Commit | Line | Data |
94b19069 |
1 | |
2 | package Class::MOP; |
3 | |
4 | use strict; |
5 | use warnings; |
6 | |
5a2932cf |
7 | use 5.008; |
8 | |
3cf322a0 |
9 | use MRO::Compat; |
10 | |
4c105333 |
11 | use Carp 'confess'; |
b1a46f91 |
12 | use Scalar::Util 'weaken', 'reftype', 'blessed'; |
a8344505 |
13 | use Try::Tiny; |
fc4f8f91 |
14 | |
e3e651fb |
15 | use Class::MOP::HasMethods; |
0531f510 |
16 | use Class::MOP::Class; |
17 | use Class::MOP::Attribute; |
18 | use Class::MOP::Method; |
19 | |
b1f5f41d |
20 | BEGIN { |
c7e28c19 |
21 | *IS_RUNNING_ON_5_10 = ($] < 5.009_005) |
11b56828 |
22 | ? sub () { 0 } |
c7e28c19 |
23 | : sub () { 1 }; |
46b23b44 |
24 | |
3ecd1b25 |
25 | # this is either part of core or set up appropriately by MRO::Compat |
26 | *check_package_cache_flag = \&mro::get_pkg_gen; |
b1f5f41d |
27 | } |
e0e4674a |
28 | |
53edec17 |
29 | our $VERSION = '0.95'; |
8a7085c1 |
30 | our $XS_VERSION = $VERSION; |
d519662a |
31 | $VERSION = eval $VERSION; |
c7e28c19 |
32 | our $AUTHORITY = 'cpan:STEVAN'; |
9d655b6d |
33 | |
4bfa5ddb |
34 | require XSLoader; |
35 | XSLoader::load( __PACKAGE__, $XS_VERSION ); |
d7bda114 |
36 | |
37 | |
be7677c7 |
38 | { |
39 | # Metaclasses are singletons, so we cache them here. |
40 | # there is no need to worry about destruction though |
41 | # because they should die only when the program dies. |
42 | # After all, do package definitions even get reaped? |
247d5b3c |
43 | # Anonymous classes manage their own destruction. |
1d68af04 |
44 | my %METAS; |
45 | |
1d68af04 |
46 | sub get_all_metaclasses { %METAS } |
47 | sub get_all_metaclass_instances { values %METAS } |
48 | sub get_all_metaclass_names { keys %METAS } |
be7677c7 |
49 | sub get_metaclass_by_name { $METAS{$_[0]} } |
1d68af04 |
50 | sub store_metaclass_by_name { $METAS{$_[0]} = $_[1] } |
51 | sub weaken_metaclass { weaken($METAS{$_[0]}) } |
be7677c7 |
52 | sub does_metaclass_exist { exists $METAS{$_[0]} && defined $METAS{$_[0]} } |
efc98200 |
53 | sub remove_metaclass_by_name { delete $METAS{$_[0]}; return } |
1d68af04 |
54 | |
86866fb5 |
55 | # This handles instances as well as class names |
56 | sub class_of { |
82999986 |
57 | return unless defined $_[0]; |
86866fb5 |
58 | my $class = blessed($_[0]) || $_[0]; |
59 | return $METAS{$class}; |
60 | } |
61 | |
be7677c7 |
62 | # NOTE: |
1d68af04 |
63 | # We only cache metaclasses, meaning instances of |
64 | # Class::MOP::Class. We do not cache instance of |
be7677c7 |
65 | # Class::MOP::Package or Class::MOP::Module. Mostly |
1d68af04 |
66 | # because I don't yet see a good reason to do so. |
be7677c7 |
67 | } |
68 | |
44da14be |
69 | sub _class_to_pmfile { |
70 | my $class = shift; |
71 | |
72 | my $file = $class . '.pm'; |
73 | $file =~ s{::}{/}g; |
74 | |
75 | return $file; |
76 | } |
77 | |
063ad0c5 |
78 | sub load_first_existing_class { |
f280f05c |
79 | my @classes = @_ |
a02f24cb |
80 | or return; |
5a24cf8a |
81 | |
82 | foreach my $class (@classes) { |
83 | unless ( _is_valid_class_name($class) ) { |
84 | my $display = defined($class) ? $class : 'undef'; |
85 | confess "Invalid class name ($display)"; |
86 | } |
ab5e2f48 |
87 | } |
88 | |
063ad0c5 |
89 | my $found; |
5a24cf8a |
90 | my %exceptions; |
063ad0c5 |
91 | |
a02f24cb |
92 | for my $class (@classes) { |
93 | my $file = _class_to_pmfile($class); |
5a24cf8a |
94 | |
a02f24cb |
95 | return $class if is_class_loaded($class);; |
07940968 |
96 | |
a02f24cb |
97 | return $class if try { |
98 | local $SIG{__DIE__}; |
99 | require $file; |
100 | return 1; |
101 | } |
102 | catch { |
103 | unless (/^Can't locate \Q$file\E in \@INC/) { |
104 | confess "Couldn't load class ($class) because: $_"; |
44da14be |
105 | } |
063ad0c5 |
106 | |
a02f24cb |
107 | return; |
108 | }; |
a8344505 |
109 | } |
a8344505 |
110 | |
a02f24cb |
111 | if ( @classes > 1 ) { |
112 | confess "Can't locate any of @classes in \@INC (\@INC contains: @INC)."; |
113 | } else { |
114 | confess "Can't locate " . _class_to_pmfile($classes[0]) . " in \@INC (\@INC contains: @INC)."; |
115 | } |
063ad0c5 |
116 | } |
117 | |
5a24cf8a |
118 | sub load_class { |
7716a8f9 |
119 | load_first_existing_class($_[0]); |
120 | |
674d9359 |
121 | # This is done to avoid breaking code which checked the return value. Said |
122 | # code is dumb. The return value was _always_ true, since it dies on |
123 | # failure! |
124 | return 1; |
448b6e55 |
125 | } |
126 | |
2c0fb064 |
127 | sub _is_valid_class_name { |
128 | my $class = shift; |
129 | |
130 | return 0 if ref($class); |
131 | return 0 unless defined($class); |
132 | return 0 unless length($class); |
133 | |
134 | return 1 if $class =~ /^\w+(?:::\w+)*$/; |
135 | |
136 | return 0; |
137 | } |
138 | |
aa448b16 |
139 | ## ---------------------------------------------------------------------------- |
140 | ## Setting up our environment ... |
141 | ## ---------------------------------------------------------------------------- |
1d68af04 |
142 | ## Class::MOP needs to have a few things in the global perl environment so |
aa448b16 |
143 | ## that it can operate effectively. Those things are done here. |
144 | ## ---------------------------------------------------------------------------- |
145 | |
3bf7644b |
146 | # ... nothing yet actually ;) |
8b978dd5 |
147 | |
b51af7f9 |
148 | ## ---------------------------------------------------------------------------- |
1d68af04 |
149 | ## Bootstrapping |
b51af7f9 |
150 | ## ---------------------------------------------------------------------------- |
1d68af04 |
151 | ## The code below here is to bootstrap our MOP with itself. This is also |
b51af7f9 |
152 | ## sometimes called "tying the knot". By doing this, we make it much easier |
153 | ## to extend the MOP through subclassing and such since now you can use the |
1d68af04 |
154 | ## MOP itself to extend itself. |
155 | ## |
b51af7f9 |
156 | ## Yes, I know, thats weird and insane, but it's a good thing, trust me :) |
1d68af04 |
157 | ## ---------------------------------------------------------------------------- |
727919c5 |
158 | |
1d68af04 |
159 | # We need to add in the meta-attributes here so that |
160 | # any subclass of Class::MOP::* will be able to |
c2b256bc |
161 | # inherit them using _construct_instance |
727919c5 |
162 | |
f0480c45 |
163 | ## -------------------------------------------------------- |
e3e651fb |
164 | ## Class::MOP::HasMethods |
727919c5 |
165 | |
e3e651fb |
166 | Class::MOP::HasMethods->meta->add_attribute( |
167 | Class::MOP::Attribute->new('_methods' => ( |
b880e0de |
168 | reader => { |
e3e651fb |
169 | # NOTE: |
ce2ae40f |
170 | # we just alias the original method |
1d68af04 |
171 | # rather than re-produce it here |
e3e651fb |
172 | '_full_method_map' => \&Class::MOP::HasMethods::_full_method_map |
b880e0de |
173 | }, |
e3e651fb |
174 | default => sub { {} } |
727919c5 |
175 | )) |
176 | ); |
177 | |
e3e651fb |
178 | Class::MOP::HasMethods->meta->add_attribute( |
179 | Class::MOP::Attribute->new('method_metaclass' => ( |
180 | reader => { |
56dcfc1a |
181 | # NOTE: |
ce2ae40f |
182 | # we just alias the original method |
183 | # rather than re-produce it here |
e3e651fb |
184 | 'method_metaclass' => \&Class::MOP::HasMethods::method_metaclass |
a5e51f0b |
185 | }, |
e3e651fb |
186 | default => 'Class::MOP::Method', |
a5e51f0b |
187 | )) |
188 | ); |
189 | |
e3e651fb |
190 | Class::MOP::HasMethods->meta->add_attribute( |
191 | Class::MOP::Attribute->new('wrapped_method_metaclass' => ( |
bcef1f7c |
192 | reader => { |
193 | # NOTE: |
194 | # we just alias the original method |
195 | # rather than re-produce it here |
e3e651fb |
196 | 'wrapped_method_metaclass' => \&Class::MOP::HasMethods::wrapped_method_metaclass |
bcef1f7c |
197 | }, |
e3e651fb |
198 | default => 'Class::MOP::Method::Wrapped', |
bcef1f7c |
199 | )) |
200 | ); |
201 | |
e3e651fb |
202 | ## -------------------------------------------------------- |
203 | ## Class::MOP::Package |
204 | |
bcef1f7c |
205 | Class::MOP::Package->meta->add_attribute( |
e3e651fb |
206 | Class::MOP::Attribute->new('package' => ( |
b1ff395f |
207 | reader => { |
e3e651fb |
208 | # NOTE: we need to do this in order |
209 | # for the instance meta-object to |
210 | # not fall into meta-circular death |
211 | # |
b1ff395f |
212 | # we just alias the original method |
213 | # rather than re-produce it here |
e3e651fb |
214 | 'name' => \&Class::MOP::Package::name |
b1ff395f |
215 | }, |
b1ff395f |
216 | )) |
217 | ); |
218 | |
219 | Class::MOP::Package->meta->add_attribute( |
e3e651fb |
220 | Class::MOP::Attribute->new('namespace' => ( |
221 | reader => { |
b1ff395f |
222 | # NOTE: |
223 | # we just alias the original method |
224 | # rather than re-produce it here |
e3e651fb |
225 | 'namespace' => \&Class::MOP::Package::namespace |
b1ff395f |
226 | }, |
e3e651fb |
227 | init_arg => undef, |
228 | default => sub { \undef } |
b1ff395f |
229 | )) |
230 | ); |
231 | |
f0480c45 |
232 | ## -------------------------------------------------------- |
233 | ## Class::MOP::Module |
234 | |
235 | # NOTE: |
1d68af04 |
236 | # yeah this is kind of stretching things a bit, |
f0480c45 |
237 | # but truthfully the version should be an attribute |
1d68af04 |
238 | # of the Module, the weirdness comes from having to |
239 | # stick to Perl 5 convention and store it in the |
240 | # $VERSION package variable. Basically if you just |
241 | # squint at it, it will look how you want it to look. |
f0480c45 |
242 | # Either as a package variable, or as a attribute of |
243 | # the metaclass, isn't abstraction great :) |
244 | |
245 | Class::MOP::Module->meta->add_attribute( |
8683db0e |
246 | Class::MOP::Attribute->new('version' => ( |
f0480c45 |
247 | reader => { |
ce2ae40f |
248 | # NOTE: |
249 | # we just alias the original method |
1d68af04 |
250 | # rather than re-produce it here |
ce2ae40f |
251 | 'version' => \&Class::MOP::Module::version |
f0480c45 |
252 | }, |
2e877f58 |
253 | init_arg => undef, |
c4260b45 |
254 | default => sub { \undef } |
f0480c45 |
255 | )) |
256 | ); |
257 | |
258 | # NOTE: |
1d68af04 |
259 | # By following the same conventions as version here, |
260 | # we are opening up the possibility that people can |
261 | # use the $AUTHORITY in non-Class::MOP modules as |
262 | # well. |
f0480c45 |
263 | |
264 | Class::MOP::Module->meta->add_attribute( |
8683db0e |
265 | Class::MOP::Attribute->new('authority' => ( |
f0480c45 |
266 | reader => { |
ce2ae40f |
267 | # NOTE: |
268 | # we just alias the original method |
1d68af04 |
269 | # rather than re-produce it here |
ce2ae40f |
270 | 'authority' => \&Class::MOP::Module::authority |
1d68af04 |
271 | }, |
2e877f58 |
272 | init_arg => undef, |
c4260b45 |
273 | default => sub { \undef } |
f0480c45 |
274 | )) |
275 | ); |
276 | |
277 | ## -------------------------------------------------------- |
6d5355c3 |
278 | ## Class::MOP::Class |
279 | |
727919c5 |
280 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
281 | Class::MOP::Attribute->new('attributes' => ( |
f7259199 |
282 | reader => { |
1d68af04 |
283 | # NOTE: we need to do this in order |
284 | # for the instance meta-object to |
285 | # not fall into meta-circular death |
286 | # |
ce2ae40f |
287 | # we just alias the original method |
1d68af04 |
288 | # rather than re-produce it here |
b1aaf0dc |
289 | '_attribute_map' => \&Class::MOP::Class::_attribute_map |
f7259199 |
290 | }, |
727919c5 |
291 | default => sub { {} } |
292 | )) |
293 | ); |
294 | |
351bd7d4 |
295 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
296 | Class::MOP::Attribute->new('superclasses' => ( |
c23184fc |
297 | accessor => { |
298 | # NOTE: |
299 | # we just alias the original method |
1d68af04 |
300 | # rather than re-produce it here |
c23184fc |
301 | 'superclasses' => \&Class::MOP::Class::superclasses |
302 | }, |
2e877f58 |
303 | init_arg => undef, |
c23184fc |
304 | default => sub { \undef } |
305 | )) |
306 | ); |
307 | |
308 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
309 | Class::MOP::Attribute->new('attribute_metaclass' => ( |
1d68af04 |
310 | reader => { |
6d2118a4 |
311 | # NOTE: |
312 | # we just alias the original method |
1d68af04 |
313 | # rather than re-produce it here |
6d2118a4 |
314 | 'attribute_metaclass' => \&Class::MOP::Class::attribute_metaclass |
1d68af04 |
315 | }, |
351bd7d4 |
316 | default => 'Class::MOP::Attribute', |
317 | )) |
318 | ); |
319 | |
320 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
321 | Class::MOP::Attribute->new('instance_metaclass' => ( |
b880e0de |
322 | reader => { |
1d68af04 |
323 | # NOTE: we need to do this in order |
324 | # for the instance meta-object to |
325 | # not fall into meta-circular death |
326 | # |
ce2ae40f |
327 | # we just alias the original method |
1d68af04 |
328 | # rather than re-produce it here |
ce2ae40f |
329 | 'instance_metaclass' => \&Class::MOP::Class::instance_metaclass |
b880e0de |
330 | }, |
1d68af04 |
331 | default => 'Class::MOP::Instance', |
2bab2be6 |
332 | )) |
333 | ); |
334 | |
44d6ea77 |
335 | Class::MOP::Class->meta->add_attribute( |
f5d08022 |
336 | Class::MOP::Attribute->new('immutable_trait' => ( |
337 | reader => { |
338 | 'immutable_trait' => \&Class::MOP::Class::immutable_trait |
339 | }, |
340 | default => "Class::MOP::Class::Immutable::Trait", |
341 | )) |
342 | ); |
343 | |
344 | Class::MOP::Class->meta->add_attribute( |
345 | Class::MOP::Attribute->new('constructor_name' => ( |
44d6ea77 |
346 | reader => { |
f5d08022 |
347 | 'constructor_name' => \&Class::MOP::Class::constructor_name, |
44d6ea77 |
348 | }, |
f5d08022 |
349 | default => "new", |
350 | )) |
351 | ); |
352 | |
353 | Class::MOP::Class->meta->add_attribute( |
354 | Class::MOP::Attribute->new('constructor_class' => ( |
44d6ea77 |
355 | reader => { |
f5d08022 |
356 | 'constructor_class' => \&Class::MOP::Class::constructor_class, |
44d6ea77 |
357 | }, |
f5d08022 |
358 | default => "Class::MOP::Method::Constructor", |
359 | )) |
360 | ); |
361 | |
362 | |
363 | Class::MOP::Class->meta->add_attribute( |
364 | Class::MOP::Attribute->new('destructor_class' => ( |
365 | reader => { |
366 | 'destructor_class' => \&Class::MOP::Class::destructor_class, |
44d6ea77 |
367 | }, |
368 | )) |
369 | ); |
370 | |
9d6dce77 |
371 | # NOTE: |
1d68af04 |
372 | # we don't actually need to tie the knot with |
373 | # Class::MOP::Class here, it is actually handled |
374 | # within Class::MOP::Class itself in the |
c2b256bc |
375 | # _construct_class_instance method. |
9d6dce77 |
376 | |
f0480c45 |
377 | ## -------------------------------------------------------- |
727919c5 |
378 | ## Class::MOP::Attribute |
379 | |
7b31baf4 |
380 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
381 | Class::MOP::Attribute->new('name' => ( |
c23184fc |
382 | reader => { |
1d68af04 |
383 | # NOTE: we need to do this in order |
384 | # for the instance meta-object to |
385 | # not fall into meta-circular death |
386 | # |
ce2ae40f |
387 | # we just alias the original method |
1d68af04 |
388 | # rather than re-produce it here |
ce2ae40f |
389 | 'name' => \&Class::MOP::Attribute::name |
b880e0de |
390 | } |
7b31baf4 |
391 | )) |
392 | ); |
393 | |
394 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
395 | Class::MOP::Attribute->new('associated_class' => ( |
c23184fc |
396 | reader => { |
1d68af04 |
397 | # NOTE: we need to do this in order |
398 | # for the instance meta-object to |
399 | # not fall into meta-circular death |
400 | # |
ce2ae40f |
401 | # we just alias the original method |
1d68af04 |
402 | # rather than re-produce it here |
ce2ae40f |
403 | 'associated_class' => \&Class::MOP::Attribute::associated_class |
b880e0de |
404 | } |
7b31baf4 |
405 | )) |
406 | ); |
407 | |
408 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
409 | Class::MOP::Attribute->new('accessor' => ( |
6d2118a4 |
410 | reader => { 'accessor' => \&Class::MOP::Attribute::accessor }, |
411 | predicate => { 'has_accessor' => \&Class::MOP::Attribute::has_accessor }, |
7b31baf4 |
412 | )) |
413 | ); |
414 | |
415 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
416 | Class::MOP::Attribute->new('reader' => ( |
6d2118a4 |
417 | reader => { 'reader' => \&Class::MOP::Attribute::reader }, |
418 | predicate => { 'has_reader' => \&Class::MOP::Attribute::has_reader }, |
7b31baf4 |
419 | )) |
420 | ); |
421 | |
422 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
423 | Class::MOP::Attribute->new('initializer' => ( |
8ee74136 |
424 | reader => { 'initializer' => \&Class::MOP::Attribute::initializer }, |
425 | predicate => { 'has_initializer' => \&Class::MOP::Attribute::has_initializer }, |
0ab65f99 |
426 | )) |
427 | ); |
428 | |
429 | Class::MOP::Attribute->meta->add_attribute( |
d9d99689 |
430 | Class::MOP::Attribute->new('definition_context' => ( |
431 | reader => { 'definition_context' => \&Class::MOP::Attribute::definition_context }, |
432 | )) |
433 | ); |
434 | |
435 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
436 | Class::MOP::Attribute->new('writer' => ( |
6d2118a4 |
437 | reader => { 'writer' => \&Class::MOP::Attribute::writer }, |
438 | predicate => { 'has_writer' => \&Class::MOP::Attribute::has_writer }, |
7b31baf4 |
439 | )) |
440 | ); |
441 | |
442 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
443 | Class::MOP::Attribute->new('predicate' => ( |
6d2118a4 |
444 | reader => { 'predicate' => \&Class::MOP::Attribute::predicate }, |
445 | predicate => { 'has_predicate' => \&Class::MOP::Attribute::has_predicate }, |
7b31baf4 |
446 | )) |
447 | ); |
448 | |
449 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
450 | Class::MOP::Attribute->new('clearer' => ( |
6d2118a4 |
451 | reader => { 'clearer' => \&Class::MOP::Attribute::clearer }, |
452 | predicate => { 'has_clearer' => \&Class::MOP::Attribute::has_clearer }, |
7d28758b |
453 | )) |
454 | ); |
455 | |
456 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
457 | Class::MOP::Attribute->new('builder' => ( |
1d68af04 |
458 | reader => { 'builder' => \&Class::MOP::Attribute::builder }, |
459 | predicate => { 'has_builder' => \&Class::MOP::Attribute::has_builder }, |
460 | )) |
461 | ); |
462 | |
463 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
464 | Class::MOP::Attribute->new('init_arg' => ( |
6d2118a4 |
465 | reader => { 'init_arg' => \&Class::MOP::Attribute::init_arg }, |
466 | predicate => { 'has_init_arg' => \&Class::MOP::Attribute::has_init_arg }, |
7b31baf4 |
467 | )) |
468 | ); |
469 | |
470 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
471 | Class::MOP::Attribute->new('default' => ( |
7b31baf4 |
472 | # default has a custom 'reader' method ... |
1d68af04 |
473 | predicate => { 'has_default' => \&Class::MOP::Attribute::has_default }, |
7b31baf4 |
474 | )) |
475 | ); |
476 | |
3545c727 |
477 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
478 | Class::MOP::Attribute->new('associated_methods' => ( |
c23184fc |
479 | reader => { 'associated_methods' => \&Class::MOP::Attribute::associated_methods }, |
1d68af04 |
480 | default => sub { [] } |
3545c727 |
481 | )) |
482 | ); |
727919c5 |
483 | |
95b67145 |
484 | Class::MOP::Attribute->meta->add_attribute( |
485 | Class::MOP::Attribute->new('insertion_order' => ( |
486 | reader => { 'insertion_order' => \&Class::MOP::Attribute::insertion_order }, |
943cbe2d |
487 | writer => { '_set_insertion_order' => \&Class::MOP::Attribute::_set_insertion_order }, |
95b67145 |
488 | predicate => { 'has_insertion_order' => \&Class::MOP::Attribute::has_insertion_order }, |
489 | )) |
490 | ); |
491 | |
5659d76e |
492 | Class::MOP::Attribute->meta->add_method('clone' => sub { |
a740253a |
493 | my $self = shift; |
1d68af04 |
494 | $self->meta->clone_object($self, @_); |
727919c5 |
495 | }); |
496 | |
f0480c45 |
497 | ## -------------------------------------------------------- |
b6164407 |
498 | ## Class::MOP::Method |
b6164407 |
499 | Class::MOP::Method->meta->add_attribute( |
8683db0e |
500 | Class::MOP::Attribute->new('body' => ( |
c23184fc |
501 | reader => { 'body' => \&Class::MOP::Method::body }, |
b6164407 |
502 | )) |
503 | ); |
504 | |
4c105333 |
505 | Class::MOP::Method->meta->add_attribute( |
5e607260 |
506 | Class::MOP::Attribute->new('associated_metaclass' => ( |
5e607260 |
507 | reader => { 'associated_metaclass' => \&Class::MOP::Method::associated_metaclass }, |
508 | )) |
509 | ); |
510 | |
511 | Class::MOP::Method->meta->add_attribute( |
8683db0e |
512 | Class::MOP::Attribute->new('package_name' => ( |
4c105333 |
513 | reader => { 'package_name' => \&Class::MOP::Method::package_name }, |
514 | )) |
515 | ); |
516 | |
517 | Class::MOP::Method->meta->add_attribute( |
8683db0e |
518 | Class::MOP::Attribute->new('name' => ( |
4c105333 |
519 | reader => { 'name' => \&Class::MOP::Method::name }, |
520 | )) |
521 | ); |
522 | |
2226a8b0 |
523 | Class::MOP::Method->meta->add_attribute( |
524 | Class::MOP::Attribute->new('original_method' => ( |
525 | reader => { 'original_method' => \&Class::MOP::Method::original_method }, |
526 | writer => { '_set_original_method' => \&Class::MOP::Method::_set_original_method }, |
527 | )) |
528 | ); |
529 | |
4c105333 |
530 | Class::MOP::Method->meta->add_method('clone' => sub { |
531 | my $self = shift; |
2226a8b0 |
532 | my $clone = $self->meta->clone_object($self, @_); |
533 | $clone->_set_original_method($self); |
534 | return $clone; |
4c105333 |
535 | }); |
536 | |
b6164407 |
537 | ## -------------------------------------------------------- |
538 | ## Class::MOP::Method::Wrapped |
539 | |
540 | # NOTE: |
1d68af04 |
541 | # the way this item is initialized, this |
542 | # really does not follow the standard |
543 | # practices of attributes, but we put |
b6164407 |
544 | # it here for completeness |
545 | Class::MOP::Method::Wrapped->meta->add_attribute( |
8683db0e |
546 | Class::MOP::Attribute->new('modifier_table') |
b6164407 |
547 | ); |
548 | |
549 | ## -------------------------------------------------------- |
565f0cbb |
550 | ## Class::MOP::Method::Generated |
551 | |
552 | Class::MOP::Method::Generated->meta->add_attribute( |
8683db0e |
553 | Class::MOP::Attribute->new('is_inline' => ( |
565f0cbb |
554 | reader => { 'is_inline' => \&Class::MOP::Method::Generated::is_inline }, |
4c105333 |
555 | default => 0, |
1d68af04 |
556 | )) |
565f0cbb |
557 | ); |
558 | |
d9d99689 |
559 | Class::MOP::Method::Generated->meta->add_attribute( |
560 | Class::MOP::Attribute->new('definition_context' => ( |
561 | reader => { 'definition_context' => \&Class::MOP::Method::Generated::definition_context }, |
562 | )) |
563 | ); |
564 | |
29d4e92a |
565 | |
566 | ## -------------------------------------------------------- |
567 | ## Class::MOP::Method::Inlined |
568 | |
569 | Class::MOP::Method::Inlined->meta->add_attribute( |
570 | Class::MOP::Attribute->new('_expected_method_class' => ( |
571 | reader => { '_expected_method_class' => \&Class::MOP::Method::Inlined::_expected_method_class }, |
572 | )) |
573 | ); |
574 | |
565f0cbb |
575 | ## -------------------------------------------------------- |
d90b42a6 |
576 | ## Class::MOP::Method::Accessor |
577 | |
578 | Class::MOP::Method::Accessor->meta->add_attribute( |
8683db0e |
579 | Class::MOP::Attribute->new('attribute' => ( |
1d68af04 |
580 | reader => { |
581 | 'associated_attribute' => \&Class::MOP::Method::Accessor::associated_attribute |
d90b42a6 |
582 | }, |
1d68af04 |
583 | )) |
d90b42a6 |
584 | ); |
585 | |
586 | Class::MOP::Method::Accessor->meta->add_attribute( |
8683db0e |
587 | Class::MOP::Attribute->new('accessor_type' => ( |
c23184fc |
588 | reader => { 'accessor_type' => \&Class::MOP::Method::Accessor::accessor_type }, |
1d68af04 |
589 | )) |
d90b42a6 |
590 | ); |
591 | |
d90b42a6 |
592 | ## -------------------------------------------------------- |
593 | ## Class::MOP::Method::Constructor |
594 | |
595 | Class::MOP::Method::Constructor->meta->add_attribute( |
8683db0e |
596 | Class::MOP::Attribute->new('options' => ( |
1d68af04 |
597 | reader => { |
598 | 'options' => \&Class::MOP::Method::Constructor::options |
d90b42a6 |
599 | }, |
4c105333 |
600 | default => sub { +{} } |
1d68af04 |
601 | )) |
d90b42a6 |
602 | ); |
603 | |
604 | Class::MOP::Method::Constructor->meta->add_attribute( |
8683db0e |
605 | Class::MOP::Attribute->new('associated_metaclass' => ( |
e8a38403 |
606 | init_arg => "metaclass", # FIXME alias and rename |
1d68af04 |
607 | reader => { |
608 | 'associated_metaclass' => \&Class::MOP::Method::Constructor::associated_metaclass |
609 | }, |
610 | )) |
d90b42a6 |
611 | ); |
612 | |
613 | ## -------------------------------------------------------- |
86482605 |
614 | ## Class::MOP::Instance |
615 | |
616 | # NOTE: |
1d68af04 |
617 | # these don't yet do much of anything, but are just |
86482605 |
618 | # included for completeness |
619 | |
620 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
621 | Class::MOP::Attribute->new('associated_metaclass', |
622 | reader => { associated_metaclass => \&Class::MOP::Instance::associated_metaclass }, |
623 | ), |
86482605 |
624 | ); |
625 | |
626 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
627 | Class::MOP::Attribute->new('_class_name', |
628 | init_arg => undef, |
629 | reader => { _class_name => \&Class::MOP::Instance::_class_name }, |
630 | #lazy => 1, # not yet supported by Class::MOP but out our version does it anyway |
631 | #default => sub { $_[0]->associated_metaclass->name }, |
632 | ), |
633 | ); |
634 | |
635 | Class::MOP::Instance->meta->add_attribute( |
636 | Class::MOP::Attribute->new('attributes', |
0b5d46da |
637 | reader => { attributes => \&Class::MOP::Instance::get_all_attributes }, |
74890687 |
638 | ), |
32bfc810 |
639 | ); |
640 | |
641 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
642 | Class::MOP::Attribute->new('slots', |
643 | reader => { slots => \&Class::MOP::Instance::slots }, |
644 | ), |
86482605 |
645 | ); |
646 | |
63d08a9e |
647 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
648 | Class::MOP::Attribute->new('slot_hash', |
649 | reader => { slot_hash => \&Class::MOP::Instance::slot_hash }, |
650 | ), |
63d08a9e |
651 | ); |
652 | |
30229767 |
653 | require Class::MOP::Deprecated unless our $no_deprecated; |
63d08a9e |
654 | |
caa051fa |
655 | # we need the meta instance of the meta instance to be created now, in order |
656 | # for the constructor to be able to use it |
657 | Class::MOP::Instance->meta->get_meta_instance; |
658 | |
caa051fa |
659 | # pretend the add_method never happenned. it hasn't yet affected anything |
660 | undef Class::MOP::Instance->meta->{_package_cache_flag}; |
661 | |
86482605 |
662 | ## -------------------------------------------------------- |
f0480c45 |
663 | ## Now close all the Class::MOP::* classes |
4d47b77f |
664 | |
1aa13cf4 |
665 | # NOTE: we don't need to inline the the accessors this only lengthens |
666 | # the compile time of the MOP, and gives us no actual benefits. |
0b9372a2 |
667 | |
668 | $_->meta->make_immutable( |
ec9e38e5 |
669 | inline_constructor => 0, |
6c2f6b5c |
670 | constructor_name => "_new", |
45582002 |
671 | inline_accessors => 0, |
0b9372a2 |
672 | ) for qw/ |
1d68af04 |
673 | Class::MOP::Package |
674 | Class::MOP::Module |
675 | Class::MOP::Class |
676 | |
0b9372a2 |
677 | Class::MOP::Attribute |
1d68af04 |
678 | Class::MOP::Method |
679 | Class::MOP::Instance |
680 | |
681 | Class::MOP::Object |
0b9372a2 |
682 | |
565f0cbb |
683 | Class::MOP::Method::Generated |
29d4e92a |
684 | Class::MOP::Method::Inlined |
1d68af04 |
685 | |
ba38bf08 |
686 | Class::MOP::Method::Accessor |
1d68af04 |
687 | Class::MOP::Method::Constructor |
688 | Class::MOP::Method::Wrapped |
0b9372a2 |
689 | /; |
b6164407 |
690 | |
e3e651fb |
691 | $_->meta->make_immutable( |
692 | inline_constructor => 0, |
693 | constructor_name => undef, |
694 | inline_accessors => 0, |
695 | ) for qw/ |
696 | Class::MOP::HasMethods |
697 | /; |
698 | |
94b19069 |
699 | 1; |
700 | |
701 | __END__ |
702 | |
703 | =pod |
704 | |
1d68af04 |
705 | =head1 NAME |
94b19069 |
706 | |
707 | Class::MOP - A Meta Object Protocol for Perl 5 |
708 | |
5b60bf98 |
709 | =head1 DESCRIPTION |
94b19069 |
710 | |
127d39a7 |
711 | This module is a fully functioning meta object protocol for the |
1d68af04 |
712 | Perl 5 object system. It makes no attempt to change the behavior or |
713 | characteristics of the Perl 5 object system, only to create a |
27e31eaf |
714 | protocol for its manipulation and introspection. |
94b19069 |
715 | |
828ecf13 |
716 | That said, it does attempt to create the tools for building a rich set |
717 | of extensions to the Perl 5 object system. Every attempt has been made |
718 | to abide by the spirit of the Perl 5 object system that we all know |
719 | and love. |
94b19069 |
720 | |
828ecf13 |
721 | This documentation is sparse on conceptual details. We suggest looking |
722 | at the items listed in the L<SEE ALSO> section for more |
723 | information. In particular the book "The Art of the Meta Object |
724 | Protocol" was very influential in the development of this system. |
40483095 |
725 | |
bfe4d0fc |
726 | =head2 What is a Meta Object Protocol? |
727 | |
1d68af04 |
728 | A meta object protocol is an API to an object system. |
bfe4d0fc |
729 | |
828ecf13 |
730 | To be more specific, it abstracts the components of an object system |
731 | (classes, object, methods, object attributes, etc.). These |
732 | abstractions can then be used to inspect and manipulate the object |
733 | system which they describe. |
bfe4d0fc |
734 | |
1d68af04 |
735 | It can be said that there are two MOPs for any object system; the |
828ecf13 |
736 | implicit MOP and the explicit MOP. The implicit MOP handles things |
1d68af04 |
737 | like method dispatch or inheritance, which happen automatically as |
738 | part of how the object system works. The explicit MOP typically |
739 | handles the introspection/reflection features of the object system. |
bfe4d0fc |
740 | |
828ecf13 |
741 | All object systems have implicit MOPs. Without one, they would not |
5b60bf98 |
742 | work. Explicit MOPs are much less common, and depending on the |
743 | language can vary from restrictive (Reflection in Java or C#) to wide |
744 | open (CLOS is a perfect example). |
e16da3e6 |
745 | |
828ecf13 |
746 | =head2 Yet Another Class Builder! Why? |
747 | |
748 | This is B<not> a class builder so much as a I<class builder |
749 | B<builder>>. The intent is that an end user will not use this module |
750 | directly, but instead this module is used by module authors to build |
751 | extensions and features onto the Perl 5 object system. |
752 | |
753 | This system is used by L<Moose>, which supplies a powerful class |
754 | builder system built entirely on top of C<Class::MOP>. |
e16da3e6 |
755 | |
94b19069 |
756 | =head2 Who is this module for? |
757 | |
828ecf13 |
758 | This module is for anyone who has ever created or wanted to create a |
759 | module for the Class:: namespace. The tools which this module provides |
760 | make doing complex Perl 5 wizardry simpler, by removing such barriers |
761 | as the need to hack symbol tables, or understand the fine details of |
762 | method dispatch. |
94b19069 |
763 | |
bfe4d0fc |
764 | =head2 What changes do I have to make to use this module? |
765 | |
828ecf13 |
766 | This module was designed to be as unintrusive as possible. Many of its |
5b60bf98 |
767 | features are accessible without B<any> change to your existing |
828ecf13 |
768 | code. It is meant to be a compliment to your existing code and not an |
769 | intrusion on your code base. Unlike many other B<Class::> modules, |
770 | this module B<does not> require you subclass it, or even that you |
771 | C<use> it in within your module's package. |
bfe4d0fc |
772 | |
1d68af04 |
773 | The only features which requires additions to your code are the |
2eb717d5 |
774 | attribute handling and instance construction features, and these are |
1d68af04 |
775 | both completely optional features. The only reason for this is because |
776 | Perl 5's object system does not actually have these features built |
2eb717d5 |
777 | in. More information about this feature can be found below. |
bfe4d0fc |
778 | |
828ecf13 |
779 | =head2 About Performance |
780 | |
5b60bf98 |
781 | It is a common misconception that explicit MOPs are a performance hit. |
828ecf13 |
782 | This is not a universal truth, it is a side-effect of some specific |
783 | implementations. For instance, using Java reflection is slow because |
784 | the JVM cannot take advantage of any compiler optimizations, and the |
785 | JVM has to deal with much more runtime type information as well. |
bfe4d0fc |
786 | |
828ecf13 |
787 | Reflection in C# is marginally better as it was designed into the |
788 | language and runtime (the CLR). In contrast, CLOS (the Common Lisp |
789 | Object System) was built to support an explicit MOP, and so |
790 | performance is tuned for it. |
1d68af04 |
791 | |
828ecf13 |
792 | This library in particular does its absolute best to avoid putting |
1d68af04 |
793 | B<any> drain at all upon your code's performance. In fact, by itself |
828ecf13 |
794 | it does nothing to affect your existing code. So you only pay for what |
795 | you actually use. |
bfe4d0fc |
796 | |
550d56db |
797 | =head2 About Metaclass compatibility |
798 | |
1d68af04 |
799 | This module makes sure that all metaclasses created are both upwards |
800 | and downwards compatible. The topic of metaclass compatibility is |
801 | highly esoteric and is something only encountered when doing deep and |
802 | involved metaclass hacking. There are two basic kinds of metaclass |
803 | incompatibility; upwards and downwards. |
550d56db |
804 | |
1d68af04 |
805 | Upwards metaclass compatibility means that the metaclass of a |
806 | given class is either the same as (or a subclass of) all of the |
550d56db |
807 | class's ancestors. |
808 | |
1d68af04 |
809 | Downward metaclass compatibility means that the metaclasses of a |
828ecf13 |
810 | given class's ancestors are all either the same as (or a subclass |
550d56db |
811 | of) that metaclass. |
812 | |
1d68af04 |
813 | Here is a diagram showing a set of two classes (C<A> and C<B>) and |
814 | two metaclasses (C<Meta::A> and C<Meta::B>) which have correct |
550d56db |
815 | metaclass compatibility both upwards and downwards. |
816 | |
817 | +---------+ +---------+ |
818 | | Meta::A |<----| Meta::B | <....... (instance of ) |
1d68af04 |
819 | +---------+ +---------+ <------- (inherits from) |
550d56db |
820 | ^ ^ |
821 | : : |
822 | +---------+ +---------+ |
823 | | A |<----| B | |
824 | +---------+ +---------+ |
825 | |
1d68af04 |
826 | As I said this is a highly esoteric topic and one you will only run |
828ecf13 |
827 | into if you do a lot of subclassing of L<Class::MOP::Class>. If you |
828 | are interested in why this is an issue see the paper I<Uniform and |
829 | safe metaclass composition> linked to in the L<SEE ALSO> section of |
830 | this document. |
550d56db |
831 | |
aa448b16 |
832 | =head2 Using custom metaclasses |
833 | |
828ecf13 |
834 | Always use the L<metaclass> pragma when using a custom metaclass, this |
5b60bf98 |
835 | will ensure the proper initialization order and not accidentally |
836 | create an incorrect type of metaclass for you. This is a very rare |
837 | problem, and one which can only occur if you are doing deep metaclass |
aa448b16 |
838 | programming. So in other words, don't worry about it. |
839 | |
828ecf13 |
840 | Note that if you're using L<Moose> we encourage you to I<not> use |
841 | L<metaclass> pragma, and instead use L<Moose::Util::MetaRole> to apply |
842 | roles to a class's metaclasses. This topic is covered at length in |
843 | various L<Moose::Cookbook> recipes. |
844 | |
94b19069 |
845 | =head1 PROTOCOLS |
846 | |
828ecf13 |
847 | The meta-object protocol is divided into 4 main sub-protocols: |
94b19069 |
848 | |
828ecf13 |
849 | =head2 The Class protocol |
94b19069 |
850 | |
1d68af04 |
851 | This provides a means of manipulating and introspecting a Perl 5 |
828ecf13 |
852 | class. It handles symbol table hacking for you, and provides a rich |
853 | set of methods that go beyond simple package introspection. |
94b19069 |
854 | |
552e3d24 |
855 | See L<Class::MOP::Class> for more details. |
856 | |
828ecf13 |
857 | =head2 The Attribute protocol |
94b19069 |
858 | |
828ecf13 |
859 | This provides a consistent representation for an attribute of a Perl 5 |
860 | class. Since there are so many ways to create and handle attributes in |
861 | Perl 5 OO, the Attribute protocol provide as much of a unified |
862 | approach as possible. Of course, you are always free to extend this |
863 | protocol by subclassing the appropriate classes. |
94b19069 |
864 | |
552e3d24 |
865 | See L<Class::MOP::Attribute> for more details. |
866 | |
828ecf13 |
867 | =head2 The Method protocol |
94b19069 |
868 | |
828ecf13 |
869 | This provides a means of manipulating and introspecting methods in the |
870 | Perl 5 object system. As with attributes, there are many ways to |
1d68af04 |
871 | approach this topic, so we try to keep it pretty basic, while still |
94b19069 |
872 | making it possible to extend the system in many ways. |
873 | |
552e3d24 |
874 | See L<Class::MOP::Method> for more details. |
94b19069 |
875 | |
828ecf13 |
876 | =head2 The Instance protocol |
127d39a7 |
877 | |
828ecf13 |
878 | This provides a layer of abstraction for creating object instances. |
879 | Since the other layers use this protocol, it is relatively easy to |
880 | change the type of your instances from the default hash reference to |
881 | some other type of reference. Several examples are provided in the |
882 | F<examples/> directory included in this distribution. |
127d39a7 |
883 | |
884 | See L<Class::MOP::Instance> for more details. |
885 | |
be7677c7 |
886 | =head1 FUNCTIONS |
887 | |
828ecf13 |
888 | Note that this module does not export any constants or functions. |
889 | |
c1d5345a |
890 | =head2 Constants |
891 | |
892 | =over 4 |
893 | |
828ecf13 |
894 | =item I<Class::MOP::IS_RUNNING_ON_5_10> |
c1d5345a |
895 | |
828ecf13 |
896 | We set this constant depending on what version perl we are on, this |
897 | allows us to take advantage of new 5.10 features and stay backwards |
5b60bf98 |
898 | compatible. |
c1d5345a |
899 | |
900 | =back |
901 | |
448b6e55 |
902 | =head2 Utility functions |
903 | |
bd07fbdb |
904 | Note that these are all called as B<functions, not methods>. |
081a927b |
905 | |
448b6e55 |
906 | =over 4 |
907 | |
828ecf13 |
908 | =item B<Class::MOP::load_class($class_name)> |
448b6e55 |
909 | |
9d441c23 |
910 | This will load the specified C<$class_name>, if it is not already |
911 | loaded (as reported by C<is_class_loaded>). This function can be used |
828ecf13 |
912 | in place of tricks like C<eval "use $module"> or using C<require> |
7716a8f9 |
913 | unconditionally. |
448b6e55 |
914 | |
674d9359 |
915 | If the module cannot be loaded, an exception is thrown. |
916 | |
78527c84 |
917 | For historical reasons, this function explicitly returns a true value. |
674d9359 |
918 | |
828ecf13 |
919 | =item B<Class::MOP::is_class_loaded($class_name)> |
448b6e55 |
920 | |
15ab5451 |
921 | Returns a boolean indicating whether or not C<$class_name> has been |
922 | loaded. |
448b6e55 |
923 | |
828ecf13 |
924 | This does a basic check of the symbol table to try and determine as |
925 | best it can if the C<$class_name> is loaded, it is probably correct |
926 | about 99% of the time, but it can be fooled into reporting false |
9d441c23 |
927 | positives. In particular, loading any of the core L<IO> modules will |
928 | cause most of the rest of the core L<IO> modules to falsely report |
929 | having been loaded, due to the way the base L<IO> module works. |
448b6e55 |
930 | |
cdac22cc |
931 | =item B<Class::MOP::get_code_info($code)> |
932 | |
933 | This function returns two values, the name of the package the C<$code> |
934 | is from and the name of the C<$code> itself. This is used by several |
5b60bf98 |
935 | elements of the MOP to determine where a given C<$code> reference is |
cdac22cc |
936 | from. |
937 | |
44ba77a3 |
938 | =item B<Class::MOP::class_of($instance_or_class_name)> |
939 | |
3fa5b3f9 |
940 | This will return the metaclass of the given instance or class name. If the |
941 | class lacks a metaclass, no metaclass will be initialized, and C<undef> will be |
942 | returned. |
44ba77a3 |
943 | |
828ecf13 |
944 | =item B<Class::MOP::check_package_cache_flag($pkg)> |
e0e4674a |
945 | |
bd07fbdb |
946 | B<NOTE: DO NOT USE THIS FUNCTION, IT IS FOR INTERNAL USE ONLY!> |
947 | |
828ecf13 |
948 | This will return an integer that is managed by L<Class::MOP::Class> to |
949 | determine if a module's symbol table has been altered. |
127d39a7 |
950 | |
828ecf13 |
951 | In Perl 5.10 or greater, this flag is package specific. However in |
952 | versions prior to 5.10, this will use the C<PL_sub_generation> |
953 | variable which is not package specific. |
127d39a7 |
954 | |
828ecf13 |
955 | =item B<Class::MOP::load_first_existing_class(@class_names)> |
063ad0c5 |
956 | |
957 | B<NOTE: DO NOT USE THIS FUNCTION, IT IS FOR INTERNAL USE ONLY!> |
958 | |
959 | Given a list of class names, this function will attempt to load each |
960 | one in turn. |
961 | |
828ecf13 |
962 | If it finds a class it can load, it will return that class' name. If |
963 | none of the classes can be loaded, it will throw an exception. |
063ad0c5 |
964 | |
448b6e55 |
965 | =back |
966 | |
967 | =head2 Metaclass cache functions |
968 | |
6c842677 |
969 | Class::MOP holds a cache of metaclasses. The following are functions |
1d68af04 |
970 | (B<not methods>) which can be used to access that cache. It is not |
6c842677 |
971 | recommended that you mess with these. Bad things could happen, but if |
972 | you are brave and willing to risk it: go for it! |
be7677c7 |
973 | |
974 | =over 4 |
975 | |
828ecf13 |
976 | =item B<Class::MOP::get_all_metaclasses> |
be7677c7 |
977 | |
6c842677 |
978 | This will return a hash of all the metaclass instances that have |
828ecf13 |
979 | been cached by L<Class::MOP::Class>, keyed by the package name. |
b9d9fc0b |
980 | |
828ecf13 |
981 | =item B<Class::MOP::get_all_metaclass_instances> |
be7677c7 |
982 | |
6c842677 |
983 | This will return a list of all the metaclass instances that have |
828ecf13 |
984 | been cached by L<Class::MOP::Class>. |
b9d9fc0b |
985 | |
828ecf13 |
986 | =item B<Class::MOP::get_all_metaclass_names> |
be7677c7 |
987 | |
6c842677 |
988 | This will return a list of all the metaclass names that have |
828ecf13 |
989 | been cached by L<Class::MOP::Class>. |
b9d9fc0b |
990 | |
828ecf13 |
991 | =item B<Class::MOP::get_metaclass_by_name($name)> |
be7677c7 |
992 | |
828ecf13 |
993 | This will return a cached L<Class::MOP::Class> instance, or nothing |
6c842677 |
994 | if no metaclass exists with that C<$name>. |
127d39a7 |
995 | |
828ecf13 |
996 | =item B<Class::MOP::store_metaclass_by_name($name, $meta)> |
be7677c7 |
997 | |
127d39a7 |
998 | This will store a metaclass in the cache at the supplied C<$key>. |
999 | |
828ecf13 |
1000 | =item B<Class::MOP::weaken_metaclass($name)> |
be7677c7 |
1001 | |
6c842677 |
1002 | In rare cases (e.g. anonymous metaclasses) it is desirable to |
1003 | store a weakened reference in the metaclass cache. This |
1004 | function will weaken the reference to the metaclass stored |
1005 | in C<$name>. |
127d39a7 |
1006 | |
828ecf13 |
1007 | =item B<Class::MOP::does_metaclass_exist($name)> |
be7677c7 |
1008 | |
828ecf13 |
1009 | This will return true of there exists a metaclass stored in the |
6c842677 |
1010 | C<$name> key, and return false otherwise. |
127d39a7 |
1011 | |
828ecf13 |
1012 | =item B<Class::MOP::remove_metaclass_by_name($name)> |
be7677c7 |
1013 | |
6c842677 |
1014 | This will remove the metaclass stored in the C<$name> key. |
127d39a7 |
1015 | |
be7677c7 |
1016 | =back |
1017 | |
552e3d24 |
1018 | =head1 SEE ALSO |
8b978dd5 |
1019 | |
552e3d24 |
1020 | =head2 Books |
8b978dd5 |
1021 | |
1d68af04 |
1022 | There are very few books out on Meta Object Protocols and Metaclasses |
1023 | because it is such an esoteric topic. The following books are really |
1024 | the only ones I have found. If you know of any more, B<I<please>> |
a2e85e6c |
1025 | email me and let me know, I would love to hear about them. |
1026 | |
8b978dd5 |
1027 | =over 4 |
1028 | |
15ab5451 |
1029 | =item I<The Art of the Meta Object Protocol> |
8b978dd5 |
1030 | |
15ab5451 |
1031 | =item I<Advances in Object-Oriented Metalevel Architecture and Reflection> |
8b978dd5 |
1032 | |
15ab5451 |
1033 | =item I<Putting MetaClasses to Work> |
b51af7f9 |
1034 | |
15ab5451 |
1035 | =item I<Smalltalk: The Language> |
a2e85e6c |
1036 | |
94b19069 |
1037 | =back |
1038 | |
550d56db |
1039 | =head2 Papers |
1040 | |
1041 | =over 4 |
1042 | |
15ab5451 |
1043 | =item "Uniform and safe metaclass composition" |
550d56db |
1044 | |
1d68af04 |
1045 | An excellent paper by the people who brought us the original Traits paper. |
1046 | This paper is on how Traits can be used to do safe metaclass composition, |
1047 | and offers an excellent introduction section which delves into the topic of |
550d56db |
1048 | metaclass compatibility. |
1049 | |
1050 | L<http://www.iam.unibe.ch/~scg/Archive/Papers/Duca05ySafeMetaclassTrait.pdf> |
1051 | |
15ab5451 |
1052 | =item "Safe Metaclass Programming" |
550d56db |
1053 | |
1d68af04 |
1054 | This paper seems to precede the above paper, and propose a mix-in based |
1055 | approach as opposed to the Traits based approach. Both papers have similar |
1056 | information on the metaclass compatibility problem space. |
550d56db |
1057 | |
1058 | L<http://citeseer.ist.psu.edu/37617.html> |
1059 | |
1060 | =back |
1061 | |
552e3d24 |
1062 | =head2 Prior Art |
8b978dd5 |
1063 | |
1064 | =over 4 |
1065 | |
7184ca14 |
1066 | =item The Perl 6 MetaModel work in the Pugs project |
8b978dd5 |
1067 | |
1068 | =over 4 |
1069 | |
02615ef0 |
1070 | =item L<http://svn.openfoundry.org/pugs/misc/Perl-MetaModel/> |
8b978dd5 |
1071 | |
552e3d24 |
1072 | =item L<http://svn.openfoundry.org/pugs/perl5/Perl6-ObjectSpace> |
8b978dd5 |
1073 | |
1074 | =back |
1075 | |
94b19069 |
1076 | =back |
1077 | |
1d68af04 |
1078 | =head2 Articles |
f8dfcfb7 |
1079 | |
1080 | =over 4 |
1081 | |
1d68af04 |
1082 | =item CPAN Module Review of Class::MOP |
f8dfcfb7 |
1083 | |
1084 | L<http://www.oreillynet.com/onlamp/blog/2006/06/cpan_module_review_classmop.html> |
1085 | |
1086 | =back |
1087 | |
a2e85e6c |
1088 | =head1 SIMILAR MODULES |
1089 | |
1d68af04 |
1090 | As I have said above, this module is a class-builder-builder, so it is |
1091 | not the same thing as modules like L<Class::Accessor> and |
1092 | L<Class::MethodMaker>. That being said there are very few modules on CPAN |
1093 | with similar goals to this module. The one I have found which is most |
1094 | like this module is L<Class::Meta>, although it's philosophy and the MOP it |
1095 | creates are very different from this modules. |
94b19069 |
1096 | |
a2e85e6c |
1097 | =head1 BUGS |
1098 | |
1d68af04 |
1099 | All complex software has bugs lurking in it, and this module is no |
53702399 |
1100 | exception. |
1101 | |
1102 | Please report any bugs to C<bug-class-mop@rt.cpan.org>, or through the |
1103 | web interface at L<http://rt.cpan.org>. |
1104 | |
1105 | You can also discuss feature requests or possible bugs on the Moose |
1106 | mailing list (moose@perl.org) or on IRC at |
1107 | L<irc://irc.perl.org/#moose>. |
a2e85e6c |
1108 | |
1109 | =head1 ACKNOWLEDGEMENTS |
1110 | |
1111 | =over 4 |
1112 | |
b9d9fc0b |
1113 | =item Rob Kinyon |
a2e85e6c |
1114 | |
1d68af04 |
1115 | Thanks to Rob for actually getting the development of this module kick-started. |
a2e85e6c |
1116 | |
1117 | =back |
1118 | |
1a09d9cc |
1119 | =head1 AUTHORS |
94b19069 |
1120 | |
a2e85e6c |
1121 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
552e3d24 |
1122 | |
9c8cda90 |
1123 | B<with contributions from:> |
1124 | |
1125 | Brandon (blblack) Black |
1126 | |
4f116037 |
1127 | Florian (rafl) Ragwitz |
1128 | |
9c8cda90 |
1129 | Guillermo (groditi) Roditi |
1130 | |
53702399 |
1131 | Dave (autarch) Rolsky |
1132 | |
9195ddff |
1133 | Matt (mst) Trout |
1134 | |
9c8cda90 |
1135 | Rob (robkinyon) Kinyon |
1136 | |
1137 | Yuval (nothingmuch) Kogman |
1a09d9cc |
1138 | |
f430cfa4 |
1139 | Scott (konobi) McWhirter |
1140 | |
20f5ccef |
1141 | Dylan Hardison |
1142 | |
94b19069 |
1143 | =head1 COPYRIGHT AND LICENSE |
1144 | |
070bb6c9 |
1145 | Copyright 2006-2009 by Infinity Interactive, Inc. |
94b19069 |
1146 | |
1147 | L<http://www.iinteractive.com> |
1148 | |
1149 | This library is free software; you can redistribute it and/or modify |
1d68af04 |
1150 | it under the same terms as Perl itself. |
94b19069 |
1151 | |
1152 | =cut |