Commit | Line | Data |
24869f62 |
1 | |
2 | package Class::MOP::Instance; |
3 | |
4 | use strict; |
5 | use warnings; |
6 | |
fa16e528 |
7 | use Scalar::Util 'weaken', 'blessed'; |
24869f62 |
8 | |
a9f48b4b |
9 | our $VERSION = '1.11'; |
d519662a |
10 | $VERSION = eval $VERSION; |
f0480c45 |
11 | our $AUTHORITY = 'cpan:STEVAN'; |
24869f62 |
12 | |
d7b2249e |
13 | use base 'Class::MOP::Object'; |
24869f62 |
14 | |
301d65f2 |
15 | # make this not a valid method name, to avoid (most) attribute conflicts |
16 | my $RESERVED_MOP_SLOT = '<<MOP>>'; |
17 | |
63d08a9e |
18 | sub BUILDARGS { |
d43737b3 |
19 | my ($class, @args) = @_; |
20 | |
21 | if ( @args == 1 ) { |
63d08a9e |
22 | unshift @args, "associated_metaclass"; |
d43737b3 |
23 | } elsif ( @args >= 2 && blessed($args[0]) && $args[0]->isa("Class::MOP::Class") ) { |
24 | # compat mode |
25 | my ( $meta, @attrs ) = @args; |
63d08a9e |
26 | @args = ( associated_metaclass => $meta, attributes => \@attrs ); |
d43737b3 |
27 | } |
28 | |
29 | my %options = @args; |
7c7fd869 |
30 | # FIXME lazy_build |
d43737b3 |
31 | $options{slots} ||= [ map { $_->slots } @{ $options{attributes} || [] } ]; |
63d08a9e |
32 | $options{slot_hash} = { map { $_ => undef } @{ $options{slots} } }; # FIXME lazy_build |
33 | |
34 | return \%options; |
35 | } |
36 | |
37 | sub new { |
38 | my $class = shift; |
39 | my $options = $class->BUILDARGS(@_); |
d43737b3 |
40 | |
41 | # FIXME replace with a proper constructor |
b4b5d65a |
42 | my $instance = $class->_new(%$options); |
43 | |
44 | # FIXME weak_ref => 1, |
45 | weaken($instance->{'associated_metaclass'}); |
46 | |
47 | return $instance; |
48 | } |
49 | |
50 | sub _new { |
ec9e38e5 |
51 | my $class = shift; |
52 | return Class::MOP::Class->initialize($class)->new_object(@_) |
53 | if $class ne __PACKAGE__; |
54 | |
55 | my $params = @_ == 1 ? $_[0] : {@_}; |
56 | return bless { |
fc3ddd1d |
57 | # NOTE: |
58 | # I am not sure that it makes |
59 | # sense to pass in the meta |
8d2d4c67 |
60 | # The ideal would be to just |
61 | # pass in the class name, but |
62 | # that is placing too much of |
63 | # an assumption on bless(), |
fc3ddd1d |
64 | # which is *probably* a safe |
8d2d4c67 |
65 | # assumption,.. but you can |
fc3ddd1d |
66 | # never tell <:) |
ec9e38e5 |
67 | 'associated_metaclass' => $params->{associated_metaclass}, |
68 | 'attributes' => $params->{attributes}, |
69 | 'slots' => $params->{slots}, |
70 | 'slot_hash' => $params->{slot_hash}, |
8d2d4c67 |
71 | } => $class; |
24869f62 |
72 | } |
73 | |
74890687 |
74 | sub _class_name { $_[0]->{_class_name} ||= $_[0]->associated_metaclass->name } |
75 | |
76 | sub associated_metaclass { $_[0]{'associated_metaclass'} } |
c23184fc |
77 | |
49c93440 |
78 | sub create_instance { |
79 | my $self = shift; |
becd03c6 |
80 | bless {}, $self->_class_name; |
2d711cc8 |
81 | } |
82 | |
f7259199 |
83 | sub clone_instance { |
84 | my ($self, $instance) = @_; |
becd03c6 |
85 | bless { %$instance }, $self->_class_name; |
f7259199 |
86 | } |
87 | |
2d711cc8 |
88 | # operations on meta instance |
89 | |
eb49acde |
90 | sub get_all_slots { |
91 | my $self = shift; |
7c7fd869 |
92 | return @{$self->{'slots'}}; |
f7259199 |
93 | } |
94 | |
0b5d46da |
95 | sub get_all_attributes { |
96 | my $self = shift; |
97 | return @{$self->{attributes}}; |
98 | } |
99 | |
f7259199 |
100 | sub is_valid_slot { |
101 | my ($self, $slot_name) = @_; |
7c7fd869 |
102 | exists $self->{'slot_hash'}->{$slot_name}; |
839ea973 |
103 | } |
104 | |
2d711cc8 |
105 | # operations on created instances |
106 | |
839ea973 |
107 | sub get_slot_value { |
2bab2be6 |
108 | my ($self, $instance, $slot_name) = @_; |
230472a7 |
109 | $instance->{$slot_name}; |
839ea973 |
110 | } |
111 | |
2bab2be6 |
112 | sub set_slot_value { |
113 | my ($self, $instance, $slot_name, $value) = @_; |
114 | $instance->{$slot_name} = $value; |
115 | } |
116 | |
2d711cc8 |
117 | sub initialize_slot { |
49c93440 |
118 | my ($self, $instance, $slot_name) = @_; |
a007159d |
119 | return; |
2d711cc8 |
120 | } |
121 | |
7d28758b |
122 | sub deinitialize_slot { |
123 | my ( $self, $instance, $slot_name ) = @_; |
124 | delete $instance->{$slot_name}; |
125 | } |
126 | |
c174112e |
127 | sub initialize_all_slots { |
128 | my ($self, $instance) = @_; |
129 | foreach my $slot_name ($self->get_all_slots) { |
130 | $self->initialize_slot($instance, $slot_name); |
131 | } |
132 | } |
133 | |
7d28758b |
134 | sub deinitialize_all_slots { |
135 | my ($self, $instance) = @_; |
136 | foreach my $slot_name ($self->get_all_slots) { |
137 | $self->deinitialize_slot($instance, $slot_name); |
138 | } |
139 | } |
140 | |
49c93440 |
141 | sub is_slot_initialized { |
142 | my ($self, $instance, $slot_name, $value) = @_; |
230472a7 |
143 | exists $instance->{$slot_name}; |
2bab2be6 |
144 | } |
839ea973 |
145 | |
5582521c |
146 | sub weaken_slot_value { |
69e3ab0a |
147 | my ($self, $instance, $slot_name) = @_; |
148 | weaken $instance->{$slot_name}; |
5582521c |
149 | } |
150 | |
151 | sub strengthen_slot_value { |
69e3ab0a |
152 | my ($self, $instance, $slot_name) = @_; |
153 | $self->set_slot_value($instance, $slot_name, $self->get_slot_value($instance, $slot_name)); |
5582521c |
154 | } |
155 | |
3d9e4646 |
156 | sub rebless_instance_structure { |
157 | my ($self, $instance, $metaclass) = @_; |
feb93c85 |
158 | |
159 | # we use $_[1] here because of t/306_rebless_overload.t regressions on 5.8.8 |
160 | bless $_[1], $metaclass->name; |
3d9e4646 |
161 | } |
162 | |
da5680be |
163 | sub is_dependent_on_superclasses { |
164 | return; # for meta instances that require updates on inherited slot changes |
165 | } |
166 | |
301d65f2 |
167 | sub _get_mop_slot { |
168 | my ($self, $instance) = @_; |
169 | $self->get_slot_value($instance, $RESERVED_MOP_SLOT); |
170 | } |
171 | |
172 | sub _set_mop_slot { |
173 | my ($self, $instance, $value) = @_; |
174 | $self->set_slot_value($instance, $RESERVED_MOP_SLOT, $value); |
175 | } |
176 | |
177 | sub _clear_mop_slot { |
178 | my ($self, $instance) = @_; |
179 | $self->deinitialize_slot($instance, $RESERVED_MOP_SLOT); |
180 | } |
181 | |
ee7c0467 |
182 | # inlinable operation snippets |
183 | |
c0cbf4d9 |
184 | sub is_inlinable { 1 } |
185 | |
186 | sub inline_create_instance { |
187 | my ($self, $class_variable) = @_; |
188 | 'bless {} => ' . $class_variable; |
189 | } |
190 | |
ee7c0467 |
191 | sub inline_slot_access { |
192 | my ($self, $instance, $slot_name) = @_; |
5143ee94 |
193 | sprintf q[%s->{"%s"}], $instance, quotemeta($slot_name); |
ee7c0467 |
194 | } |
195 | |
4dcd4272 |
196 | sub inline_get_is_lvalue { 1 } |
197 | |
ee7c0467 |
198 | sub inline_get_slot_value { |
199 | my ($self, $instance, $slot_name) = @_; |
230472a7 |
200 | $self->inline_slot_access($instance, $slot_name); |
ee7c0467 |
201 | } |
202 | |
203 | sub inline_set_slot_value { |
204 | my ($self, $instance, $slot_name, $value) = @_; |
8d2d4c67 |
205 | $self->inline_slot_access($instance, $slot_name) . " = $value", |
ee7c0467 |
206 | } |
207 | |
208 | sub inline_initialize_slot { |
209 | my ($self, $instance, $slot_name) = @_; |
a007159d |
210 | return ''; |
ee7c0467 |
211 | } |
212 | |
7d28758b |
213 | sub inline_deinitialize_slot { |
214 | my ($self, $instance, $slot_name) = @_; |
215 | "delete " . $self->inline_slot_access($instance, $slot_name); |
216 | } |
ee7c0467 |
217 | sub inline_is_slot_initialized { |
218 | my ($self, $instance, $slot_name) = @_; |
230472a7 |
219 | "exists " . $self->inline_slot_access($instance, $slot_name); |
ee7c0467 |
220 | } |
221 | |
222 | sub inline_weaken_slot_value { |
223 | my ($self, $instance, $slot_name) = @_; |
224 | sprintf "Scalar::Util::weaken( %s )", $self->inline_slot_access($instance, $slot_name); |
225 | } |
226 | |
227 | sub inline_strengthen_slot_value { |
228 | my ($self, $instance, $slot_name) = @_; |
229 | $self->inline_set_slot_value($instance, $slot_name, $self->inline_slot_access($instance, $slot_name)); |
230 | } |
231 | |
bc3c58a0 |
232 | sub inline_rebless_instance_structure { |
233 | my ($self, $instance, $class_variable) = @_; |
234 | "bless $instance => $class_variable"; |
235 | } |
236 | |
7931f7db |
237 | sub _inline_get_mop_slot { |
238 | my ($self, $instance) = @_; |
239 | $self->inline_get_slot_value($instance, $RESERVED_MOP_SLOT); |
240 | } |
241 | |
242 | sub _inline_set_mop_slot { |
243 | my ($self, $instance, $value) = @_; |
244 | $self->inline_set_slot_value($instance, $RESERVED_MOP_SLOT, $value); |
245 | } |
246 | |
247 | sub _inline_clear_mop_slot { |
248 | my ($self, $instance) = @_; |
249 | $self->inline_deinitialize_slot($instance, $RESERVED_MOP_SLOT); |
250 | } |
251 | |
24869f62 |
252 | 1; |
253 | |
254 | __END__ |
255 | |
256 | =pod |
257 | |
8d2d4c67 |
258 | =head1 NAME |
24869f62 |
259 | |
260 | Class::MOP::Instance - Instance Meta Object |
261 | |
24869f62 |
262 | =head1 DESCRIPTION |
263 | |
1cbf42df |
264 | The Instance Protocol controls the creation of object instances, and |
88bb3cf1 |
265 | the storage of attribute values in those instances. |
266 | |
267 | Using this API directly in your own code violates encapsulation, and |
268 | we recommend that you use the appropriate APIs in L<Class::MOP::Class> |
269 | and L<Class::MOP::Attribute> instead. Those APIs in turn call the |
270 | methods in this class as appropriate. |
271 | |
272 | This class also participates in generating inlined code by providing |
273 | snippets of code to access an object instance. |
9fa4d0b4 |
274 | |
24869f62 |
275 | =head1 METHODS |
276 | |
88bb3cf1 |
277 | =head2 Object construction |
278 | |
24869f62 |
279 | =over 4 |
280 | |
88bb3cf1 |
281 | =item B<< Class::MOP::Instance->new(%options) >> |
9fa4d0b4 |
282 | |
88bb3cf1 |
283 | This method creates a new meta-instance object. |
9fa4d0b4 |
284 | |
88bb3cf1 |
285 | It accepts the following keys in C<%options>: |
63d08a9e |
286 | |
88bb3cf1 |
287 | =over 8 |
63d08a9e |
288 | |
88bb3cf1 |
289 | =item * associated_metaclass |
9fa4d0b4 |
290 | |
88bb3cf1 |
291 | The L<Class::MOP::Class> object for which instances will be created. |
9fa4d0b4 |
292 | |
88bb3cf1 |
293 | =item * attributes |
9fa4d0b4 |
294 | |
88bb3cf1 |
295 | An array reference of L<Class::MOP::Attribute> objects. These are the |
296 | attributes which can be stored in each instance. |
9fa4d0b4 |
297 | |
88bb3cf1 |
298 | =back |
24869f62 |
299 | |
88bb3cf1 |
300 | =back |
58287a97 |
301 | |
88bb3cf1 |
302 | =head2 Creating and altering instances |
0e76a376 |
303 | |
88bb3cf1 |
304 | =over 4 |
839ea973 |
305 | |
88bb3cf1 |
306 | =item B<< $metainstance->create_instance >> |
0e76a376 |
307 | |
88bb3cf1 |
308 | This method returns a reference blessed into the associated |
309 | metaclass's class. |
becd03c6 |
310 | |
88bb3cf1 |
311 | The default is to use a hash reference. Subclasses can override this. |
f7259199 |
312 | |
88bb3cf1 |
313 | =item B<< $metainstance->clone_instance($instance) >> |
314 | |
315 | Given an instance, this method creates a new object by making |
316 | I<shallow> clone of the original. |
127d39a7 |
317 | |
9fa4d0b4 |
318 | =back |
839ea973 |
319 | |
98bf345b |
320 | =head2 Introspection |
58287a97 |
321 | |
9fa4d0b4 |
322 | =over 4 |
323 | |
88bb3cf1 |
324 | =item B<< $metainstance->associated_metaclass >> |
c23184fc |
325 | |
88bb3cf1 |
326 | This returns the L<Class::MOP::Class> object associated with the |
327 | meta-instance object. |
127d39a7 |
328 | |
88bb3cf1 |
329 | =item B<< $metainstance->get_all_slots >> |
9fa4d0b4 |
330 | |
88bb3cf1 |
331 | This returns a list of slot names stored in object instances. In |
332 | almost all cases, slot names correspond directly attribute names. |
58287a97 |
333 | |
88bb3cf1 |
334 | =item B<< $metainstance->is_valid_slot($slot_name) >> |
f7259199 |
335 | |
127d39a7 |
336 | This will return true if C<$slot_name> is a valid slot name. |
337 | |
88bb3cf1 |
338 | =item B<< $metainstance->get_all_attributes >> |
da5680be |
339 | |
88bb3cf1 |
340 | This returns a list of attributes corresponding to the attributes |
341 | passed to the constructor. |
0202ee96 |
342 | |
24869f62 |
343 | =back |
344 | |
9fa4d0b4 |
345 | =head2 Operations on Instance Structures |
346 | |
88bb3cf1 |
347 | It's important to understand that the meta-instance object is a |
348 | different entity from the actual instances it creates. For this |
349 | reason, any operations on the C<$instance_structure> always require |
350 | that the object instance be passed to the method. |
127d39a7 |
351 | |
24869f62 |
352 | =over 4 |
353 | |
88bb3cf1 |
354 | =item B<< $metainstance->get_slot_value($instance_structure, $slot_name) >> |
355 | |
356 | =item B<< $metainstance->set_slot_value($instance_structure, $slot_name, $value) >> |
24869f62 |
357 | |
88bb3cf1 |
358 | =item B<< $metainstance->initialize_slot($instance_structure, $slot_name) >> |
9fa4d0b4 |
359 | |
88bb3cf1 |
360 | =item B<< $metainstance->deinitialize_slot($instance_structure, $slot_name) >> |
9fa4d0b4 |
361 | |
88bb3cf1 |
362 | =item B<< $metainstance->initialize_all_slots($instance_structure) >> |
7d28758b |
363 | |
88bb3cf1 |
364 | =item B<< $metainstance->deinitialize_all_slots($instance_structure) >> |
9fa4d0b4 |
365 | |
88bb3cf1 |
366 | =item B<< $metainstance->is_slot_initialized($instance_structure, $slot_name) >> |
7d28758b |
367 | |
88bb3cf1 |
368 | =item B<< $metainstance->weaken_slot_value($instance_structure, $slot_name) >> |
24869f62 |
369 | |
88bb3cf1 |
370 | =item B<< $metainstance->strengthen_slot_value($instance_structure, $slot_name) >> |
ee7c0467 |
371 | |
88bb3cf1 |
372 | =item B<< $metainstance->rebless_instance_structure($instance_structure, $new_metaclass) >> |
ee7c0467 |
373 | |
88bb3cf1 |
374 | The exact details of what each method does should be fairly obvious |
375 | from the method name. |
5fdf066d |
376 | |
ee7c0467 |
377 | =back |
378 | |
88bb3cf1 |
379 | =head2 Inlinable Instance Operations |
ee7c0467 |
380 | |
381 | =over 4 |
382 | |
88bb3cf1 |
383 | =item B<< $metainstance->is_inlinable >> |
c0cbf4d9 |
384 | |
88bb3cf1 |
385 | This is a boolean that indicates whether or not slot access operations |
386 | can be inlined. By default it is true, but subclasses can override |
387 | this. |
c0cbf4d9 |
388 | |
88bb3cf1 |
389 | =item B<< $metainstance->inline_create_instance($class_variable) >> |
495af518 |
390 | |
88bb3cf1 |
391 | This method expects a string that, I<when inlined>, will become a |
392 | class name. This would literally be something like C<'$class'>, not an |
393 | actual class name. |
ee7c0467 |
394 | |
88bb3cf1 |
395 | It returns a snippet of code that creates a new object for the |
396 | class. This is something like C< bless {}, $class_name >. |
ee7c0467 |
397 | |
4dcd4272 |
398 | =item B<< $metainstance->inline_get_is_lvalue >> |
399 | |
400 | Returns whether or not C<inline_get_slot_value> is a valid lvalue. This can be |
401 | used to do extra optimizations when generating inlined methods. |
402 | |
88bb3cf1 |
403 | =item B<< $metainstance->inline_slot_access($instance_variable, $slot_name) >> |
ee7c0467 |
404 | |
88bb3cf1 |
405 | =item B<< $metainstance->inline_get_slot_value($instance_variable, $slot_name) >> |
ee7c0467 |
406 | |
88bb3cf1 |
407 | =item B<< $metainstance->inline_set_slot_value($instance_variable, $slot_name, $value) >> |
408 | |
409 | =item B<< $metainstance->inline_initialize_slot($instance_variable, $slot_name) >> |
410 | |
411 | =item B<< $metainstance->inline_deinitialize_slot($instance_variable, $slot_name) >> |
412 | |
413 | =item B<< $metainstance->inline_is_slot_initialized($instance_variable, $slot_name) >> |
414 | |
415 | =item B<< $metainstance->inline_weaken_slot_value($instance_variable, $slot_name) >> |
416 | |
417 | =item B<< $metainstance->inline_strengthen_slot_value($instance_variable, $slot_name) >> |
418 | |
419 | These methods all expect two arguments. The first is the name of a |
420 | variable, than when inlined, will represent the object |
421 | instance. Typically this will be a literal string like C<'$_[0]'>. |
422 | |
423 | The second argument is a slot name. |
424 | |
425 | The method returns a snippet of code that, when inlined, performs some |
426 | operation on the instance. |
427 | |
0fab42eb |
428 | =item B<< $metainstance->inline_rebless_instance_structure($instance_variable, $class_variable) >> |
429 | |
430 | This takes the name of a variable that will, when inlined, represent the object |
431 | instance, and the name of a variable that will represent the class to rebless |
432 | into, and returns code to rebless an instance into a class. |
433 | |
88bb3cf1 |
434 | =back |
435 | |
436 | =head2 Introspection |
437 | |
438 | =over 4 |
7d28758b |
439 | |
88bb3cf1 |
440 | =item B<< Class::MOP::Instance->meta >> |
5582521c |
441 | |
88bb3cf1 |
442 | This will return a L<Class::MOP::Class> instance for this class. |
5582521c |
443 | |
88bb3cf1 |
444 | It should also be noted that L<Class::MOP> will actually bootstrap |
445 | this module by installing a number of attribute meta-objects into its |
446 | metaclass. |
5582521c |
447 | |
24869f62 |
448 | =back |
449 | |
1a09d9cc |
450 | =head1 AUTHORS |
24869f62 |
451 | |
9fa4d0b4 |
452 | Yuval Kogman E<lt>nothingmuch@woobling.comE<gt> |
453 | |
24869f62 |
454 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
455 | |
456 | =head1 COPYRIGHT AND LICENSE |
457 | |
3e2c8600 |
458 | Copyright 2006-2010 by Infinity Interactive, Inc. |
24869f62 |
459 | |
460 | L<http://www.iinteractive.com> |
461 | |
462 | This library is free software; you can redistribute it and/or modify |
8d2d4c67 |
463 | it under the same terms as Perl itself. |
24869f62 |
464 | |
84ef30d1 |
465 | =cut |
5582521c |
466 | |