2 package Class::MOP::Method::Constructor;
8 use Scalar::Util 'blessed', 'weaken', 'looks_like_number';
10 our $VERSION = '0.77';
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 {
95 $source .= "\n" . 'my $class = shift;';
97 $source .= "\n" . 'return Class::MOP::Class->initialize($class)->new_object(@_)';
98 $source .= "\n" . ' if $class ne \'' . $self->associated_metaclass->name . '\';';
100 $source .= "\n" . 'my $params = @_ == 1 ? $_[0] : {@_};';
102 $source .= "\n" . 'my $instance = ' . $self->meta_instance->inline_create_instance('$class');
103 $source .= ";\n" . (join ";\n" => map {
104 $self->_generate_slot_initializer($_, $close_over)
105 } 0 .. (@{$self->attributes} - 1));
106 $source .= ";\n" . 'return $instance';
107 $source .= ";\n" . '}';
108 warn $source if $self->options->{debug};
110 return $self->_eval_closure(
116 sub _generate_slot_initializer {
121 my $attr = $self->attributes->[$index];
124 if ($attr->has_default) {
126 # default values can either be CODE refs
127 # in which case we need to call them. Or
128 # they can be scalars (strings/numbers)
129 # in which case we can just deal with them
130 # in the code we eval.
131 if ($attr->is_default_a_coderef) {
132 my $idx = @{$close->{'@defaults'}||=[]};
133 push(@{$close->{'@defaults'}}, $attr->default);
134 $default = '$defaults[' . $idx . ']->($instance)';
137 $default = $attr->default;
138 # make sure to quote strings ...
139 unless (looks_like_number($default)) {
140 $default = "'$default'";
143 } elsif( $attr->has_builder ) {
144 $default = '$instance->'.$attr->builder;
147 if ( defined $attr->init_arg ) {
149 'if(exists $params->{\'' . $attr->init_arg . '\'}){' . "\n" .
150 $self->meta_instance->inline_set_slot_value(
152 ("'" . $attr->name . "'"),
153 '$params->{\'' . $attr->init_arg . '\'}' ) . "\n" .
154 '} ' . (!defined $default ? '' : 'else {' . "\n" .
155 $self->meta_instance->inline_set_slot_value(
157 ("'" . $attr->name . "'"),
161 } elsif ( defined $default ) {
163 $self->meta_instance->inline_set_slot_value(
165 ("'" . $attr->name . "'"),
179 Class::MOP::Method::Constructor - Method Meta Object for constructors
183 use Class::MOP::Method::Constructor;
185 my $constructor = Class::MOP::Method::Constructor->new(
186 metaclass => $metaclass,
188 debug => 1, # this is all for now
192 # calling the constructor ...
193 $constructor->body->execute($metaclass->name, %params);
197 This is a subclass of C<Class::MOP::Method> which deals with
198 class constructors. This is used when making a class immutable
199 to generate an optimized constructor.
205 =item B<new (metaclass => $meta, options => \%options)>
209 This returns the options HASH which is passed into C<new>.
211 =item B<associated_metaclass>
213 This returns the metaclass which is passed into C<new>.
217 This returns the list of attributes which are associated with the
218 metaclass which is passed into C<new>.
220 =item B<meta_instance>
222 This returns the meta instance which is associated with the
223 metaclass which is passed into C<new>.
227 This returns a boolean, but since constructors are very rarely
228 not inlined, this always returns true for now.
230 =item B<can_be_inlined>
232 This method always returns true in this class. It exists so that
233 subclasses (like in Moose) can override and do some sort of checking
234 to determine whether or not inlining the constructor is safe.
236 =item B<initialize_body>
238 This creates the code reference for the constructor itself.
242 =head2 Method Generators
246 =item B<generate_constructor_method>
248 =item B<generate_constructor_method_inline>
254 Stevan Little E<lt>stevan@iinteractive.comE<gt>
256 =head1 COPYRIGHT AND LICENSE
258 Copyright 2006-2008 by Infinity Interactive, Inc.
260 L<http://www.iinteractive.com>
262 This library is free software; you can redistribute it and/or modify
263 it under the same terms as Perl itself.