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'; |
12 | use Scalar::Util 'weaken'; |
8b978dd5 |
13 | |
fc4f8f91 |
14 | |
0531f510 |
15 | use Class::MOP::Class; |
16 | use Class::MOP::Attribute; |
17 | use Class::MOP::Method; |
18 | |
19 | use Class::MOP::Immutable; |
20 | |
b1f5f41d |
21 | BEGIN { |
11b56828 |
22 | *IS_RUNNING_ON_5_10 = ($] < 5.009_005) |
23 | ? sub () { 0 } |
4c105333 |
24 | : sub () { 1 }; |
46b23b44 |
25 | |
9efe16ca |
26 | *HAVE_ISAREV = defined(&mro::get_isarev) |
27 | ? sub () { 1 } |
28 | : sub () { 1 }; |
3ecd1b25 |
29 | |
30 | # this is either part of core or set up appropriately by MRO::Compat |
31 | *check_package_cache_flag = \&mro::get_pkg_gen; |
b1f5f41d |
32 | } |
e0e4674a |
33 | |
9d655b6d |
34 | our $VERSION = '0.76'; |
8a7085c1 |
35 | our $XS_VERSION = $VERSION; |
d519662a |
36 | $VERSION = eval $VERSION; |
fc4f8f91 |
37 | our $AUTHORITY = 'cpan:STEVAN'; |
9d655b6d |
38 | |
d7bda114 |
39 | _try_load_xs() or _load_pure_perl(); |
40 | |
41 | sub _try_load_xs { |
42 | return if $ENV{CLASS_MOP_NO_XS}; |
43 | |
0531f510 |
44 | my $e = do { |
45 | local $@; |
46 | eval { |
47 | require XSLoader; |
d7bda114 |
48 | # just doing this - no warnings 'redefine' - doesn't work |
49 | # for some reason |
50 | local $^W = 0; |
8a7085c1 |
51 | __PACKAGE__->XSLoader::load($XS_VERSION); |
3ecd1b25 |
52 | |
53 | require Sub::Name; |
54 | Sub::Name->import(qw(subname)); |
55 | |
56 | require Devel::GlobalDestruction; |
57 | Devel::GlobalDestruction->import("in_global_destruction"); |
9d655b6d |
58 | |
59 | *USING_XS = sub () { 1 }; |
0531f510 |
60 | }; |
61 | $@; |
62 | }; |
15273f3c |
63 | |
0531f510 |
64 | die $e if $e && $e !~ /object version|loadable object/; |
d7bda114 |
65 | |
66 | return $e ? 0 : 1; |
0531f510 |
67 | } |
15273f3c |
68 | |
d7bda114 |
69 | sub _load_pure_perl { |
70 | require Sub::Identify; |
71 | Sub::Identify->import('get_code_info'); |
3ecd1b25 |
72 | |
73 | *subname = sub { $_[1] }; |
9d655b6d |
74 | *in_global_destruction = sub () { !1 }; |
75 | |
76 | *USING_XS = sub () { 0 }; |
d7bda114 |
77 | } |
78 | |
79 | |
be7677c7 |
80 | { |
81 | # Metaclasses are singletons, so we cache them here. |
82 | # there is no need to worry about destruction though |
83 | # because they should die only when the program dies. |
84 | # After all, do package definitions even get reaped? |
1d68af04 |
85 | my %METAS; |
86 | |
87 | # means of accessing all the metaclasses that have |
be7677c7 |
88 | # been initialized thus far (for mugwumps obj browser) |
1d68af04 |
89 | sub get_all_metaclasses { %METAS } |
90 | sub get_all_metaclass_instances { values %METAS } |
91 | sub get_all_metaclass_names { keys %METAS } |
be7677c7 |
92 | sub get_metaclass_by_name { $METAS{$_[0]} } |
1d68af04 |
93 | sub store_metaclass_by_name { $METAS{$_[0]} = $_[1] } |
94 | sub weaken_metaclass { weaken($METAS{$_[0]}) } |
be7677c7 |
95 | sub does_metaclass_exist { exists $METAS{$_[0]} && defined $METAS{$_[0]} } |
1d68af04 |
96 | sub remove_metaclass_by_name { $METAS{$_[0]} = undef } |
97 | |
be7677c7 |
98 | # NOTE: |
1d68af04 |
99 | # We only cache metaclasses, meaning instances of |
100 | # Class::MOP::Class. We do not cache instance of |
be7677c7 |
101 | # Class::MOP::Package or Class::MOP::Module. Mostly |
1d68af04 |
102 | # because I don't yet see a good reason to do so. |
be7677c7 |
103 | } |
104 | |
063ad0c5 |
105 | sub load_first_existing_class { |
f280f05c |
106 | my @classes = @_ |
107 | or return; |
5a24cf8a |
108 | |
109 | foreach my $class (@classes) { |
110 | unless ( _is_valid_class_name($class) ) { |
111 | my $display = defined($class) ? $class : 'undef'; |
112 | confess "Invalid class name ($display)"; |
113 | } |
ab5e2f48 |
114 | } |
115 | |
063ad0c5 |
116 | my $found; |
5a24cf8a |
117 | my %exceptions; |
063ad0c5 |
118 | for my $class (@classes) { |
119 | my $e = _try_load_one_class($class); |
120 | |
5a24cf8a |
121 | if ($e) { |
063ad0c5 |
122 | $exceptions{$class} = $e; |
5a24cf8a |
123 | } |
124 | else { |
063ad0c5 |
125 | $found = $class; |
126 | last; |
5a24cf8a |
127 | } |
063ad0c5 |
128 | } |
5a24cf8a |
129 | |
1d8153bd |
130 | return $found if $found; |
07940968 |
131 | |
063ad0c5 |
132 | confess join( |
133 | "\n", |
134 | map { |
135 | sprintf( |
fea44045 |
136 | "Could not load class (%s) because : %s", $_, |
063ad0c5 |
137 | $exceptions{$_} |
138 | ) |
139 | } @classes |
f280f05c |
140 | ); |
5a24cf8a |
141 | } |
142 | |
063ad0c5 |
143 | sub _try_load_one_class { |
144 | my $class = shift; |
145 | |
146 | return if is_class_loaded($class); |
147 | |
148 | my $file = $class . '.pm'; |
149 | $file =~ s{::}{/}g; |
150 | |
151 | return do { |
152 | local $@; |
153 | eval { require($file) }; |
154 | $@; |
155 | }; |
156 | } |
157 | |
5a24cf8a |
158 | sub load_class { |
1d8153bd |
159 | my $class = load_first_existing_class($_[0]); |
160 | return get_metaclass_by_name($class) || $class; |
448b6e55 |
161 | } |
162 | |
2c0fb064 |
163 | sub _is_valid_class_name { |
164 | my $class = shift; |
165 | |
166 | return 0 if ref($class); |
167 | return 0 unless defined($class); |
168 | return 0 unless length($class); |
169 | |
170 | return 1 if $class =~ /^\w+(?:::\w+)*$/; |
171 | |
172 | return 0; |
173 | } |
174 | |
448b6e55 |
175 | sub is_class_loaded { |
c1d5345a |
176 | my $class = shift; |
26fcef27 |
177 | |
bd5672fb |
178 | return 0 unless _is_valid_class_name($class); |
26fcef27 |
179 | |
180 | # walk the symbol table tree to avoid autovififying |
181 | # \*{${main::}{"Foo::"}} == \*main::Foo:: |
182 | |
183 | my $pack = \*::; |
184 | foreach my $part (split('::', $class)) { |
185 | return 0 unless exists ${$$pack}{"${part}::"}; |
186 | $pack = \*{${$$pack}{"${part}::"}}; |
c1d5345a |
187 | } |
26fcef27 |
188 | |
189 | # check for $VERSION or @ISA |
190 | return 1 if exists ${$$pack}{VERSION} |
191 | && defined *{${$$pack}{VERSION}}{SCALAR}; |
192 | return 1 if exists ${$$pack}{ISA} |
193 | && defined *{${$$pack}{ISA}}{ARRAY}; |
194 | |
195 | # check for any method |
196 | foreach ( keys %{$$pack} ) { |
197 | next if substr($_, -2, 2) eq '::'; |
d5be3722 |
198 | |
199 | my $glob = ${$$pack}{$_} || next; |
200 | |
9e275e86 |
201 | # constant subs |
d5be3722 |
202 | if ( IS_RUNNING_ON_5_10 ) { |
203 | return 1 if ref $glob eq 'SCALAR'; |
204 | } |
205 | |
206 | return 1 if defined *{$glob}{CODE}; |
26fcef27 |
207 | } |
208 | |
209 | # fail |
c1d5345a |
210 | return 0; |
448b6e55 |
211 | } |
212 | |
213 | |
aa448b16 |
214 | ## ---------------------------------------------------------------------------- |
215 | ## Setting up our environment ... |
216 | ## ---------------------------------------------------------------------------- |
1d68af04 |
217 | ## Class::MOP needs to have a few things in the global perl environment so |
aa448b16 |
218 | ## that it can operate effectively. Those things are done here. |
219 | ## ---------------------------------------------------------------------------- |
220 | |
3bf7644b |
221 | # ... nothing yet actually ;) |
8b978dd5 |
222 | |
b51af7f9 |
223 | ## ---------------------------------------------------------------------------- |
1d68af04 |
224 | ## Bootstrapping |
b51af7f9 |
225 | ## ---------------------------------------------------------------------------- |
1d68af04 |
226 | ## The code below here is to bootstrap our MOP with itself. This is also |
b51af7f9 |
227 | ## sometimes called "tying the knot". By doing this, we make it much easier |
228 | ## to extend the MOP through subclassing and such since now you can use the |
1d68af04 |
229 | ## MOP itself to extend itself. |
230 | ## |
b51af7f9 |
231 | ## Yes, I know, thats weird and insane, but it's a good thing, trust me :) |
1d68af04 |
232 | ## ---------------------------------------------------------------------------- |
727919c5 |
233 | |
1d68af04 |
234 | # We need to add in the meta-attributes here so that |
235 | # any subclass of Class::MOP::* will be able to |
727919c5 |
236 | # inherit them using &construct_instance |
237 | |
f0480c45 |
238 | ## -------------------------------------------------------- |
6d5355c3 |
239 | ## Class::MOP::Package |
727919c5 |
240 | |
6d5355c3 |
241 | Class::MOP::Package->meta->add_attribute( |
8683db0e |
242 | Class::MOP::Attribute->new('package' => ( |
b880e0de |
243 | reader => { |
1d68af04 |
244 | # NOTE: we need to do this in order |
245 | # for the instance meta-object to |
b880e0de |
246 | # not fall into meta-circular death |
1d68af04 |
247 | # |
ce2ae40f |
248 | # we just alias the original method |
1d68af04 |
249 | # rather than re-produce it here |
ce2ae40f |
250 | 'name' => \&Class::MOP::Package::name |
b880e0de |
251 | }, |
727919c5 |
252 | )) |
253 | ); |
254 | |
a5e51f0b |
255 | Class::MOP::Package->meta->add_attribute( |
8683db0e |
256 | Class::MOP::Attribute->new('namespace' => ( |
a5e51f0b |
257 | reader => { |
56dcfc1a |
258 | # NOTE: |
ce2ae40f |
259 | # we just alias the original method |
260 | # rather than re-produce it here |
261 | 'namespace' => \&Class::MOP::Package::namespace |
a5e51f0b |
262 | }, |
2e877f58 |
263 | init_arg => undef, |
c4260b45 |
264 | default => sub { \undef } |
a5e51f0b |
265 | )) |
266 | ); |
267 | |
f0480c45 |
268 | ## -------------------------------------------------------- |
269 | ## Class::MOP::Module |
270 | |
271 | # NOTE: |
1d68af04 |
272 | # yeah this is kind of stretching things a bit, |
f0480c45 |
273 | # but truthfully the version should be an attribute |
1d68af04 |
274 | # of the Module, the weirdness comes from having to |
275 | # stick to Perl 5 convention and store it in the |
276 | # $VERSION package variable. Basically if you just |
277 | # squint at it, it will look how you want it to look. |
f0480c45 |
278 | # Either as a package variable, or as a attribute of |
279 | # the metaclass, isn't abstraction great :) |
280 | |
281 | Class::MOP::Module->meta->add_attribute( |
8683db0e |
282 | Class::MOP::Attribute->new('version' => ( |
f0480c45 |
283 | reader => { |
ce2ae40f |
284 | # NOTE: |
285 | # we just alias the original method |
1d68af04 |
286 | # rather than re-produce it here |
ce2ae40f |
287 | 'version' => \&Class::MOP::Module::version |
f0480c45 |
288 | }, |
2e877f58 |
289 | init_arg => undef, |
c4260b45 |
290 | default => sub { \undef } |
f0480c45 |
291 | )) |
292 | ); |
293 | |
294 | # NOTE: |
1d68af04 |
295 | # By following the same conventions as version here, |
296 | # we are opening up the possibility that people can |
297 | # use the $AUTHORITY in non-Class::MOP modules as |
298 | # well. |
f0480c45 |
299 | |
300 | Class::MOP::Module->meta->add_attribute( |
8683db0e |
301 | Class::MOP::Attribute->new('authority' => ( |
f0480c45 |
302 | reader => { |
ce2ae40f |
303 | # NOTE: |
304 | # we just alias the original method |
1d68af04 |
305 | # rather than re-produce it here |
ce2ae40f |
306 | 'authority' => \&Class::MOP::Module::authority |
1d68af04 |
307 | }, |
2e877f58 |
308 | init_arg => undef, |
c4260b45 |
309 | default => sub { \undef } |
f0480c45 |
310 | )) |
311 | ); |
312 | |
313 | ## -------------------------------------------------------- |
6d5355c3 |
314 | ## Class::MOP::Class |
315 | |
727919c5 |
316 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
317 | Class::MOP::Attribute->new('attributes' => ( |
f7259199 |
318 | reader => { |
1d68af04 |
319 | # NOTE: we need to do this in order |
320 | # for the instance meta-object to |
321 | # not fall into meta-circular death |
322 | # |
ce2ae40f |
323 | # we just alias the original method |
1d68af04 |
324 | # rather than re-produce it here |
ce2ae40f |
325 | 'get_attribute_map' => \&Class::MOP::Class::get_attribute_map |
f7259199 |
326 | }, |
727919c5 |
327 | default => sub { {} } |
328 | )) |
329 | ); |
330 | |
351bd7d4 |
331 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
332 | Class::MOP::Attribute->new('methods' => ( |
1d68af04 |
333 | reader => { |
ce2ae40f |
334 | # NOTE: |
335 | # we just alias the original method |
1d68af04 |
336 | # rather than re-produce it here |
ce2ae40f |
337 | 'get_method_map' => \&Class::MOP::Class::get_method_map |
92330ee2 |
338 | }, |
7855ddba |
339 | default => sub { {} } |
c4260b45 |
340 | )) |
341 | ); |
342 | |
343 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
344 | Class::MOP::Attribute->new('superclasses' => ( |
c23184fc |
345 | accessor => { |
346 | # NOTE: |
347 | # we just alias the original method |
1d68af04 |
348 | # rather than re-produce it here |
c23184fc |
349 | 'superclasses' => \&Class::MOP::Class::superclasses |
350 | }, |
2e877f58 |
351 | init_arg => undef, |
c23184fc |
352 | default => sub { \undef } |
353 | )) |
354 | ); |
355 | |
356 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
357 | Class::MOP::Attribute->new('attribute_metaclass' => ( |
1d68af04 |
358 | reader => { |
6d2118a4 |
359 | # NOTE: |
360 | # we just alias the original method |
1d68af04 |
361 | # rather than re-produce it here |
6d2118a4 |
362 | 'attribute_metaclass' => \&Class::MOP::Class::attribute_metaclass |
1d68af04 |
363 | }, |
351bd7d4 |
364 | default => 'Class::MOP::Attribute', |
365 | )) |
366 | ); |
367 | |
368 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
369 | Class::MOP::Attribute->new('method_metaclass' => ( |
1d68af04 |
370 | reader => { |
6d2118a4 |
371 | # NOTE: |
372 | # we just alias the original method |
1d68af04 |
373 | # rather than re-produce it here |
6d2118a4 |
374 | 'method_metaclass' => \&Class::MOP::Class::method_metaclass |
375 | }, |
1d68af04 |
376 | default => 'Class::MOP::Method', |
351bd7d4 |
377 | )) |
378 | ); |
379 | |
2bab2be6 |
380 | Class::MOP::Class->meta->add_attribute( |
8683db0e |
381 | Class::MOP::Attribute->new('instance_metaclass' => ( |
b880e0de |
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 | 'instance_metaclass' => \&Class::MOP::Class::instance_metaclass |
b880e0de |
390 | }, |
1d68af04 |
391 | default => 'Class::MOP::Instance', |
2bab2be6 |
392 | )) |
393 | ); |
394 | |
9d6dce77 |
395 | # NOTE: |
1d68af04 |
396 | # we don't actually need to tie the knot with |
397 | # Class::MOP::Class here, it is actually handled |
398 | # within Class::MOP::Class itself in the |
399 | # construct_class_instance method. |
9d6dce77 |
400 | |
f0480c45 |
401 | ## -------------------------------------------------------- |
727919c5 |
402 | ## Class::MOP::Attribute |
403 | |
7b31baf4 |
404 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
405 | Class::MOP::Attribute->new('name' => ( |
c23184fc |
406 | reader => { |
1d68af04 |
407 | # NOTE: we need to do this in order |
408 | # for the instance meta-object to |
409 | # not fall into meta-circular death |
410 | # |
ce2ae40f |
411 | # we just alias the original method |
1d68af04 |
412 | # rather than re-produce it here |
ce2ae40f |
413 | 'name' => \&Class::MOP::Attribute::name |
b880e0de |
414 | } |
7b31baf4 |
415 | )) |
416 | ); |
417 | |
418 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
419 | Class::MOP::Attribute->new('associated_class' => ( |
c23184fc |
420 | reader => { |
1d68af04 |
421 | # NOTE: we need to do this in order |
422 | # for the instance meta-object to |
423 | # not fall into meta-circular death |
424 | # |
ce2ae40f |
425 | # we just alias the original method |
1d68af04 |
426 | # rather than re-produce it here |
ce2ae40f |
427 | 'associated_class' => \&Class::MOP::Attribute::associated_class |
b880e0de |
428 | } |
7b31baf4 |
429 | )) |
430 | ); |
431 | |
432 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
433 | Class::MOP::Attribute->new('accessor' => ( |
6d2118a4 |
434 | reader => { 'accessor' => \&Class::MOP::Attribute::accessor }, |
435 | predicate => { 'has_accessor' => \&Class::MOP::Attribute::has_accessor }, |
7b31baf4 |
436 | )) |
437 | ); |
438 | |
439 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
440 | Class::MOP::Attribute->new('reader' => ( |
6d2118a4 |
441 | reader => { 'reader' => \&Class::MOP::Attribute::reader }, |
442 | predicate => { 'has_reader' => \&Class::MOP::Attribute::has_reader }, |
7b31baf4 |
443 | )) |
444 | ); |
445 | |
446 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
447 | Class::MOP::Attribute->new('initializer' => ( |
8ee74136 |
448 | reader => { 'initializer' => \&Class::MOP::Attribute::initializer }, |
449 | predicate => { 'has_initializer' => \&Class::MOP::Attribute::has_initializer }, |
0ab65f99 |
450 | )) |
451 | ); |
452 | |
453 | Class::MOP::Attribute->meta->add_attribute( |
d9d99689 |
454 | Class::MOP::Attribute->new('definition_context' => ( |
455 | reader => { 'definition_context' => \&Class::MOP::Attribute::definition_context }, |
456 | )) |
457 | ); |
458 | |
459 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
460 | Class::MOP::Attribute->new('writer' => ( |
6d2118a4 |
461 | reader => { 'writer' => \&Class::MOP::Attribute::writer }, |
462 | predicate => { 'has_writer' => \&Class::MOP::Attribute::has_writer }, |
7b31baf4 |
463 | )) |
464 | ); |
465 | |
466 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
467 | Class::MOP::Attribute->new('predicate' => ( |
6d2118a4 |
468 | reader => { 'predicate' => \&Class::MOP::Attribute::predicate }, |
469 | predicate => { 'has_predicate' => \&Class::MOP::Attribute::has_predicate }, |
7b31baf4 |
470 | )) |
471 | ); |
472 | |
473 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
474 | Class::MOP::Attribute->new('clearer' => ( |
6d2118a4 |
475 | reader => { 'clearer' => \&Class::MOP::Attribute::clearer }, |
476 | predicate => { 'has_clearer' => \&Class::MOP::Attribute::has_clearer }, |
7d28758b |
477 | )) |
478 | ); |
479 | |
480 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
481 | Class::MOP::Attribute->new('builder' => ( |
1d68af04 |
482 | reader => { 'builder' => \&Class::MOP::Attribute::builder }, |
483 | predicate => { 'has_builder' => \&Class::MOP::Attribute::has_builder }, |
484 | )) |
485 | ); |
486 | |
487 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
488 | Class::MOP::Attribute->new('init_arg' => ( |
6d2118a4 |
489 | reader => { 'init_arg' => \&Class::MOP::Attribute::init_arg }, |
490 | predicate => { 'has_init_arg' => \&Class::MOP::Attribute::has_init_arg }, |
7b31baf4 |
491 | )) |
492 | ); |
493 | |
494 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
495 | Class::MOP::Attribute->new('default' => ( |
7b31baf4 |
496 | # default has a custom 'reader' method ... |
1d68af04 |
497 | predicate => { 'has_default' => \&Class::MOP::Attribute::has_default }, |
7b31baf4 |
498 | )) |
499 | ); |
500 | |
3545c727 |
501 | Class::MOP::Attribute->meta->add_attribute( |
8683db0e |
502 | Class::MOP::Attribute->new('associated_methods' => ( |
c23184fc |
503 | reader => { 'associated_methods' => \&Class::MOP::Attribute::associated_methods }, |
1d68af04 |
504 | default => sub { [] } |
3545c727 |
505 | )) |
506 | ); |
727919c5 |
507 | |
5659d76e |
508 | Class::MOP::Attribute->meta->add_method('clone' => sub { |
a740253a |
509 | my $self = shift; |
1d68af04 |
510 | $self->meta->clone_object($self, @_); |
727919c5 |
511 | }); |
512 | |
f0480c45 |
513 | ## -------------------------------------------------------- |
b6164407 |
514 | ## Class::MOP::Method |
b6164407 |
515 | Class::MOP::Method->meta->add_attribute( |
8683db0e |
516 | Class::MOP::Attribute->new('body' => ( |
c23184fc |
517 | reader => { 'body' => \&Class::MOP::Method::body }, |
b6164407 |
518 | )) |
519 | ); |
520 | |
4c105333 |
521 | Class::MOP::Method->meta->add_attribute( |
5e607260 |
522 | Class::MOP::Attribute->new('associated_metaclass' => ( |
5e607260 |
523 | reader => { 'associated_metaclass' => \&Class::MOP::Method::associated_metaclass }, |
524 | )) |
525 | ); |
526 | |
527 | Class::MOP::Method->meta->add_attribute( |
8683db0e |
528 | Class::MOP::Attribute->new('package_name' => ( |
4c105333 |
529 | reader => { 'package_name' => \&Class::MOP::Method::package_name }, |
530 | )) |
531 | ); |
532 | |
533 | Class::MOP::Method->meta->add_attribute( |
8683db0e |
534 | Class::MOP::Attribute->new('name' => ( |
4c105333 |
535 | reader => { 'name' => \&Class::MOP::Method::name }, |
536 | )) |
537 | ); |
538 | |
2226a8b0 |
539 | Class::MOP::Method->meta->add_attribute( |
540 | Class::MOP::Attribute->new('original_method' => ( |
541 | reader => { 'original_method' => \&Class::MOP::Method::original_method }, |
542 | writer => { '_set_original_method' => \&Class::MOP::Method::_set_original_method }, |
543 | )) |
544 | ); |
545 | |
4c105333 |
546 | Class::MOP::Method->meta->add_method('clone' => sub { |
547 | my $self = shift; |
2226a8b0 |
548 | my $clone = $self->meta->clone_object($self, @_); |
549 | $clone->_set_original_method($self); |
550 | return $clone; |
4c105333 |
551 | }); |
552 | |
b6164407 |
553 | ## -------------------------------------------------------- |
554 | ## Class::MOP::Method::Wrapped |
555 | |
556 | # NOTE: |
1d68af04 |
557 | # the way this item is initialized, this |
558 | # really does not follow the standard |
559 | # practices of attributes, but we put |
b6164407 |
560 | # it here for completeness |
561 | Class::MOP::Method::Wrapped->meta->add_attribute( |
8683db0e |
562 | Class::MOP::Attribute->new('modifier_table') |
b6164407 |
563 | ); |
564 | |
565 | ## -------------------------------------------------------- |
565f0cbb |
566 | ## Class::MOP::Method::Generated |
567 | |
568 | Class::MOP::Method::Generated->meta->add_attribute( |
8683db0e |
569 | Class::MOP::Attribute->new('is_inline' => ( |
565f0cbb |
570 | reader => { 'is_inline' => \&Class::MOP::Method::Generated::is_inline }, |
4c105333 |
571 | default => 0, |
1d68af04 |
572 | )) |
565f0cbb |
573 | ); |
574 | |
d9d99689 |
575 | Class::MOP::Method::Generated->meta->add_attribute( |
576 | Class::MOP::Attribute->new('definition_context' => ( |
577 | reader => { 'definition_context' => \&Class::MOP::Method::Generated::definition_context }, |
578 | )) |
579 | ); |
580 | |
565f0cbb |
581 | ## -------------------------------------------------------- |
d90b42a6 |
582 | ## Class::MOP::Method::Accessor |
583 | |
584 | Class::MOP::Method::Accessor->meta->add_attribute( |
8683db0e |
585 | Class::MOP::Attribute->new('attribute' => ( |
1d68af04 |
586 | reader => { |
587 | 'associated_attribute' => \&Class::MOP::Method::Accessor::associated_attribute |
d90b42a6 |
588 | }, |
1d68af04 |
589 | )) |
d90b42a6 |
590 | ); |
591 | |
592 | Class::MOP::Method::Accessor->meta->add_attribute( |
8683db0e |
593 | Class::MOP::Attribute->new('accessor_type' => ( |
c23184fc |
594 | reader => { 'accessor_type' => \&Class::MOP::Method::Accessor::accessor_type }, |
1d68af04 |
595 | )) |
d90b42a6 |
596 | ); |
597 | |
d90b42a6 |
598 | ## -------------------------------------------------------- |
599 | ## Class::MOP::Method::Constructor |
600 | |
601 | Class::MOP::Method::Constructor->meta->add_attribute( |
8683db0e |
602 | Class::MOP::Attribute->new('options' => ( |
1d68af04 |
603 | reader => { |
604 | 'options' => \&Class::MOP::Method::Constructor::options |
d90b42a6 |
605 | }, |
4c105333 |
606 | default => sub { +{} } |
1d68af04 |
607 | )) |
d90b42a6 |
608 | ); |
609 | |
610 | Class::MOP::Method::Constructor->meta->add_attribute( |
8683db0e |
611 | Class::MOP::Attribute->new('associated_metaclass' => ( |
e8a38403 |
612 | init_arg => "metaclass", # FIXME alias and rename |
1d68af04 |
613 | reader => { |
614 | 'associated_metaclass' => \&Class::MOP::Method::Constructor::associated_metaclass |
615 | }, |
616 | )) |
d90b42a6 |
617 | ); |
618 | |
619 | ## -------------------------------------------------------- |
86482605 |
620 | ## Class::MOP::Instance |
621 | |
622 | # NOTE: |
1d68af04 |
623 | # these don't yet do much of anything, but are just |
86482605 |
624 | # included for completeness |
625 | |
626 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
627 | Class::MOP::Attribute->new('associated_metaclass', |
628 | reader => { associated_metaclass => \&Class::MOP::Instance::associated_metaclass }, |
629 | ), |
86482605 |
630 | ); |
631 | |
632 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
633 | Class::MOP::Attribute->new('_class_name', |
634 | init_arg => undef, |
635 | reader => { _class_name => \&Class::MOP::Instance::_class_name }, |
636 | #lazy => 1, # not yet supported by Class::MOP but out our version does it anyway |
637 | #default => sub { $_[0]->associated_metaclass->name }, |
638 | ), |
639 | ); |
640 | |
641 | Class::MOP::Instance->meta->add_attribute( |
642 | Class::MOP::Attribute->new('attributes', |
0b5d46da |
643 | reader => { attributes => \&Class::MOP::Instance::get_all_attributes }, |
74890687 |
644 | ), |
32bfc810 |
645 | ); |
646 | |
647 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
648 | Class::MOP::Attribute->new('slots', |
649 | reader => { slots => \&Class::MOP::Instance::slots }, |
650 | ), |
86482605 |
651 | ); |
652 | |
63d08a9e |
653 | Class::MOP::Instance->meta->add_attribute( |
74890687 |
654 | Class::MOP::Attribute->new('slot_hash', |
655 | reader => { slot_hash => \&Class::MOP::Instance::slot_hash }, |
656 | ), |
63d08a9e |
657 | ); |
658 | |
659 | |
caa051fa |
660 | # we need the meta instance of the meta instance to be created now, in order |
661 | # for the constructor to be able to use it |
662 | Class::MOP::Instance->meta->get_meta_instance; |
663 | |
caa051fa |
664 | # pretend the add_method never happenned. it hasn't yet affected anything |
665 | undef Class::MOP::Instance->meta->{_package_cache_flag}; |
666 | |
86482605 |
667 | ## -------------------------------------------------------- |
f0480c45 |
668 | ## Now close all the Class::MOP::* classes |
4d47b77f |
669 | |
1aa13cf4 |
670 | # NOTE: we don't need to inline the the accessors this only lengthens |
671 | # the compile time of the MOP, and gives us no actual benefits. |
0b9372a2 |
672 | |
673 | $_->meta->make_immutable( |
6c2f6b5c |
674 | inline_constructor => 1, |
675 | replace_constructor => 1, |
676 | constructor_name => "_new", |
45582002 |
677 | inline_accessors => 0, |
0b9372a2 |
678 | ) for qw/ |
1d68af04 |
679 | Class::MOP::Package |
680 | Class::MOP::Module |
681 | Class::MOP::Class |
682 | |
0b9372a2 |
683 | Class::MOP::Attribute |
1d68af04 |
684 | Class::MOP::Method |
685 | Class::MOP::Instance |
686 | |
687 | Class::MOP::Object |
0b9372a2 |
688 | |
565f0cbb |
689 | Class::MOP::Method::Generated |
1d68af04 |
690 | |
ba38bf08 |
691 | Class::MOP::Method::Accessor |
1d68af04 |
692 | Class::MOP::Method::Constructor |
693 | Class::MOP::Method::Wrapped |
0b9372a2 |
694 | /; |
b6164407 |
695 | |
94b19069 |
696 | 1; |
697 | |
698 | __END__ |
699 | |
700 | =pod |
701 | |
1d68af04 |
702 | =head1 NAME |
94b19069 |
703 | |
704 | Class::MOP - A Meta Object Protocol for Perl 5 |
705 | |
94b19069 |
706 | =head1 DESCRIPTON |
707 | |
127d39a7 |
708 | This module is a fully functioning meta object protocol for the |
1d68af04 |
709 | Perl 5 object system. It makes no attempt to change the behavior or |
710 | characteristics of the Perl 5 object system, only to create a |
27e31eaf |
711 | protocol for its manipulation and introspection. |
94b19069 |
712 | |
1d68af04 |
713 | That said, it does attempt to create the tools for building a rich |
714 | set of extensions to the Perl 5 object system. Every attempt has been |
715 | made for these tools to keep to the spirit of the Perl 5 object |
94b19069 |
716 | system that we all know and love. |
717 | |
1d68af04 |
718 | This documentation is admittedly sparse on details, as time permits |
719 | I will try to improve them. For now, I suggest looking at the items |
720 | listed in the L<SEE ALSO> section for more information. In particular |
721 | the book "The Art of the Meta Object Protocol" was very influential |
40483095 |
722 | in the development of this system. |
723 | |
bfe4d0fc |
724 | =head2 What is a Meta Object Protocol? |
725 | |
1d68af04 |
726 | A meta object protocol is an API to an object system. |
bfe4d0fc |
727 | |
1d68af04 |
728 | To be more specific, it is a set of abstractions of the components of |
729 | an object system (typically things like; classes, object, methods, |
730 | object attributes, etc.). These abstractions can then be used to both |
bfe4d0fc |
731 | inspect and manipulate the object system which they describe. |
732 | |
1d68af04 |
733 | It can be said that there are two MOPs for any object system; the |
734 | implicit MOP, and the explicit MOP. The implicit MOP handles things |
735 | like method dispatch or inheritance, which happen automatically as |
736 | part of how the object system works. The explicit MOP typically |
737 | handles the introspection/reflection features of the object system. |
738 | All object systems have implicit MOPs, without one, they would not |
739 | work. Explict MOPs however as less common, and depending on the |
740 | language can vary from restrictive (Reflection in Java or C#) to |
741 | wide open (CLOS is a perfect example). |
bfe4d0fc |
742 | |
e16da3e6 |
743 | =head2 Yet Another Class Builder!! Why? |
744 | |
1d68af04 |
745 | This is B<not> a class builder so much as it is a I<class builder |
746 | B<builder>>. My intent is that an end user does not use this module |
747 | directly, but instead this module is used by module authors to |
748 | build extensions and features onto the Perl 5 object system. |
e16da3e6 |
749 | |
94b19069 |
750 | =head2 Who is this module for? |
751 | |
1d68af04 |
752 | This module is specifically for anyone who has ever created or |
753 | wanted to create a module for the Class:: namespace. The tools which |
754 | this module will provide will hopefully make it easier to do more |
755 | complex things with Perl 5 classes by removing such barriers as |
756 | the need to hack the symbol tables, or understand the fine details |
757 | of method dispatch. |
94b19069 |
758 | |
bfe4d0fc |
759 | =head2 What changes do I have to make to use this module? |
760 | |
1d68af04 |
761 | This module was designed to be as unintrusive as possible. Many of |
762 | its features are accessible without B<any> change to your existsing |
763 | code at all. It is meant to be a compliment to your existing code and |
764 | not an intrusion on your code base. Unlike many other B<Class::> |
765 | modules, this module B<does not> require you subclass it, or even that |
766 | you C<use> it in within your module's package. |
bfe4d0fc |
767 | |
1d68af04 |
768 | The only features which requires additions to your code are the |
2eb717d5 |
769 | attribute handling and instance construction features, and these are |
1d68af04 |
770 | both completely optional features. The only reason for this is because |
771 | Perl 5's object system does not actually have these features built |
2eb717d5 |
772 | in. More information about this feature can be found below. |
bfe4d0fc |
773 | |
774 | =head2 A Note about Performance? |
775 | |
1d68af04 |
776 | It is a common misconception that explict MOPs are performance drains. |
777 | But this is not a universal truth at all, it is an side-effect of |
778 | specific implementations. For instance, using Java reflection is much |
779 | slower because the JVM cannot take advantage of any compiler |
780 | optimizations, and the JVM has to deal with much more runtime type |
781 | information as well. Reflection in C# is marginally better as it was |
782 | designed into the language and runtime (the CLR). In contrast, CLOS |
783 | (the Common Lisp Object System) was built to support an explicit MOP, |
784 | and so performance is tuned for it. |
785 | |
786 | This library in particular does it's absolute best to avoid putting |
787 | B<any> drain at all upon your code's performance. In fact, by itself |
788 | it does nothing to affect your existing code. So you only pay for |
2eb717d5 |
789 | what you actually use. |
bfe4d0fc |
790 | |
550d56db |
791 | =head2 About Metaclass compatibility |
792 | |
1d68af04 |
793 | This module makes sure that all metaclasses created are both upwards |
794 | and downwards compatible. The topic of metaclass compatibility is |
795 | highly esoteric and is something only encountered when doing deep and |
796 | involved metaclass hacking. There are two basic kinds of metaclass |
797 | incompatibility; upwards and downwards. |
550d56db |
798 | |
1d68af04 |
799 | Upwards metaclass compatibility means that the metaclass of a |
800 | given class is either the same as (or a subclass of) all of the |
550d56db |
801 | class's ancestors. |
802 | |
1d68af04 |
803 | Downward metaclass compatibility means that the metaclasses of a |
804 | given class's anscestors are all either the same as (or a subclass |
550d56db |
805 | of) that metaclass. |
806 | |
1d68af04 |
807 | Here is a diagram showing a set of two classes (C<A> and C<B>) and |
808 | two metaclasses (C<Meta::A> and C<Meta::B>) which have correct |
550d56db |
809 | metaclass compatibility both upwards and downwards. |
810 | |
811 | +---------+ +---------+ |
812 | | Meta::A |<----| Meta::B | <....... (instance of ) |
1d68af04 |
813 | +---------+ +---------+ <------- (inherits from) |
550d56db |
814 | ^ ^ |
815 | : : |
816 | +---------+ +---------+ |
817 | | A |<----| B | |
818 | +---------+ +---------+ |
819 | |
1d68af04 |
820 | As I said this is a highly esoteric topic and one you will only run |
821 | into if you do a lot of subclassing of B<Class::MOP::Class>. If you |
822 | are interested in why this is an issue see the paper |
823 | I<Uniform and safe metaclass composition> linked to in the |
550d56db |
824 | L<SEE ALSO> section of this document. |
825 | |
aa448b16 |
826 | =head2 Using custom metaclasses |
827 | |
1d68af04 |
828 | Always use the metaclass pragma when using a custom metaclass, this |
829 | will ensure the proper initialization order and not accidentely |
830 | create an incorrect type of metaclass for you. This is a very rare |
831 | problem, and one which can only occur if you are doing deep metaclass |
aa448b16 |
832 | programming. So in other words, don't worry about it. |
833 | |
94b19069 |
834 | =head1 PROTOCOLS |
835 | |
127d39a7 |
836 | The protocol is divided into 4 main sub-protocols: |
94b19069 |
837 | |
838 | =over 4 |
839 | |
840 | =item The Class protocol |
841 | |
1d68af04 |
842 | This provides a means of manipulating and introspecting a Perl 5 |
843 | class. It handles all of symbol table hacking for you, and provides |
94b19069 |
844 | a rich set of methods that go beyond simple package introspection. |
845 | |
552e3d24 |
846 | See L<Class::MOP::Class> for more details. |
847 | |
94b19069 |
848 | =item The Attribute protocol |
849 | |
1d68af04 |
850 | This provides a consistent represenation for an attribute of a |
851 | Perl 5 class. Since there are so many ways to create and handle |
127d39a7 |
852 | attributes in Perl 5 OO, this attempts to provide as much of a |
1d68af04 |
853 | unified approach as possible, while giving the freedom and |
94b19069 |
854 | flexibility to subclass for specialization. |
855 | |
552e3d24 |
856 | See L<Class::MOP::Attribute> for more details. |
857 | |
94b19069 |
858 | =item The Method protocol |
859 | |
1d68af04 |
860 | This provides a means of manipulating and introspecting methods in |
861 | the Perl 5 object system. As with attributes, there are many ways to |
862 | approach this topic, so we try to keep it pretty basic, while still |
94b19069 |
863 | making it possible to extend the system in many ways. |
864 | |
552e3d24 |
865 | See L<Class::MOP::Method> for more details. |
94b19069 |
866 | |
127d39a7 |
867 | =item The Instance protocol |
868 | |
869 | This provides a layer of abstraction for creating object instances. |
870 | Since the other layers use this protocol, it is relatively easy to |
871 | change the type of your instances from the default HASH ref to other |
872 | types of references. Several examples are provided in the F<examples/> |
873 | directory included in this distribution. |
874 | |
875 | See L<Class::MOP::Instance> for more details. |
876 | |
94b19069 |
877 | =back |
878 | |
be7677c7 |
879 | =head1 FUNCTIONS |
880 | |
c1d5345a |
881 | =head2 Constants |
882 | |
883 | =over 4 |
884 | |
885 | =item I<IS_RUNNING_ON_5_10> |
886 | |
887 | We set this constant depending on what version perl we are on, this |
888 | allows us to take advantage of new 5.10 features and stay backwards |
889 | compat. |
890 | |
9efe16ca |
891 | =item I<HAVE_ISAREV> |
892 | |
893 | Whether or not C<mro> provides C<get_isarev>, a much faster way to get all the |
894 | subclasses of a certain class. |
895 | |
c1d5345a |
896 | =back |
897 | |
448b6e55 |
898 | =head2 Utility functions |
899 | |
bd07fbdb |
900 | Note that these are all called as B<functions, not methods>. |
081a927b |
901 | |
448b6e55 |
902 | =over 4 |
903 | |
904 | =item B<load_class ($class_name)> |
905 | |
1d68af04 |
906 | This will load a given C<$class_name> and if it does not have an |
448b6e55 |
907 | already initialized metaclass, then it will intialize one for it. |
127d39a7 |
908 | This function can be used in place of tricks like |
909 | C<eval "use $module"> or using C<require>. |
448b6e55 |
910 | |
911 | =item B<is_class_loaded ($class_name)> |
912 | |
1d68af04 |
913 | This will return a boolean depending on if the C<$class_name> has |
914 | been loaded. |
448b6e55 |
915 | |
1d68af04 |
916 | NOTE: This does a basic check of the symbol table to try and |
448b6e55 |
917 | determine as best it can if the C<$class_name> is loaded, it |
1d68af04 |
918 | is probably correct about 99% of the time. |
448b6e55 |
919 | |
b1f5f41d |
920 | =item B<check_package_cache_flag ($pkg)> |
e0e4674a |
921 | |
bd07fbdb |
922 | B<NOTE: DO NOT USE THIS FUNCTION, IT IS FOR INTERNAL USE ONLY!> |
923 | |
127d39a7 |
924 | This will return an integer that is managed by C<Class::MOP::Class> |
925 | to determine if a module's symbol table has been altered. |
926 | |
927 | In Perl 5.10 or greater, this flag is package specific. However in |
928 | versions prior to 5.10, this will use the C<PL_sub_generation> variable |
929 | which is not package specific. |
930 | |
e0e4674a |
931 | =item B<get_code_info ($code)> |
932 | |
bd07fbdb |
933 | B<NOTE: DO NOT USE THIS FUNCTION, IT IS FOR INTERNAL USE ONLY!> |
934 | |
127d39a7 |
935 | This function returns two values, the name of the package the C<$code> |
936 | is from and the name of the C<$code> itself. This is used by several |
937 | elements of the MOP to detemine where a given C<$code> reference is from. |
938 | |
4c105333 |
939 | =item B<subname ($name, $code)> |
940 | |
941 | B<NOTE: DO NOT USE THIS FUNCTION, IT IS FOR INTERNAL USE ONLY!> |
942 | |
943 | If possible, we will load the L<Sub::Name> module and this will function |
944 | as C<Sub::Name::subname> does, otherwise it will just return the C<$code> |
945 | argument. |
946 | |
6f49cf3f |
947 | =item B<in_global_destruction> |
948 | |
bd07fbdb |
949 | B<NOTE: DO NOT USE THIS FUNCTION, IT IS FOR INTERNAL USE ONLY!> |
950 | |
6f49cf3f |
951 | If L<Devel::GlobalDestruction> is available, this returns true under global |
952 | destruction. |
953 | |
954 | Otherwise it's a constant returning false. |
955 | |
063ad0c5 |
956 | =item B<load_first_existing_class ($class_name, [$class_name, ...])> |
957 | |
958 | B<NOTE: DO NOT USE THIS FUNCTION, IT IS FOR INTERNAL USE ONLY!> |
959 | |
960 | Given a list of class names, this function will attempt to load each |
961 | one in turn. |
962 | |
1d8153bd |
963 | If it finds a class it can load, it will return that class' name. |
964 | If none of the classes can be loaded, it will throw an exception. |
063ad0c5 |
965 | |
448b6e55 |
966 | =back |
967 | |
968 | =head2 Metaclass cache functions |
969 | |
6c842677 |
970 | Class::MOP holds a cache of metaclasses. The following are functions |
1d68af04 |
971 | (B<not methods>) which can be used to access that cache. It is not |
6c842677 |
972 | recommended that you mess with these. Bad things could happen, but if |
973 | you are brave and willing to risk it: go for it! |
be7677c7 |
974 | |
975 | =over 4 |
976 | |
977 | =item B<get_all_metaclasses> |
978 | |
6c842677 |
979 | This will return a hash of all the metaclass instances that have |
980 | been cached by B<Class::MOP::Class>, keyed by the package name. |
b9d9fc0b |
981 | |
be7677c7 |
982 | =item B<get_all_metaclass_instances> |
983 | |
6c842677 |
984 | This will return a list of all the metaclass instances that have |
b9d9fc0b |
985 | been cached by B<Class::MOP::Class>. |
986 | |
be7677c7 |
987 | =item B<get_all_metaclass_names> |
988 | |
6c842677 |
989 | This will return a list of all the metaclass names that have |
b9d9fc0b |
990 | been cached by B<Class::MOP::Class>. |
991 | |
be7677c7 |
992 | =item B<get_metaclass_by_name ($name)> |
993 | |
e5ca9cbb |
994 | This will return a cached B<Class::MOP::Class> instance, or nothing |
6c842677 |
995 | if no metaclass exists with that C<$name>. |
127d39a7 |
996 | |
be7677c7 |
997 | =item B<store_metaclass_by_name ($name, $meta)> |
998 | |
127d39a7 |
999 | This will store a metaclass in the cache at the supplied C<$key>. |
1000 | |
be7677c7 |
1001 | =item B<weaken_metaclass ($name)> |
1002 | |
6c842677 |
1003 | In rare cases (e.g. anonymous metaclasses) it is desirable to |
1004 | store a weakened reference in the metaclass cache. This |
1005 | function will weaken the reference to the metaclass stored |
1006 | in C<$name>. |
127d39a7 |
1007 | |
be7677c7 |
1008 | =item B<does_metaclass_exist ($name)> |
1009 | |
127d39a7 |
1010 | This will return true of there exists a metaclass stored in the |
6c842677 |
1011 | C<$name> key, and return false otherwise. |
127d39a7 |
1012 | |
be7677c7 |
1013 | =item B<remove_metaclass_by_name ($name)> |
1014 | |
6c842677 |
1015 | This will remove the metaclass stored in the C<$name> key. |
127d39a7 |
1016 | |
be7677c7 |
1017 | =back |
1018 | |
552e3d24 |
1019 | =head1 SEE ALSO |
8b978dd5 |
1020 | |
552e3d24 |
1021 | =head2 Books |
8b978dd5 |
1022 | |
1d68af04 |
1023 | There are very few books out on Meta Object Protocols and Metaclasses |
1024 | because it is such an esoteric topic. The following books are really |
1025 | the only ones I have found. If you know of any more, B<I<please>> |
a2e85e6c |
1026 | email me and let me know, I would love to hear about them. |
1027 | |
8b978dd5 |
1028 | =over 4 |
1029 | |
552e3d24 |
1030 | =item "The Art of the Meta Object Protocol" |
8b978dd5 |
1031 | |
552e3d24 |
1032 | =item "Advances in Object-Oriented Metalevel Architecture and Reflection" |
8b978dd5 |
1033 | |
b51af7f9 |
1034 | =item "Putting MetaClasses to Work" |
1035 | |
a2e85e6c |
1036 | =item "Smalltalk: The Language" |
1037 | |
94b19069 |
1038 | =back |
1039 | |
550d56db |
1040 | =head2 Papers |
1041 | |
1042 | =over 4 |
1043 | |
1044 | =item Uniform and safe metaclass composition |
1045 | |
1d68af04 |
1046 | An excellent paper by the people who brought us the original Traits paper. |
1047 | This paper is on how Traits can be used to do safe metaclass composition, |
1048 | and offers an excellent introduction section which delves into the topic of |
550d56db |
1049 | metaclass compatibility. |
1050 | |
1051 | L<http://www.iam.unibe.ch/~scg/Archive/Papers/Duca05ySafeMetaclassTrait.pdf> |
1052 | |
1053 | =item Safe Metaclass Programming |
1054 | |
1d68af04 |
1055 | This paper seems to precede the above paper, and propose a mix-in based |
1056 | approach as opposed to the Traits based approach. Both papers have similar |
1057 | information on the metaclass compatibility problem space. |
550d56db |
1058 | |
1059 | L<http://citeseer.ist.psu.edu/37617.html> |
1060 | |
1061 | =back |
1062 | |
552e3d24 |
1063 | =head2 Prior Art |
8b978dd5 |
1064 | |
1065 | =over 4 |
1066 | |
7184ca14 |
1067 | =item The Perl 6 MetaModel work in the Pugs project |
8b978dd5 |
1068 | |
1069 | =over 4 |
1070 | |
552e3d24 |
1071 | =item L<http://svn.openfoundry.org/pugs/perl5/Perl6-MetaModel> |
8b978dd5 |
1072 | |
552e3d24 |
1073 | =item L<http://svn.openfoundry.org/pugs/perl5/Perl6-ObjectSpace> |
8b978dd5 |
1074 | |
1075 | =back |
1076 | |
94b19069 |
1077 | =back |
1078 | |
1d68af04 |
1079 | =head2 Articles |
f8dfcfb7 |
1080 | |
1081 | =over 4 |
1082 | |
1d68af04 |
1083 | =item CPAN Module Review of Class::MOP |
f8dfcfb7 |
1084 | |
1085 | L<http://www.oreillynet.com/onlamp/blog/2006/06/cpan_module_review_classmop.html> |
1086 | |
1087 | =back |
1088 | |
a2e85e6c |
1089 | =head1 SIMILAR MODULES |
1090 | |
1d68af04 |
1091 | As I have said above, this module is a class-builder-builder, so it is |
1092 | not the same thing as modules like L<Class::Accessor> and |
1093 | L<Class::MethodMaker>. That being said there are very few modules on CPAN |
1094 | with similar goals to this module. The one I have found which is most |
1095 | like this module is L<Class::Meta>, although it's philosophy and the MOP it |
1096 | creates are very different from this modules. |
94b19069 |
1097 | |
a2e85e6c |
1098 | =head1 BUGS |
1099 | |
1d68af04 |
1100 | All complex software has bugs lurking in it, and this module is no |
a2e85e6c |
1101 | exception. If you find a bug please either email me, or add the bug |
1102 | to cpan-RT. |
1103 | |
1104 | =head1 ACKNOWLEDGEMENTS |
1105 | |
1106 | =over 4 |
1107 | |
b9d9fc0b |
1108 | =item Rob Kinyon |
a2e85e6c |
1109 | |
1d68af04 |
1110 | Thanks to Rob for actually getting the development of this module kick-started. |
a2e85e6c |
1111 | |
1112 | =back |
1113 | |
1a09d9cc |
1114 | =head1 AUTHORS |
94b19069 |
1115 | |
a2e85e6c |
1116 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
552e3d24 |
1117 | |
9c8cda90 |
1118 | B<with contributions from:> |
1119 | |
1120 | Brandon (blblack) Black |
1121 | |
4f116037 |
1122 | Florian (rafl) Ragwitz |
1123 | |
9c8cda90 |
1124 | Guillermo (groditi) Roditi |
1125 | |
9195ddff |
1126 | Matt (mst) Trout |
1127 | |
9c8cda90 |
1128 | Rob (robkinyon) Kinyon |
1129 | |
1130 | Yuval (nothingmuch) Kogman |
1a09d9cc |
1131 | |
f430cfa4 |
1132 | Scott (konobi) McWhirter |
1133 | |
94b19069 |
1134 | =head1 COPYRIGHT AND LICENSE |
1135 | |
69e3ab0a |
1136 | Copyright 2006-2008 by Infinity Interactive, Inc. |
94b19069 |
1137 | |
1138 | L<http://www.iinteractive.com> |
1139 | |
1140 | This library is free software; you can redistribute it and/or modify |
1d68af04 |
1141 | it under the same terms as Perl itself. |
94b19069 |
1142 | |
1143 | =cut |