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 | |
2eb717d5 |
12 | use Class::MOP::Class; |
13 | use Class::MOP::Attribute; |
14 | use Class::MOP::Method; |
15 | |
c23184fc |
16 | use Class::MOP::Immutable; |
857f87a7 |
17 | |
b1f5f41d |
18 | BEGIN { |
8c5cc782 |
19 | our $VERSION = '0.60'; |
b1f5f41d |
20 | our $AUTHORITY = 'cpan:STEVAN'; |
21 | |
11b56828 |
22 | *IS_RUNNING_ON_5_10 = ($] < 5.009_005) |
23 | ? sub () { 0 } |
4c105333 |
24 | : sub () { 1 }; |
46b23b44 |
25 | |
4c105333 |
26 | # NOTE: |
27 | # we may not use this yet, but once |
28 | # the get_code_info XS gets merged |
29 | # upstream to it, we will always use |
30 | # it. But for now it is just kinda |
31 | # extra overhead. |
32 | # - SL |
33 | require Sub::Identify; |
34 | |
35 | # stash these for a sec, and see how things go |
36 | my $_PP_subname = sub { $_[1] }; |
a982eca7 |
37 | my $_PP_get_code_info = \&Sub::Identify::get_code_info; |
4c105333 |
38 | |
e2d4fc55 |
39 | if ($ENV{CLASS_MOP_NO_XS}) { |
4c105333 |
40 | # NOTE: |
41 | # this is if you really want things |
42 | # to be slow, then you can force the |
43 | # no-XS rule this way, otherwise we |
44 | # make an effort to load as much of |
45 | # the XS as possible. |
46 | # - SL |
47 | no warnings 'prototype', 'redefine'; |
6c34db07 |
48 | |
49 | unless (IS_RUNNING_ON_5_10()) { |
50 | # get this from MRO::Compat ... |
51 | *check_package_cache_flag = \&MRO::Compat::__get_pkg_gen_pp; |
52 | } |
53 | else { |
54 | # NOTE: |
55 | # but if we are running 5.10 |
56 | # there is no need to use the |
57 | # Pure Perl version since we |
58 | # can use the built in mro |
59 | # version instead. |
60 | # - SL |
61 | *check_package_cache_flag = \&mro::get_pkg_gen; |
62 | } |
4c105333 |
63 | # our own version of Sub::Name |
64 | *subname = $_PP_subname; |
65 | # and the Sub::Identify version of the get_code_info |
66 | *get_code_info = $_PP_get_code_info; |
67 | } |
68 | else { |
69 | # now try our best to get as much |
70 | # of the XS loaded as possible |
71 | { |
72 | local $@; |
73 | eval { |
74 | require XSLoader; |
75 | XSLoader::load( 'Class::MOP', $VERSION ); |
76 | }; |
77 | die $@ if $@ && $@ !~ /object version|loadable object/; |
78 | |
79 | # okay, so the XS failed to load, so |
80 | # use the pure perl one instead. |
81 | *get_code_info = $_PP_get_code_info if $@; |
82 | } |
83 | |
84 | # get it from MRO::Compat |
85 | *check_package_cache_flag = \&mro::get_pkg_gen; |
86 | |
87 | # now try and load the Sub::Name |
88 | # module and use that as a means |
89 | # for naming our CVs, if not, we |
90 | # use the workaround instead. |
91 | if ( eval { require Sub::Name } ) { |
6c34db07 |
92 | *subname = \&Sub::Name::subname; |
4c105333 |
93 | } |
94 | else { |
95 | *subname = $_PP_subname; |
96 | } |
97 | } |
b1f5f41d |
98 | } |
e0e4674a |
99 | |
be7677c7 |
100 | { |
101 | # Metaclasses are singletons, so we cache them here. |
102 | # there is no need to worry about destruction though |
103 | # because they should die only when the program dies. |
104 | # After all, do package definitions even get reaped? |
1d68af04 |
105 | my %METAS; |
106 | |
107 | # means of accessing all the metaclasses that have |
be7677c7 |
108 | # been initialized thus far (for mugwumps obj browser) |
1d68af04 |
109 | sub get_all_metaclasses { %METAS } |
110 | sub get_all_metaclass_instances { values %METAS } |
111 | sub get_all_metaclass_names { keys %METAS } |
be7677c7 |
112 | sub get_metaclass_by_name { $METAS{$_[0]} } |
1d68af04 |
113 | sub store_metaclass_by_name { $METAS{$_[0]} = $_[1] } |
114 | sub weaken_metaclass { weaken($METAS{$_[0]}) } |
be7677c7 |
115 | sub does_metaclass_exist { exists $METAS{$_[0]} && defined $METAS{$_[0]} } |
1d68af04 |
116 | sub remove_metaclass_by_name { $METAS{$_[0]} = undef } |
117 | |
be7677c7 |
118 | # NOTE: |
1d68af04 |
119 | # We only cache metaclasses, meaning instances of |
120 | # Class::MOP::Class. We do not cache instance of |
be7677c7 |
121 | # Class::MOP::Package or Class::MOP::Module. Mostly |
1d68af04 |
122 | # because I don't yet see a good reason to do so. |
be7677c7 |
123 | } |
124 | |
448b6e55 |
125 | sub load_class { |
126 | my $class = shift; |
ab5e2f48 |
127 | |
128 | if (ref($class) || !defined($class) || !length($class)) { |
129 | my $display = defined($class) ? $class : 'undef'; |
130 | confess "Invalid class name ($display)"; |
131 | } |
132 | |
1d68af04 |
133 | # see if this is already |
448b6e55 |
134 | # loaded in the symbol table |
135 | return 1 if is_class_loaded($class); |
136 | # otherwise require it ... |
137 | my $file = $class . '.pm'; |
138 | $file =~ s{::}{/}g; |
139 | eval { CORE::require($file) }; |
140 | confess "Could not load class ($class) because : $@" if $@; |
141 | unless (does_metaclass_exist($class)) { |
142 | eval { Class::MOP::Class->initialize($class) }; |
1d68af04 |
143 | confess "Could not initialize class ($class) because : $@" if $@; |
448b6e55 |
144 | } |
145 | 1; # return true if it worked |
146 | } |
147 | |
148 | sub is_class_loaded { |
c1d5345a |
149 | my $class = shift; |
26fcef27 |
150 | |
151 | return 0 if ref($class) || !defined($class) || !length($class); |
152 | |
153 | # walk the symbol table tree to avoid autovififying |
154 | # \*{${main::}{"Foo::"}} == \*main::Foo:: |
155 | |
156 | my $pack = \*::; |
157 | foreach my $part (split('::', $class)) { |
158 | return 0 unless exists ${$$pack}{"${part}::"}; |
159 | $pack = \*{${$$pack}{"${part}::"}}; |
c1d5345a |
160 | } |
26fcef27 |
161 | |
162 | # check for $VERSION or @ISA |
163 | return 1 if exists ${$$pack}{VERSION} |
164 | && defined *{${$$pack}{VERSION}}{SCALAR}; |
165 | return 1 if exists ${$$pack}{ISA} |
166 | && defined *{${$$pack}{ISA}}{ARRAY}; |
167 | |
168 | # check for any method |
169 | foreach ( keys %{$$pack} ) { |
170 | next if substr($_, -2, 2) eq '::'; |
171 | return 1 if defined *{${$$pack}{$_}}{CODE}; |
172 | } |
173 | |
174 | # fail |
c1d5345a |
175 | return 0; |
448b6e55 |
176 | } |
177 | |
178 | |
aa448b16 |
179 | ## ---------------------------------------------------------------------------- |
180 | ## Setting up our environment ... |
181 | ## ---------------------------------------------------------------------------- |
1d68af04 |
182 | ## Class::MOP needs to have a few things in the global perl environment so |
aa448b16 |
183 | ## that it can operate effectively. Those things are done here. |
184 | ## ---------------------------------------------------------------------------- |
185 | |
3bf7644b |
186 | # ... nothing yet actually ;) |
8b978dd5 |
187 | |
b51af7f9 |
188 | ## ---------------------------------------------------------------------------- |
1d68af04 |
189 | ## Bootstrapping |
b51af7f9 |
190 | ## ---------------------------------------------------------------------------- |
1d68af04 |
191 | ## The code below here is to bootstrap our MOP with itself. This is also |
b51af7f9 |
192 | ## sometimes called "tying the knot". By doing this, we make it much easier |
193 | ## to extend the MOP through subclassing and such since now you can use the |
1d68af04 |
194 | ## MOP itself to extend itself. |
195 | ## |
b51af7f9 |
196 | ## Yes, I know, thats weird and insane, but it's a good thing, trust me :) |
1d68af04 |
197 | ## ---------------------------------------------------------------------------- |
727919c5 |
198 | |
1d68af04 |
199 | # We need to add in the meta-attributes here so that |
200 | # any subclass of Class::MOP::* will be able to |
727919c5 |
201 | # inherit them using &construct_instance |
202 | |
f0480c45 |
203 | ## -------------------------------------------------------- |
6d5355c3 |
204 | ## Class::MOP::Package |
727919c5 |
205 | |
6d5355c3 |
206 | Class::MOP::Package->meta->add_attribute( |
c23184fc |
207 | Class::MOP::Attribute->new('$!package' => ( |
b880e0de |
208 | reader => { |
1d68af04 |
209 | # NOTE: we need to do this in order |
210 | # for the instance meta-object to |
b880e0de |
211 | # not fall into meta-circular death |
1d68af04 |
212 | # |
ce2ae40f |
213 | # we just alias the original method |
1d68af04 |
214 | # rather than re-produce it here |
ce2ae40f |
215 | 'name' => \&Class::MOP::Package::name |
b880e0de |
216 | }, |
c23184fc |
217 | init_arg => 'package', |
727919c5 |
218 | )) |
219 | ); |
220 | |
a5e51f0b |
221 | Class::MOP::Package->meta->add_attribute( |
c23184fc |
222 | Class::MOP::Attribute->new('%!namespace' => ( |
a5e51f0b |
223 | reader => { |
56dcfc1a |
224 | # NOTE: |
ce2ae40f |
225 | # we just alias the original method |
226 | # rather than re-produce it here |
227 | 'namespace' => \&Class::MOP::Package::namespace |
a5e51f0b |
228 | }, |
2e877f58 |
229 | init_arg => undef, |
c4260b45 |
230 | default => sub { \undef } |
a5e51f0b |
231 | )) |
232 | ); |
233 | |
9d6dce77 |
234 | # NOTE: |
235 | # use the metaclass to construct the meta-package |
236 | # which is a superclass of the metaclass itself :P |
237 | Class::MOP::Package->meta->add_method('initialize' => sub { |
238 | my $class = shift; |
239 | my $package_name = shift; |
1d68af04 |
240 | $class->meta->new_object('package' => $package_name, @_); |
9d6dce77 |
241 | }); |
242 | |
f0480c45 |
243 | ## -------------------------------------------------------- |
244 | ## Class::MOP::Module |
245 | |
246 | # NOTE: |
1d68af04 |
247 | # yeah this is kind of stretching things a bit, |
f0480c45 |
248 | # but truthfully the version should be an attribute |
1d68af04 |
249 | # of the Module, the weirdness comes from having to |
250 | # stick to Perl 5 convention and store it in the |
251 | # $VERSION package variable. Basically if you just |
252 | # squint at it, it will look how you want it to look. |
f0480c45 |
253 | # Either as a package variable, or as a attribute of |
254 | # the metaclass, isn't abstraction great :) |
255 | |
256 | Class::MOP::Module->meta->add_attribute( |
c23184fc |
257 | Class::MOP::Attribute->new('$!version' => ( |
f0480c45 |
258 | reader => { |
ce2ae40f |
259 | # NOTE: |
260 | # we just alias the original method |
1d68af04 |
261 | # rather than re-produce it here |
ce2ae40f |
262 | 'version' => \&Class::MOP::Module::version |
f0480c45 |
263 | }, |
2e877f58 |
264 | init_arg => undef, |
c4260b45 |
265 | default => sub { \undef } |
f0480c45 |
266 | )) |
267 | ); |
268 | |
269 | # NOTE: |
1d68af04 |
270 | # By following the same conventions as version here, |
271 | # we are opening up the possibility that people can |
272 | # use the $AUTHORITY in non-Class::MOP modules as |
273 | # well. |
f0480c45 |
274 | |
275 | Class::MOP::Module->meta->add_attribute( |
c23184fc |
276 | Class::MOP::Attribute->new('$!authority' => ( |
f0480c45 |
277 | reader => { |
ce2ae40f |
278 | # NOTE: |
279 | # we just alias the original method |
1d68af04 |
280 | # rather than re-produce it here |
ce2ae40f |
281 | 'authority' => \&Class::MOP::Module::authority |
1d68af04 |
282 | }, |
2e877f58 |
283 | init_arg => undef, |
c4260b45 |
284 | default => sub { \undef } |
f0480c45 |
285 | )) |
286 | ); |
287 | |
288 | ## -------------------------------------------------------- |
6d5355c3 |
289 | ## Class::MOP::Class |
290 | |
727919c5 |
291 | Class::MOP::Class->meta->add_attribute( |
c23184fc |
292 | Class::MOP::Attribute->new('%!attributes' => ( |
f7259199 |
293 | reader => { |
1d68af04 |
294 | # NOTE: we need to do this in order |
295 | # for the instance meta-object to |
296 | # not fall into meta-circular death |
297 | # |
ce2ae40f |
298 | # we just alias the original method |
1d68af04 |
299 | # rather than re-produce it here |
ce2ae40f |
300 | 'get_attribute_map' => \&Class::MOP::Class::get_attribute_map |
f7259199 |
301 | }, |
c23184fc |
302 | init_arg => 'attributes', |
727919c5 |
303 | default => sub { {} } |
304 | )) |
305 | ); |
306 | |
351bd7d4 |
307 | Class::MOP::Class->meta->add_attribute( |
c23184fc |
308 | Class::MOP::Attribute->new('%!methods' => ( |
309 | init_arg => 'methods', |
1d68af04 |
310 | reader => { |
ce2ae40f |
311 | # NOTE: |
312 | # we just alias the original method |
1d68af04 |
313 | # rather than re-produce it here |
ce2ae40f |
314 | 'get_method_map' => \&Class::MOP::Class::get_method_map |
92330ee2 |
315 | }, |
7855ddba |
316 | default => sub { {} } |
c4260b45 |
317 | )) |
318 | ); |
319 | |
320 | Class::MOP::Class->meta->add_attribute( |
c23184fc |
321 | Class::MOP::Attribute->new('@!superclasses' => ( |
322 | accessor => { |
323 | # NOTE: |
324 | # we just alias the original method |
1d68af04 |
325 | # rather than re-produce it here |
c23184fc |
326 | 'superclasses' => \&Class::MOP::Class::superclasses |
327 | }, |
2e877f58 |
328 | init_arg => undef, |
c23184fc |
329 | default => sub { \undef } |
330 | )) |
331 | ); |
332 | |
333 | Class::MOP::Class->meta->add_attribute( |
334 | Class::MOP::Attribute->new('$!attribute_metaclass' => ( |
1d68af04 |
335 | reader => { |
6d2118a4 |
336 | # NOTE: |
337 | # we just alias the original method |
1d68af04 |
338 | # rather than re-produce it here |
6d2118a4 |
339 | 'attribute_metaclass' => \&Class::MOP::Class::attribute_metaclass |
1d68af04 |
340 | }, |
c23184fc |
341 | init_arg => 'attribute_metaclass', |
351bd7d4 |
342 | default => 'Class::MOP::Attribute', |
343 | )) |
344 | ); |
345 | |
346 | Class::MOP::Class->meta->add_attribute( |
c23184fc |
347 | Class::MOP::Attribute->new('$!method_metaclass' => ( |
1d68af04 |
348 | reader => { |
6d2118a4 |
349 | # NOTE: |
350 | # we just alias the original method |
1d68af04 |
351 | # rather than re-produce it here |
6d2118a4 |
352 | 'method_metaclass' => \&Class::MOP::Class::method_metaclass |
353 | }, |
c23184fc |
354 | init_arg => 'method_metaclass', |
1d68af04 |
355 | default => 'Class::MOP::Method', |
351bd7d4 |
356 | )) |
357 | ); |
358 | |
2bab2be6 |
359 | Class::MOP::Class->meta->add_attribute( |
c23184fc |
360 | Class::MOP::Attribute->new('$!instance_metaclass' => ( |
b880e0de |
361 | reader => { |
1d68af04 |
362 | # NOTE: we need to do this in order |
363 | # for the instance meta-object to |
364 | # not fall into meta-circular death |
365 | # |
ce2ae40f |
366 | # we just alias the original method |
1d68af04 |
367 | # rather than re-produce it here |
ce2ae40f |
368 | 'instance_metaclass' => \&Class::MOP::Class::instance_metaclass |
b880e0de |
369 | }, |
c23184fc |
370 | init_arg => 'instance_metaclass', |
1d68af04 |
371 | default => 'Class::MOP::Instance', |
2bab2be6 |
372 | )) |
373 | ); |
374 | |
9d6dce77 |
375 | # NOTE: |
1d68af04 |
376 | # we don't actually need to tie the knot with |
377 | # Class::MOP::Class here, it is actually handled |
378 | # within Class::MOP::Class itself in the |
379 | # construct_class_instance method. |
9d6dce77 |
380 | |
f0480c45 |
381 | ## -------------------------------------------------------- |
727919c5 |
382 | ## Class::MOP::Attribute |
383 | |
7b31baf4 |
384 | Class::MOP::Attribute->meta->add_attribute( |
c23184fc |
385 | Class::MOP::Attribute->new('$!name' => ( |
386 | init_arg => 'name', |
387 | reader => { |
1d68af04 |
388 | # NOTE: we need to do this in order |
389 | # for the instance meta-object to |
390 | # not fall into meta-circular death |
391 | # |
ce2ae40f |
392 | # we just alias the original method |
1d68af04 |
393 | # rather than re-produce it here |
ce2ae40f |
394 | 'name' => \&Class::MOP::Attribute::name |
b880e0de |
395 | } |
7b31baf4 |
396 | )) |
397 | ); |
398 | |
399 | Class::MOP::Attribute->meta->add_attribute( |
c23184fc |
400 | Class::MOP::Attribute->new('$!associated_class' => ( |
401 | init_arg => 'associated_class', |
402 | reader => { |
1d68af04 |
403 | # NOTE: we need to do this in order |
404 | # for the instance meta-object to |
405 | # not fall into meta-circular death |
406 | # |
ce2ae40f |
407 | # we just alias the original method |
1d68af04 |
408 | # rather than re-produce it here |
ce2ae40f |
409 | 'associated_class' => \&Class::MOP::Attribute::associated_class |
b880e0de |
410 | } |
7b31baf4 |
411 | )) |
412 | ); |
413 | |
414 | Class::MOP::Attribute->meta->add_attribute( |
c23184fc |
415 | Class::MOP::Attribute->new('$!accessor' => ( |
416 | init_arg => 'accessor', |
6d2118a4 |
417 | reader => { 'accessor' => \&Class::MOP::Attribute::accessor }, |
418 | predicate => { 'has_accessor' => \&Class::MOP::Attribute::has_accessor }, |
7b31baf4 |
419 | )) |
420 | ); |
421 | |
422 | Class::MOP::Attribute->meta->add_attribute( |
c23184fc |
423 | Class::MOP::Attribute->new('$!reader' => ( |
424 | init_arg => 'reader', |
6d2118a4 |
425 | reader => { 'reader' => \&Class::MOP::Attribute::reader }, |
426 | predicate => { 'has_reader' => \&Class::MOP::Attribute::has_reader }, |
7b31baf4 |
427 | )) |
428 | ); |
429 | |
430 | Class::MOP::Attribute->meta->add_attribute( |
0ab65f99 |
431 | Class::MOP::Attribute->new('$!initializer' => ( |
432 | init_arg => 'initializer', |
8ee74136 |
433 | reader => { 'initializer' => \&Class::MOP::Attribute::initializer }, |
434 | predicate => { 'has_initializer' => \&Class::MOP::Attribute::has_initializer }, |
0ab65f99 |
435 | )) |
436 | ); |
437 | |
438 | Class::MOP::Attribute->meta->add_attribute( |
c23184fc |
439 | Class::MOP::Attribute->new('$!writer' => ( |
440 | init_arg => 'writer', |
6d2118a4 |
441 | reader => { 'writer' => \&Class::MOP::Attribute::writer }, |
442 | predicate => { 'has_writer' => \&Class::MOP::Attribute::has_writer }, |
7b31baf4 |
443 | )) |
444 | ); |
445 | |
446 | Class::MOP::Attribute->meta->add_attribute( |
c23184fc |
447 | Class::MOP::Attribute->new('$!predicate' => ( |
448 | init_arg => 'predicate', |
6d2118a4 |
449 | reader => { 'predicate' => \&Class::MOP::Attribute::predicate }, |
450 | predicate => { 'has_predicate' => \&Class::MOP::Attribute::has_predicate }, |
7b31baf4 |
451 | )) |
452 | ); |
453 | |
454 | Class::MOP::Attribute->meta->add_attribute( |
c23184fc |
455 | Class::MOP::Attribute->new('$!clearer' => ( |
456 | init_arg => 'clearer', |
6d2118a4 |
457 | reader => { 'clearer' => \&Class::MOP::Attribute::clearer }, |
458 | predicate => { 'has_clearer' => \&Class::MOP::Attribute::has_clearer }, |
7d28758b |
459 | )) |
460 | ); |
461 | |
462 | Class::MOP::Attribute->meta->add_attribute( |
1d68af04 |
463 | Class::MOP::Attribute->new('$!builder' => ( |
464 | init_arg => 'builder', |
465 | reader => { 'builder' => \&Class::MOP::Attribute::builder }, |
466 | predicate => { 'has_builder' => \&Class::MOP::Attribute::has_builder }, |
467 | )) |
468 | ); |
469 | |
470 | Class::MOP::Attribute->meta->add_attribute( |
c23184fc |
471 | Class::MOP::Attribute->new('$!init_arg' => ( |
472 | init_arg => 'init_arg', |
6d2118a4 |
473 | reader => { 'init_arg' => \&Class::MOP::Attribute::init_arg }, |
474 | predicate => { 'has_init_arg' => \&Class::MOP::Attribute::has_init_arg }, |
7b31baf4 |
475 | )) |
476 | ); |
477 | |
478 | Class::MOP::Attribute->meta->add_attribute( |
c23184fc |
479 | Class::MOP::Attribute->new('$!default' => ( |
480 | init_arg => 'default', |
7b31baf4 |
481 | # default has a custom 'reader' method ... |
1d68af04 |
482 | predicate => { 'has_default' => \&Class::MOP::Attribute::has_default }, |
7b31baf4 |
483 | )) |
484 | ); |
485 | |
3545c727 |
486 | Class::MOP::Attribute->meta->add_attribute( |
c23184fc |
487 | Class::MOP::Attribute->new('@!associated_methods' => ( |
488 | init_arg => 'associated_methods', |
489 | reader => { 'associated_methods' => \&Class::MOP::Attribute::associated_methods }, |
1d68af04 |
490 | default => sub { [] } |
3545c727 |
491 | )) |
492 | ); |
727919c5 |
493 | |
494 | # NOTE: (meta-circularity) |
495 | # This should be one of the last things done |
496 | # it will "tie the knot" with Class::MOP::Attribute |
1d68af04 |
497 | # so that it uses the attributes meta-objects |
498 | # to construct itself. |
727919c5 |
499 | Class::MOP::Attribute->meta->add_method('new' => sub { |
500 | my $class = shift; |
501 | my $name = shift; |
1d68af04 |
502 | my %options = @_; |
503 | |
727919c5 |
504 | (defined $name && $name) |
505 | || confess "You must provide a name for the attribute"; |
1d68af04 |
506 | $options{init_arg} = $name |
5659d76e |
507 | if not exists $options{init_arg}; |
1d68af04 |
508 | |
509 | if(exists $options{builder}){ |
510 | confess("builder must be a defined scalar value which is a method name") |
511 | if ref $options{builder} || !(defined $options{builder}); |
512 | confess("Setting both default and builder is not allowed.") |
513 | if exists $options{default}; |
8fe581e5 |
514 | } else { |
515 | (Class::MOP::Attribute::is_default_a_coderef(\%options)) |
516 | || confess("References are not allowed as default values, you must ". |
3c0a8087 |
517 | "wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])") |
8fe581e5 |
518 | if exists $options{default} && ref $options{default}; |
1d68af04 |
519 | } |
5659d76e |
520 | # return the new object |
521 | $class->meta->new_object(name => $name, %options); |
522 | }); |
523 | |
524 | Class::MOP::Attribute->meta->add_method('clone' => sub { |
a740253a |
525 | my $self = shift; |
1d68af04 |
526 | $self->meta->clone_object($self, @_); |
727919c5 |
527 | }); |
528 | |
f0480c45 |
529 | ## -------------------------------------------------------- |
b6164407 |
530 | ## Class::MOP::Method |
531 | |
532 | Class::MOP::Method->meta->add_attribute( |
c23184fc |
533 | Class::MOP::Attribute->new('&!body' => ( |
534 | init_arg => 'body', |
535 | reader => { 'body' => \&Class::MOP::Method::body }, |
b6164407 |
536 | )) |
537 | ); |
538 | |
4c105333 |
539 | Class::MOP::Method->meta->add_attribute( |
540 | Class::MOP::Attribute->new('$!package_name' => ( |
541 | init_arg => 'package_name', |
542 | reader => { 'package_name' => \&Class::MOP::Method::package_name }, |
543 | )) |
544 | ); |
545 | |
546 | Class::MOP::Method->meta->add_attribute( |
547 | Class::MOP::Attribute->new('$!name' => ( |
548 | init_arg => 'name', |
549 | reader => { 'name' => \&Class::MOP::Method::name }, |
550 | )) |
551 | ); |
552 | |
553 | Class::MOP::Method->meta->add_method('wrap' => sub { |
554 | my $class = shift; |
555 | my $code = shift; |
556 | my %options = @_; |
557 | |
9b522fc4 |
558 | ('CODE' eq ref($code)) |
4c105333 |
559 | || confess "You must supply a CODE reference to bless, not (" . ($code || 'undef') . ")"; |
560 | |
b38f3848 |
561 | ($options{package_name} && $options{name}) |
562 | || confess "You must supply the package_name and name parameters"; |
563 | |
4c105333 |
564 | # return the new object |
565 | $class->meta->new_object(body => $code, %options); |
566 | }); |
567 | |
568 | Class::MOP::Method->meta->add_method('clone' => sub { |
569 | my $self = shift; |
570 | $self->meta->clone_object($self, @_); |
571 | }); |
572 | |
b6164407 |
573 | ## -------------------------------------------------------- |
574 | ## Class::MOP::Method::Wrapped |
575 | |
576 | # NOTE: |
1d68af04 |
577 | # the way this item is initialized, this |
578 | # really does not follow the standard |
579 | # practices of attributes, but we put |
b6164407 |
580 | # it here for completeness |
581 | Class::MOP::Method::Wrapped->meta->add_attribute( |
c23184fc |
582 | Class::MOP::Attribute->new('%!modifier_table') |
b6164407 |
583 | ); |
584 | |
585 | ## -------------------------------------------------------- |
565f0cbb |
586 | ## Class::MOP::Method::Generated |
587 | |
588 | Class::MOP::Method::Generated->meta->add_attribute( |
589 | Class::MOP::Attribute->new('$!is_inline' => ( |
590 | init_arg => 'is_inline', |
591 | reader => { 'is_inline' => \&Class::MOP::Method::Generated::is_inline }, |
4c105333 |
592 | default => 0, |
1d68af04 |
593 | )) |
565f0cbb |
594 | ); |
595 | |
4c105333 |
596 | Class::MOP::Method::Generated->meta->add_method('new' => sub { |
597 | my ($class, %options) = @_; |
b38f3848 |
598 | ($options{package_name} && $options{name}) |
599 | || confess "You must supply the package_name and name parameters"; |
4c105333 |
600 | my $self = $class->meta->new_object(%options); |
601 | $self->initialize_body; |
602 | $self; |
603 | }); |
604 | |
565f0cbb |
605 | ## -------------------------------------------------------- |
d90b42a6 |
606 | ## Class::MOP::Method::Accessor |
607 | |
608 | Class::MOP::Method::Accessor->meta->add_attribute( |
c23184fc |
609 | Class::MOP::Attribute->new('$!attribute' => ( |
610 | init_arg => '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( |
c23184fc |
618 | Class::MOP::Attribute->new('$!accessor_type' => ( |
619 | init_arg => 'accessor_type', |
620 | reader => { 'accessor_type' => \&Class::MOP::Method::Accessor::accessor_type }, |
1d68af04 |
621 | )) |
d90b42a6 |
622 | ); |
623 | |
4c105333 |
624 | Class::MOP::Method::Accessor->meta->add_method('new' => sub { |
625 | my $class = shift; |
626 | my %options = @_; |
627 | |
628 | (exists $options{attribute}) |
629 | || confess "You must supply an attribute to construct with"; |
630 | |
631 | (exists $options{accessor_type}) |
632 | || confess "You must supply an accessor_type to construct with"; |
633 | |
634 | (Scalar::Util::blessed($options{attribute}) && $options{attribute}->isa('Class::MOP::Attribute')) |
635 | || confess "You must supply an attribute which is a 'Class::MOP::Attribute' instance"; |
636 | |
b38f3848 |
637 | ($options{package_name} && $options{name}) |
638 | || confess "You must supply the package_name and name parameters"; |
639 | |
4c105333 |
640 | # return the new object |
641 | my $self = $class->meta->new_object(%options); |
642 | |
643 | # we don't want this creating |
644 | # a cycle in the code, if not |
645 | # needed |
646 | Scalar::Util::weaken($self->{'$!attribute'}); |
647 | |
648 | $self->initialize_body; |
649 | |
650 | $self; |
651 | }); |
652 | |
d90b42a6 |
653 | |
654 | ## -------------------------------------------------------- |
655 | ## Class::MOP::Method::Constructor |
656 | |
657 | Class::MOP::Method::Constructor->meta->add_attribute( |
c23184fc |
658 | Class::MOP::Attribute->new('%!options' => ( |
659 | init_arg => 'options', |
1d68af04 |
660 | reader => { |
661 | 'options' => \&Class::MOP::Method::Constructor::options |
d90b42a6 |
662 | }, |
4c105333 |
663 | default => sub { +{} } |
1d68af04 |
664 | )) |
d90b42a6 |
665 | ); |
666 | |
667 | Class::MOP::Method::Constructor->meta->add_attribute( |
c23184fc |
668 | Class::MOP::Attribute->new('$!associated_metaclass' => ( |
669 | init_arg => 'metaclass', |
1d68af04 |
670 | reader => { |
671 | 'associated_metaclass' => \&Class::MOP::Method::Constructor::associated_metaclass |
672 | }, |
673 | )) |
d90b42a6 |
674 | ); |
675 | |
4c105333 |
676 | Class::MOP::Method::Constructor->meta->add_method('new' => sub { |
677 | my $class = shift; |
678 | my %options = @_; |
679 | |
680 | (Scalar::Util::blessed $options{metaclass} && $options{metaclass}->isa('Class::MOP::Class')) |
681 | || confess "You must pass a metaclass instance if you want to inline" |
682 | if $options{is_inline}; |
683 | |
b38f3848 |
684 | ($options{package_name} && $options{name}) |
685 | || confess "You must supply the package_name and name parameters"; |
686 | |
4c105333 |
687 | # return the new object |
688 | my $self = $class->meta->new_object(%options); |
689 | |
690 | # we don't want this creating |
691 | # a cycle in the code, if not |
692 | # needed |
693 | Scalar::Util::weaken($self->{'$!associated_metaclass'}); |
694 | |
695 | $self->initialize_body; |
696 | |
697 | $self; |
698 | }); |
699 | |
d90b42a6 |
700 | ## -------------------------------------------------------- |
86482605 |
701 | ## Class::MOP::Instance |
702 | |
703 | # NOTE: |
1d68af04 |
704 | # these don't yet do much of anything, but are just |
86482605 |
705 | # included for completeness |
706 | |
707 | Class::MOP::Instance->meta->add_attribute( |
c23184fc |
708 | Class::MOP::Attribute->new('$!meta') |
86482605 |
709 | ); |
710 | |
711 | Class::MOP::Instance->meta->add_attribute( |
c23184fc |
712 | Class::MOP::Attribute->new('@!slots') |
86482605 |
713 | ); |
714 | |
715 | ## -------------------------------------------------------- |
f0480c45 |
716 | ## Now close all the Class::MOP::* classes |
4d47b77f |
717 | |
0b9372a2 |
718 | # NOTE: |
1d68af04 |
719 | # we don't need to inline the |
720 | # constructors or the accessors |
721 | # this only lengthens the compile |
722 | # time of the MOP, and gives us |
0b9372a2 |
723 | # no actual benefits. |
724 | |
725 | $_->meta->make_immutable( |
726 | inline_constructor => 0, |
727 | inline_accessors => 0, |
728 | ) for qw/ |
1d68af04 |
729 | Class::MOP::Package |
730 | Class::MOP::Module |
731 | Class::MOP::Class |
732 | |
0b9372a2 |
733 | Class::MOP::Attribute |
1d68af04 |
734 | Class::MOP::Method |
735 | Class::MOP::Instance |
736 | |
737 | Class::MOP::Object |
0b9372a2 |
738 | |
565f0cbb |
739 | Class::MOP::Method::Generated |
1d68af04 |
740 | |
ba38bf08 |
741 | Class::MOP::Method::Accessor |
1d68af04 |
742 | Class::MOP::Method::Constructor |
743 | Class::MOP::Method::Wrapped |
0b9372a2 |
744 | /; |
b6164407 |
745 | |
94b19069 |
746 | 1; |
747 | |
748 | __END__ |
749 | |
750 | =pod |
751 | |
1d68af04 |
752 | =head1 NAME |
94b19069 |
753 | |
754 | Class::MOP - A Meta Object Protocol for Perl 5 |
755 | |
94b19069 |
756 | =head1 DESCRIPTON |
757 | |
127d39a7 |
758 | This module is a fully functioning meta object protocol for the |
1d68af04 |
759 | Perl 5 object system. It makes no attempt to change the behavior or |
760 | characteristics of the Perl 5 object system, only to create a |
27e31eaf |
761 | protocol for its manipulation and introspection. |
94b19069 |
762 | |
1d68af04 |
763 | That said, it does attempt to create the tools for building a rich |
764 | set of extensions to the Perl 5 object system. Every attempt has been |
765 | made for these tools to keep to the spirit of the Perl 5 object |
94b19069 |
766 | system that we all know and love. |
767 | |
1d68af04 |
768 | This documentation is admittedly sparse on details, as time permits |
769 | I will try to improve them. For now, I suggest looking at the items |
770 | listed in the L<SEE ALSO> section for more information. In particular |
771 | the book "The Art of the Meta Object Protocol" was very influential |
40483095 |
772 | in the development of this system. |
773 | |
bfe4d0fc |
774 | =head2 What is a Meta Object Protocol? |
775 | |
1d68af04 |
776 | A meta object protocol is an API to an object system. |
bfe4d0fc |
777 | |
1d68af04 |
778 | To be more specific, it is a set of abstractions of the components of |
779 | an object system (typically things like; classes, object, methods, |
780 | object attributes, etc.). These abstractions can then be used to both |
bfe4d0fc |
781 | inspect and manipulate the object system which they describe. |
782 | |
1d68af04 |
783 | It can be said that there are two MOPs for any object system; the |
784 | implicit MOP, and the explicit MOP. The implicit MOP handles things |
785 | like method dispatch or inheritance, which happen automatically as |
786 | part of how the object system works. The explicit MOP typically |
787 | handles the introspection/reflection features of the object system. |
788 | All object systems have implicit MOPs, without one, they would not |
789 | work. Explict MOPs however as less common, and depending on the |
790 | language can vary from restrictive (Reflection in Java or C#) to |
791 | wide open (CLOS is a perfect example). |
bfe4d0fc |
792 | |
e16da3e6 |
793 | =head2 Yet Another Class Builder!! Why? |
794 | |
1d68af04 |
795 | This is B<not> a class builder so much as it is a I<class builder |
796 | B<builder>>. My intent is that an end user does not use this module |
797 | directly, but instead this module is used by module authors to |
798 | build extensions and features onto the Perl 5 object system. |
e16da3e6 |
799 | |
94b19069 |
800 | =head2 Who is this module for? |
801 | |
1d68af04 |
802 | This module is specifically for anyone who has ever created or |
803 | wanted to create a module for the Class:: namespace. The tools which |
804 | this module will provide will hopefully make it easier to do more |
805 | complex things with Perl 5 classes by removing such barriers as |
806 | the need to hack the symbol tables, or understand the fine details |
807 | of method dispatch. |
94b19069 |
808 | |
bfe4d0fc |
809 | =head2 What changes do I have to make to use this module? |
810 | |
1d68af04 |
811 | This module was designed to be as unintrusive as possible. Many of |
812 | its features are accessible without B<any> change to your existsing |
813 | code at all. It is meant to be a compliment to your existing code and |
814 | not an intrusion on your code base. Unlike many other B<Class::> |
815 | modules, this module B<does not> require you subclass it, or even that |
816 | you C<use> it in within your module's package. |
bfe4d0fc |
817 | |
1d68af04 |
818 | The only features which requires additions to your code are the |
2eb717d5 |
819 | attribute handling and instance construction features, and these are |
1d68af04 |
820 | both completely optional features. The only reason for this is because |
821 | Perl 5's object system does not actually have these features built |
2eb717d5 |
822 | in. More information about this feature can be found below. |
bfe4d0fc |
823 | |
824 | =head2 A Note about Performance? |
825 | |
1d68af04 |
826 | It is a common misconception that explict MOPs are performance drains. |
827 | But this is not a universal truth at all, it is an side-effect of |
828 | specific implementations. For instance, using Java reflection is much |
829 | slower because the JVM cannot take advantage of any compiler |
830 | optimizations, and the JVM has to deal with much more runtime type |
831 | information as well. Reflection in C# is marginally better as it was |
832 | designed into the language and runtime (the CLR). In contrast, CLOS |
833 | (the Common Lisp Object System) was built to support an explicit MOP, |
834 | and so performance is tuned for it. |
835 | |
836 | This library in particular does it's absolute best to avoid putting |
837 | B<any> drain at all upon your code's performance. In fact, by itself |
838 | it does nothing to affect your existing code. So you only pay for |
2eb717d5 |
839 | what you actually use. |
bfe4d0fc |
840 | |
550d56db |
841 | =head2 About Metaclass compatibility |
842 | |
1d68af04 |
843 | This module makes sure that all metaclasses created are both upwards |
844 | and downwards compatible. The topic of metaclass compatibility is |
845 | highly esoteric and is something only encountered when doing deep and |
846 | involved metaclass hacking. There are two basic kinds of metaclass |
847 | incompatibility; upwards and downwards. |
550d56db |
848 | |
1d68af04 |
849 | Upwards metaclass compatibility means that the metaclass of a |
850 | given class is either the same as (or a subclass of) all of the |
550d56db |
851 | class's ancestors. |
852 | |
1d68af04 |
853 | Downward metaclass compatibility means that the metaclasses of a |
854 | given class's anscestors are all either the same as (or a subclass |
550d56db |
855 | of) that metaclass. |
856 | |
1d68af04 |
857 | Here is a diagram showing a set of two classes (C<A> and C<B>) and |
858 | two metaclasses (C<Meta::A> and C<Meta::B>) which have correct |
550d56db |
859 | metaclass compatibility both upwards and downwards. |
860 | |
861 | +---------+ +---------+ |
862 | | Meta::A |<----| Meta::B | <....... (instance of ) |
1d68af04 |
863 | +---------+ +---------+ <------- (inherits from) |
550d56db |
864 | ^ ^ |
865 | : : |
866 | +---------+ +---------+ |
867 | | A |<----| B | |
868 | +---------+ +---------+ |
869 | |
1d68af04 |
870 | As I said this is a highly esoteric topic and one you will only run |
871 | into if you do a lot of subclassing of B<Class::MOP::Class>. If you |
872 | are interested in why this is an issue see the paper |
873 | I<Uniform and safe metaclass composition> linked to in the |
550d56db |
874 | L<SEE ALSO> section of this document. |
875 | |
aa448b16 |
876 | =head2 Using custom metaclasses |
877 | |
1d68af04 |
878 | Always use the metaclass pragma when using a custom metaclass, this |
879 | will ensure the proper initialization order and not accidentely |
880 | create an incorrect type of metaclass for you. This is a very rare |
881 | problem, and one which can only occur if you are doing deep metaclass |
aa448b16 |
882 | programming. So in other words, don't worry about it. |
883 | |
94b19069 |
884 | =head1 PROTOCOLS |
885 | |
127d39a7 |
886 | The protocol is divided into 4 main sub-protocols: |
94b19069 |
887 | |
888 | =over 4 |
889 | |
890 | =item The Class protocol |
891 | |
1d68af04 |
892 | This provides a means of manipulating and introspecting a Perl 5 |
893 | class. It handles all of symbol table hacking for you, and provides |
94b19069 |
894 | a rich set of methods that go beyond simple package introspection. |
895 | |
552e3d24 |
896 | See L<Class::MOP::Class> for more details. |
897 | |
94b19069 |
898 | =item The Attribute protocol |
899 | |
1d68af04 |
900 | This provides a consistent represenation for an attribute of a |
901 | Perl 5 class. Since there are so many ways to create and handle |
127d39a7 |
902 | attributes in Perl 5 OO, this attempts to provide as much of a |
1d68af04 |
903 | unified approach as possible, while giving the freedom and |
94b19069 |
904 | flexibility to subclass for specialization. |
905 | |
552e3d24 |
906 | See L<Class::MOP::Attribute> for more details. |
907 | |
94b19069 |
908 | =item The Method protocol |
909 | |
1d68af04 |
910 | This provides a means of manipulating and introspecting methods in |
911 | the Perl 5 object system. As with attributes, there are many ways to |
912 | approach this topic, so we try to keep it pretty basic, while still |
94b19069 |
913 | making it possible to extend the system in many ways. |
914 | |
552e3d24 |
915 | See L<Class::MOP::Method> for more details. |
94b19069 |
916 | |
127d39a7 |
917 | =item The Instance protocol |
918 | |
919 | This provides a layer of abstraction for creating object instances. |
920 | Since the other layers use this protocol, it is relatively easy to |
921 | change the type of your instances from the default HASH ref to other |
922 | types of references. Several examples are provided in the F<examples/> |
923 | directory included in this distribution. |
924 | |
925 | See L<Class::MOP::Instance> for more details. |
926 | |
94b19069 |
927 | =back |
928 | |
be7677c7 |
929 | =head1 FUNCTIONS |
930 | |
c1d5345a |
931 | =head2 Constants |
932 | |
933 | =over 4 |
934 | |
935 | =item I<IS_RUNNING_ON_5_10> |
936 | |
937 | We set this constant depending on what version perl we are on, this |
938 | allows us to take advantage of new 5.10 features and stay backwards |
939 | compat. |
940 | |
941 | =back |
942 | |
448b6e55 |
943 | =head2 Utility functions |
944 | |
945 | =over 4 |
946 | |
947 | =item B<load_class ($class_name)> |
948 | |
1d68af04 |
949 | This will load a given C<$class_name> and if it does not have an |
448b6e55 |
950 | already initialized metaclass, then it will intialize one for it. |
127d39a7 |
951 | This function can be used in place of tricks like |
952 | C<eval "use $module"> or using C<require>. |
448b6e55 |
953 | |
954 | =item B<is_class_loaded ($class_name)> |
955 | |
1d68af04 |
956 | This will return a boolean depending on if the C<$class_name> has |
957 | been loaded. |
448b6e55 |
958 | |
1d68af04 |
959 | NOTE: This does a basic check of the symbol table to try and |
448b6e55 |
960 | determine as best it can if the C<$class_name> is loaded, it |
1d68af04 |
961 | is probably correct about 99% of the time. |
448b6e55 |
962 | |
b1f5f41d |
963 | =item B<check_package_cache_flag ($pkg)> |
e0e4674a |
964 | |
127d39a7 |
965 | This will return an integer that is managed by C<Class::MOP::Class> |
966 | to determine if a module's symbol table has been altered. |
967 | |
968 | In Perl 5.10 or greater, this flag is package specific. However in |
969 | versions prior to 5.10, this will use the C<PL_sub_generation> variable |
970 | which is not package specific. |
971 | |
e0e4674a |
972 | =item B<get_code_info ($code)> |
973 | |
127d39a7 |
974 | This function returns two values, the name of the package the C<$code> |
975 | is from and the name of the C<$code> itself. This is used by several |
976 | elements of the MOP to detemine where a given C<$code> reference is from. |
977 | |
4c105333 |
978 | =item B<subname ($name, $code)> |
979 | |
980 | B<NOTE: DO NOT USE THIS FUNCTION, IT IS FOR INTERNAL USE ONLY!> |
981 | |
982 | If possible, we will load the L<Sub::Name> module and this will function |
983 | as C<Sub::Name::subname> does, otherwise it will just return the C<$code> |
984 | argument. |
985 | |
448b6e55 |
986 | =back |
987 | |
988 | =head2 Metaclass cache functions |
989 | |
1d68af04 |
990 | Class::MOP holds a cache of metaclasses, the following are functions |
991 | (B<not methods>) which can be used to access that cache. It is not |
992 | recommended that you mess with this, bad things could happen. But if |
be7677c7 |
993 | you are brave and willing to risk it, go for it. |
994 | |
995 | =over 4 |
996 | |
997 | =item B<get_all_metaclasses> |
998 | |
1d68af04 |
999 | This will return an hash of all the metaclass instances that have |
1000 | been cached by B<Class::MOP::Class> keyed by the package name. |
b9d9fc0b |
1001 | |
be7677c7 |
1002 | =item B<get_all_metaclass_instances> |
1003 | |
1d68af04 |
1004 | This will return an array of all the metaclass instances that have |
b9d9fc0b |
1005 | been cached by B<Class::MOP::Class>. |
1006 | |
be7677c7 |
1007 | =item B<get_all_metaclass_names> |
1008 | |
1d68af04 |
1009 | This will return an array of all the metaclass names that have |
b9d9fc0b |
1010 | been cached by B<Class::MOP::Class>. |
1011 | |
be7677c7 |
1012 | =item B<get_metaclass_by_name ($name)> |
1013 | |
127d39a7 |
1014 | This will return a cached B<Class::MOP::Class> instance of nothing |
1015 | if no metaclass exist by that C<$name>. |
1016 | |
be7677c7 |
1017 | =item B<store_metaclass_by_name ($name, $meta)> |
1018 | |
127d39a7 |
1019 | This will store a metaclass in the cache at the supplied C<$key>. |
1020 | |
be7677c7 |
1021 | =item B<weaken_metaclass ($name)> |
1022 | |
127d39a7 |
1023 | In rare cases it is desireable to store a weakened reference in |
1024 | the metaclass cache. This function will weaken the reference to |
1025 | the metaclass stored in C<$name>. |
1026 | |
be7677c7 |
1027 | =item B<does_metaclass_exist ($name)> |
1028 | |
127d39a7 |
1029 | This will return true of there exists a metaclass stored in the |
1030 | C<$name> key and return false otherwise. |
1031 | |
be7677c7 |
1032 | =item B<remove_metaclass_by_name ($name)> |
1033 | |
127d39a7 |
1034 | This will remove a the metaclass stored in the C<$name> key. |
1035 | |
be7677c7 |
1036 | =back |
1037 | |
552e3d24 |
1038 | =head1 SEE ALSO |
8b978dd5 |
1039 | |
552e3d24 |
1040 | =head2 Books |
8b978dd5 |
1041 | |
1d68af04 |
1042 | There are very few books out on Meta Object Protocols and Metaclasses |
1043 | because it is such an esoteric topic. The following books are really |
1044 | the only ones I have found. If you know of any more, B<I<please>> |
a2e85e6c |
1045 | email me and let me know, I would love to hear about them. |
1046 | |
8b978dd5 |
1047 | =over 4 |
1048 | |
552e3d24 |
1049 | =item "The Art of the Meta Object Protocol" |
8b978dd5 |
1050 | |
552e3d24 |
1051 | =item "Advances in Object-Oriented Metalevel Architecture and Reflection" |
8b978dd5 |
1052 | |
b51af7f9 |
1053 | =item "Putting MetaClasses to Work" |
1054 | |
a2e85e6c |
1055 | =item "Smalltalk: The Language" |
1056 | |
94b19069 |
1057 | =back |
1058 | |
550d56db |
1059 | =head2 Papers |
1060 | |
1061 | =over 4 |
1062 | |
1063 | =item Uniform and safe metaclass composition |
1064 | |
1d68af04 |
1065 | An excellent paper by the people who brought us the original Traits paper. |
1066 | This paper is on how Traits can be used to do safe metaclass composition, |
1067 | and offers an excellent introduction section which delves into the topic of |
550d56db |
1068 | metaclass compatibility. |
1069 | |
1070 | L<http://www.iam.unibe.ch/~scg/Archive/Papers/Duca05ySafeMetaclassTrait.pdf> |
1071 | |
1072 | =item Safe Metaclass Programming |
1073 | |
1d68af04 |
1074 | This paper seems to precede the above paper, and propose a mix-in based |
1075 | approach as opposed to the Traits based approach. Both papers have similar |
1076 | information on the metaclass compatibility problem space. |
550d56db |
1077 | |
1078 | L<http://citeseer.ist.psu.edu/37617.html> |
1079 | |
1080 | =back |
1081 | |
552e3d24 |
1082 | =head2 Prior Art |
8b978dd5 |
1083 | |
1084 | =over 4 |
1085 | |
7184ca14 |
1086 | =item The Perl 6 MetaModel work in the Pugs project |
8b978dd5 |
1087 | |
1088 | =over 4 |
1089 | |
552e3d24 |
1090 | =item L<http://svn.openfoundry.org/pugs/perl5/Perl6-MetaModel> |
8b978dd5 |
1091 | |
552e3d24 |
1092 | =item L<http://svn.openfoundry.org/pugs/perl5/Perl6-ObjectSpace> |
8b978dd5 |
1093 | |
1094 | =back |
1095 | |
94b19069 |
1096 | =back |
1097 | |
1d68af04 |
1098 | =head2 Articles |
f8dfcfb7 |
1099 | |
1100 | =over 4 |
1101 | |
1d68af04 |
1102 | =item CPAN Module Review of Class::MOP |
f8dfcfb7 |
1103 | |
1104 | L<http://www.oreillynet.com/onlamp/blog/2006/06/cpan_module_review_classmop.html> |
1105 | |
1106 | =back |
1107 | |
a2e85e6c |
1108 | =head1 SIMILAR MODULES |
1109 | |
1d68af04 |
1110 | As I have said above, this module is a class-builder-builder, so it is |
1111 | not the same thing as modules like L<Class::Accessor> and |
1112 | L<Class::MethodMaker>. That being said there are very few modules on CPAN |
1113 | with similar goals to this module. The one I have found which is most |
1114 | like this module is L<Class::Meta>, although it's philosophy and the MOP it |
1115 | creates are very different from this modules. |
94b19069 |
1116 | |
a2e85e6c |
1117 | =head1 BUGS |
1118 | |
1d68af04 |
1119 | All complex software has bugs lurking in it, and this module is no |
a2e85e6c |
1120 | exception. If you find a bug please either email me, or add the bug |
1121 | to cpan-RT. |
1122 | |
1123 | =head1 ACKNOWLEDGEMENTS |
1124 | |
1125 | =over 4 |
1126 | |
b9d9fc0b |
1127 | =item Rob Kinyon |
a2e85e6c |
1128 | |
1d68af04 |
1129 | Thanks to Rob for actually getting the development of this module kick-started. |
a2e85e6c |
1130 | |
1131 | =back |
1132 | |
1a09d9cc |
1133 | =head1 AUTHORS |
94b19069 |
1134 | |
a2e85e6c |
1135 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
552e3d24 |
1136 | |
9c8cda90 |
1137 | B<with contributions from:> |
1138 | |
1139 | Brandon (blblack) Black |
1140 | |
1141 | Guillermo (groditi) Roditi |
1142 | |
9195ddff |
1143 | Matt (mst) Trout |
1144 | |
9c8cda90 |
1145 | Rob (robkinyon) Kinyon |
1146 | |
1147 | Yuval (nothingmuch) Kogman |
1a09d9cc |
1148 | |
f430cfa4 |
1149 | Scott (konobi) McWhirter |
1150 | |
94b19069 |
1151 | =head1 COPYRIGHT AND LICENSE |
1152 | |
69e3ab0a |
1153 | Copyright 2006-2008 by Infinity Interactive, Inc. |
94b19069 |
1154 | |
1155 | L<http://www.iinteractive.com> |
1156 | |
1157 | This library is free software; you can redistribute it and/or modify |
1d68af04 |
1158 | it under the same terms as Perl itself. |
94b19069 |
1159 | |
1160 | =cut |