Commit | Line | Data |
d90b42a6 |
1 | |
2 | package Class::MOP::Method::Constructor; |
3 | |
4 | use strict; |
5 | use warnings; |
6 | |
7 | use Carp 'confess'; |
8 | use Scalar::Util 'blessed', 'weaken', 'looks_like_number'; |
9 | |
0c6f4c4a |
10 | our $VERSION = '0.04'; |
d90b42a6 |
11 | our $AUTHORITY = 'cpan:STEVAN'; |
12 | |
565f0cbb |
13 | use base 'Class::MOP::Method::Generated'; |
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14 | |
15 | sub new { |
16 | my $class = shift; |
17 | my %options = @_; |
8d2d4c67 |
18 | |
ad315b75 |
19 | (blessed $options{metaclass} && $options{metaclass}->isa('Class::MOP::Class')) |
20 | || confess "You must pass a metaclass instance if you want to inline" |
8d2d4c67 |
21 | if $options{is_inline}; |
22 | |
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23 | my $self = bless { |
24 | # from our superclass |
4c105333 |
25 | '&!body' => undef, |
26 | '$!package_name' => $options{package_name}, |
27 | '$!name' => $options{name}, |
d90b42a6 |
28 | # specific to this subclass |
ad315b75 |
29 | '%!options' => $options{options} || {}, |
c23184fc |
30 | '$!associated_metaclass' => $options{metaclass}, |
8d2d4c67 |
31 | '$!is_inline' => ($options{is_inline} || 0), |
d90b42a6 |
32 | } => $class; |
33 | |
8d2d4c67 |
34 | # we don't want this creating |
35 | # a cycle in the code, if not |
d90b42a6 |
36 | # needed |
8d2d4c67 |
37 | weaken($self->{'$!associated_metaclass'}); |
d90b42a6 |
38 | |
565f0cbb |
39 | $self->initialize_body; |
d90b42a6 |
40 | |
8d2d4c67 |
41 | return $self; |
d90b42a6 |
42 | } |
43 | |
8d2d4c67 |
44 | ## accessors |
c23184fc |
45 | |
565f0cbb |
46 | sub options { (shift)->{'%!options'} } |
47 | sub associated_metaclass { (shift)->{'$!associated_metaclass'} } |
c23184fc |
48 | |
565f0cbb |
49 | ## cached values ... |
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50 | |
8d2d4c67 |
51 | sub meta_instance { |
565f0cbb |
52 | my $self = shift; |
53 | $self->{'$!meta_instance'} ||= $self->associated_metaclass->get_meta_instance; |
54 | } |
c23184fc |
55 | |
8d2d4c67 |
56 | sub attributes { |
565f0cbb |
57 | my $self = shift; |
58 | $self->{'@!attributes'} ||= [ $self->associated_metaclass->compute_all_applicable_attributes ] |
59 | } |
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60 | |
61 | ## method |
62 | |
565f0cbb |
63 | sub initialize_body { |
64 | my $self = shift; |
65 | my $method_name = 'generate_constructor_method'; |
8d2d4c67 |
66 | |
565f0cbb |
67 | $method_name .= '_inline' if $self->is_inline; |
8d2d4c67 |
68 | |
565f0cbb |
69 | $self->{'&!body'} = $self->$method_name; |
70 | } |
71 | |
72 | sub generate_constructor_method { |
2a2b8458 |
73 | return sub { Class::MOP::Class->initialize(shift)->new_object(@_) } |
565f0cbb |
74 | } |
75 | |
76 | sub generate_constructor_method_inline { |
d90b42a6 |
77 | my $self = shift; |
565f0cbb |
78 | |
d90b42a6 |
79 | my $source = 'sub {'; |
80 | $source .= "\n" . 'my ($class, %params) = @_;'; |
8d2d4c67 |
81 | |
2a2b8458 |
82 | $source .= "\n" . 'return Class::MOP::Class->initialize($class)->new_object(%params)'; |
8d2d4c67 |
83 | $source .= "\n" . ' if $class ne \'' . $self->associated_metaclass->name . '\';'; |
84 | |
d90b42a6 |
85 | $source .= "\n" . 'my $instance = ' . $self->meta_instance->inline_create_instance('$class'); |
8d2d4c67 |
86 | $source .= ";\n" . (join ";\n" => map { |
87 | $self->_generate_slot_initializer($_) |
d90b42a6 |
88 | } 0 .. (@{$self->attributes} - 1)); |
89 | $source .= ";\n" . 'return $instance'; |
8d2d4c67 |
90 | $source .= ";\n" . '}'; |
91 | warn $source if $self->options->{debug}; |
92 | |
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93 | my $code; |
94 | { |
95 | # NOTE: |
96 | # create the nessecary lexicals |
8d2d4c67 |
97 | # to be picked up in the eval |
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98 | my $attrs = $self->attributes; |
8d2d4c67 |
99 | |
d90b42a6 |
100 | $code = eval $source; |
101 | confess "Could not eval the constructor :\n\n$source\n\nbecause :\n\n$@" if $@; |
102 | } |
565f0cbb |
103 | return $code; |
d90b42a6 |
104 | } |
105 | |
106 | sub _generate_slot_initializer { |
107 | my $self = shift; |
108 | my $index = shift; |
8d2d4c67 |
109 | |
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110 | my $attr = $self->attributes->[$index]; |
8d2d4c67 |
111 | |
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112 | my $default; |
113 | if ($attr->has_default) { |
114 | # NOTE: |
115 | # default values can either be CODE refs |
8d2d4c67 |
116 | # in which case we need to call them. Or |
d90b42a6 |
117 | # they can be scalars (strings/numbers) |
118 | # in which case we can just deal with them |
119 | # in the code we eval. |
120 | if ($attr->is_default_a_coderef) { |
121 | $default = '$attrs->[' . $index . ']->default($instance)'; |
122 | } |
123 | else { |
124 | $default = $attr->default; |
125 | # make sure to quote strings ... |
126 | unless (looks_like_number($default)) { |
127 | $default = "'$default'"; |
128 | } |
129 | } |
8d2d4c67 |
130 | } elsif( $attr->has_builder ) { |
131 | $default = '$instance->'.$attr->builder; |
d90b42a6 |
132 | } |
8d2d4c67 |
133 | |
c16c9c1b |
134 | if ( defined $attr->init_arg ) { |
135 | return ( |
136 | 'if(exists $params{\'' . $attr->init_arg . '\'}){' . "\n" . |
137 | $self->meta_instance->inline_set_slot_value( |
138 | '$instance', |
139 | ("'" . $attr->name . "'"), |
140 | '$params{\'' . $attr->init_arg . '\'}' ) . "\n" . |
141 | '} ' . (!defined $default ? '' : 'else {' . "\n" . |
142 | $self->meta_instance->inline_set_slot_value( |
143 | '$instance', |
144 | ("'" . $attr->name . "'"), |
145 | $default ) . "\n" . |
146 | '}') |
147 | ); |
148 | } elsif ( defined $default ) { |
149 | return ( |
150 | $self->meta_instance->inline_set_slot_value( |
151 | '$instance', |
152 | ("'" . $attr->name . "'"), |
153 | $default ) . "\n" |
154 | ); |
155 | } else { return '' } |
d90b42a6 |
156 | } |
157 | |
158 | 1; |
159 | |
160 | 1; |
161 | |
162 | __END__ |
163 | |
164 | =pod |
165 | |
8d2d4c67 |
166 | =head1 NAME |
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167 | |
168 | Class::MOP::Method::Constructor - Method Meta Object for constructors |
169 | |
170 | =head1 SYNOPSIS |
171 | |
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172 | use Class::MOP::Method::Constructor; |
8d2d4c67 |
173 | |
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174 | my $constructor = Class::MOP::Method::Constructor->new( |
8d2d4c67 |
175 | metaclass => $metaclass, |
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176 | options => { |
177 | debug => 1, # this is all for now |
8d2d4c67 |
178 | }, |
96e38ba6 |
179 | ); |
8d2d4c67 |
180 | |
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181 | # calling the constructor ... |
182 | $constructor->body->($metaclass->name, %params); |
8d2d4c67 |
183 | |
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184 | =head1 DESCRIPTION |
185 | |
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186 | This is a subclass of C<Class::MOP::Method> which deals with |
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187 | class constructors. This is used when making a class immutable |
188 | to generate an optimized constructor. |
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189 | |
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190 | =head1 METHODS |
191 | |
192 | =over 4 |
193 | |
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194 | =item B<new (metaclass => $meta, options => \%options)> |
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195 | |
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196 | =item B<options> |
197 | |
198 | This returns the options HASH which is passed into C<new>. |
199 | |
200 | =item B<associated_metaclass> |
201 | |
202 | This returns the metaclass which is passed into C<new>. |
c23184fc |
203 | |
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204 | =item B<attributes> |
205 | |
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206 | This returns the list of attributes which are associated with the |
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207 | metaclass which is passed into C<new>. |
208 | |
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209 | =item B<meta_instance> |
210 | |
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211 | This returns the meta instance which is associated with the |
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212 | metaclass which is passed into C<new>. |
c23184fc |
213 | |
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214 | =item B<is_inline> |
215 | |
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216 | This returns a boolean, but since constructors are very rarely |
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217 | not inlined, this always returns true for now. |
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218 | |
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219 | =item B<initialize_body> |
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220 | |
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221 | This creates the code reference for the constructor itself. |
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222 | |
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223 | =back |
224 | |
127d39a7 |
225 | =head2 Method Generators |
565f0cbb |
226 | |
227 | =over 4 |
228 | |
229 | =item B<generate_constructor_method> |
230 | |
231 | =item B<generate_constructor_method_inline> |
232 | |
233 | =back |
234 | |
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235 | =head1 AUTHORS |
236 | |
237 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
238 | |
239 | =head1 COPYRIGHT AND LICENSE |
240 | |
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241 | Copyright 2006-2008 by Infinity Interactive, Inc. |
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242 | |
243 | L<http://www.iinteractive.com> |
244 | |
245 | This library is free software; you can redistribute it and/or modify |
8d2d4c67 |
246 | it under the same terms as Perl itself. |
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247 | |
248 | =cut |
249 | |