2 package Class::MOP::Method::Constructor;
8 use Scalar::Util 'blessed', 'weaken', 'looks_like_number';
10 our $VERSION = '0.71_01';
11 $VERSION = eval $VERSION;
12 our $AUTHORITY = 'cpan:STEVAN';
14 use base 'Class::MOP::Method::Generated';
20 (blessed $options{metaclass} && $options{metaclass}->isa('Class::MOP::Class'))
21 || confess "You must pass a metaclass instance if you want to inline"
22 if $options{is_inline};
24 ($options{package_name} && $options{name})
25 || confess "You must supply the package_name and name parameters $Class::MOP::Method::UPGRADE_ERROR_TEXT";
27 my $self = $class->_new(\%options);
29 # we don't want this creating
30 # a cycle in the code, if not
32 weaken($self->{'associated_metaclass'});
34 $self->initialize_body;
41 my $options = @_ == 1 ? $_[0] : {@_};
46 'package_name' => $options->{package_name},
47 'name' => $options->{name},
48 # specific to this subclass
49 'options' => $options->{options} || {},
50 'associated_metaclass' => $options->{metaclass},
51 'is_inline' => ($options->{is_inline} || 0),
55 sub can_be_inlined { 1 }
59 sub options { (shift)->{'options'} }
60 sub associated_metaclass { (shift)->{'associated_metaclass'} }
66 $self->{'meta_instance'} ||= $self->associated_metaclass->get_meta_instance;
71 $self->{'attributes'} ||= [ $self->associated_metaclass->compute_all_applicable_attributes ]
78 my $method_name = 'generate_constructor_method';
80 $method_name .= '_inline' if $self->is_inline;
82 $self->{'body'} = $self->$method_name;
85 sub generate_constructor_method {
86 return sub { Class::MOP::Class->initialize(shift)->new_object(@_) }
89 sub generate_constructor_method_inline {
93 $source .= "\n" . 'my $class = shift;';
95 $source .= "\n" . 'return Class::MOP::Class->initialize($class)->new_object(@_)';
96 $source .= "\n" . ' if $class ne \'' . $self->associated_metaclass->name . '\';';
98 $source .= "\n" . 'my $params = @_ == 1 ? $_[0] : {@_};';
100 $source .= "\n" . 'my $instance = ' . $self->meta_instance->inline_create_instance('$class');
101 $source .= ";\n" . (join ";\n" => map {
102 $self->_generate_slot_initializer($_)
103 } 0 .. (@{$self->attributes} - 1));
104 $source .= ";\n" . 'return $instance';
105 $source .= ";\n" . '}';
106 warn $source if $self->options->{debug};
111 # create the nessecary lexicals
112 # to be picked up in the eval
114 $code = $self->_eval_closure(
115 q{my $attrs = $self->attributes;},
118 confess "Could not eval the constructor :\n\n$source\n\nbecause :\n\n$@" if $@;
123 sub _generate_slot_initializer {
127 my $attr = $self->attributes->[$index];
130 if ($attr->has_default) {
132 # default values can either be CODE refs
133 # in which case we need to call them. Or
134 # they can be scalars (strings/numbers)
135 # in which case we can just deal with them
136 # in the code we eval.
137 if ($attr->is_default_a_coderef) {
138 $default = '$attrs->[' . $index . ']->default($instance)';
141 $default = $attr->default;
142 # make sure to quote strings ...
143 unless (looks_like_number($default)) {
144 $default = "'$default'";
147 } elsif( $attr->has_builder ) {
148 $default = '$instance->'.$attr->builder;
151 if ( defined $attr->init_arg ) {
153 'if(exists $params->{\'' . $attr->init_arg . '\'}){' . "\n" .
154 $self->meta_instance->inline_set_slot_value(
156 ("'" . $attr->name . "'"),
157 '$params->{\'' . $attr->init_arg . '\'}' ) . "\n" .
158 '} ' . (!defined $default ? '' : 'else {' . "\n" .
159 $self->meta_instance->inline_set_slot_value(
161 ("'" . $attr->name . "'"),
165 } elsif ( defined $default ) {
167 $self->meta_instance->inline_set_slot_value(
169 ("'" . $attr->name . "'"),
183 Class::MOP::Method::Constructor - Method Meta Object for constructors
187 use Class::MOP::Method::Constructor;
189 my $constructor = Class::MOP::Method::Constructor->new(
190 metaclass => $metaclass,
192 debug => 1, # this is all for now
196 # calling the constructor ...
197 $constructor->body->execute($metaclass->name, %params);
201 This is a subclass of C<Class::MOP::Method> which deals with
202 class constructors. This is used when making a class immutable
203 to generate an optimized constructor.
209 =item B<new (metaclass => $meta, options => \%options)>
213 This returns the options HASH which is passed into C<new>.
215 =item B<associated_metaclass>
217 This returns the metaclass which is passed into C<new>.
221 This returns the list of attributes which are associated with the
222 metaclass which is passed into C<new>.
224 =item B<meta_instance>
226 This returns the meta instance which is associated with the
227 metaclass which is passed into C<new>.
231 This returns a boolean, but since constructors are very rarely
232 not inlined, this always returns true for now.
234 =item B<can_be_inlined>
236 This method always returns true in this class. It exists so that
237 subclasses (like in Moose) can override and do some sort of checking
238 to determine whether or not inlining the constructor is safe.
240 =item B<initialize_body>
242 This creates the code reference for the constructor itself.
246 =head2 Method Generators
250 =item B<generate_constructor_method>
252 =item B<generate_constructor_method_inline>
258 Stevan Little E<lt>stevan@iinteractive.comE<gt>
260 =head1 COPYRIGHT AND LICENSE
262 Copyright 2006-2008 by Infinity Interactive, Inc.
264 L<http://www.iinteractive.com>
266 This library is free software; you can redistribute it and/or modify
267 it under the same terms as Perl itself.