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'; |
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8 | |
9ca19585 |
9 | our $VERSION = '0.03'; |
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10 | |
11 | sub meta { |
12 | require Class::MOP::Class; |
13 | Class::MOP::Class->initialize(blessed($_[0]) || $_[0]); |
14 | } |
15 | |
16 | sub new { |
052c2a1a |
17 | my ($class, $meta, @attrs) = @_; |
c57c8b10 |
18 | my @slots = map { $_->slots } @attrs; |
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19 | bless { |
fc3ddd1d |
20 | # NOTE: |
21 | # I am not sure that it makes |
22 | # sense to pass in the meta |
23 | # The ideal would be to just |
24 | # pass in the class name, but |
25 | # that is placing too much of |
26 | # an assumption on bless(), |
27 | # which is *probably* a safe |
28 | # assumption,.. but you can |
29 | # never tell <:) |
49c93440 |
30 | meta => $meta, |
f7259199 |
31 | slots => { map { $_ => undef } @slots }, |
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32 | } => $class; |
33 | } |
34 | |
49c93440 |
35 | sub create_instance { |
36 | my $self = shift; |
37 | $self->bless_instance_structure({}); |
2d711cc8 |
38 | } |
39 | |
49c93440 |
40 | sub bless_instance_structure { |
41 | my ($self, $instance_structure) = @_; |
42 | bless $instance_structure, $self->{meta}->name; |
2d711cc8 |
43 | } |
44 | |
f7259199 |
45 | sub clone_instance { |
46 | my ($self, $instance) = @_; |
47 | $self->bless_instance_structure({ %$instance }); |
48 | } |
49 | |
2d711cc8 |
50 | # operations on meta instance |
51 | |
eb49acde |
52 | sub get_all_slots { |
53 | my $self = shift; |
f7259199 |
54 | return keys %{$self->{slots}}; |
55 | } |
56 | |
57 | sub is_valid_slot { |
58 | my ($self, $slot_name) = @_; |
59 | exists $self->{slots}->{$slot_name} ? 1 : 0; |
839ea973 |
60 | } |
61 | |
2d711cc8 |
62 | # operations on created instances |
63 | |
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64 | sub get_slot_value { |
2bab2be6 |
65 | my ($self, $instance, $slot_name) = @_; |
66 | return $instance->{$slot_name}; |
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67 | } |
68 | |
2bab2be6 |
69 | sub set_slot_value { |
70 | my ($self, $instance, $slot_name, $value) = @_; |
71 | $instance->{$slot_name} = $value; |
72 | } |
73 | |
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74 | sub initialize_slot { |
49c93440 |
75 | my ($self, $instance, $slot_name) = @_; |
d82060fe |
76 | $self->set_slot_value($instance, $slot_name, undef); |
2d711cc8 |
77 | } |
78 | |
7d28758b |
79 | sub deinitialize_slot { |
80 | my ( $self, $instance, $slot_name ) = @_; |
81 | delete $instance->{$slot_name}; |
82 | } |
83 | |
c174112e |
84 | sub initialize_all_slots { |
85 | my ($self, $instance) = @_; |
86 | foreach my $slot_name ($self->get_all_slots) { |
87 | $self->initialize_slot($instance, $slot_name); |
88 | } |
89 | } |
90 | |
7d28758b |
91 | sub deinitialize_all_slots { |
92 | my ($self, $instance) = @_; |
93 | foreach my $slot_name ($self->get_all_slots) { |
94 | $self->deinitialize_slot($instance, $slot_name); |
95 | } |
96 | } |
97 | |
49c93440 |
98 | sub is_slot_initialized { |
99 | my ($self, $instance, $slot_name, $value) = @_; |
2d711cc8 |
100 | exists $instance->{$slot_name} ? 1 : 0; |
2bab2be6 |
101 | } |
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102 | |
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103 | sub weaken_slot_value { |
104 | my ($self, $instance, $slot_name) = @_; |
105 | weaken $instance->{$slot_name}; |
106 | } |
107 | |
108 | sub strengthen_slot_value { |
109 | my ($self, $instance, $slot_name) = @_; |
110 | $self->set_slot_value($instance, $slot_name, $self->get_slot_value($instance, $slot_name)); |
111 | } |
112 | |
ee7c0467 |
113 | # inlinable operation snippets |
114 | |
c0cbf4d9 |
115 | sub is_inlinable { 1 } |
116 | |
117 | sub inline_create_instance { |
118 | my ($self, $class_variable) = @_; |
119 | 'bless {} => ' . $class_variable; |
120 | } |
121 | |
ee7c0467 |
122 | sub inline_slot_access { |
123 | my ($self, $instance, $slot_name) = @_; |
124 | sprintf "%s->{%s}", $instance, $slot_name; |
125 | } |
126 | |
127 | sub inline_get_slot_value { |
128 | my ($self, $instance, $slot_name) = @_; |
129 | $self->inline_slot_access($instance, $slot_name); |
130 | } |
131 | |
132 | sub inline_set_slot_value { |
133 | my ($self, $instance, $slot_name, $value) = @_; |
134 | $self->inline_slot_access($instance, $slot_name) . " = $value", |
135 | } |
136 | |
137 | sub inline_initialize_slot { |
138 | my ($self, $instance, $slot_name) = @_; |
139 | $self->inline_set_slot_value($instance, $slot_name, 'undef'), |
140 | } |
141 | |
7d28758b |
142 | sub inline_deinitialize_slot { |
143 | my ($self, $instance, $slot_name) = @_; |
144 | "delete " . $self->inline_slot_access($instance, $slot_name); |
145 | } |
ee7c0467 |
146 | sub inline_is_slot_initialized { |
147 | my ($self, $instance, $slot_name) = @_; |
148 | "exists " . $self->inline_slot_access($instance, $slot_name) . " ? 1 : 0"; |
149 | } |
150 | |
151 | sub inline_weaken_slot_value { |
152 | my ($self, $instance, $slot_name) = @_; |
153 | sprintf "Scalar::Util::weaken( %s )", $self->inline_slot_access($instance, $slot_name); |
154 | } |
155 | |
156 | sub inline_strengthen_slot_value { |
157 | my ($self, $instance, $slot_name) = @_; |
158 | $self->inline_set_slot_value($instance, $slot_name, $self->inline_slot_access($instance, $slot_name)); |
159 | } |
160 | |
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161 | 1; |
162 | |
163 | __END__ |
164 | |
165 | =pod |
166 | |
167 | =head1 NAME |
168 | |
169 | Class::MOP::Instance - Instance Meta Object |
170 | |
171 | =head1 SYNOPSIS |
172 | |
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173 | # for the most part, this protocol is internal |
174 | # and not for public usage, but this how one |
175 | # might use it |
176 | |
177 | package Foo; |
178 | |
179 | use strict; |
180 | use warnings; |
1becdfcc |
181 | use metaclass ( |
9fa4d0b4 |
182 | ':instance_metaclass' => 'ArrayBasedStorage::Instance', |
183 | ); |
184 | |
185 | # now Foo->new produces blessed ARRAY ref based objects |
186 | |
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187 | =head1 DESCRIPTION |
188 | |
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189 | This is a sub-protocol which governs instance creation |
190 | and access to the slots of the instance structure. |
191 | |
192 | This may seem like over-abstraction, but by abstracting |
193 | this process into a sub-protocol we make it possible to |
194 | easily switch the details of how an object's instance is |
195 | stored with minimal impact. In most cases just subclassing |
1becdfcc |
196 | this class will be all you need to do (see the examples; |
197 | F<examples/ArrayBasedStorage.pod> and |
198 | F<examples/InsideOutClass.pod> for details). |
9fa4d0b4 |
199 | |
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200 | =head1 METHODS |
201 | |
202 | =over 4 |
203 | |
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204 | =item B<new ($meta, @attrs)> |
205 | |
206 | Creates a new instance meta-object and gathers all the slots from |
207 | the list of C<@attrs> given. |
208 | |
209 | =item B<meta> |
210 | |
211 | This will return a B<Class::MOP::Class> instance which is related |
212 | to this class. |
213 | |
214 | =back |
215 | |
216 | =head2 Creation of Instances |
217 | |
218 | =over 4 |
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219 | |
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220 | =item B<create_instance> |
221 | |
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222 | This creates the appropriate structure needed for the instance and |
223 | then calls C<bless_instance_structure> to bless it into the class. |
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224 | |
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225 | =item B<bless_instance_structure ($instance_structure)> |
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226 | |
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227 | This does just exactly what it says it does. |
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228 | |
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229 | =item B<clone_instance ($instance_structure)> |
230 | |
9fa4d0b4 |
231 | =back |
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232 | |
9fa4d0b4 |
233 | =head2 Instrospection |
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234 | |
9fa4d0b4 |
235 | NOTE: There might be more methods added to this part of the API, |
236 | we will add then when we need them basically. |
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237 | |
9fa4d0b4 |
238 | =over 4 |
239 | |
240 | =item B<get_all_slots> |
241 | |
242 | This will return the current list of slots based on what was |
243 | given to this object in C<new>. |
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244 | |
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245 | =item B<is_valid_slot ($slot_name)> |
246 | |
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247 | =back |
248 | |
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249 | =head2 Operations on Instance Structures |
250 | |
251 | An important distinction of this sub-protocol is that the |
252 | instance meta-object is a different entity from the actual |
253 | instance it creates. For this reason, any actions on slots |
254 | require that the C<$instance_structure> is passed into them. |
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255 | |
256 | =over 4 |
257 | |
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258 | =item B<get_slot_value ($instance_structure, $slot_name)> |
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259 | |
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260 | =item B<set_slot_value ($instance_structure, $slot_name, $value)> |
261 | |
262 | =item B<initialize_slot ($instance_structure, $slot_name)> |
263 | |
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264 | =item B<deinitialize_slot ($instance_structure, $slot_name)> |
265 | |
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266 | =item B<initialize_all_slots ($instance_structure)> |
267 | |
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268 | =item B<deinitialize_all_slots ($instance_structure)> |
269 | |
9fa4d0b4 |
270 | =item B<is_slot_initialized ($instance_structure, $slot_name)> |
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271 | |
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272 | =item B<weaken_slot_value ($instance_structure, $slot_name)> |
273 | |
274 | =item B<strengthen_slot_value ($instance_structure, $slot_name)> |
275 | |
276 | =back |
277 | |
278 | =head2 Inlineable Instance Operations |
279 | |
f7259199 |
280 | This part of the API is currently un-used. It is there for use |
281 | in future experiments in class finailization mostly. Best to |
282 | ignore this for now. |
283 | |
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284 | =over 4 |
285 | |
c0cbf4d9 |
286 | =item B<is_inlinable> |
287 | |
288 | Each meta-instance should override this method to tell Class::MOP if it's |
289 | possible to inline the slot access. |
290 | |
291 | This is currently only used by Class::MOP::Class::Immutable when performing |
292 | optimizations. |
293 | |
495af518 |
294 | =item B<inline_create_instance> |
295 | |
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296 | =item B<inline_slot_access ($instance_structure, $slot_name)> |
297 | |
298 | =item B<inline_get_slot_value ($instance_structure, $slot_name)> |
299 | |
300 | =item B<inline_set_slot_value ($instance_structure, $slot_name, $value)> |
301 | |
302 | =item B<inline_initialize_slot ($instance_structure, $slot_name)> |
303 | |
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304 | =item B<inline_deinitialize_slot ($instance_structure, $slot_name)> |
305 | |
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306 | =item B<inline_is_slot_initialized ($instance_structure, $slot_name)> |
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307 | |
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308 | =item B<inline_weaken_slot_value ($instance_structure, $slot_name)> |
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309 | |
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310 | =item B<inline_strengthen_slot_value ($instance_structure, $slot_name)> |
5582521c |
311 | |
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312 | =back |
313 | |
1a09d9cc |
314 | =head1 AUTHORS |
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315 | |
9fa4d0b4 |
316 | Yuval Kogman E<lt>nothingmuch@woobling.comE<gt> |
317 | |
24869f62 |
318 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
319 | |
320 | =head1 COPYRIGHT AND LICENSE |
321 | |
322 | Copyright 2006 by Infinity Interactive, Inc. |
323 | |
324 | L<http://www.iinteractive.com> |
325 | |
326 | This library is free software; you can redistribute it and/or modify |
327 | it under the same terms as Perl itself. |
328 | |
84ef30d1 |
329 | =cut |
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330 | |