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 | |
3ecd1b25 |
23 | # this is either part of core or set up appropriately by MRO::Compat |
24 | *check_package_cache_flag = \&mro::get_pkg_gen; |
b1f5f41d |
25 | } |
e0e4674a |
26 | |
d499b013 |
27 | our $VERSION = '0.92_01'; |
8a7085c1 |
28 | our $XS_VERSION = $VERSION; |
d519662a |
29 | $VERSION = eval $VERSION; |
c7e28c19 |
30 | our $AUTHORITY = 'cpan:STEVAN'; |
9d655b6d |
31 | |
4bfa5ddb |
32 | require XSLoader; |
33 | XSLoader::load( __PACKAGE__, $XS_VERSION ); |
d7bda114 |
34 | |
35 | |
be7677c7 |
36 | { |
37 | # Metaclasses are singletons, so we cache them here. |
38 | # there is no need to worry about destruction though |
39 | # because they should die only when the program dies. |
40 | # After all, do package definitions even get reaped? |
247d5b3c |
41 | # Anonymous classes manage their own destruction. |
1d68af04 |
42 | my %METAS; |
43 | |
1d68af04 |
44 | sub get_all_metaclasses { %METAS } |
45 | sub get_all_metaclass_instances { values %METAS } |
46 | sub get_all_metaclass_names { keys %METAS } |
be7677c7 |
47 | sub get_metaclass_by_name { $METAS{$_[0]} } |
1d68af04 |
48 | sub store_metaclass_by_name { $METAS{$_[0]} = $_[1] } |
49 | sub weaken_metaclass { weaken($METAS{$_[0]}) } |
be7677c7 |
50 | sub does_metaclass_exist { exists $METAS{$_[0]} && defined $METAS{$_[0]} } |
efc98200 |
51 | sub remove_metaclass_by_name { delete $METAS{$_[0]}; return } |
1d68af04 |
52 | |
86866fb5 |
53 | # This handles instances as well as class names |
54 | sub class_of { |
82999986 |
55 | return unless defined $_[0]; |
86866fb5 |
56 | my $class = blessed($_[0]) || $_[0]; |
57 | return $METAS{$class}; |
58 | } |
59 | |
be7677c7 |
60 | # NOTE: |
1d68af04 |
61 | # We only cache metaclasses, meaning instances of |
62 | # Class::MOP::Class. We do not cache instance of |
be7677c7 |
63 | # Class::MOP::Package or Class::MOP::Module. Mostly |
1d68af04 |
64 | # because I don't yet see a good reason to do so. |
be7677c7 |
65 | } |
66 | |
44da14be |
67 | sub _class_to_pmfile { |
68 | my $class = shift; |
69 | |
70 | my $file = $class . '.pm'; |
71 | $file =~ s{::}{/}g; |
72 | |
73 | return $file; |
74 | } |
75 | |
063ad0c5 |
76 | sub load_first_existing_class { |
f280f05c |
77 | my @classes = @_ |
78 | or return; |
5a24cf8a |
79 | |
80 | foreach my $class (@classes) { |
81 | unless ( _is_valid_class_name($class) ) { |
82 | my $display = defined($class) ? $class : 'undef'; |
83 | confess "Invalid class name ($display)"; |
84 | } |
ab5e2f48 |
85 | } |
86 | |
063ad0c5 |
87 | my $found; |
5a24cf8a |
88 | my %exceptions; |
063ad0c5 |
89 | for my $class (@classes) { |
90 | my $e = _try_load_one_class($class); |
91 | |
5a24cf8a |
92 | if ($e) { |
a3f2cdc0 |
93 | my $pmfile = _class_to_pmfile($class); |
063ad0c5 |
94 | $exceptions{$class} = $e; |
44da14be |
95 | last if $e !~ /^Can't locate \Q$pmfile\E in \@INC/; |
5a24cf8a |
96 | } |
97 | else { |
063ad0c5 |
98 | $found = $class; |
99 | last; |
5a24cf8a |
100 | } |
063ad0c5 |
101 | } |
5a24cf8a |
102 | |
1d8153bd |
103 | return $found if $found; |
07940968 |
104 | |
063ad0c5 |
105 | confess join( |
106 | "\n", |
107 | map { |
108 | sprintf( |
fea44045 |
109 | "Could not load class (%s) because : %s", $_, |
063ad0c5 |
110 | $exceptions{$_} |
111 | ) |
44da14be |
112 | } |
113 | grep { |
114 | exists $exceptions{$_} |
063ad0c5 |
115 | } @classes |
f280f05c |
116 | ); |
5a24cf8a |
117 | } |
118 | |
063ad0c5 |
119 | sub _try_load_one_class { |
120 | my $class = shift; |
121 | |
122 | return if is_class_loaded($class); |
2beec805 |
123 | |
44da14be |
124 | my $file = _class_to_pmfile($class); |
063ad0c5 |
125 | |
126 | return do { |
127 | local $@; |
b3813a8c |
128 | local $SIG{__DIE__}; |
063ad0c5 |
129 | eval { require($file) }; |
130 | $@; |
131 | }; |
132 | } |
133 | |
5a24cf8a |
134 | sub load_class { |
7716a8f9 |
135 | load_first_existing_class($_[0]); |
136 | |
674d9359 |
137 | # This is done to avoid breaking code which checked the return value. Said |
138 | # code is dumb. The return value was _always_ true, since it dies on |
139 | # failure! |
140 | return 1; |
448b6e55 |
141 | } |
142 | |
2c0fb064 |
143 | sub _is_valid_class_name { |
144 | my $class = shift; |
145 | |
146 | return 0 if ref($class); |
147 | return 0 unless defined($class); |
148 | return 0 unless length($class); |
149 | |
150 | return 1 if $class =~ /^\w+(?:::\w+)*$/; |
151 | |
152 | return 0; |
153 | } |
154 | |
aa448b16 |
155 | ## ---------------------------------------------------------------------------- |
156 | ## Setting up our environment ... |
157 | ## ---------------------------------------------------------------------------- |
1d68af04 |
158 | ## Class::MOP needs to have a few things in the global perl environment so |
aa448b16 |
159 | ## that it can operate effectively. Those things are done here. |
160 | ## ---------------------------------------------------------------------------- |
161 | |
3bf7644b |
162 | # ... nothing yet actually ;) |
8b978dd5 |
163 | |
b51af7f9 |
164 | ## ---------------------------------------------------------------------------- |
1d68af04 |
165 | ## Bootstrapping |
b51af7f9 |
166 | ## ---------------------------------------------------------------------------- |
1d68af04 |
167 | ## The code below here is to bootstrap our MOP with itself. This is also |
b51af7f9 |
168 | ## sometimes called "tying the knot". By doing this, we make it much easier |
169 | ## to extend the MOP through subclassing and such since now you can use the |
1d68af04 |
170 | ## MOP itself to extend itself. |
171 | ## |
b51af7f9 |
172 | ## Yes, I know, thats weird and insane, but it's a good thing, trust me :) |
1d68af04 |
173 | ## ---------------------------------------------------------------------------- |
727919c5 |
174 | |
1d68af04 |
175 | # We need to add in the meta-attributes here so that |
176 | # any subclass of Class::MOP::* will be able to |
c2b256bc |
177 | # inherit them using _construct_instance |
727919c5 |
178 | |
f0480c45 |
179 | ## -------------------------------------------------------- |
6d5355c3 |
180 | ## Class::MOP::Package |
727919c5 |
181 | |
6d5355c3 |
182 | Class::MOP::Package->meta->add_attribute( |
8683db0e |
183 | Class::MOP::Attribute->new('package' => ( |
b880e0de |
184 | reader => { |
1d68af04 |
185 | # NOTE: we need to do this in order |
186 | # for the instance meta-object to |
b880e0de |
187 | # not fall into meta-circular death |
1d68af04 |
188 | # |
ce2ae40f |
189 | # we just alias the original method |
1d68af04 |
190 | # rather than re-produce it here |
ce2ae40f |
191 | 'name' => \&Class::MOP::Package::name |
b880e0de |
192 | }, |
727919c5 |
193 | )) |
194 | ); |
195 | |
a5e51f0b |
196 | Class::MOP::Package->meta->add_attribute( |
8683db0e |
197 | Class::MOP::Attribute->new('namespace' => ( |
a5e51f0b |
198 | reader => { |
56dcfc1a |
199 | # NOTE: |
ce2ae40f |
200 | # we just alias the original method |
201 | # rather than re-produce it here |
202 | 'namespace' => \&Class::MOP::Package::namespace |
a5e51f0b |
203 | }, |
2e877f58 |
204 | init_arg => undef, |
c4260b45 |
205 | default => sub { \undef } |
a5e51f0b |
206 | )) |
207 | ); |
208 | |
b1ff395f |
209 | Class::MOP::Package->meta->add_attribute( |
bcef1f7c |
210 | Class::MOP::Attribute->new('_methods' => ( |
211 | reader => { |
212 | # NOTE: |
213 | # we just alias the original method |
214 | # rather than re-produce it here |
215 | '_full_method_map' => \&Class::MOP::Package::_full_method_map |
216 | }, |
217 | default => sub { {} } |
218 | )) |
219 | ); |
220 | |
221 | Class::MOP::Package->meta->add_attribute( |
b1ff395f |
222 | Class::MOP::Attribute->new('method_metaclass' => ( |
223 | reader => { |
224 | # NOTE: |
225 | # we just alias the original method |
226 | # rather than re-produce it here |
227 | 'method_metaclass' => \&Class::MOP::Package::method_metaclass |
228 | }, |
229 | default => 'Class::MOP::Method', |
230 | )) |
231 | ); |
232 | |
233 | Class::MOP::Package->meta->add_attribute( |
234 | Class::MOP::Attribute->new('wrapped_method_metaclass' => ( |
235 | reader => { |
236 | # NOTE: |
237 | # we just alias the original method |
238 | # rather than re-produce it here |
239 | 'wrapped_method_metaclass' => \&Class::MOP::Package::wrapped_method_metaclass |
240 | }, |
241 | default => 'Class::MOP::Method::Wrapped', |
242 | )) |
243 | ); |
244 | |
f0480c45 |
245 | ## -------------------------------------------------------- |
246 | ## Class::MOP::Module |
247 | |
248 | # NOTE: |
1d68af04 |
249 | # yeah this is kind of stretching things a bit, |
f0480c45 |
250 | # but truthfully the version should be an attribute |
1d68af04 |
251 | # of the Module, the weirdness comes from having to |
252 | # stick to Perl 5 convention and store it in the |
253 | # $VERSION package variable. Basically if you just |
254 | # squint at it, it will look how you want it to look. |
f0480c45 |
255 | # Either as a package variable, or as a attribute of |
256 | # the metaclass, isn't abstraction great :) |
257 | |
258 | Class::MOP::Module->meta->add_attribute( |
8683db0e |
259 | Class::MOP::Attribute->new('version' => ( |
f0480c45 |
260 | reader => { |
ce2ae40f |
261 | # NOTE: |
262 | # we just alias the original method |
1d68af04 |
263 | # rather than re-produce it here |
ce2ae40f |
264 | 'version' => \&Class::MOP::Module::version |
f0480c45 |
265 | }, |
2e877f58 |
266 | init_arg => undef, |
c4260b45 |
267 | default => sub { \undef } |
f0480c45 |
268 | )) |
269 | ); |
270 | |
271 | # NOTE: |
1d68af04 |
272 | # By following the same conventions as version here, |
273 | # we are opening up the possibility that people can |
274 | # use the $AUTHORITY in non-Class::MOP modules as |
275 | # well. |
f0480c45 |
276 | |
277 | Class::MOP::Module->meta->add_attribute( |
8683db0e |
278 | Class::MOP::Attribute->new('authority' => ( |
f0480c45 |
279 | reader => { |
ce2ae40f |
280 | # NOTE: |
281 | # we just alias the original method |
1d68af04 |
282 | # rather than re-produce it here |
ce2ae40f |
283 | 'authority' => \&Class::MOP::Module::authority |
1d68af04 |
284 | }, |
2e877f58 |
285 | init_arg => undef, |
c4260b45 |
286 | default => sub { \undef } |
f0480c45 |
287 | )) |
288 | ); |
289 | |
290 | ## -------------------------------------------------------- |
6d5355c3 |
291 | ## Class::MOP::Class |
292 | |
727919c5 |
293 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
294 | Class::MOP::Attribute->new('attributes' => ( |
f7259199 |
295 | reader => { |
1d68af04 |
296 | # NOTE: we need to do this in order |
297 | # for the instance meta-object to |
298 | # not fall into meta-circular death |
299 | # |
ce2ae40f |
300 | # we just alias the original method |
1d68af04 |
301 | # rather than re-produce it here |
ce2ae40f |
302 | 'get_attribute_map' => \&Class::MOP::Class::get_attribute_map |
f7259199 |
303 | }, |
727919c5 |
304 | default => sub { {} } |
305 | )) |
306 | ); |
307 | |
351bd7d4 |
308 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
309 | Class::MOP::Attribute->new('superclasses' => ( |
c23184fc |
310 | accessor => { |
311 | # NOTE: |
312 | # we just alias the original method |
1d68af04 |
313 | # rather than re-produce it here |
c23184fc |
314 | 'superclasses' => \&Class::MOP::Class::superclasses |
315 | }, |
2e877f58 |
316 | init_arg => undef, |
c23184fc |
317 | default => sub { \undef } |
318 | )) |
319 | ); |
320 | |
321 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
322 | Class::MOP::Attribute->new('attribute_metaclass' => ( |
1d68af04 |
323 | reader => { |
6d2118a4 |
324 | # NOTE: |
325 | # we just alias the original method |
1d68af04 |
326 | # rather than re-produce it here |
6d2118a4 |
327 | 'attribute_metaclass' => \&Class::MOP::Class::attribute_metaclass |
1d68af04 |
328 | }, |
351bd7d4 |
329 | default => 'Class::MOP::Attribute', |
330 | )) |
331 | ); |
332 | |
333 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
334 | Class::MOP::Attribute->new('instance_metaclass' => ( |
b880e0de |
335 | reader => { |
1d68af04 |
336 | # NOTE: we need to do this in order |
337 | # for the instance meta-object to |
338 | # not fall into meta-circular death |
339 | # |
ce2ae40f |
340 | # we just alias the original method |
1d68af04 |
341 | # rather than re-produce it here |
ce2ae40f |
342 | 'instance_metaclass' => \&Class::MOP::Class::instance_metaclass |
b880e0de |
343 | }, |
1d68af04 |
344 | default => 'Class::MOP::Instance', |
2bab2be6 |
345 | )) |
346 | ); |
347 | |
44d6ea77 |
348 | Class::MOP::Class->meta->add_attribute( |
f5d08022 |
349 | Class::MOP::Attribute->new('immutable_trait' => ( |
350 | reader => { |
351 | 'immutable_trait' => \&Class::MOP::Class::immutable_trait |
352 | }, |
353 | default => "Class::MOP::Class::Immutable::Trait", |
354 | )) |
355 | ); |
356 | |
357 | Class::MOP::Class->meta->add_attribute( |
358 | Class::MOP::Attribute->new('constructor_name' => ( |
44d6ea77 |
359 | reader => { |
f5d08022 |
360 | 'constructor_name' => \&Class::MOP::Class::constructor_name, |
44d6ea77 |
361 | }, |
f5d08022 |
362 | default => "new", |
363 | )) |
364 | ); |
365 | |
366 | Class::MOP::Class->meta->add_attribute( |
367 | Class::MOP::Attribute->new('constructor_class' => ( |
44d6ea77 |
368 | reader => { |
f5d08022 |
369 | 'constructor_class' => \&Class::MOP::Class::constructor_class, |
44d6ea77 |
370 | }, |
f5d08022 |
371 | default => "Class::MOP::Method::Constructor", |
372 | )) |
373 | ); |
374 | |
375 | |
376 | Class::MOP::Class->meta->add_attribute( |
377 | Class::MOP::Attribute->new('destructor_class' => ( |
378 | reader => { |
379 | 'destructor_class' => \&Class::MOP::Class::destructor_class, |
44d6ea77 |
380 | }, |
381 | )) |
382 | ); |
383 | |
9d6dce77 |
384 | # NOTE: |
1d68af04 |
385 | # we don't actually need to tie the knot with |
386 | # Class::MOP::Class here, it is actually handled |
387 | # within Class::MOP::Class itself in the |
c2b256bc |
388 | # _construct_class_instance method. |
9d6dce77 |
389 | |
f0480c45 |
390 | ## -------------------------------------------------------- |
727919c5 |
391 | ## Class::MOP::Attribute |
392 | |
7b31baf4 |
393 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
394 | Class::MOP::Attribute->new('name' => ( |
c23184fc |
395 | reader => { |
1d68af04 |
396 | # NOTE: we need to do this in order |
397 | # for the instance meta-object to |
398 | # not fall into meta-circular death |
399 | # |
ce2ae40f |
400 | # we just alias the original method |
1d68af04 |
401 | # rather than re-produce it here |
ce2ae40f |
402 | 'name' => \&Class::MOP::Attribute::name |
b880e0de |
403 | } |
7b31baf4 |
404 | )) |
405 | ); |
406 | |
407 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
408 | Class::MOP::Attribute->new('associated_class' => ( |
c23184fc |
409 | reader => { |
1d68af04 |
410 | # NOTE: we need to do this in order |
411 | # for the instance meta-object to |
412 | # not fall into meta-circular death |
413 | # |
ce2ae40f |
414 | # we just alias the original method |
1d68af04 |
415 | # rather than re-produce it here |
ce2ae40f |
416 | 'associated_class' => \&Class::MOP::Attribute::associated_class |
b880e0de |
417 | } |
7b31baf4 |
418 | )) |
419 | ); |
420 | |
421 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
422 | Class::MOP::Attribute->new('accessor' => ( |
6d2118a4 |
423 | reader => { 'accessor' => \&Class::MOP::Attribute::accessor }, |
424 | predicate => { 'has_accessor' => \&Class::MOP::Attribute::has_accessor }, |
7b31baf4 |
425 | )) |
426 | ); |
427 | |
428 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
429 | Class::MOP::Attribute->new('reader' => ( |
6d2118a4 |
430 | reader => { 'reader' => \&Class::MOP::Attribute::reader }, |
431 | predicate => { 'has_reader' => \&Class::MOP::Attribute::has_reader }, |
7b31baf4 |
432 | )) |
433 | ); |
434 | |
435 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
436 | Class::MOP::Attribute->new('initializer' => ( |
8ee74136 |
437 | reader => { 'initializer' => \&Class::MOP::Attribute::initializer }, |
438 | predicate => { 'has_initializer' => \&Class::MOP::Attribute::has_initializer }, |
0ab65f99 |
439 | )) |
440 | ); |
441 | |
442 | Class::MOP::Attribute->meta->add_attribute( |
d9d99689 |
443 | Class::MOP::Attribute->new('definition_context' => ( |
444 | reader => { 'definition_context' => \&Class::MOP::Attribute::definition_context }, |
445 | )) |
446 | ); |
447 | |
448 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
449 | Class::MOP::Attribute->new('writer' => ( |
6d2118a4 |
450 | reader => { 'writer' => \&Class::MOP::Attribute::writer }, |
451 | predicate => { 'has_writer' => \&Class::MOP::Attribute::has_writer }, |
7b31baf4 |
452 | )) |
453 | ); |
454 | |
455 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
456 | Class::MOP::Attribute->new('predicate' => ( |
6d2118a4 |
457 | reader => { 'predicate' => \&Class::MOP::Attribute::predicate }, |
458 | predicate => { 'has_predicate' => \&Class::MOP::Attribute::has_predicate }, |
7b31baf4 |
459 | )) |
460 | ); |
461 | |
462 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
463 | Class::MOP::Attribute->new('clearer' => ( |
6d2118a4 |
464 | reader => { 'clearer' => \&Class::MOP::Attribute::clearer }, |
465 | predicate => { 'has_clearer' => \&Class::MOP::Attribute::has_clearer }, |
7d28758b |
466 | )) |
467 | ); |
468 | |
469 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
470 | Class::MOP::Attribute->new('builder' => ( |
1d68af04 |
471 | reader => { 'builder' => \&Class::MOP::Attribute::builder }, |
472 | predicate => { 'has_builder' => \&Class::MOP::Attribute::has_builder }, |
473 | )) |
474 | ); |
475 | |
476 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
477 | Class::MOP::Attribute->new('init_arg' => ( |
6d2118a4 |
478 | reader => { 'init_arg' => \&Class::MOP::Attribute::init_arg }, |
479 | predicate => { 'has_init_arg' => \&Class::MOP::Attribute::has_init_arg }, |
7b31baf4 |
480 | )) |
481 | ); |
482 | |
483 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
484 | Class::MOP::Attribute->new('default' => ( |
7b31baf4 |
485 | # default has a custom 'reader' method ... |
1d68af04 |
486 | predicate => { 'has_default' => \&Class::MOP::Attribute::has_default }, |
7b31baf4 |
487 | )) |
488 | ); |
489 | |
3545c727 |
490 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
491 | Class::MOP::Attribute->new('associated_methods' => ( |
c23184fc |
492 | reader => { 'associated_methods' => \&Class::MOP::Attribute::associated_methods }, |
1d68af04 |
493 | default => sub { [] } |
3545c727 |
494 | )) |
495 | ); |
727919c5 |
496 | |
95b67145 |
497 | Class::MOP::Attribute->meta->add_attribute( |
498 | Class::MOP::Attribute->new('insertion_order' => ( |
499 | reader => { 'insertion_order' => \&Class::MOP::Attribute::insertion_order }, |
943cbe2d |
500 | writer => { '_set_insertion_order' => \&Class::MOP::Attribute::_set_insertion_order }, |
95b67145 |
501 | predicate => { 'has_insertion_order' => \&Class::MOP::Attribute::has_insertion_order }, |
502 | )) |
503 | ); |
504 | |
5659d76e |
505 | Class::MOP::Attribute->meta->add_method('clone' => sub { |
a740253a |
506 | my $self = shift; |
1d68af04 |
507 | $self->meta->clone_object($self, @_); |
727919c5 |
508 | }); |
509 | |
f0480c45 |
510 | ## -------------------------------------------------------- |
b6164407 |
511 | ## Class::MOP::Method |
b6164407 |
512 | Class::MOP::Method->meta->add_attribute( |
8683db0e |
513 | Class::MOP::Attribute->new('body' => ( |
c23184fc |
514 | reader => { 'body' => \&Class::MOP::Method::body }, |
b6164407 |
515 | )) |
516 | ); |
517 | |
4c105333 |
518 | Class::MOP::Method->meta->add_attribute( |
5e607260 |
519 | Class::MOP::Attribute->new('associated_metaclass' => ( |
5e607260 |
520 | reader => { 'associated_metaclass' => \&Class::MOP::Method::associated_metaclass }, |
521 | )) |
522 | ); |
523 | |
524 | Class::MOP::Method->meta->add_attribute( |
8683db0e |
525 | Class::MOP::Attribute->new('package_name' => ( |
4c105333 |
526 | reader => { 'package_name' => \&Class::MOP::Method::package_name }, |
527 | )) |
528 | ); |
529 | |
530 | Class::MOP::Method->meta->add_attribute( |
8683db0e |
531 | Class::MOP::Attribute->new('name' => ( |
4c105333 |
532 | reader => { 'name' => \&Class::MOP::Method::name }, |
533 | )) |
534 | ); |
535 | |
2226a8b0 |
536 | Class::MOP::Method->meta->add_attribute( |
537 | Class::MOP::Attribute->new('original_method' => ( |
538 | reader => { 'original_method' => \&Class::MOP::Method::original_method }, |
539 | writer => { '_set_original_method' => \&Class::MOP::Method::_set_original_method }, |
540 | )) |
541 | ); |
542 | |
4c105333 |
543 | Class::MOP::Method->meta->add_method('clone' => sub { |
544 | my $self = shift; |
2226a8b0 |
545 | my $clone = $self->meta->clone_object($self, @_); |
546 | $clone->_set_original_method($self); |
547 | return $clone; |
4c105333 |
548 | }); |
549 | |
b6164407 |
550 | ## -------------------------------------------------------- |
551 | ## Class::MOP::Method::Wrapped |
552 | |
553 | # NOTE: |
1d68af04 |
554 | # the way this item is initialized, this |
555 | # really does not follow the standard |
556 | # practices of attributes, but we put |
b6164407 |
557 | # it here for completeness |
558 | Class::MOP::Method::Wrapped->meta->add_attribute( |
8683db0e |
559 | Class::MOP::Attribute->new('modifier_table') |
b6164407 |
560 | ); |
561 | |
562 | ## -------------------------------------------------------- |
565f0cbb |
563 | ## Class::MOP::Method::Generated |
564 | |
565 | Class::MOP::Method::Generated->meta->add_attribute( |
8683db0e |
566 | Class::MOP::Attribute->new('is_inline' => ( |
565f0cbb |
567 | reader => { 'is_inline' => \&Class::MOP::Method::Generated::is_inline }, |
4c105333 |
568 | default => 0, |
1d68af04 |
569 | )) |
565f0cbb |
570 | ); |
571 | |
d9d99689 |
572 | Class::MOP::Method::Generated->meta->add_attribute( |
573 | Class::MOP::Attribute->new('definition_context' => ( |
574 | reader => { 'definition_context' => \&Class::MOP::Method::Generated::definition_context }, |
575 | )) |
576 | ); |
577 | |
29d4e92a |
578 | |
579 | ## -------------------------------------------------------- |
580 | ## Class::MOP::Method::Inlined |
581 | |
582 | Class::MOP::Method::Inlined->meta->add_attribute( |
583 | Class::MOP::Attribute->new('_expected_method_class' => ( |
584 | reader => { '_expected_method_class' => \&Class::MOP::Method::Inlined::_expected_method_class }, |
585 | )) |
586 | ); |
587 | |
565f0cbb |
588 | ## -------------------------------------------------------- |
d90b42a6 |
589 | ## Class::MOP::Method::Accessor |
590 | |
591 | Class::MOP::Method::Accessor->meta->add_attribute( |
8683db0e |
592 | Class::MOP::Attribute->new('attribute' => ( |
1d68af04 |
593 | reader => { |
594 | 'associated_attribute' => \&Class::MOP::Method::Accessor::associated_attribute |
d90b42a6 |
595 | }, |
1d68af04 |
596 | )) |
d90b42a6 |
597 | ); |
598 | |
599 | Class::MOP::Method::Accessor->meta->add_attribute( |
8683db0e |
600 | Class::MOP::Attribute->new('accessor_type' => ( |
c23184fc |
601 | reader => { 'accessor_type' => \&Class::MOP::Method::Accessor::accessor_type }, |
1d68af04 |
602 | )) |
d90b42a6 |
603 | ); |
604 | |
d90b42a6 |
605 | ## -------------------------------------------------------- |
606 | ## Class::MOP::Method::Constructor |
607 | |
608 | Class::MOP::Method::Constructor->meta->add_attribute( |
8683db0e |
609 | Class::MOP::Attribute->new('options' => ( |
1d68af04 |
610 | reader => { |
611 | 'options' => \&Class::MOP::Method::Constructor::options |
d90b42a6 |
612 | }, |
4c105333 |
613 | default => sub { +{} } |
1d68af04 |
614 | )) |
d90b42a6 |
615 | ); |
616 | |
617 | Class::MOP::Method::Constructor->meta->add_attribute( |
8683db0e |
618 | Class::MOP::Attribute->new('associated_metaclass' => ( |
e8a38403 |
619 | init_arg => "metaclass", # FIXME alias and rename |
1d68af04 |
620 | reader => { |
621 | 'associated_metaclass' => \&Class::MOP::Method::Constructor::associated_metaclass |
622 | }, |
623 | )) |
d90b42a6 |
624 | ); |
625 | |
626 | ## -------------------------------------------------------- |
86482605 |
627 | ## Class::MOP::Instance |
628 | |
629 | # NOTE: |
1d68af04 |
630 | # these don't yet do much of anything, but are just |
86482605 |
631 | # included for completeness |
632 | |
633 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
634 | Class::MOP::Attribute->new('associated_metaclass', |
635 | reader => { associated_metaclass => \&Class::MOP::Instance::associated_metaclass }, |
636 | ), |
86482605 |
637 | ); |
638 | |
639 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
640 | Class::MOP::Attribute->new('_class_name', |
641 | init_arg => undef, |
642 | reader => { _class_name => \&Class::MOP::Instance::_class_name }, |
643 | #lazy => 1, # not yet supported by Class::MOP but out our version does it anyway |
644 | #default => sub { $_[0]->associated_metaclass->name }, |
645 | ), |
646 | ); |
647 | |
648 | Class::MOP::Instance->meta->add_attribute( |
649 | Class::MOP::Attribute->new('attributes', |
0b5d46da |
650 | reader => { attributes => \&Class::MOP::Instance::get_all_attributes }, |
74890687 |
651 | ), |
32bfc810 |
652 | ); |
653 | |
654 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
655 | Class::MOP::Attribute->new('slots', |
656 | reader => { slots => \&Class::MOP::Instance::slots }, |
657 | ), |
86482605 |
658 | ); |
659 | |
63d08a9e |
660 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
661 | Class::MOP::Attribute->new('slot_hash', |
662 | reader => { slot_hash => \&Class::MOP::Instance::slot_hash }, |
663 | ), |
63d08a9e |
664 | ); |
665 | |
30229767 |
666 | require Class::MOP::Deprecated unless our $no_deprecated; |
63d08a9e |
667 | |
caa051fa |
668 | # we need the meta instance of the meta instance to be created now, in order |
669 | # for the constructor to be able to use it |
670 | Class::MOP::Instance->meta->get_meta_instance; |
671 | |
caa051fa |
672 | # pretend the add_method never happenned. it hasn't yet affected anything |
673 | undef Class::MOP::Instance->meta->{_package_cache_flag}; |
674 | |
86482605 |
675 | ## -------------------------------------------------------- |
f0480c45 |
676 | ## Now close all the Class::MOP::* classes |
4d47b77f |
677 | |
1aa13cf4 |
678 | # NOTE: we don't need to inline the the accessors this only lengthens |
679 | # the compile time of the MOP, and gives us no actual benefits. |
0b9372a2 |
680 | |
681 | $_->meta->make_immutable( |
ec9e38e5 |
682 | inline_constructor => 0, |
6c2f6b5c |
683 | constructor_name => "_new", |
45582002 |
684 | inline_accessors => 0, |
0b9372a2 |
685 | ) for qw/ |
1d68af04 |
686 | Class::MOP::Package |
687 | Class::MOP::Module |
688 | Class::MOP::Class |
689 | |
0b9372a2 |
690 | Class::MOP::Attribute |
1d68af04 |
691 | Class::MOP::Method |
692 | Class::MOP::Instance |
693 | |
694 | Class::MOP::Object |
0b9372a2 |
695 | |
565f0cbb |
696 | Class::MOP::Method::Generated |
29d4e92a |
697 | Class::MOP::Method::Inlined |
1d68af04 |
698 | |
ba38bf08 |
699 | Class::MOP::Method::Accessor |
1d68af04 |
700 | Class::MOP::Method::Constructor |
701 | Class::MOP::Method::Wrapped |
0b9372a2 |
702 | /; |
b6164407 |
703 | |
94b19069 |
704 | 1; |
705 | |
706 | __END__ |
707 | |
708 | =pod |
709 | |
1d68af04 |
710 | =head1 NAME |
94b19069 |
711 | |
712 | Class::MOP - A Meta Object Protocol for Perl 5 |
713 | |
5b60bf98 |
714 | =head1 DESCRIPTION |
94b19069 |
715 | |
127d39a7 |
716 | This module is a fully functioning meta object protocol for the |
1d68af04 |
717 | Perl 5 object system. It makes no attempt to change the behavior or |
718 | characteristics of the Perl 5 object system, only to create a |
27e31eaf |
719 | protocol for its manipulation and introspection. |
94b19069 |
720 | |
828ecf13 |
721 | That said, it does attempt to create the tools for building a rich set |
722 | of extensions to the Perl 5 object system. Every attempt has been made |
723 | to abide by the spirit of the Perl 5 object system that we all know |
724 | and love. |
94b19069 |
725 | |
828ecf13 |
726 | This documentation is sparse on conceptual details. We suggest looking |
727 | at the items listed in the L<SEE ALSO> section for more |
728 | information. In particular the book "The Art of the Meta Object |
729 | Protocol" was very influential in the development of this system. |
40483095 |
730 | |
bfe4d0fc |
731 | =head2 What is a Meta Object Protocol? |
732 | |
1d68af04 |
733 | A meta object protocol is an API to an object system. |
bfe4d0fc |
734 | |
828ecf13 |
735 | To be more specific, it abstracts the components of an object system |
736 | (classes, object, methods, object attributes, etc.). These |
737 | abstractions can then be used to inspect and manipulate the object |
738 | system which they describe. |
bfe4d0fc |
739 | |
1d68af04 |
740 | It can be said that there are two MOPs for any object system; the |
828ecf13 |
741 | implicit MOP and the explicit MOP. The implicit MOP handles things |
1d68af04 |
742 | like method dispatch or inheritance, which happen automatically as |
743 | part of how the object system works. The explicit MOP typically |
744 | handles the introspection/reflection features of the object system. |
bfe4d0fc |
745 | |
828ecf13 |
746 | All object systems have implicit MOPs. Without one, they would not |
5b60bf98 |
747 | work. Explicit MOPs are much less common, and depending on the |
748 | language can vary from restrictive (Reflection in Java or C#) to wide |
749 | open (CLOS is a perfect example). |
e16da3e6 |
750 | |
828ecf13 |
751 | =head2 Yet Another Class Builder! Why? |
752 | |
753 | This is B<not> a class builder so much as a I<class builder |
754 | B<builder>>. The intent is that an end user will not use this module |
755 | directly, but instead this module is used by module authors to build |
756 | extensions and features onto the Perl 5 object system. |
757 | |
758 | This system is used by L<Moose>, which supplies a powerful class |
759 | builder system built entirely on top of C<Class::MOP>. |
e16da3e6 |
760 | |
94b19069 |
761 | =head2 Who is this module for? |
762 | |
828ecf13 |
763 | This module is for anyone who has ever created or wanted to create a |
764 | module for the Class:: namespace. The tools which this module provides |
765 | make doing complex Perl 5 wizardry simpler, by removing such barriers |
766 | as the need to hack symbol tables, or understand the fine details of |
767 | method dispatch. |
94b19069 |
768 | |
bfe4d0fc |
769 | =head2 What changes do I have to make to use this module? |
770 | |
828ecf13 |
771 | This module was designed to be as unintrusive as possible. Many of its |
5b60bf98 |
772 | features are accessible without B<any> change to your existing |
828ecf13 |
773 | code. It is meant to be a compliment to your existing code and not an |
774 | intrusion on your code base. Unlike many other B<Class::> modules, |
775 | this module B<does not> require you subclass it, or even that you |
776 | C<use> it in within your module's package. |
bfe4d0fc |
777 | |
1d68af04 |
778 | The only features which requires additions to your code are the |
2eb717d5 |
779 | attribute handling and instance construction features, and these are |
1d68af04 |
780 | both completely optional features. The only reason for this is because |
781 | Perl 5's object system does not actually have these features built |
2eb717d5 |
782 | in. More information about this feature can be found below. |
bfe4d0fc |
783 | |
828ecf13 |
784 | =head2 About Performance |
785 | |
5b60bf98 |
786 | It is a common misconception that explicit MOPs are a performance hit. |
828ecf13 |
787 | This is not a universal truth, it is a side-effect of some specific |
788 | implementations. For instance, using Java reflection is slow because |
789 | the JVM cannot take advantage of any compiler optimizations, and the |
790 | JVM has to deal with much more runtime type information as well. |
bfe4d0fc |
791 | |
828ecf13 |
792 | Reflection in C# is marginally better as it was designed into the |
793 | language and runtime (the CLR). In contrast, CLOS (the Common Lisp |
794 | Object System) was built to support an explicit MOP, and so |
795 | performance is tuned for it. |
1d68af04 |
796 | |
828ecf13 |
797 | This library in particular does its absolute best to avoid putting |
1d68af04 |
798 | B<any> drain at all upon your code's performance. In fact, by itself |
828ecf13 |
799 | it does nothing to affect your existing code. So you only pay for what |
800 | you actually use. |
bfe4d0fc |
801 | |
550d56db |
802 | =head2 About Metaclass compatibility |
803 | |
1d68af04 |
804 | This module makes sure that all metaclasses created are both upwards |
805 | and downwards compatible. The topic of metaclass compatibility is |
806 | highly esoteric and is something only encountered when doing deep and |
807 | involved metaclass hacking. There are two basic kinds of metaclass |
808 | incompatibility; upwards and downwards. |
550d56db |
809 | |
1d68af04 |
810 | Upwards metaclass compatibility means that the metaclass of a |
811 | given class is either the same as (or a subclass of) all of the |
550d56db |
812 | class's ancestors. |
813 | |
1d68af04 |
814 | Downward metaclass compatibility means that the metaclasses of a |
828ecf13 |
815 | given class's ancestors are all either the same as (or a subclass |
550d56db |
816 | of) that metaclass. |
817 | |
1d68af04 |
818 | Here is a diagram showing a set of two classes (C<A> and C<B>) and |
819 | two metaclasses (C<Meta::A> and C<Meta::B>) which have correct |
550d56db |
820 | metaclass compatibility both upwards and downwards. |
821 | |
822 | +---------+ +---------+ |
823 | | Meta::A |<----| Meta::B | <....... (instance of ) |
1d68af04 |
824 | +---------+ +---------+ <------- (inherits from) |
550d56db |
825 | ^ ^ |
826 | : : |
827 | +---------+ +---------+ |
828 | | A |<----| B | |
829 | +---------+ +---------+ |
830 | |
1d68af04 |
831 | As I said this is a highly esoteric topic and one you will only run |
828ecf13 |
832 | into if you do a lot of subclassing of L<Class::MOP::Class>. If you |
833 | are interested in why this is an issue see the paper I<Uniform and |
834 | safe metaclass composition> linked to in the L<SEE ALSO> section of |
835 | this document. |
550d56db |
836 | |
aa448b16 |
837 | =head2 Using custom metaclasses |
838 | |
828ecf13 |
839 | Always use the L<metaclass> pragma when using a custom metaclass, this |
5b60bf98 |
840 | will ensure the proper initialization order and not accidentally |
841 | create an incorrect type of metaclass for you. This is a very rare |
842 | problem, and one which can only occur if you are doing deep metaclass |
aa448b16 |
843 | programming. So in other words, don't worry about it. |
844 | |
828ecf13 |
845 | Note that if you're using L<Moose> we encourage you to I<not> use |
846 | L<metaclass> pragma, and instead use L<Moose::Util::MetaRole> to apply |
847 | roles to a class's metaclasses. This topic is covered at length in |
848 | various L<Moose::Cookbook> recipes. |
849 | |
94b19069 |
850 | =head1 PROTOCOLS |
851 | |
828ecf13 |
852 | The meta-object protocol is divided into 4 main sub-protocols: |
94b19069 |
853 | |
828ecf13 |
854 | =head2 The Class protocol |
94b19069 |
855 | |
1d68af04 |
856 | This provides a means of manipulating and introspecting a Perl 5 |
828ecf13 |
857 | class. It handles symbol table hacking for you, and provides a rich |
858 | set of methods that go beyond simple package introspection. |
94b19069 |
859 | |
552e3d24 |
860 | See L<Class::MOP::Class> for more details. |
861 | |
828ecf13 |
862 | =head2 The Attribute protocol |
94b19069 |
863 | |
828ecf13 |
864 | This provides a consistent representation for an attribute of a Perl 5 |
865 | class. Since there are so many ways to create and handle attributes in |
866 | Perl 5 OO, the Attribute protocol provide as much of a unified |
867 | approach as possible. Of course, you are always free to extend this |
868 | protocol by subclassing the appropriate classes. |
94b19069 |
869 | |
552e3d24 |
870 | See L<Class::MOP::Attribute> for more details. |
871 | |
828ecf13 |
872 | =head2 The Method protocol |
94b19069 |
873 | |
828ecf13 |
874 | This provides a means of manipulating and introspecting methods in the |
875 | Perl 5 object system. As with attributes, there are many ways to |
1d68af04 |
876 | approach this topic, so we try to keep it pretty basic, while still |
94b19069 |
877 | making it possible to extend the system in many ways. |
878 | |
552e3d24 |
879 | See L<Class::MOP::Method> for more details. |
94b19069 |
880 | |
828ecf13 |
881 | =head2 The Instance protocol |
127d39a7 |
882 | |
828ecf13 |
883 | This provides a layer of abstraction for creating object instances. |
884 | Since the other layers use this protocol, it is relatively easy to |
885 | change the type of your instances from the default hash reference to |
886 | some other type of reference. Several examples are provided in the |
887 | F<examples/> directory included in this distribution. |
127d39a7 |
888 | |
889 | See L<Class::MOP::Instance> for more details. |
890 | |
be7677c7 |
891 | =head1 FUNCTIONS |
892 | |
828ecf13 |
893 | Note that this module does not export any constants or functions. |
894 | |
c1d5345a |
895 | =head2 Constants |
896 | |
897 | =over 4 |
898 | |
828ecf13 |
899 | =item I<Class::MOP::IS_RUNNING_ON_5_10> |
c1d5345a |
900 | |
828ecf13 |
901 | We set this constant depending on what version perl we are on, this |
902 | allows us to take advantage of new 5.10 features and stay backwards |
5b60bf98 |
903 | compatible. |
c1d5345a |
904 | |
905 | =back |
906 | |
448b6e55 |
907 | =head2 Utility functions |
908 | |
bd07fbdb |
909 | Note that these are all called as B<functions, not methods>. |
081a927b |
910 | |
448b6e55 |
911 | =over 4 |
912 | |
828ecf13 |
913 | =item B<Class::MOP::load_class($class_name)> |
448b6e55 |
914 | |
9d441c23 |
915 | This will load the specified C<$class_name>, if it is not already |
916 | loaded (as reported by C<is_class_loaded>). This function can be used |
828ecf13 |
917 | in place of tricks like C<eval "use $module"> or using C<require> |
7716a8f9 |
918 | unconditionally. |
448b6e55 |
919 | |
674d9359 |
920 | If the module cannot be loaded, an exception is thrown. |
921 | |
922 | For historical reasons, this function returns explicitly returns a true value. |
923 | |
828ecf13 |
924 | =item B<Class::MOP::is_class_loaded($class_name)> |
448b6e55 |
925 | |
15ab5451 |
926 | Returns a boolean indicating whether or not C<$class_name> has been |
927 | loaded. |
448b6e55 |
928 | |
828ecf13 |
929 | This does a basic check of the symbol table to try and determine as |
930 | best it can if the C<$class_name> is loaded, it is probably correct |
931 | about 99% of the time, but it can be fooled into reporting false |
9d441c23 |
932 | positives. In particular, loading any of the core L<IO> modules will |
933 | cause most of the rest of the core L<IO> modules to falsely report |
934 | having been loaded, due to the way the base L<IO> module works. |
448b6e55 |
935 | |
cdac22cc |
936 | =item B<Class::MOP::get_code_info($code)> |
937 | |
938 | This function returns two values, the name of the package the C<$code> |
939 | is from and the name of the C<$code> itself. This is used by several |
5b60bf98 |
940 | elements of the MOP to determine where a given C<$code> reference is |
cdac22cc |
941 | from. |
942 | |
44ba77a3 |
943 | =item B<Class::MOP::class_of($instance_or_class_name)> |
944 | |
3fa5b3f9 |
945 | This will return the metaclass of the given instance or class name. If the |
946 | class lacks a metaclass, no metaclass will be initialized, and C<undef> will be |
947 | returned. |
44ba77a3 |
948 | |
828ecf13 |
949 | =item B<Class::MOP::check_package_cache_flag($pkg)> |
e0e4674a |
950 | |
bd07fbdb |
951 | B<NOTE: DO NOT USE THIS FUNCTION, IT IS FOR INTERNAL USE ONLY!> |
952 | |
828ecf13 |
953 | This will return an integer that is managed by L<Class::MOP::Class> to |
954 | determine if a module's symbol table has been altered. |
127d39a7 |
955 | |
828ecf13 |
956 | In Perl 5.10 or greater, this flag is package specific. However in |
957 | versions prior to 5.10, this will use the C<PL_sub_generation> |
958 | variable which is not package specific. |
127d39a7 |
959 | |
828ecf13 |
960 | =item B<Class::MOP::load_first_existing_class(@class_names)> |
063ad0c5 |
961 | |
962 | B<NOTE: DO NOT USE THIS FUNCTION, IT IS FOR INTERNAL USE ONLY!> |
963 | |
964 | Given a list of class names, this function will attempt to load each |
965 | one in turn. |
966 | |
828ecf13 |
967 | If it finds a class it can load, it will return that class' name. If |
968 | none of the classes can be loaded, it will throw an exception. |
063ad0c5 |
969 | |
448b6e55 |
970 | =back |
971 | |
972 | =head2 Metaclass cache functions |
973 | |
6c842677 |
974 | Class::MOP holds a cache of metaclasses. The following are functions |
1d68af04 |
975 | (B<not methods>) which can be used to access that cache. It is not |
6c842677 |
976 | recommended that you mess with these. Bad things could happen, but if |
977 | you are brave and willing to risk it: go for it! |
be7677c7 |
978 | |
979 | =over 4 |
980 | |
828ecf13 |
981 | =item B<Class::MOP::get_all_metaclasses> |
be7677c7 |
982 | |
6c842677 |
983 | This will return a hash of all the metaclass instances that have |
828ecf13 |
984 | been cached by L<Class::MOP::Class>, keyed by the package name. |
b9d9fc0b |
985 | |
828ecf13 |
986 | =item B<Class::MOP::get_all_metaclass_instances> |
be7677c7 |
987 | |
6c842677 |
988 | This will return a list of all the metaclass instances that have |
828ecf13 |
989 | been cached by L<Class::MOP::Class>. |
b9d9fc0b |
990 | |
828ecf13 |
991 | =item B<Class::MOP::get_all_metaclass_names> |
be7677c7 |
992 | |
6c842677 |
993 | This will return a list of all the metaclass names that have |
828ecf13 |
994 | been cached by L<Class::MOP::Class>. |
b9d9fc0b |
995 | |
828ecf13 |
996 | =item B<Class::MOP::get_metaclass_by_name($name)> |
be7677c7 |
997 | |
828ecf13 |
998 | This will return a cached L<Class::MOP::Class> instance, or nothing |
6c842677 |
999 | if no metaclass exists with that C<$name>. |
127d39a7 |
1000 | |
828ecf13 |
1001 | =item B<Class::MOP::store_metaclass_by_name($name, $meta)> |
be7677c7 |
1002 | |
127d39a7 |
1003 | This will store a metaclass in the cache at the supplied C<$key>. |
1004 | |
828ecf13 |
1005 | =item B<Class::MOP::weaken_metaclass($name)> |
be7677c7 |
1006 | |
6c842677 |
1007 | In rare cases (e.g. anonymous metaclasses) it is desirable to |
1008 | store a weakened reference in the metaclass cache. This |
1009 | function will weaken the reference to the metaclass stored |
1010 | in C<$name>. |
127d39a7 |
1011 | |
828ecf13 |
1012 | =item B<Class::MOP::does_metaclass_exist($name)> |
be7677c7 |
1013 | |
828ecf13 |
1014 | This will return true of there exists a metaclass stored in the |
6c842677 |
1015 | C<$name> key, and return false otherwise. |
127d39a7 |
1016 | |
828ecf13 |
1017 | =item B<Class::MOP::remove_metaclass_by_name($name)> |
be7677c7 |
1018 | |
6c842677 |
1019 | This will remove the metaclass stored in the C<$name> key. |
127d39a7 |
1020 | |
be7677c7 |
1021 | =back |
1022 | |
552e3d24 |
1023 | =head1 SEE ALSO |
8b978dd5 |
1024 | |
552e3d24 |
1025 | =head2 Books |
8b978dd5 |
1026 | |
1d68af04 |
1027 | There are very few books out on Meta Object Protocols and Metaclasses |
1028 | because it is such an esoteric topic. The following books are really |
1029 | the only ones I have found. If you know of any more, B<I<please>> |
a2e85e6c |
1030 | email me and let me know, I would love to hear about them. |
1031 | |
8b978dd5 |
1032 | =over 4 |
1033 | |
15ab5451 |
1034 | =item I<The Art of the Meta Object Protocol> |
8b978dd5 |
1035 | |
15ab5451 |
1036 | =item I<Advances in Object-Oriented Metalevel Architecture and Reflection> |
8b978dd5 |
1037 | |
15ab5451 |
1038 | =item I<Putting MetaClasses to Work> |
b51af7f9 |
1039 | |
15ab5451 |
1040 | =item I<Smalltalk: The Language> |
a2e85e6c |
1041 | |
94b19069 |
1042 | =back |
1043 | |
550d56db |
1044 | =head2 Papers |
1045 | |
1046 | =over 4 |
1047 | |
15ab5451 |
1048 | =item "Uniform and safe metaclass composition" |
550d56db |
1049 | |
1d68af04 |
1050 | An excellent paper by the people who brought us the original Traits paper. |
1051 | This paper is on how Traits can be used to do safe metaclass composition, |
1052 | and offers an excellent introduction section which delves into the topic of |
550d56db |
1053 | metaclass compatibility. |
1054 | |
1055 | L<http://www.iam.unibe.ch/~scg/Archive/Papers/Duca05ySafeMetaclassTrait.pdf> |
1056 | |
15ab5451 |
1057 | =item "Safe Metaclass Programming" |
550d56db |
1058 | |
1d68af04 |
1059 | This paper seems to precede the above paper, and propose a mix-in based |
1060 | approach as opposed to the Traits based approach. Both papers have similar |
1061 | information on the metaclass compatibility problem space. |
550d56db |
1062 | |
1063 | L<http://citeseer.ist.psu.edu/37617.html> |
1064 | |
1065 | =back |
1066 | |
552e3d24 |
1067 | =head2 Prior Art |
8b978dd5 |
1068 | |
1069 | =over 4 |
1070 | |
7184ca14 |
1071 | =item The Perl 6 MetaModel work in the Pugs project |
8b978dd5 |
1072 | |
1073 | =over 4 |
1074 | |
02615ef0 |
1075 | =item L<http://svn.openfoundry.org/pugs/misc/Perl-MetaModel/> |
8b978dd5 |
1076 | |
552e3d24 |
1077 | =item L<http://svn.openfoundry.org/pugs/perl5/Perl6-ObjectSpace> |
8b978dd5 |
1078 | |
1079 | =back |
1080 | |
94b19069 |
1081 | =back |
1082 | |
1d68af04 |
1083 | =head2 Articles |
f8dfcfb7 |
1084 | |
1085 | =over 4 |
1086 | |
1d68af04 |
1087 | =item CPAN Module Review of Class::MOP |
f8dfcfb7 |
1088 | |
1089 | L<http://www.oreillynet.com/onlamp/blog/2006/06/cpan_module_review_classmop.html> |
1090 | |
1091 | =back |
1092 | |
a2e85e6c |
1093 | =head1 SIMILAR MODULES |
1094 | |
1d68af04 |
1095 | As I have said above, this module is a class-builder-builder, so it is |
1096 | not the same thing as modules like L<Class::Accessor> and |
1097 | L<Class::MethodMaker>. That being said there are very few modules on CPAN |
1098 | with similar goals to this module. The one I have found which is most |
1099 | like this module is L<Class::Meta>, although it's philosophy and the MOP it |
1100 | creates are very different from this modules. |
94b19069 |
1101 | |
a2e85e6c |
1102 | =head1 BUGS |
1103 | |
1d68af04 |
1104 | All complex software has bugs lurking in it, and this module is no |
53702399 |
1105 | exception. |
1106 | |
1107 | Please report any bugs to C<bug-class-mop@rt.cpan.org>, or through the |
1108 | web interface at L<http://rt.cpan.org>. |
1109 | |
1110 | You can also discuss feature requests or possible bugs on the Moose |
1111 | mailing list (moose@perl.org) or on IRC at |
1112 | L<irc://irc.perl.org/#moose>. |
a2e85e6c |
1113 | |
1114 | =head1 ACKNOWLEDGEMENTS |
1115 | |
1116 | =over 4 |
1117 | |
b9d9fc0b |
1118 | =item Rob Kinyon |
a2e85e6c |
1119 | |
1d68af04 |
1120 | Thanks to Rob for actually getting the development of this module kick-started. |
a2e85e6c |
1121 | |
1122 | =back |
1123 | |
1a09d9cc |
1124 | =head1 AUTHORS |
94b19069 |
1125 | |
a2e85e6c |
1126 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
552e3d24 |
1127 | |
9c8cda90 |
1128 | B<with contributions from:> |
1129 | |
1130 | Brandon (blblack) Black |
1131 | |
4f116037 |
1132 | Florian (rafl) Ragwitz |
1133 | |
9c8cda90 |
1134 | Guillermo (groditi) Roditi |
1135 | |
53702399 |
1136 | Dave (autarch) Rolsky |
1137 | |
9195ddff |
1138 | Matt (mst) Trout |
1139 | |
9c8cda90 |
1140 | Rob (robkinyon) Kinyon |
1141 | |
1142 | Yuval (nothingmuch) Kogman |
1a09d9cc |
1143 | |
f430cfa4 |
1144 | Scott (konobi) McWhirter |
1145 | |
20f5ccef |
1146 | Dylan Hardison |
1147 | |
94b19069 |
1148 | =head1 COPYRIGHT AND LICENSE |
1149 | |
070bb6c9 |
1150 | Copyright 2006-2009 by Infinity Interactive, Inc. |
94b19069 |
1151 | |
1152 | L<http://www.iinteractive.com> |
1153 | |
1154 | This library is free software; you can redistribute it and/or modify |
1d68af04 |
1155 | it under the same terms as Perl itself. |
94b19069 |
1156 | |
1157 | =cut |