Commit | Line | Data |
94b19069 |
1 | |
2 | package Class::MOP; |
3 | |
4 | use strict; |
5 | use warnings; |
6 | |
3cf322a0 |
7 | use MRO::Compat; |
8 | |
4c105333 |
9 | use Carp 'confess'; |
10 | use Scalar::Util 'weaken'; |
8b978dd5 |
11 | |
b1f5f41d |
12 | BEGIN { |
70ad0655 |
13 | |
2e5c1a3f |
14 | our $VERSION = '0.65'; |
b1f5f41d |
15 | our $AUTHORITY = 'cpan:STEVAN'; |
16 | |
11b56828 |
17 | *IS_RUNNING_ON_5_10 = ($] < 5.009_005) |
18 | ? sub () { 0 } |
4c105333 |
19 | : sub () { 1 }; |
46b23b44 |
20 | |
9efe16ca |
21 | *HAVE_ISAREV = defined(&mro::get_isarev) |
22 | ? sub () { 1 } |
23 | : sub () { 1 }; |
24 | |
4c105333 |
25 | # NOTE: |
26 | # we may not use this yet, but once |
27 | # the get_code_info XS gets merged |
28 | # upstream to it, we will always use |
29 | # it. But for now it is just kinda |
30 | # extra overhead. |
31 | # - SL |
32 | require Sub::Identify; |
33 | |
34 | # stash these for a sec, and see how things go |
35 | my $_PP_subname = sub { $_[1] }; |
a982eca7 |
36 | my $_PP_get_code_info = \&Sub::Identify::get_code_info; |
4c105333 |
37 | |
e2d4fc55 |
38 | if ($ENV{CLASS_MOP_NO_XS}) { |
4c105333 |
39 | # NOTE: |
40 | # this is if you really want things |
41 | # to be slow, then you can force the |
42 | # no-XS rule this way, otherwise we |
43 | # make an effort to load as much of |
44 | # the XS as possible. |
45 | # - SL |
46 | no warnings 'prototype', 'redefine'; |
6c34db07 |
47 | |
3c489bcb |
48 | # this is either part of core or set up appropriately by MRO::Compat |
49 | *check_package_cache_flag = \&mro::get_pkg_gen; |
50 | |
4c105333 |
51 | # our own version of Sub::Name |
52 | *subname = $_PP_subname; |
53 | # and the Sub::Identify version of the get_code_info |
54 | *get_code_info = $_PP_get_code_info; |
55 | } |
56 | else { |
57 | # now try our best to get as much |
58 | # of the XS loaded as possible |
59 | { |
15273f3c |
60 | my $e = do { |
61 | local $@; |
62 | eval { |
63 | require XSLoader; |
64 | __PACKAGE__->XSLoader::load($VERSION); |
65 | }; |
66 | $@; |
4c105333 |
67 | }; |
15273f3c |
68 | |
69 | die $e if $e && $e !~ /object version|loadable object/; |
4c105333 |
70 | |
71 | # okay, so the XS failed to load, so |
72 | # use the pure perl one instead. |
15273f3c |
73 | *get_code_info = $_PP_get_code_info if $e; |
4c105333 |
74 | } |
75 | |
76 | # get it from MRO::Compat |
77 | *check_package_cache_flag = \&mro::get_pkg_gen; |
78 | |
79 | # now try and load the Sub::Name |
80 | # module and use that as a means |
81 | # for naming our CVs, if not, we |
82 | # use the workaround instead. |
1b8d9282 |
83 | local $@; |
4c105333 |
84 | if ( eval { require Sub::Name } ) { |
6c34db07 |
85 | *subname = \&Sub::Name::subname; |
4c105333 |
86 | } |
87 | else { |
88 | *subname = $_PP_subname; |
89 | } |
90 | } |
b1f5f41d |
91 | } |
e0e4674a |
92 | |
15273f3c |
93 | use Class::MOP::Class; |
94 | use Class::MOP::Attribute; |
95 | use Class::MOP::Method; |
96 | |
97 | use Class::MOP::Immutable; |
98 | |
be7677c7 |
99 | { |
100 | # Metaclasses are singletons, so we cache them here. |
101 | # there is no need to worry about destruction though |
102 | # because they should die only when the program dies. |
103 | # After all, do package definitions even get reaped? |
1d68af04 |
104 | my %METAS; |
105 | |
106 | # means of accessing all the metaclasses that have |
be7677c7 |
107 | # been initialized thus far (for mugwumps obj browser) |
1d68af04 |
108 | sub get_all_metaclasses { %METAS } |
109 | sub get_all_metaclass_instances { values %METAS } |
110 | sub get_all_metaclass_names { keys %METAS } |
be7677c7 |
111 | sub get_metaclass_by_name { $METAS{$_[0]} } |
1d68af04 |
112 | sub store_metaclass_by_name { $METAS{$_[0]} = $_[1] } |
113 | sub weaken_metaclass { weaken($METAS{$_[0]}) } |
be7677c7 |
114 | sub does_metaclass_exist { exists $METAS{$_[0]} && defined $METAS{$_[0]} } |
1d68af04 |
115 | sub remove_metaclass_by_name { $METAS{$_[0]} = undef } |
116 | |
be7677c7 |
117 | # NOTE: |
1d68af04 |
118 | # We only cache metaclasses, meaning instances of |
119 | # Class::MOP::Class. We do not cache instance of |
be7677c7 |
120 | # Class::MOP::Package or Class::MOP::Module. Mostly |
1d68af04 |
121 | # because I don't yet see a good reason to do so. |
be7677c7 |
122 | } |
123 | |
448b6e55 |
124 | sub load_class { |
125 | my $class = shift; |
ab5e2f48 |
126 | |
127 | if (ref($class) || !defined($class) || !length($class)) { |
128 | my $display = defined($class) ? $class : 'undef'; |
129 | confess "Invalid class name ($display)"; |
130 | } |
131 | |
07940968 |
132 | # if the class is not already loaded in the symbol table.. |
133 | unless (is_class_loaded($class)) { |
134 | # require it |
135 | my $file = $class . '.pm'; |
136 | $file =~ s{::}{/}g; |
1b8d9282 |
137 | my $e = do { local $@; eval { require($file) }; $@ }; |
138 | confess "Could not load class ($class) because : $e" if $e; |
07940968 |
139 | } |
140 | |
141 | # initialize a metaclass if necessary |
448b6e55 |
142 | unless (does_metaclass_exist($class)) { |
1b8d9282 |
143 | my $e = do { local $@; eval { Class::MOP::Class->initialize($class) }; $@ }; |
144 | confess "Could not initialize class ($class) because : $e" if $e; |
448b6e55 |
145 | } |
07940968 |
146 | |
1b8d9282 |
147 | return get_metaclass_by_name($class) if defined wantarray; |
448b6e55 |
148 | } |
149 | |
150 | sub is_class_loaded { |
c1d5345a |
151 | my $class = shift; |
26fcef27 |
152 | |
153 | return 0 if ref($class) || !defined($class) || !length($class); |
154 | |
155 | # walk the symbol table tree to avoid autovififying |
156 | # \*{${main::}{"Foo::"}} == \*main::Foo:: |
157 | |
158 | my $pack = \*::; |
159 | foreach my $part (split('::', $class)) { |
160 | return 0 unless exists ${$$pack}{"${part}::"}; |
161 | $pack = \*{${$$pack}{"${part}::"}}; |
c1d5345a |
162 | } |
26fcef27 |
163 | |
164 | # check for $VERSION or @ISA |
165 | return 1 if exists ${$$pack}{VERSION} |
166 | && defined *{${$$pack}{VERSION}}{SCALAR}; |
167 | return 1 if exists ${$$pack}{ISA} |
168 | && defined *{${$$pack}{ISA}}{ARRAY}; |
169 | |
170 | # check for any method |
171 | foreach ( keys %{$$pack} ) { |
172 | next if substr($_, -2, 2) eq '::'; |
d5be3722 |
173 | |
174 | my $glob = ${$$pack}{$_} || next; |
175 | |
9e275e86 |
176 | # constant subs |
d5be3722 |
177 | if ( IS_RUNNING_ON_5_10 ) { |
178 | return 1 if ref $glob eq 'SCALAR'; |
179 | } |
180 | |
181 | return 1 if defined *{$glob}{CODE}; |
26fcef27 |
182 | } |
183 | |
184 | # fail |
c1d5345a |
185 | return 0; |
448b6e55 |
186 | } |
187 | |
188 | |
aa448b16 |
189 | ## ---------------------------------------------------------------------------- |
190 | ## Setting up our environment ... |
191 | ## ---------------------------------------------------------------------------- |
1d68af04 |
192 | ## Class::MOP needs to have a few things in the global perl environment so |
aa448b16 |
193 | ## that it can operate effectively. Those things are done here. |
194 | ## ---------------------------------------------------------------------------- |
195 | |
3bf7644b |
196 | # ... nothing yet actually ;) |
8b978dd5 |
197 | |
b51af7f9 |
198 | ## ---------------------------------------------------------------------------- |
1d68af04 |
199 | ## Bootstrapping |
b51af7f9 |
200 | ## ---------------------------------------------------------------------------- |
1d68af04 |
201 | ## The code below here is to bootstrap our MOP with itself. This is also |
b51af7f9 |
202 | ## sometimes called "tying the knot". By doing this, we make it much easier |
203 | ## to extend the MOP through subclassing and such since now you can use the |
1d68af04 |
204 | ## MOP itself to extend itself. |
205 | ## |
b51af7f9 |
206 | ## Yes, I know, thats weird and insane, but it's a good thing, trust me :) |
1d68af04 |
207 | ## ---------------------------------------------------------------------------- |
727919c5 |
208 | |
1d68af04 |
209 | # We need to add in the meta-attributes here so that |
210 | # any subclass of Class::MOP::* will be able to |
727919c5 |
211 | # inherit them using &construct_instance |
212 | |
f0480c45 |
213 | ## -------------------------------------------------------- |
6d5355c3 |
214 | ## Class::MOP::Package |
727919c5 |
215 | |
6d5355c3 |
216 | Class::MOP::Package->meta->add_attribute( |
8683db0e |
217 | Class::MOP::Attribute->new('package' => ( |
b880e0de |
218 | reader => { |
1d68af04 |
219 | # NOTE: we need to do this in order |
220 | # for the instance meta-object to |
b880e0de |
221 | # not fall into meta-circular death |
1d68af04 |
222 | # |
ce2ae40f |
223 | # we just alias the original method |
1d68af04 |
224 | # rather than re-produce it here |
ce2ae40f |
225 | 'name' => \&Class::MOP::Package::name |
b880e0de |
226 | }, |
727919c5 |
227 | )) |
228 | ); |
229 | |
a5e51f0b |
230 | Class::MOP::Package->meta->add_attribute( |
8683db0e |
231 | Class::MOP::Attribute->new('namespace' => ( |
a5e51f0b |
232 | reader => { |
56dcfc1a |
233 | # NOTE: |
ce2ae40f |
234 | # we just alias the original method |
235 | # rather than re-produce it here |
236 | 'namespace' => \&Class::MOP::Package::namespace |
a5e51f0b |
237 | }, |
2e877f58 |
238 | init_arg => undef, |
c4260b45 |
239 | default => sub { \undef } |
a5e51f0b |
240 | )) |
241 | ); |
242 | |
9d6dce77 |
243 | # NOTE: |
244 | # use the metaclass to construct the meta-package |
245 | # which is a superclass of the metaclass itself :P |
246 | Class::MOP::Package->meta->add_method('initialize' => sub { |
247 | my $class = shift; |
248 | my $package_name = shift; |
1d68af04 |
249 | $class->meta->new_object('package' => $package_name, @_); |
9d6dce77 |
250 | }); |
251 | |
f0480c45 |
252 | ## -------------------------------------------------------- |
253 | ## Class::MOP::Module |
254 | |
255 | # NOTE: |
1d68af04 |
256 | # yeah this is kind of stretching things a bit, |
f0480c45 |
257 | # but truthfully the version should be an attribute |
1d68af04 |
258 | # of the Module, the weirdness comes from having to |
259 | # stick to Perl 5 convention and store it in the |
260 | # $VERSION package variable. Basically if you just |
261 | # squint at it, it will look how you want it to look. |
f0480c45 |
262 | # Either as a package variable, or as a attribute of |
263 | # the metaclass, isn't abstraction great :) |
264 | |
265 | Class::MOP::Module->meta->add_attribute( |
8683db0e |
266 | Class::MOP::Attribute->new('version' => ( |
f0480c45 |
267 | reader => { |
ce2ae40f |
268 | # NOTE: |
269 | # we just alias the original method |
1d68af04 |
270 | # rather than re-produce it here |
ce2ae40f |
271 | 'version' => \&Class::MOP::Module::version |
f0480c45 |
272 | }, |
2e877f58 |
273 | init_arg => undef, |
c4260b45 |
274 | default => sub { \undef } |
f0480c45 |
275 | )) |
276 | ); |
277 | |
278 | # NOTE: |
1d68af04 |
279 | # By following the same conventions as version here, |
280 | # we are opening up the possibility that people can |
281 | # use the $AUTHORITY in non-Class::MOP modules as |
282 | # well. |
f0480c45 |
283 | |
284 | Class::MOP::Module->meta->add_attribute( |
8683db0e |
285 | Class::MOP::Attribute->new('authority' => ( |
f0480c45 |
286 | reader => { |
ce2ae40f |
287 | # NOTE: |
288 | # we just alias the original method |
1d68af04 |
289 | # rather than re-produce it here |
ce2ae40f |
290 | 'authority' => \&Class::MOP::Module::authority |
1d68af04 |
291 | }, |
2e877f58 |
292 | init_arg => undef, |
c4260b45 |
293 | default => sub { \undef } |
f0480c45 |
294 | )) |
295 | ); |
296 | |
297 | ## -------------------------------------------------------- |
6d5355c3 |
298 | ## Class::MOP::Class |
299 | |
727919c5 |
300 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
301 | Class::MOP::Attribute->new('attributes' => ( |
f7259199 |
302 | reader => { |
1d68af04 |
303 | # NOTE: we need to do this in order |
304 | # for the instance meta-object to |
305 | # not fall into meta-circular death |
306 | # |
ce2ae40f |
307 | # we just alias the original method |
1d68af04 |
308 | # rather than re-produce it here |
ce2ae40f |
309 | 'get_attribute_map' => \&Class::MOP::Class::get_attribute_map |
f7259199 |
310 | }, |
727919c5 |
311 | default => sub { {} } |
312 | )) |
313 | ); |
314 | |
351bd7d4 |
315 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
316 | Class::MOP::Attribute->new('methods' => ( |
1d68af04 |
317 | reader => { |
ce2ae40f |
318 | # NOTE: |
319 | # we just alias the original method |
1d68af04 |
320 | # rather than re-produce it here |
ce2ae40f |
321 | 'get_method_map' => \&Class::MOP::Class::get_method_map |
92330ee2 |
322 | }, |
7855ddba |
323 | default => sub { {} } |
c4260b45 |
324 | )) |
325 | ); |
326 | |
327 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
328 | Class::MOP::Attribute->new('superclasses' => ( |
c23184fc |
329 | accessor => { |
330 | # NOTE: |
331 | # we just alias the original method |
1d68af04 |
332 | # rather than re-produce it here |
c23184fc |
333 | 'superclasses' => \&Class::MOP::Class::superclasses |
334 | }, |
2e877f58 |
335 | init_arg => undef, |
c23184fc |
336 | default => sub { \undef } |
337 | )) |
338 | ); |
339 | |
340 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
341 | Class::MOP::Attribute->new('attribute_metaclass' => ( |
1d68af04 |
342 | reader => { |
6d2118a4 |
343 | # NOTE: |
344 | # we just alias the original method |
1d68af04 |
345 | # rather than re-produce it here |
6d2118a4 |
346 | 'attribute_metaclass' => \&Class::MOP::Class::attribute_metaclass |
1d68af04 |
347 | }, |
351bd7d4 |
348 | default => 'Class::MOP::Attribute', |
349 | )) |
350 | ); |
351 | |
352 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
353 | Class::MOP::Attribute->new('method_metaclass' => ( |
1d68af04 |
354 | reader => { |
6d2118a4 |
355 | # NOTE: |
356 | # we just alias the original method |
1d68af04 |
357 | # rather than re-produce it here |
6d2118a4 |
358 | 'method_metaclass' => \&Class::MOP::Class::method_metaclass |
359 | }, |
1d68af04 |
360 | default => 'Class::MOP::Method', |
351bd7d4 |
361 | )) |
362 | ); |
363 | |
2bab2be6 |
364 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
365 | Class::MOP::Attribute->new('instance_metaclass' => ( |
b880e0de |
366 | reader => { |
1d68af04 |
367 | # NOTE: we need to do this in order |
368 | # for the instance meta-object to |
369 | # not fall into meta-circular death |
370 | # |
ce2ae40f |
371 | # we just alias the original method |
1d68af04 |
372 | # rather than re-produce it here |
ce2ae40f |
373 | 'instance_metaclass' => \&Class::MOP::Class::instance_metaclass |
b880e0de |
374 | }, |
1d68af04 |
375 | default => 'Class::MOP::Instance', |
2bab2be6 |
376 | )) |
377 | ); |
378 | |
9d6dce77 |
379 | # NOTE: |
1d68af04 |
380 | # we don't actually need to tie the knot with |
381 | # Class::MOP::Class here, it is actually handled |
382 | # within Class::MOP::Class itself in the |
383 | # construct_class_instance method. |
9d6dce77 |
384 | |
f0480c45 |
385 | ## -------------------------------------------------------- |
727919c5 |
386 | ## Class::MOP::Attribute |
387 | |
7b31baf4 |
388 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
389 | Class::MOP::Attribute->new('name' => ( |
c23184fc |
390 | reader => { |
1d68af04 |
391 | # NOTE: we need to do this in order |
392 | # for the instance meta-object to |
393 | # not fall into meta-circular death |
394 | # |
ce2ae40f |
395 | # we just alias the original method |
1d68af04 |
396 | # rather than re-produce it here |
ce2ae40f |
397 | 'name' => \&Class::MOP::Attribute::name |
b880e0de |
398 | } |
7b31baf4 |
399 | )) |
400 | ); |
401 | |
402 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
403 | Class::MOP::Attribute->new('associated_class' => ( |
c23184fc |
404 | reader => { |
1d68af04 |
405 | # NOTE: we need to do this in order |
406 | # for the instance meta-object to |
407 | # not fall into meta-circular death |
408 | # |
ce2ae40f |
409 | # we just alias the original method |
1d68af04 |
410 | # rather than re-produce it here |
ce2ae40f |
411 | 'associated_class' => \&Class::MOP::Attribute::associated_class |
b880e0de |
412 | } |
7b31baf4 |
413 | )) |
414 | ); |
415 | |
416 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
417 | Class::MOP::Attribute->new('accessor' => ( |
6d2118a4 |
418 | reader => { 'accessor' => \&Class::MOP::Attribute::accessor }, |
419 | predicate => { 'has_accessor' => \&Class::MOP::Attribute::has_accessor }, |
7b31baf4 |
420 | )) |
421 | ); |
422 | |
423 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
424 | Class::MOP::Attribute->new('reader' => ( |
6d2118a4 |
425 | reader => { 'reader' => \&Class::MOP::Attribute::reader }, |
426 | predicate => { 'has_reader' => \&Class::MOP::Attribute::has_reader }, |
7b31baf4 |
427 | )) |
428 | ); |
429 | |
430 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
431 | Class::MOP::Attribute->new('initializer' => ( |
8ee74136 |
432 | reader => { 'initializer' => \&Class::MOP::Attribute::initializer }, |
433 | predicate => { 'has_initializer' => \&Class::MOP::Attribute::has_initializer }, |
0ab65f99 |
434 | )) |
435 | ); |
436 | |
437 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
438 | Class::MOP::Attribute->new('writer' => ( |
6d2118a4 |
439 | reader => { 'writer' => \&Class::MOP::Attribute::writer }, |
440 | predicate => { 'has_writer' => \&Class::MOP::Attribute::has_writer }, |
7b31baf4 |
441 | )) |
442 | ); |
443 | |
444 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
445 | Class::MOP::Attribute->new('predicate' => ( |
6d2118a4 |
446 | reader => { 'predicate' => \&Class::MOP::Attribute::predicate }, |
447 | predicate => { 'has_predicate' => \&Class::MOP::Attribute::has_predicate }, |
7b31baf4 |
448 | )) |
449 | ); |
450 | |
451 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
452 | Class::MOP::Attribute->new('clearer' => ( |
6d2118a4 |
453 | reader => { 'clearer' => \&Class::MOP::Attribute::clearer }, |
454 | predicate => { 'has_clearer' => \&Class::MOP::Attribute::has_clearer }, |
7d28758b |
455 | )) |
456 | ); |
457 | |
458 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
459 | Class::MOP::Attribute->new('builder' => ( |
1d68af04 |
460 | reader => { 'builder' => \&Class::MOP::Attribute::builder }, |
461 | predicate => { 'has_builder' => \&Class::MOP::Attribute::has_builder }, |
462 | )) |
463 | ); |
464 | |
465 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
466 | Class::MOP::Attribute->new('init_arg' => ( |
6d2118a4 |
467 | reader => { 'init_arg' => \&Class::MOP::Attribute::init_arg }, |
468 | predicate => { 'has_init_arg' => \&Class::MOP::Attribute::has_init_arg }, |
7b31baf4 |
469 | )) |
470 | ); |
471 | |
472 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
473 | Class::MOP::Attribute->new('default' => ( |
7b31baf4 |
474 | # default has a custom 'reader' method ... |
1d68af04 |
475 | predicate => { 'has_default' => \&Class::MOP::Attribute::has_default }, |
7b31baf4 |
476 | )) |
477 | ); |
478 | |
3545c727 |
479 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
480 | Class::MOP::Attribute->new('associated_methods' => ( |
c23184fc |
481 | reader => { 'associated_methods' => \&Class::MOP::Attribute::associated_methods }, |
1d68af04 |
482 | default => sub { [] } |
3545c727 |
483 | )) |
484 | ); |
727919c5 |
485 | |
486 | # NOTE: (meta-circularity) |
487 | # This should be one of the last things done |
488 | # it will "tie the knot" with Class::MOP::Attribute |
1d68af04 |
489 | # so that it uses the attributes meta-objects |
490 | # to construct itself. |
727919c5 |
491 | Class::MOP::Attribute->meta->add_method('new' => sub { |
649efb63 |
492 | my ( $class, @args ) = @_; |
493 | |
494 | unshift @args, "name" if @args % 2 == 1; |
495 | my %options = @args; |
496 | |
497 | my $name = $options{name}; |
1d68af04 |
498 | |
727919c5 |
499 | (defined $name && $name) |
500 | || confess "You must provide a name for the attribute"; |
1d68af04 |
501 | $options{init_arg} = $name |
5659d76e |
502 | if not exists $options{init_arg}; |
1d68af04 |
503 | |
504 | if(exists $options{builder}){ |
505 | confess("builder must be a defined scalar value which is a method name") |
506 | if ref $options{builder} || !(defined $options{builder}); |
507 | confess("Setting both default and builder is not allowed.") |
508 | if exists $options{default}; |
8fe581e5 |
509 | } else { |
510 | (Class::MOP::Attribute::is_default_a_coderef(\%options)) |
511 | || confess("References are not allowed as default values, you must ". |
3c0a8087 |
512 | "wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])") |
8fe581e5 |
513 | if exists $options{default} && ref $options{default}; |
1d68af04 |
514 | } |
8683db0e |
515 | |
5659d76e |
516 | # return the new object |
649efb63 |
517 | $class->meta->new_object(%options); |
5659d76e |
518 | }); |
519 | |
520 | Class::MOP::Attribute->meta->add_method('clone' => sub { |
a740253a |
521 | my $self = shift; |
1d68af04 |
522 | $self->meta->clone_object($self, @_); |
727919c5 |
523 | }); |
524 | |
f0480c45 |
525 | ## -------------------------------------------------------- |
b6164407 |
526 | ## Class::MOP::Method |
b6164407 |
527 | Class::MOP::Method->meta->add_attribute( |
8683db0e |
528 | Class::MOP::Attribute->new('body' => ( |
c23184fc |
529 | reader => { 'body' => \&Class::MOP::Method::body }, |
b6164407 |
530 | )) |
531 | ); |
532 | |
4c105333 |
533 | Class::MOP::Method->meta->add_attribute( |
5e607260 |
534 | Class::MOP::Attribute->new('associated_metaclass' => ( |
5e607260 |
535 | reader => { 'associated_metaclass' => \&Class::MOP::Method::associated_metaclass }, |
536 | )) |
537 | ); |
538 | |
539 | Class::MOP::Method->meta->add_attribute( |
8683db0e |
540 | Class::MOP::Attribute->new('package_name' => ( |
4c105333 |
541 | reader => { 'package_name' => \&Class::MOP::Method::package_name }, |
542 | )) |
543 | ); |
544 | |
545 | Class::MOP::Method->meta->add_attribute( |
8683db0e |
546 | Class::MOP::Attribute->new('name' => ( |
4c105333 |
547 | reader => { 'name' => \&Class::MOP::Method::name }, |
548 | )) |
549 | ); |
550 | |
1a29bc4d |
551 | # FIMXE prime candidate for immutablization |
4c105333 |
552 | Class::MOP::Method->meta->add_method('wrap' => sub { |
5caf45ce |
553 | my ( $class, @args ) = @_; |
554 | |
555 | unshift @args, 'body' if @args % 2 == 1; |
556 | |
557 | my %options = @args; |
558 | my $code = $options{body}; |
4c105333 |
559 | |
9b522fc4 |
560 | ('CODE' eq ref($code)) |
4c105333 |
561 | || confess "You must supply a CODE reference to bless, not (" . ($code || 'undef') . ")"; |
562 | |
b38f3848 |
563 | ($options{package_name} && $options{name}) |
564 | || confess "You must supply the package_name and name parameters"; |
565 | |
4c105333 |
566 | # return the new object |
5caf45ce |
567 | $class->meta->new_object(%options); |
4c105333 |
568 | }); |
569 | |
570 | Class::MOP::Method->meta->add_method('clone' => sub { |
571 | my $self = shift; |
572 | $self->meta->clone_object($self, @_); |
573 | }); |
574 | |
b6164407 |
575 | ## -------------------------------------------------------- |
576 | ## Class::MOP::Method::Wrapped |
577 | |
578 | # NOTE: |
1d68af04 |
579 | # the way this item is initialized, this |
580 | # really does not follow the standard |
581 | # practices of attributes, but we put |
b6164407 |
582 | # it here for completeness |
583 | Class::MOP::Method::Wrapped->meta->add_attribute( |
8683db0e |
584 | Class::MOP::Attribute->new('modifier_table') |
b6164407 |
585 | ); |
586 | |
587 | ## -------------------------------------------------------- |
565f0cbb |
588 | ## Class::MOP::Method::Generated |
589 | |
590 | Class::MOP::Method::Generated->meta->add_attribute( |
8683db0e |
591 | Class::MOP::Attribute->new('is_inline' => ( |
565f0cbb |
592 | reader => { 'is_inline' => \&Class::MOP::Method::Generated::is_inline }, |
4c105333 |
593 | default => 0, |
1d68af04 |
594 | )) |
565f0cbb |
595 | ); |
596 | |
4c105333 |
597 | Class::MOP::Method::Generated->meta->add_method('new' => sub { |
598 | my ($class, %options) = @_; |
b38f3848 |
599 | ($options{package_name} && $options{name}) |
600 | || confess "You must supply the package_name and name parameters"; |
4c105333 |
601 | my $self = $class->meta->new_object(%options); |
602 | $self->initialize_body; |
603 | $self; |
604 | }); |
605 | |
565f0cbb |
606 | ## -------------------------------------------------------- |
d90b42a6 |
607 | ## Class::MOP::Method::Accessor |
608 | |
609 | Class::MOP::Method::Accessor->meta->add_attribute( |
8683db0e |
610 | Class::MOP::Attribute->new('attribute' => ( |
1d68af04 |
611 | reader => { |
612 | 'associated_attribute' => \&Class::MOP::Method::Accessor::associated_attribute |
d90b42a6 |
613 | }, |
1d68af04 |
614 | )) |
d90b42a6 |
615 | ); |
616 | |
617 | Class::MOP::Method::Accessor->meta->add_attribute( |
8683db0e |
618 | Class::MOP::Attribute->new('accessor_type' => ( |
c23184fc |
619 | reader => { 'accessor_type' => \&Class::MOP::Method::Accessor::accessor_type }, |
1d68af04 |
620 | )) |
d90b42a6 |
621 | ); |
622 | |
4c105333 |
623 | Class::MOP::Method::Accessor->meta->add_method('new' => sub { |
624 | my $class = shift; |
625 | my %options = @_; |
626 | |
627 | (exists $options{attribute}) |
628 | || confess "You must supply an attribute to construct with"; |
629 | |
630 | (exists $options{accessor_type}) |
631 | || confess "You must supply an accessor_type to construct with"; |
632 | |
633 | (Scalar::Util::blessed($options{attribute}) && $options{attribute}->isa('Class::MOP::Attribute')) |
634 | || confess "You must supply an attribute which is a 'Class::MOP::Attribute' instance"; |
635 | |
b38f3848 |
636 | ($options{package_name} && $options{name}) |
637 | || confess "You must supply the package_name and name parameters"; |
638 | |
4c105333 |
639 | # return the new object |
640 | my $self = $class->meta->new_object(%options); |
641 | |
642 | # we don't want this creating |
643 | # a cycle in the code, if not |
644 | # needed |
8683db0e |
645 | Scalar::Util::weaken($self->{'attribute'}); |
4c105333 |
646 | |
647 | $self->initialize_body; |
648 | |
649 | $self; |
650 | }); |
651 | |
d90b42a6 |
652 | |
653 | ## -------------------------------------------------------- |
654 | ## Class::MOP::Method::Constructor |
655 | |
656 | Class::MOP::Method::Constructor->meta->add_attribute( |
8683db0e |
657 | Class::MOP::Attribute->new('options' => ( |
1d68af04 |
658 | reader => { |
659 | 'options' => \&Class::MOP::Method::Constructor::options |
d90b42a6 |
660 | }, |
4c105333 |
661 | default => sub { +{} } |
1d68af04 |
662 | )) |
d90b42a6 |
663 | ); |
664 | |
665 | Class::MOP::Method::Constructor->meta->add_attribute( |
8683db0e |
666 | Class::MOP::Attribute->new('associated_metaclass' => ( |
e8a38403 |
667 | init_arg => "metaclass", # FIXME alias and rename |
1d68af04 |
668 | reader => { |
669 | 'associated_metaclass' => \&Class::MOP::Method::Constructor::associated_metaclass |
670 | }, |
671 | )) |
d90b42a6 |
672 | ); |
673 | |
4c105333 |
674 | Class::MOP::Method::Constructor->meta->add_method('new' => sub { |
675 | my $class = shift; |
676 | my %options = @_; |
677 | |
678 | (Scalar::Util::blessed $options{metaclass} && $options{metaclass}->isa('Class::MOP::Class')) |
679 | || confess "You must pass a metaclass instance if you want to inline" |
680 | if $options{is_inline}; |
681 | |
b38f3848 |
682 | ($options{package_name} && $options{name}) |
683 | || confess "You must supply the package_name and name parameters"; |
684 | |
4c105333 |
685 | # return the new object |
686 | my $self = $class->meta->new_object(%options); |
687 | |
688 | # we don't want this creating |
689 | # a cycle in the code, if not |
690 | # needed |
8683db0e |
691 | Scalar::Util::weaken($self->{'associated_metaclass'}); |
4c105333 |
692 | |
693 | $self->initialize_body; |
694 | |
695 | $self; |
696 | }); |
697 | |
d90b42a6 |
698 | ## -------------------------------------------------------- |
86482605 |
699 | ## Class::MOP::Instance |
700 | |
701 | # NOTE: |
1d68af04 |
702 | # these don't yet do much of anything, but are just |
86482605 |
703 | # included for completeness |
704 | |
705 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
706 | Class::MOP::Attribute->new('associated_metaclass', |
707 | reader => { associated_metaclass => \&Class::MOP::Instance::associated_metaclass }, |
708 | ), |
86482605 |
709 | ); |
710 | |
711 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
712 | Class::MOP::Attribute->new('_class_name', |
713 | init_arg => undef, |
714 | reader => { _class_name => \&Class::MOP::Instance::_class_name }, |
715 | #lazy => 1, # not yet supported by Class::MOP but out our version does it anyway |
716 | #default => sub { $_[0]->associated_metaclass->name }, |
717 | ), |
718 | ); |
719 | |
720 | Class::MOP::Instance->meta->add_attribute( |
721 | Class::MOP::Attribute->new('attributes', |
722 | reader => { attributes => \&Class::MOP::Instance::attributes }, |
723 | ), |
32bfc810 |
724 | ); |
725 | |
726 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
727 | Class::MOP::Attribute->new('slots', |
728 | reader => { slots => \&Class::MOP::Instance::slots }, |
729 | ), |
86482605 |
730 | ); |
731 | |
63d08a9e |
732 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
733 | Class::MOP::Attribute->new('slot_hash', |
734 | reader => { slot_hash => \&Class::MOP::Instance::slot_hash }, |
735 | ), |
63d08a9e |
736 | ); |
737 | |
738 | |
caa051fa |
739 | # we need the meta instance of the meta instance to be created now, in order |
740 | # for the constructor to be able to use it |
741 | Class::MOP::Instance->meta->get_meta_instance; |
742 | |
743 | Class::MOP::Instance->meta->add_method('new' => sub { |
744 | my $class = shift; |
745 | my $options = $class->BUILDARGS(@_); |
746 | |
747 | my $self = $class->meta->new_object(%$options); |
748 | |
749 | Scalar::Util::weaken($self->{'associated_metaclass'}); |
750 | |
751 | $self; |
752 | }); |
753 | |
754 | # pretend the add_method never happenned. it hasn't yet affected anything |
755 | undef Class::MOP::Instance->meta->{_package_cache_flag}; |
756 | |
86482605 |
757 | ## -------------------------------------------------------- |
f0480c45 |
758 | ## Now close all the Class::MOP::* classes |
4d47b77f |
759 | |
0b9372a2 |
760 | # NOTE: |
1d68af04 |
761 | # we don't need to inline the |
762 | # constructors or the accessors |
763 | # this only lengthens the compile |
764 | # time of the MOP, and gives us |
0b9372a2 |
765 | # no actual benefits. |
766 | |
767 | $_->meta->make_immutable( |
768 | inline_constructor => 0, |
769 | inline_accessors => 0, |
770 | ) for qw/ |
1d68af04 |
771 | Class::MOP::Package |
772 | Class::MOP::Module |
773 | Class::MOP::Class |
774 | |
0b9372a2 |
775 | Class::MOP::Attribute |
1d68af04 |
776 | Class::MOP::Method |
777 | Class::MOP::Instance |
778 | |
779 | Class::MOP::Object |
0b9372a2 |
780 | |
565f0cbb |
781 | Class::MOP::Method::Generated |
1d68af04 |
782 | |
ba38bf08 |
783 | Class::MOP::Method::Accessor |
1d68af04 |
784 | Class::MOP::Method::Constructor |
785 | Class::MOP::Method::Wrapped |
0b9372a2 |
786 | /; |
b6164407 |
787 | |
94b19069 |
788 | 1; |
789 | |
790 | __END__ |
791 | |
792 | =pod |
793 | |
1d68af04 |
794 | =head1 NAME |
94b19069 |
795 | |
796 | Class::MOP - A Meta Object Protocol for Perl 5 |
797 | |
94b19069 |
798 | =head1 DESCRIPTON |
799 | |
127d39a7 |
800 | This module is a fully functioning meta object protocol for the |
1d68af04 |
801 | Perl 5 object system. It makes no attempt to change the behavior or |
802 | characteristics of the Perl 5 object system, only to create a |
27e31eaf |
803 | protocol for its manipulation and introspection. |
94b19069 |
804 | |
1d68af04 |
805 | That said, it does attempt to create the tools for building a rich |
806 | set of extensions to the Perl 5 object system. Every attempt has been |
807 | made for these tools to keep to the spirit of the Perl 5 object |
94b19069 |
808 | system that we all know and love. |
809 | |
1d68af04 |
810 | This documentation is admittedly sparse on details, as time permits |
811 | I will try to improve them. For now, I suggest looking at the items |
812 | listed in the L<SEE ALSO> section for more information. In particular |
813 | the book "The Art of the Meta Object Protocol" was very influential |
40483095 |
814 | in the development of this system. |
815 | |
bfe4d0fc |
816 | =head2 What is a Meta Object Protocol? |
817 | |
1d68af04 |
818 | A meta object protocol is an API to an object system. |
bfe4d0fc |
819 | |
1d68af04 |
820 | To be more specific, it is a set of abstractions of the components of |
821 | an object system (typically things like; classes, object, methods, |
822 | object attributes, etc.). These abstractions can then be used to both |
bfe4d0fc |
823 | inspect and manipulate the object system which they describe. |
824 | |
1d68af04 |
825 | It can be said that there are two MOPs for any object system; the |
826 | implicit MOP, and the explicit MOP. The implicit MOP handles things |
827 | like method dispatch or inheritance, which happen automatically as |
828 | part of how the object system works. The explicit MOP typically |
829 | handles the introspection/reflection features of the object system. |
830 | All object systems have implicit MOPs, without one, they would not |
831 | work. Explict MOPs however as less common, and depending on the |
832 | language can vary from restrictive (Reflection in Java or C#) to |
833 | wide open (CLOS is a perfect example). |
bfe4d0fc |
834 | |
e16da3e6 |
835 | =head2 Yet Another Class Builder!! Why? |
836 | |
1d68af04 |
837 | This is B<not> a class builder so much as it is a I<class builder |
838 | B<builder>>. My intent is that an end user does not use this module |
839 | directly, but instead this module is used by module authors to |
840 | build extensions and features onto the Perl 5 object system. |
e16da3e6 |
841 | |
94b19069 |
842 | =head2 Who is this module for? |
843 | |
1d68af04 |
844 | This module is specifically for anyone who has ever created or |
845 | wanted to create a module for the Class:: namespace. The tools which |
846 | this module will provide will hopefully make it easier to do more |
847 | complex things with Perl 5 classes by removing such barriers as |
848 | the need to hack the symbol tables, or understand the fine details |
849 | of method dispatch. |
94b19069 |
850 | |
bfe4d0fc |
851 | =head2 What changes do I have to make to use this module? |
852 | |
1d68af04 |
853 | This module was designed to be as unintrusive as possible. Many of |
854 | its features are accessible without B<any> change to your existsing |
855 | code at all. It is meant to be a compliment to your existing code and |
856 | not an intrusion on your code base. Unlike many other B<Class::> |
857 | modules, this module B<does not> require you subclass it, or even that |
858 | you C<use> it in within your module's package. |
bfe4d0fc |
859 | |
1d68af04 |
860 | The only features which requires additions to your code are the |
2eb717d5 |
861 | attribute handling and instance construction features, and these are |
1d68af04 |
862 | both completely optional features. The only reason for this is because |
863 | Perl 5's object system does not actually have these features built |
2eb717d5 |
864 | in. More information about this feature can be found below. |
bfe4d0fc |
865 | |
866 | =head2 A Note about Performance? |
867 | |
1d68af04 |
868 | It is a common misconception that explict MOPs are performance drains. |
869 | But this is not a universal truth at all, it is an side-effect of |
870 | specific implementations. For instance, using Java reflection is much |
871 | slower because the JVM cannot take advantage of any compiler |
872 | optimizations, and the JVM has to deal with much more runtime type |
873 | information as well. Reflection in C# is marginally better as it was |
874 | designed into the language and runtime (the CLR). In contrast, CLOS |
875 | (the Common Lisp Object System) was built to support an explicit MOP, |
876 | and so performance is tuned for it. |
877 | |
878 | This library in particular does it's absolute best to avoid putting |
879 | B<any> drain at all upon your code's performance. In fact, by itself |
880 | it does nothing to affect your existing code. So you only pay for |
2eb717d5 |
881 | what you actually use. |
bfe4d0fc |
882 | |
550d56db |
883 | =head2 About Metaclass compatibility |
884 | |
1d68af04 |
885 | This module makes sure that all metaclasses created are both upwards |
886 | and downwards compatible. The topic of metaclass compatibility is |
887 | highly esoteric and is something only encountered when doing deep and |
888 | involved metaclass hacking. There are two basic kinds of metaclass |
889 | incompatibility; upwards and downwards. |
550d56db |
890 | |
1d68af04 |
891 | Upwards metaclass compatibility means that the metaclass of a |
892 | given class is either the same as (or a subclass of) all of the |
550d56db |
893 | class's ancestors. |
894 | |
1d68af04 |
895 | Downward metaclass compatibility means that the metaclasses of a |
896 | given class's anscestors are all either the same as (or a subclass |
550d56db |
897 | of) that metaclass. |
898 | |
1d68af04 |
899 | Here is a diagram showing a set of two classes (C<A> and C<B>) and |
900 | two metaclasses (C<Meta::A> and C<Meta::B>) which have correct |
550d56db |
901 | metaclass compatibility both upwards and downwards. |
902 | |
903 | +---------+ +---------+ |
904 | | Meta::A |<----| Meta::B | <....... (instance of ) |
1d68af04 |
905 | +---------+ +---------+ <------- (inherits from) |
550d56db |
906 | ^ ^ |
907 | : : |
908 | +---------+ +---------+ |
909 | | A |<----| B | |
910 | +---------+ +---------+ |
911 | |
1d68af04 |
912 | As I said this is a highly esoteric topic and one you will only run |
913 | into if you do a lot of subclassing of B<Class::MOP::Class>. If you |
914 | are interested in why this is an issue see the paper |
915 | I<Uniform and safe metaclass composition> linked to in the |
550d56db |
916 | L<SEE ALSO> section of this document. |
917 | |
aa448b16 |
918 | =head2 Using custom metaclasses |
919 | |
1d68af04 |
920 | Always use the metaclass pragma when using a custom metaclass, this |
921 | will ensure the proper initialization order and not accidentely |
922 | create an incorrect type of metaclass for you. This is a very rare |
923 | problem, and one which can only occur if you are doing deep metaclass |
aa448b16 |
924 | programming. So in other words, don't worry about it. |
925 | |
94b19069 |
926 | =head1 PROTOCOLS |
927 | |
127d39a7 |
928 | The protocol is divided into 4 main sub-protocols: |
94b19069 |
929 | |
930 | =over 4 |
931 | |
932 | =item The Class protocol |
933 | |
1d68af04 |
934 | This provides a means of manipulating and introspecting a Perl 5 |
935 | class. It handles all of symbol table hacking for you, and provides |
94b19069 |
936 | a rich set of methods that go beyond simple package introspection. |
937 | |
552e3d24 |
938 | See L<Class::MOP::Class> for more details. |
939 | |
94b19069 |
940 | =item The Attribute protocol |
941 | |
1d68af04 |
942 | This provides a consistent represenation for an attribute of a |
943 | Perl 5 class. Since there are so many ways to create and handle |
127d39a7 |
944 | attributes in Perl 5 OO, this attempts to provide as much of a |
1d68af04 |
945 | unified approach as possible, while giving the freedom and |
94b19069 |
946 | flexibility to subclass for specialization. |
947 | |
552e3d24 |
948 | See L<Class::MOP::Attribute> for more details. |
949 | |
94b19069 |
950 | =item The Method protocol |
951 | |
1d68af04 |
952 | This provides a means of manipulating and introspecting methods in |
953 | the Perl 5 object system. As with attributes, there are many ways to |
954 | approach this topic, so we try to keep it pretty basic, while still |
94b19069 |
955 | making it possible to extend the system in many ways. |
956 | |
552e3d24 |
957 | See L<Class::MOP::Method> for more details. |
94b19069 |
958 | |
127d39a7 |
959 | =item The Instance protocol |
960 | |
961 | This provides a layer of abstraction for creating object instances. |
962 | Since the other layers use this protocol, it is relatively easy to |
963 | change the type of your instances from the default HASH ref to other |
964 | types of references. Several examples are provided in the F<examples/> |
965 | directory included in this distribution. |
966 | |
967 | See L<Class::MOP::Instance> for more details. |
968 | |
94b19069 |
969 | =back |
970 | |
be7677c7 |
971 | =head1 FUNCTIONS |
972 | |
c1d5345a |
973 | =head2 Constants |
974 | |
975 | =over 4 |
976 | |
977 | =item I<IS_RUNNING_ON_5_10> |
978 | |
979 | We set this constant depending on what version perl we are on, this |
980 | allows us to take advantage of new 5.10 features and stay backwards |
981 | compat. |
982 | |
9efe16ca |
983 | =item I<HAVE_ISAREV> |
984 | |
985 | Whether or not C<mro> provides C<get_isarev>, a much faster way to get all the |
986 | subclasses of a certain class. |
987 | |
c1d5345a |
988 | =back |
989 | |
448b6e55 |
990 | =head2 Utility functions |
991 | |
992 | =over 4 |
993 | |
994 | =item B<load_class ($class_name)> |
995 | |
1d68af04 |
996 | This will load a given C<$class_name> and if it does not have an |
448b6e55 |
997 | already initialized metaclass, then it will intialize one for it. |
127d39a7 |
998 | This function can be used in place of tricks like |
999 | C<eval "use $module"> or using C<require>. |
448b6e55 |
1000 | |
1001 | =item B<is_class_loaded ($class_name)> |
1002 | |
1d68af04 |
1003 | This will return a boolean depending on if the C<$class_name> has |
1004 | been loaded. |
448b6e55 |
1005 | |
1d68af04 |
1006 | NOTE: This does a basic check of the symbol table to try and |
448b6e55 |
1007 | determine as best it can if the C<$class_name> is loaded, it |
1d68af04 |
1008 | is probably correct about 99% of the time. |
448b6e55 |
1009 | |
b1f5f41d |
1010 | =item B<check_package_cache_flag ($pkg)> |
e0e4674a |
1011 | |
127d39a7 |
1012 | This will return an integer that is managed by C<Class::MOP::Class> |
1013 | to determine if a module's symbol table has been altered. |
1014 | |
1015 | In Perl 5.10 or greater, this flag is package specific. However in |
1016 | versions prior to 5.10, this will use the C<PL_sub_generation> variable |
1017 | which is not package specific. |
1018 | |
e0e4674a |
1019 | =item B<get_code_info ($code)> |
1020 | |
127d39a7 |
1021 | This function returns two values, the name of the package the C<$code> |
1022 | is from and the name of the C<$code> itself. This is used by several |
1023 | elements of the MOP to detemine where a given C<$code> reference is from. |
1024 | |
4c105333 |
1025 | =item B<subname ($name, $code)> |
1026 | |
1027 | B<NOTE: DO NOT USE THIS FUNCTION, IT IS FOR INTERNAL USE ONLY!> |
1028 | |
1029 | If possible, we will load the L<Sub::Name> module and this will function |
1030 | as C<Sub::Name::subname> does, otherwise it will just return the C<$code> |
1031 | argument. |
1032 | |
448b6e55 |
1033 | =back |
1034 | |
1035 | =head2 Metaclass cache functions |
1036 | |
1d68af04 |
1037 | Class::MOP holds a cache of metaclasses, the following are functions |
1038 | (B<not methods>) which can be used to access that cache. It is not |
1039 | recommended that you mess with this, bad things could happen. But if |
be7677c7 |
1040 | you are brave and willing to risk it, go for it. |
1041 | |
1042 | =over 4 |
1043 | |
1044 | =item B<get_all_metaclasses> |
1045 | |
1d68af04 |
1046 | This will return an hash of all the metaclass instances that have |
1047 | been cached by B<Class::MOP::Class> keyed by the package name. |
b9d9fc0b |
1048 | |
be7677c7 |
1049 | =item B<get_all_metaclass_instances> |
1050 | |
1d68af04 |
1051 | This will return an array of all the metaclass instances that have |
b9d9fc0b |
1052 | been cached by B<Class::MOP::Class>. |
1053 | |
be7677c7 |
1054 | =item B<get_all_metaclass_names> |
1055 | |
1d68af04 |
1056 | This will return an array of all the metaclass names that have |
b9d9fc0b |
1057 | been cached by B<Class::MOP::Class>. |
1058 | |
be7677c7 |
1059 | =item B<get_metaclass_by_name ($name)> |
1060 | |
127d39a7 |
1061 | This will return a cached B<Class::MOP::Class> instance of nothing |
1062 | if no metaclass exist by that C<$name>. |
1063 | |
be7677c7 |
1064 | =item B<store_metaclass_by_name ($name, $meta)> |
1065 | |
127d39a7 |
1066 | This will store a metaclass in the cache at the supplied C<$key>. |
1067 | |
be7677c7 |
1068 | =item B<weaken_metaclass ($name)> |
1069 | |
127d39a7 |
1070 | In rare cases it is desireable to store a weakened reference in |
1071 | the metaclass cache. This function will weaken the reference to |
1072 | the metaclass stored in C<$name>. |
1073 | |
be7677c7 |
1074 | =item B<does_metaclass_exist ($name)> |
1075 | |
127d39a7 |
1076 | This will return true of there exists a metaclass stored in the |
1077 | C<$name> key and return false otherwise. |
1078 | |
be7677c7 |
1079 | =item B<remove_metaclass_by_name ($name)> |
1080 | |
127d39a7 |
1081 | This will remove a the metaclass stored in the C<$name> key. |
1082 | |
be7677c7 |
1083 | =back |
1084 | |
552e3d24 |
1085 | =head1 SEE ALSO |
8b978dd5 |
1086 | |
552e3d24 |
1087 | =head2 Books |
8b978dd5 |
1088 | |
1d68af04 |
1089 | There are very few books out on Meta Object Protocols and Metaclasses |
1090 | because it is such an esoteric topic. The following books are really |
1091 | the only ones I have found. If you know of any more, B<I<please>> |
a2e85e6c |
1092 | email me and let me know, I would love to hear about them. |
1093 | |
8b978dd5 |
1094 | =over 4 |
1095 | |
552e3d24 |
1096 | =item "The Art of the Meta Object Protocol" |
8b978dd5 |
1097 | |
552e3d24 |
1098 | =item "Advances in Object-Oriented Metalevel Architecture and Reflection" |
8b978dd5 |
1099 | |
b51af7f9 |
1100 | =item "Putting MetaClasses to Work" |
1101 | |
a2e85e6c |
1102 | =item "Smalltalk: The Language" |
1103 | |
94b19069 |
1104 | =back |
1105 | |
550d56db |
1106 | =head2 Papers |
1107 | |
1108 | =over 4 |
1109 | |
1110 | =item Uniform and safe metaclass composition |
1111 | |
1d68af04 |
1112 | An excellent paper by the people who brought us the original Traits paper. |
1113 | This paper is on how Traits can be used to do safe metaclass composition, |
1114 | and offers an excellent introduction section which delves into the topic of |
550d56db |
1115 | metaclass compatibility. |
1116 | |
1117 | L<http://www.iam.unibe.ch/~scg/Archive/Papers/Duca05ySafeMetaclassTrait.pdf> |
1118 | |
1119 | =item Safe Metaclass Programming |
1120 | |
1d68af04 |
1121 | This paper seems to precede the above paper, and propose a mix-in based |
1122 | approach as opposed to the Traits based approach. Both papers have similar |
1123 | information on the metaclass compatibility problem space. |
550d56db |
1124 | |
1125 | L<http://citeseer.ist.psu.edu/37617.html> |
1126 | |
1127 | =back |
1128 | |
552e3d24 |
1129 | =head2 Prior Art |
8b978dd5 |
1130 | |
1131 | =over 4 |
1132 | |
7184ca14 |
1133 | =item The Perl 6 MetaModel work in the Pugs project |
8b978dd5 |
1134 | |
1135 | =over 4 |
1136 | |
552e3d24 |
1137 | =item L<http://svn.openfoundry.org/pugs/perl5/Perl6-MetaModel> |
8b978dd5 |
1138 | |
552e3d24 |
1139 | =item L<http://svn.openfoundry.org/pugs/perl5/Perl6-ObjectSpace> |
8b978dd5 |
1140 | |
1141 | =back |
1142 | |
94b19069 |
1143 | =back |
1144 | |
1d68af04 |
1145 | =head2 Articles |
f8dfcfb7 |
1146 | |
1147 | =over 4 |
1148 | |
1d68af04 |
1149 | =item CPAN Module Review of Class::MOP |
f8dfcfb7 |
1150 | |
1151 | L<http://www.oreillynet.com/onlamp/blog/2006/06/cpan_module_review_classmop.html> |
1152 | |
1153 | =back |
1154 | |
a2e85e6c |
1155 | =head1 SIMILAR MODULES |
1156 | |
1d68af04 |
1157 | As I have said above, this module is a class-builder-builder, so it is |
1158 | not the same thing as modules like L<Class::Accessor> and |
1159 | L<Class::MethodMaker>. That being said there are very few modules on CPAN |
1160 | with similar goals to this module. The one I have found which is most |
1161 | like this module is L<Class::Meta>, although it's philosophy and the MOP it |
1162 | creates are very different from this modules. |
94b19069 |
1163 | |
a2e85e6c |
1164 | =head1 BUGS |
1165 | |
1d68af04 |
1166 | All complex software has bugs lurking in it, and this module is no |
a2e85e6c |
1167 | exception. If you find a bug please either email me, or add the bug |
1168 | to cpan-RT. |
1169 | |
1170 | =head1 ACKNOWLEDGEMENTS |
1171 | |
1172 | =over 4 |
1173 | |
b9d9fc0b |
1174 | =item Rob Kinyon |
a2e85e6c |
1175 | |
1d68af04 |
1176 | Thanks to Rob for actually getting the development of this module kick-started. |
a2e85e6c |
1177 | |
1178 | =back |
1179 | |
1a09d9cc |
1180 | =head1 AUTHORS |
94b19069 |
1181 | |
a2e85e6c |
1182 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
552e3d24 |
1183 | |
9c8cda90 |
1184 | B<with contributions from:> |
1185 | |
1186 | Brandon (blblack) Black |
1187 | |
1188 | Guillermo (groditi) Roditi |
1189 | |
9195ddff |
1190 | Matt (mst) Trout |
1191 | |
9c8cda90 |
1192 | Rob (robkinyon) Kinyon |
1193 | |
1194 | Yuval (nothingmuch) Kogman |
1a09d9cc |
1195 | |
f430cfa4 |
1196 | Scott (konobi) McWhirter |
1197 | |
94b19069 |
1198 | =head1 COPYRIGHT AND LICENSE |
1199 | |
69e3ab0a |
1200 | Copyright 2006-2008 by Infinity Interactive, Inc. |
94b19069 |
1201 | |
1202 | L<http://www.iinteractive.com> |
1203 | |
1204 | This library is free software; you can redistribute it and/or modify |
1d68af04 |
1205 | it under the same terms as Perl itself. |
94b19069 |
1206 | |
1207 | =cut |