Commit | Line | Data |
306290e8 |
1 | package Mouse::Meta::Attribute; |
bc69ee88 |
2 | use Mouse::Util qw(:meta); # enables strict and warnings |
c3398f5b |
3 | |
2efc0af1 |
4 | use Carp (); |
2efc0af1 |
5 | |
684db121 |
6 | use Mouse::Meta::TypeConstraint; |
d7d8d49b |
7 | |
87ca293b |
8 | sub _process_options{ |
9 | my($class, $name, $args) = @_; |
c3398f5b |
10 | |
2efc0af1 |
11 | # taken from Class::MOP::Attribute::new |
12 | |
13 | defined($name) |
14 | or $class->throw_error('You must provide a name for the attribute'); |
2e7e86c6 |
15 | |
1b9e472d |
16 | if(!exists $args->{init_arg}){ |
17 | $args->{init_arg} = $name; |
2efc0af1 |
18 | } |
19 | |
20 | # 'required' requires eigher 'init_arg', 'builder', or 'default' |
1b9e472d |
21 | my $can_be_required = defined( $args->{init_arg} ); |
2efc0af1 |
22 | |
1b9e472d |
23 | if(exists $args->{builder}){ |
c6d8f5ca |
24 | # XXX: |
25 | # Moose refuses a CODE ref builder, but Mouse doesn't for backward compatibility |
26 | # This feature will be changed in a future. (gfx) |
121acb8a |
27 | $class->throw_error('builder must be a defined scalar value which is a method name') |
c6d8f5ca |
28 | #if ref $args->{builder} || !defined $args->{builder}; |
29 | if !defined $args->{builder}; |
2efc0af1 |
30 | |
31 | $can_be_required++; |
32 | } |
1b9e472d |
33 | elsif(exists $args->{default}){ |
34 | if(ref $args->{default} && ref($args->{default}) ne 'CODE'){ |
2efc0af1 |
35 | $class->throw_error("References are not allowed as default values, you must " |
36 | . "wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])"); |
37 | } |
38 | $can_be_required++; |
39 | } |
40 | |
1b9e472d |
41 | if( $args->{required} && !$can_be_required ) { |
121acb8a |
42 | $class->throw_error("You cannot have a required attribute ($name) without a default, builder, or an init_arg"); |
2efc0af1 |
43 | } |
44 | |
1b9e472d |
45 | # taken from Mouse::Meta::Attribute->new and _process_args-> |
2efc0af1 |
46 | |
1b9e472d |
47 | if(exists $args->{is}){ |
48 | my $is = $args->{is}; |
2efc0af1 |
49 | |
50 | if($is eq 'ro'){ |
1b9e472d |
51 | $args->{reader} ||= $name; |
2efc0af1 |
52 | } |
53 | elsif($is eq 'rw'){ |
1b9e472d |
54 | if(exists $args->{writer}){ |
55 | $args->{reader} ||= $name; |
2efc0af1 |
56 | } |
57 | else{ |
1b9e472d |
58 | $args->{accessor} ||= $name; |
2efc0af1 |
59 | } |
60 | } |
61 | elsif($is eq 'bare'){ |
62 | # do nothing, but don't complain (later) about missing methods |
63 | } |
64 | else{ |
65 | $is = 'undef' if !defined $is; |
66 | $class->throw_error("I do not understand this option (is => $is) on attribute ($name)"); |
67 | } |
68 | } |
69 | |
70 | my $tc; |
1b9e472d |
71 | if(exists $args->{isa}){ |
72 | $args->{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_isa_type_constraint($args->{isa}); |
2efc0af1 |
73 | } |
1b9e472d |
74 | elsif(exists $args->{does}){ |
9f74c401 |
75 | $args->{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_does_type_constraint($args->{does}); |
2efc0af1 |
76 | } |
1b9e472d |
77 | $tc = $args->{type_constraint}; |
2efc0af1 |
78 | |
1b9e472d |
79 | if($args->{coerce}){ |
2efc0af1 |
80 | defined($tc) |
81 | || $class->throw_error("You cannot have coercion without specifying a type constraint on attribute ($name)"); |
82 | |
1b9e472d |
83 | $args->{weak_ref} |
121acb8a |
84 | && $class->throw_error("You cannot have a weak reference to a coerced value on attribute ($name)"); |
2efc0af1 |
85 | } |
86 | |
1b9e472d |
87 | if ($args->{lazy_build}) { |
88 | exists($args->{default}) |
121acb8a |
89 | && $class->throw_error("You can not use lazy_build and default for the same attribute ($name)"); |
90 | |
1b9e472d |
91 | $args->{lazy} = 1; |
92 | $args->{builder} ||= "_build_${name}"; |
121acb8a |
93 | if ($name =~ /^_/) { |
1b9e472d |
94 | $args->{clearer} ||= "_clear${name}"; |
95 | $args->{predicate} ||= "_has${name}"; |
121acb8a |
96 | } |
97 | else { |
1b9e472d |
98 | $args->{clearer} ||= "clear_${name}"; |
99 | $args->{predicate} ||= "has_${name}"; |
121acb8a |
100 | } |
2efc0af1 |
101 | } |
102 | |
1b9e472d |
103 | if ($args->{auto_deref}) { |
121acb8a |
104 | defined($tc) |
105 | || $class->throw_error("You cannot auto-dereference without specifying a type constraint on attribute ($name)"); |
2efc0af1 |
106 | |
121acb8a |
107 | ( $tc->is_a_type_of('ArrayRef') || $tc->is_a_type_of('HashRef') ) |
108 | || $class->throw_error("You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)"); |
2efc0af1 |
109 | } |
110 | |
1b9e472d |
111 | if (exists $args->{trigger}) { |
112 | ('CODE' eq ref $args->{trigger}) |
121acb8a |
113 | || $class->throw_error("Trigger must be a CODE ref on attribute ($name)"); |
2efc0af1 |
114 | } |
45959ffa |
115 | |
1b9e472d |
116 | if ($args->{lazy}) { |
117 | (exists $args->{default} || defined $args->{builder}) |
121acb8a |
118 | || $class->throw_error("You cannot have lazy attribute ($name) without specifying a default value for it"); |
2efc0af1 |
119 | } |
90fe520e |
120 | |
87ca293b |
121 | return; |
122 | } |
123 | |
124 | sub new { |
125 | my $class = shift; |
126 | my $name = shift; |
127 | |
128 | my %args = (@_ == 1) ? %{ $_[0] } : @_; |
129 | |
130 | $class->_process_options($name, \%args); |
131 | |
132 | $args{name} = $name; |
133 | |
926290ac |
134 | my $self = bless \%args, $class; |
2efc0af1 |
135 | |
1b9e472d |
136 | # extra attributes |
137 | if($class ne __PACKAGE__){ |
926290ac |
138 | $class->meta->_initialize_object($self, \%args); |
90fe520e |
139 | } |
c3398f5b |
140 | |
2efc0af1 |
141 | # XXX: there is no fast way to check attribute validity |
1b9e472d |
142 | # my @bad = ...; |
2efc0af1 |
143 | # if(@bad){ |
144 | # @bad = sort @bad; |
145 | # Carp::cluck("Found unknown argument(s) passed to '$name' attribute constructor in '$class': @bad"); |
146 | # } |
147 | |
926290ac |
148 | return $self; |
c3398f5b |
149 | } |
150 | |
43165725 |
151 | sub has_read_method { $_[0]->has_reader || $_[0]->has_accessor } |
152 | sub has_write_method { $_[0]->has_writer || $_[0]->has_accessor } |
1b9e472d |
153 | |
87ca293b |
154 | sub interpolate_class{ |
8cf51b82 |
155 | my($class, $args) = @_; |
c3398f5b |
156 | |
1b9e472d |
157 | if(my $metaclass = delete $args->{metaclass}){ |
158 | $class = Mouse::Util::resolve_metaclass_alias( Attribute => $metaclass ); |
159 | } |
1bfebf5f |
160 | |
87ca293b |
161 | my @traits; |
1b9e472d |
162 | if(my $traits_ref = delete $args->{traits}){ |
87ca293b |
163 | |
f3f04eed |
164 | for (my $i = 0; $i < @{$traits_ref}; $i++) { |
165 | my $trait = Mouse::Util::resolve_metaclass_alias(Attribute => $traits_ref->[$i], trait => 1); |
b2500191 |
166 | |
f3f04eed |
167 | next if $class->does($trait); |
74be9f76 |
168 | |
f3f04eed |
169 | push @traits, $trait; |
1b9e472d |
170 | |
f3f04eed |
171 | # are there options? |
172 | push @traits, $traits_ref->[++$i] |
173 | if ref($traits_ref->[$i+1]); |
174 | } |
c3398f5b |
175 | |
1b9e472d |
176 | if (@traits) { |
177 | $class = Mouse::Meta::Class->create_anon_class( |
178 | superclasses => [ $class ], |
179 | roles => \@traits, |
180 | cache => 1, |
181 | )->name; |
1b9e472d |
182 | } |
74be9f76 |
183 | } |
184 | |
87ca293b |
185 | return( $class, @traits ); |
1b9e472d |
186 | } |
187 | |
ffbbf459 |
188 | sub _coerce_and_verify { |
189 | my($self, $value, $instance) = @_; |
190 | |
191 | my $type_constraint = $self->{type_constraint}; |
4331a3f9 |
192 | return $value if !defined $type_constraint; |
ffbbf459 |
193 | |
194 | if ($self->should_coerce && $type_constraint->has_coercion) { |
195 | $value = $type_constraint->coerce($value); |
196 | } |
197 | |
ffbbf459 |
198 | $self->verify_against_type_constraint($value); |
199 | |
200 | return $value; |
201 | } |
202 | |
20e25eb9 |
203 | sub verify_against_type_constraint { |
f55f60dd |
204 | my ($self, $value) = @_; |
5aa30ced |
205 | |
ffbbf459 |
206 | my $type_constraint = $self->{type_constraint}; |
4331a3f9 |
207 | return 1 if !$type_constraint; |
ffbbf459 |
208 | return 1 if $type_constraint->check($value); |
5aa30ced |
209 | |
da23cd4a |
210 | $self->_throw_type_constraint_error($value, $type_constraint); |
b3b74cc6 |
211 | } |
5aa30ced |
212 | |
da23cd4a |
213 | sub _throw_type_constraint_error { |
2a96ea85 |
214 | my($self, $value, $type) = @_; |
215 | |
216 | $self->throw_error( |
217 | sprintf q{Attribute (%s) does not pass the type constraint because: %s}, |
218 | $self->name, |
219 | $type->get_message($value), |
220 | ); |
5aa30ced |
221 | } |
222 | |
1b9e472d |
223 | sub clone_and_inherit_options{ |
8cf51b82 |
224 | my($self, %args) = @_; |
225 | |
226 | my($attribute_class, @traits) = ref($self)->interpolate_class(\%args); |
1b9e472d |
227 | |
8cf51b82 |
228 | $args{traits} = \@traits if @traits; |
4f41d79b |
229 | # do not inherit the 'handles' attribute |
230 | foreach my $name(keys %{$self}){ |
231 | if(!exists $args{$name} && $name ne 'handles'){ |
232 | $args{$name} = $self->{$name}; |
233 | } |
234 | } |
235 | return $attribute_class->new($self->name, %args); |
1b9e472d |
236 | } |
237 | |
0126c27c |
238 | sub get_read_method { |
751de1a1 |
239 | return $_[0]->reader || $_[0]->accessor |
df77fd72 |
240 | } |
0126c27c |
241 | sub get_write_method { |
751de1a1 |
242 | return $_[0]->writer || $_[0]->accessor |
243 | } |
244 | |
245 | sub _get_accessor_method_ref { |
246 | my($self, $type, $generator) = @_; |
247 | |
248 | my $metaclass = $self->associated_class |
249 | || $self->throw_error('No asocciated class for ' . $self->name); |
250 | |
251 | my $accessor = $self->$type(); |
252 | if($accessor){ |
253 | return $metaclass->get_method_body($accessor); |
254 | } |
255 | else{ |
256 | return $self->accessor_metaclass->$generator($self, $metaclass); |
257 | } |
df77fd72 |
258 | } |
2a464664 |
259 | |
260 | sub get_read_method_ref{ |
261 | my($self) = @_; |
751de1a1 |
262 | return $self->{_read_method_ref} ||= $self->_get_accessor_method_ref('get_read_method', '_generate_reader'); |
2a464664 |
263 | } |
264 | |
265 | sub get_write_method_ref{ |
266 | my($self) = @_; |
751de1a1 |
267 | return $self->{_write_method_ref} ||= $self->_get_accessor_method_ref('get_write_method', '_generate_writer'); |
268 | } |
2a464664 |
269 | |
751de1a1 |
270 | sub set_value { |
271 | my($self, $object, $value) = @_; |
272 | return $self->get_write_method_ref()->($object, $value); |
273 | } |
274 | |
275 | sub get_value { |
276 | my($self, $object) = @_; |
277 | return $self->get_read_method_ref()->($object); |
2a464664 |
278 | } |
279 | |
751de1a1 |
280 | sub has_value { |
281 | my($self, $object) = @_; |
060f9228 |
282 | my $accessor_ref = $self->{_predicate_ref} |
751de1a1 |
283 | ||= $self->_get_accessor_method_ref('predicate', '_generate_predicate'); |
284 | |
060f9228 |
285 | return $accessor_ref->($object); |
751de1a1 |
286 | } |
287 | |
288 | sub clear_value { |
289 | my($self, $object) = @_; |
060f9228 |
290 | my $accessor_ref = $self->{_crealer_ref} |
751de1a1 |
291 | ||= $self->_get_accessor_method_ref('clearer', '_generate_clearer'); |
292 | |
060f9228 |
293 | return $accessor_ref->($object); |
751de1a1 |
294 | } |
295 | |
296 | |
04493075 |
297 | sub associate_method{ |
e5e22afd |
298 | my ($attribute, $method_name) = @_; |
04493075 |
299 | $attribute->{associated_methods}++; |
300 | return; |
301 | } |
302 | |
1b9e472d |
303 | sub install_accessors{ |
304 | my($attribute) = @_; |
305 | |
93540011 |
306 | my $metaclass = $attribute->associated_class; |
4ab51fb0 |
307 | my $accessor_class = $attribute->accessor_metaclass; |
1b9e472d |
308 | |
4ab51fb0 |
309 | foreach my $type(qw(accessor reader writer predicate clearer)){ |
1b9e472d |
310 | if(exists $attribute->{$type}){ |
4ab51fb0 |
311 | my $generator = '_generate_' . $type; |
312 | my $code = $accessor_class->$generator($attribute, $metaclass); |
313 | $metaclass->add_method($attribute->{$type} => $code); |
e5e22afd |
314 | $attribute->associate_method($attribute->{$type}); |
4ab51fb0 |
315 | } |
316 | } |
7ca5c5fb |
317 | |
4ab51fb0 |
318 | # install delegation |
319 | if(exists $attribute->{handles}){ |
320 | my %handles = $attribute->_canonicalize_handles($attribute->{handles}); |
feaa7084 |
321 | |
cbb81058 |
322 | while(my($handle, $method_to_call) = each %handles){ |
323 | $metaclass->add_method($handle => |
324 | $attribute->_make_delegation_method( |
325 | $handle, $method_to_call)); |
4ab51fb0 |
326 | |
cbb81058 |
327 | $attribute->associate_method($handle); |
1b9e472d |
328 | } |
329 | } |
330 | |
1b9e472d |
331 | return; |
332 | } |
333 | |
cbb81058 |
334 | sub delegation_metaclass() { 'Mouse::Meta::Method::Delegation' } |
335 | |
336 | sub _canonicalize_handles { |
337 | my($self, $handles) = @_; |
338 | |
339 | if (ref($handles) eq 'HASH') { |
340 | return %$handles; |
341 | } |
342 | elsif (ref($handles) eq 'ARRAY') { |
343 | return map { $_ => $_ } @$handles; |
344 | } |
345 | elsif (ref($handles) eq 'Regexp') { |
346 | my $class_or_role = ($self->{isa} || $self->{does}) |
347 | || $self->throw_error("Cannot delegate methods based on a Regexp without a type constraint (isa)"); |
348 | |
349 | my $meta = Mouse::Meta::Class->initialize("$class_or_role"); # "" for stringify |
350 | return map { $_ => $_ } |
351 | grep { !Mouse::Object->can($_) && $_ =~ $handles } |
352 | Mouse::Util::is_a_metarole($meta) |
353 | ? $meta->get_method_list |
354 | : $meta->get_all_method_names; |
355 | } |
356 | else { |
357 | $self->throw_error("Unable to canonicalize the 'handles' option with $handles"); |
358 | } |
359 | } |
360 | |
361 | sub _make_delegation_method { |
362 | my($self, $handle, $method_to_call) = @_; |
363 | my $delegator = $self->delegation_metaclass; |
364 | Mouse::Util::load_class($delegator); |
365 | |
366 | return $delegator->_generate_delegation($self, $handle, $method_to_call); |
367 | } |
368 | |
fce211ae |
369 | sub throw_error{ |
370 | my $self = shift; |
371 | |
372 | my $metaclass = (ref $self && $self->associated_class) || 'Mouse::Meta::Class'; |
373 | $metaclass->throw_error(@_, depth => 1); |
1bfebf5f |
374 | } |
375 | |
c3398f5b |
376 | 1; |
c3398f5b |
377 | __END__ |
378 | |
379 | =head1 NAME |
380 | |
bedd575c |
381 | Mouse::Meta::Attribute - The Mouse attribute metaclass |
c3398f5b |
382 | |
a25ca8d6 |
383 | =head1 VERSION |
384 | |
81fd550d |
385 | This document describes Mouse version 0.45 |
a25ca8d6 |
386 | |
c3398f5b |
387 | =head1 METHODS |
388 | |
1820fffe |
389 | =head2 C<< new(%options) -> Mouse::Meta::Attribute >> |
c3398f5b |
390 | |
306290e8 |
391 | Instantiates a new Mouse::Meta::Attribute. Does nothing else. |
c3398f5b |
392 | |
1820fffe |
393 | It adds the following options to the constructor: |
c3398f5b |
394 | |
1820fffe |
395 | =over 4 |
c3398f5b |
396 | |
612d3e1a |
397 | =item C<< is => 'ro', 'rw', 'bare' >> |
c3398f5b |
398 | |
1820fffe |
399 | This provides a shorthand for specifying the C<reader>, C<writer>, or |
400 | C<accessor> names. If the attribute is read-only ('ro') then it will |
401 | have a C<reader> method with the same attribute as the name. |
c3398f5b |
402 | |
1820fffe |
403 | If it is read-write ('rw') then it will have an C<accessor> method |
404 | with the same name. If you provide an explicit C<writer> for a |
405 | read-write attribute, then you will have a C<reader> with the same |
406 | name as the attribute, and a C<writer> with the name you provided. |
c3398f5b |
407 | |
1820fffe |
408 | Use 'bare' when you are deliberately not installing any methods |
409 | (accessor, reader, etc.) associated with this attribute; otherwise, |
410 | Moose will issue a deprecation warning when this attribute is added to a |
411 | metaclass. |
c3398f5b |
412 | |
612d3e1a |
413 | =item C<< isa => Type >> |
ab27a55e |
414 | |
1820fffe |
415 | This option accepts a type. The type can be a string, which should be |
416 | a type name. If the type name is unknown, it is assumed to be a class |
417 | name. |
ab27a55e |
418 | |
1820fffe |
419 | This option can also accept a L<Moose::Meta::TypeConstraint> object. |
ab27a55e |
420 | |
1820fffe |
421 | If you I<also> provide a C<does> option, then your C<isa> option must |
422 | be a class name, and that class must do the role specified with |
423 | C<does>. |
ab27a55e |
424 | |
612d3e1a |
425 | =item C<< does => Role >> |
ab27a55e |
426 | |
1820fffe |
427 | This is short-hand for saying that the attribute's type must be an |
428 | object which does the named role. |
c3398f5b |
429 | |
1820fffe |
430 | B<This option is not yet supported.> |
c3398f5b |
431 | |
612d3e1a |
432 | =item C<< coerce => Bool >> |
ab27a55e |
433 | |
1820fffe |
434 | This option is only valid for objects with a type constraint |
435 | (C<isa>). If this is true, then coercions will be applied whenever |
436 | this attribute is set. |
c3398f5b |
437 | |
1820fffe |
438 | You can make both this and the C<weak_ref> option true. |
c3398f5b |
439 | |
612d3e1a |
440 | =item C<< trigger => CodeRef >> |
ab27a55e |
441 | |
1820fffe |
442 | This option accepts a subroutine reference, which will be called after |
443 | the attribute is set. |
ab27a55e |
444 | |
612d3e1a |
445 | =item C<< required => Bool >> |
ab27a55e |
446 | |
1820fffe |
447 | An attribute which is required must be provided to the constructor. An |
448 | attribute which is required can also have a C<default> or C<builder>, |
449 | which will satisfy its required-ness. |
ab27a55e |
450 | |
1820fffe |
451 | A required attribute must have a C<default>, C<builder> or a |
452 | non-C<undef> C<init_arg> |
ab27a55e |
453 | |
612d3e1a |
454 | =item C<< lazy => Bool >> |
ab27a55e |
455 | |
1820fffe |
456 | A lazy attribute must have a C<default> or C<builder>. When an |
457 | attribute is lazy, the default value will not be calculated until the |
458 | attribute is read. |
93f08899 |
459 | |
612d3e1a |
460 | =item C<< weak_ref => Bool >> |
0fff36e6 |
461 | |
1820fffe |
462 | If this is true, the attribute's value will be stored as a weak |
463 | reference. |
c3398f5b |
464 | |
612d3e1a |
465 | =item C<< auto_deref => Bool >> |
fb706f5c |
466 | |
1820fffe |
467 | If this is true, then the reader will dereference the value when it is |
468 | called. The attribute must have a type constraint which defines the |
469 | attribute as an array or hash reference. |
470 | |
612d3e1a |
471 | =item C<< lazy_build => Bool >> |
1820fffe |
472 | |
473 | Setting this to true makes the attribute lazy and provides a number of |
474 | default methods. |
fb706f5c |
475 | |
1820fffe |
476 | has 'size' => ( |
477 | is => 'ro', |
478 | lazy_build => 1, |
479 | ); |
93d190e0 |
480 | |
1820fffe |
481 | is equivalent to this: |
93d190e0 |
482 | |
1820fffe |
483 | has 'size' => ( |
484 | is => 'ro', |
485 | lazy => 1, |
486 | builder => '_build_size', |
487 | clearer => 'clear_size', |
488 | predicate => 'has_size', |
489 | ); |
93d190e0 |
490 | |
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491 | =back |
492 | |
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493 | =head2 C<< associate_method(MethodName) >> |
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494 | |
495 | Associates a method with the attribute. Typically, this is called internally |
496 | when an attribute generates its accessors. |
497 | |
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498 | Currently the argument I<MethodName> is ignored in Mouse. |
31c5194b |
499 | |
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500 | =head2 C<< verify_against_type_constraint(Item) -> TRUE | ERROR >> |
501 | |
502 | Checks that the given value passes this attribute's type constraint. Returns C<true> |
503 | on success, otherwise C<confess>es. |
93d190e0 |
504 | |
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505 | =head2 C<< clone_and_inherit_options(options) -> Mouse::Meta::Attribute >> |
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506 | |
612d3e1a |
507 | Creates a new attribute in the owner class, inheriting options from parent classes. |
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508 | Accessors and helper methods are installed. Some error checking is done. |
509 | |
9ae9702e |
510 | =head2 C<< get_read_method_ref >> |
511 | |
512 | =head2 C<< get_write_method_ref >> |
513 | |
514 | Returns the subroutine reference of a method suitable for reading or |
515 | writing the attribute's value in the associated class. These methods |
516 | always return a subroutine reference, regardless of whether or not the |
df77fd72 |
517 | attribute is read- or write-only. |
518 | |
1820fffe |
519 | =head1 SEE ALSO |
f7b11a21 |
520 | |
1820fffe |
521 | L<Moose::Meta::Attribute> |
f7b11a21 |
522 | |
31c5194b |
523 | L<Class::MOP::Attribute> |
524 | |
c3398f5b |
525 | =cut |
526 | |