |
1164 | it under the same terms as Perl itself. |
94b19069 |
1165 | |
1166 | =cut |