add introspection methods to Class::MOP::Instance
[gitmo/Class-MOP.git] / lib / Class / MOP / Instance.pm
CommitLineData
24869f62 1
2package Class::MOP::Instance;
3
4use strict;
5use warnings;
6
7use Carp 'confess';
8use Scalar::Util 'blessed', 'reftype', 'weaken';
9
10our $VERSION = '0.01';
11
12sub meta {
13 require Class::MOP::Class;
14 Class::MOP::Class->initialize(blessed($_[0]) || $_[0]);
15}
16
17sub new {
2d711cc8 18 my ( $class, $meta ) = @_;
24869f62 19 bless {
2d711cc8 20 meta => $meta,
21 instance_layout => {}
24869f62 22 } => $class;
23}
24
2d711cc8 25sub create_instance {
26 my ( $self, $class ) = @_;
27
28 # rely on autovivification
29 $self->bless_instance_structure( {}, $class );
30}
31
32sub bless_instance_structure {
33 my ( $self, $instance_structure, $class ) = @_;
34 $class ||= $self->{meta}->name;
35 bless $instance_structure, $class;
36}
37
38sub get_all_parents {
39 my $self = shift;
40 my @parents = $self->{meta}->class_precedence_list;
41 shift @parents; # shift off ourselves
42 return map { $_->get_meta_instance } map { $_->meta || () } @parents;
43}
44
45# operations on meta instance
46
24869f62 47sub add_slot {
2d711cc8 48 my ($self, $slot_name ) = @_;
49 confess "The slot '$slot_name' already exists"
eb49acde 50 if 0 && $self->has_slot_recursively( $slot_name ); # FIXME
2d711cc8 51 $self->{instance_layout}->{$slot_name} = undef;
24869f62 52}
53
eb49acde 54sub get_all_slots {
55 my $self = shift;
56 keys %{ $self->{instance_layout} };
57}
58
59sub get_all_slots_recursively {
60 my $self = shift;
61 return (
62 $self->get_all_slots,
63 map { $_->get_all_slots } $self->get_all_parents,
64 ),
65}
66
839ea973 67sub has_slot {
68 my ($self, $slot_name) = @_;
2d711cc8 69 exists $self->{instance_layout}->{$slot_name} ? 1 : 0;
70}
71
72sub has_slot_recursively {
73 my ( $self, $slot_name ) = @_;
74 return 1 if $self->has_slot($slot_name);
75 $_->has_slot_recursively($slot_name) && return 1 for $self->get_all_parents;
76 return 0;
839ea973 77}
78
2d711cc8 79sub remove_slot {
80 my ( $self, $slot_name ) = @_;
81 # NOTE:
82 # this does not search recursively cause
83 # that is not the domain of this meta-instance
84 # it is specific to this class ...
85 confess "The slot '$slot_name' does not exist (maybe it's inherited?)"
eb49acde 86 if 0 && $self->has_slot( $slot_name ); # FIXME
2d711cc8 87 delete $self->{instance_layout}->{$slot_name};
88}
89
90
91# operations on created instances
92
839ea973 93sub get_slot_value {
2bab2be6 94 my ($self, $instance, $slot_name) = @_;
95 return $instance->{$slot_name};
839ea973 96}
97
2d711cc8 98# can be called only after initialize_slot_value
2bab2be6 99sub set_slot_value {
100 my ($self, $instance, $slot_name, $value) = @_;
101 $instance->{$slot_name} = $value;
102}
103
2d711cc8 104# convenience method
105# non autovivifying stores will have this as { initialize_slot unless slot_initlized; set_slot_value }
106sub set_slot_value_with_init {
107 my ( $self, $instance, $slot_name, $value ) = @_;
108 $self->set_slot_value( $instance, $slot_name, $value );
109}
110
111sub initialize_slot {
112 my ( $self, $instance, $slot_name ) = @_;
113}
114
115sub slot_initialized {
2bab2be6 116 my ($self, $instance, $slot_name) = @_;
2d711cc8 117 exists $instance->{$slot_name} ? 1 : 0;
2bab2be6 118}
839ea973 119
2d711cc8 120
121# inlinable operation snippets
122
123sub inline_get_slot_value {
124 my ($self, $instance, $slot_name) = @_;
125 sprintf "%s->{%s}", $instance, $slot_name;
126}
127
128sub inline_set_slot_value {
129 my ($self, $instance, $slot_name, $value) = @_;
130 $self->_inline_slot_lvalue . " = $value",
131}
132
133sub inline_set_slot_value_with_init {
134 my ( $self, $instance, $slot_name, $value) = @_;
135 $self->inline_set_slot_value( $instance, $slot_name, $value ) . ";";
136}
137
138sub inline_initialize_slot {
139 return "";
140}
141
142sub inline_slot_initialized {
143 my ($self, $instance, $slot_name) = @_;
144 "exists " . $self->inline_get_slot_value;
145}
146
147sub _inline_slot_lvalue {
148 my ($self, $instance, $slot_name) = @_;
149 $self->inline_slot_value;
150}
24869f62 151
1521;
153
154__END__
155
156=pod
157
158=head1 NAME
159
160Class::MOP::Instance - Instance Meta Object
161
162=head1 SYNOPSIS
163
164=head1 DESCRIPTION
165
166=head1 METHODS
167
168=over 4
169
170=item B<new>
171
172=item B<add_slot>
173
58287a97 174=item B<bless_instance_structure>
175
176=item B<create_instance>
177
178=item B<get_all_parents>
839ea973 179
180=item B<get_slot_value>
181
58287a97 182=item B<has_slot>
183
184=item B<has_slot_recursively>
185
186=item B<initialize_slot>
187
188=item B<inline_get_slot_value>
189
190=item B<inline_initialize_slot>
191
192=item B<inline_set_slot_value>
193
194=item B<inline_set_slot_value_with_init>
195
196=item B<inline_slot_initialized>
197
198=item B<remove_slot>
199
839ea973 200=item B<set_slot_value>
201
58287a97 202=item B<set_slot_value_with_init>
203
204=item B<slot_initialized>
2bab2be6 205
24869f62 206=back
207
208=head2 Introspection
209
210=over 4
211
212=item B<meta>
213
214This will return a B<Class::MOP::Class> instance which is related
215to this class.
216
217=back
218
219=head1 AUTHOR
220
221Stevan Little E<lt>stevan@iinteractive.comE<gt>
222
223=head1 COPYRIGHT AND LICENSE
224
225Copyright 2006 by Infinity Interactive, Inc.
226
227L<http://www.iinteractive.com>
228
229This library is free software; you can redistribute it and/or modify
230it under the same terms as Perl itself.
231
232=cut