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158c88c0 |
1 | package Catalyst::Component; |
2 | |
a7caa492 |
3 | use Moose; |
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4 | use Class::MOP; |
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5 | use Class::MOP::Object; |
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6 | use Catalyst::Utils; |
cb89a296 |
7 | use Class::C3::Adopt::NEXT; |
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8 | use Devel::InnerPackage (); |
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9 | use MRO::Compat; |
10 | use mro 'c3'; |
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11 | use Scalar::Util 'blessed'; |
e7399d8b |
12 | use Class::Load 'is_class_loaded'; |
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13 | use Moose::Util 'find_meta'; |
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14 | use namespace::clean -except => 'meta'; |
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15 | |
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16 | with 'MooseX::Emulate::Class::Accessor::Fast'; |
17 | with 'Catalyst::ClassData'; |
18 | |
19 | |
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20 | =head1 NAME |
21 | |
22 | Catalyst::Component - Catalyst Component Base Class |
23 | |
24 | =head1 SYNOPSIS |
25 | |
26 | # lib/MyApp/Model/Something.pm |
27 | package MyApp::Model::Something; |
28 | |
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29 | use base 'Catalyst::Component'; |
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30 | |
31 | __PACKAGE__->config( foo => 'bar' ); |
32 | |
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33 | has foo => ( |
34 | is => 'ro', |
35 | ); |
36 | |
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37 | sub test { |
38 | my $self = shift; |
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39 | return $self->foo; |
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40 | } |
41 | |
42 | sub forward_to_me { |
43 | my ( $self, $c ) = @_; |
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44 | $c->response->output( $self->foo ); |
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45 | } |
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46 | |
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47 | 1; |
48 | |
49 | # Methods can be a request step |
50 | $c->forward(qw/MyApp::Model::Something forward_to_me/); |
51 | |
52 | # Or just methods |
53 | print $c->comp('MyApp::Model::Something')->test; |
54 | |
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55 | print $c->comp('MyApp::Model::Something')->foo; |
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56 | |
57 | =head1 DESCRIPTION |
58 | |
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59 | This is the universal base class for Catalyst components |
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60 | (Model/View/Controller). |
61 | |
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62 | It provides you with a generic new() for component construction through Catalyst's |
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63 | component loader with config() support and a process() method placeholder. |
64 | |
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65 | B<Note> that calling C<< $self->config >> inside a component is strongly |
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66 | not recommended - the correctly merged config should have already been |
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67 | passed to the constructor and stored in attributes - accessing |
68 | the config accessor directly from an instance is likely to get the |
69 | wrong values (as it only holds the class wide config, not things loaded |
70 | from the config file!) |
71 | |
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72 | =cut |
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73 | |
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74 | __PACKAGE__->mk_classdata('_plugins'); |
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75 | __PACKAGE__->mk_classdata('_config'); |
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76 | |
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77 | has catalyst_component_name => ( is => 'ro' ); # Cannot be required => 1 as context |
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78 | # class @ISA component - HATE |
79 | # Make accessor callable as a class method, as we need to call setup_actions |
80 | # on the application class, which we don't have an instance of, ewwwww |
e65d000f |
81 | # Also, naughty modules like Catalyst::View::JSON try to write to _everything_, |
82 | # so spit a warning, ignore that (and try to do the right thing anyway) here.. |
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83 | around catalyst_component_name => sub { |
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84 | my ($orig, $self) = (shift, shift); |
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85 | Carp::cluck("Tried to write to the catalyst_component_name accessor - is your component broken or just mad? (Write ignored - using default value.)") if scalar @_; |
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86 | blessed($self) ? $self->$orig() || blessed($self) : $self; |
d2598ac8 |
87 | }; |
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88 | |
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89 | sub BUILDARGS { |
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90 | my $class = shift; |
91 | my $args = {}; |
92 | |
93 | if (@_ == 1) { |
94 | $args = $_[0] if ref($_[0]) eq 'HASH'; |
95 | } elsif (@_ == 2) { # is it ($app, $args) or foo => 'bar' ? |
96 | if (blessed($_[0])) { |
97 | $args = $_[1] if ref($_[1]) eq 'HASH'; |
e7399d8b |
98 | } elsif (is_class_loaded($_[0]) && |
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99 | $_[0]->isa('Catalyst') && ref($_[1]) eq 'HASH') { |
100 | $args = $_[1]; |
7a5ed4ef |
101 | } else { |
102 | $args = +{ @_ }; |
103 | } |
104 | } elsif (@_ % 2 == 0) { |
105 | $args = +{ @_ }; |
106 | } |
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107 | |
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108 | return $class->merge_config_hashes( $class->config, $args ); |
2ef59958 |
109 | } |
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110 | |
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111 | sub COMPONENT { |
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112 | my ( $class, $c ) = @_; |
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113 | |
114 | # Temporary fix, some components does not pass context to constructor |
115 | my $arguments = ( ref( $_[-1] ) eq 'HASH' ) ? $_[-1] : {}; |
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116 | if ( my $next = $class->next::can ) { |
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117 | my ($next_package) = Class::MOP::get_code_info($next); |
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118 | warn "There is a COMPONENT method resolving after Catalyst::Component in ${next_package}.\n"; |
119 | warn "This behavior can no longer be supported, and so your application is probably broken.\n"; |
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120 | warn "Your linearized isa hierarchy is: " . join(', ', @{ mro::get_linear_isa($class) }) . "\n"; |
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121 | warn "Please see perldoc Catalyst::Upgrading for more information about this issue.\n"; |
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122 | } |
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123 | return $class->new($c, $arguments); |
22247e54 |
124 | } |
125 | |
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126 | sub config { |
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127 | my $self = shift; |
df960201 |
128 | # Uncomment once sane to do so |
129 | #Carp::cluck("config method called on instance") if ref $self; |
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130 | my $config = $self->_config || {}; |
131 | if (@_) { |
132 | my $newconfig = { %{@_ > 1 ? {@_} : $_[0]} }; |
133 | $self->_config( |
134 | $self->merge_config_hashes( $config, $newconfig ) |
135 | ); |
136 | } else { |
137 | # this is a bit of a kludge, required to make |
138 | # __PACKAGE__->config->{foo} = 'bar'; |
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139 | # work in a subclass. |
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140 | # TODO maybe this should be a ClassData option? |
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141 | my $class = blessed($self) || $self; |
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142 | my $meta = find_meta($class); |
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143 | unless (${ $meta->get_or_add_package_symbol('$_config') }) { |
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144 | # Call merge_hashes to ensure we deep copy the parent |
145 | # config onto the subclass |
146 | $self->_config( Catalyst::Utils::merge_hashes($config, {}) ); |
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147 | } |
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148 | } |
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149 | return $self->_config; |
158c88c0 |
150 | } |
151 | |
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152 | sub merge_config_hashes { |
153 | my ( $self, $lefthash, $righthash ) = @_; |
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154 | |
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155 | return Catalyst::Utils::merge_hashes( $lefthash, $righthash ); |
156 | } |
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157 | |
158 | sub process { |
159 | |
160 | Catalyst::Exception->throw( message => ( ref $_[0] || $_[0] ) |
161 | . " did not override Catalyst::Component::process" ); |
162 | } |
163 | |
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164 | sub expand_modules { |
165 | my ($class, $component) = @_; |
166 | return Devel::InnerPackage::list_packages( $component ); |
167 | } |
168 | |
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169 | __PACKAGE__->meta->make_immutable; |
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170 | |
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171 | 1; |
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172 | |
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173 | __END__ |
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174 | |
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175 | =head1 METHODS |
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176 | |
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177 | =head2 new($app, $arguments) |
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178 | |
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179 | Called by COMPONENT to instantiate the component; should return an object |
180 | to be stored in the application's component hash. |
181 | |
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182 | =head2 COMPONENT |
183 | |
184 | C<< my $component_instance = $component->COMPONENT($app, $arguments); >> |
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185 | |
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186 | If this method is present (as it is on all Catalyst::Component subclasses), |
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187 | it is called by Catalyst during setup_components with the application class |
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188 | as $app and any config entry on the application for this component (for example, |
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189 | in the case of MyApp::Controller::Foo this would be |
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190 | C<< MyApp->config('Controller::Foo' => \%conf >>). |
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191 | |
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192 | The arguments are expected to be a hashref and are merged with the |
193 | C<< __PACKAGE__->config >> hashref before calling C<< ->new >> |
194 | to instantiate the component. |
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195 | |
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196 | You can override it in your components to do custom construction, using |
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197 | something like this: |
198 | |
199 | sub COMPONENT { |
200 | my ($class, $app, $args) = @_; |
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201 | $args = $class->merge_config_hashes($class->config, $args); |
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202 | return $class->new($app, $args); |
203 | } |
204 | |
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205 | B<NOTE:> Generally when L<Catalyst> starts, it initializes all the components |
206 | and passes the hashref present in any configutation information to the |
207 | COMPONET method. For example |
208 | |
209 | MyApp->config( |
210 | 'Model::Foo' => { |
211 | bar => 'baz', |
212 | }); |
213 | |
214 | You would expect COMPONENT to be called like this ->COMPONENT( 'MyApp', +{ bar=>'baz'}); |
215 | |
216 | This would happen ONCE during setup. |
217 | |
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218 | =head2 $c->config |
219 | |
220 | =head2 $c->config($hashref) |
221 | |
222 | =head2 $c->config($key, $value, ...) |
223 | |
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224 | Accessor for this component's config hash. Config values can be set as |
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225 | key value pair, or you can specify a hashref. In either case the keys |
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226 | will be merged with any existing config settings. Each component in |
227 | a Catalyst application has its own config hash. |
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228 | |
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229 | The component's config hash is merged with any config entry on the |
230 | application for this component and passed to C<new()> (as mentioned |
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231 | above at L</COMPONENT>). The recommended practice to access the merged |
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232 | config is to use a Moose attribute for each config entry on the |
233 | receiving component. |
234 | |
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235 | =head2 $c->process() |
236 | |
237 | This is the default method called on a Catalyst component in the dispatcher. |
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238 | For instance, Views implement this action to render the response body |
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239 | when you forward to them. The default is an abstract method. |
240 | |
241 | =head2 $c->merge_config_hashes( $hashref, $hashref ) |
242 | |
243 | Merges two hashes together recursively, giving right-hand precedence. |
244 | Alias for the method in L<Catalyst::Utils>. |
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245 | |
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246 | =head2 $c->expand_modules( $setup_component_config ) |
247 | |
248 | Return a list of extra components that this component has created. By default, |
249 | it just looks for a list of inner packages of this component |
250 | |
251 | =cut |
252 | |
825dbf85 |
253 | =head1 OPTIONAL METHODS |
254 | |
255 | =head2 ACCEPT_CONTEXT($c, @args) |
256 | |
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257 | Catalyst components are normally initialized during server startup, either |
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258 | as a Class or a Instance. However, some components require information about |
259 | the current request. To do so, they can implement an ACCEPT_CONTEXT method. |
260 | |
261 | If this method is present, it is called during $c->comp/controller/model/view |
262 | with the current $c and any additional args (e.g. $c->model('Foo', qw/bar baz/) |
263 | would cause your MyApp::Model::Foo instance's ACCEPT_CONTEXT to be called with |
264 | ($c, 'bar', 'baz')) and the return value of this method is returned to the |
265 | calling code in the application rather than the component itself. |
266 | |
3e560748 |
267 | B<NOTE:> All classes that are L<Catalyst::Component>s will have a COMPONENT |
268 | method, but classes that are intended to be factories or generators will |
269 | have ACCEPT_CONTEXT. If you have initialization arguments (such as from |
270 | configuration) that you wish to expose to the ACCEPT_CONTEXT you should |
271 | proxy them in the factory instance. For example: |
272 | |
273 | MyApp::Model::FooFactory; |
274 | |
275 | use Moose; |
276 | extends 'Catalyst::Model'; |
277 | |
278 | has type => (is=>'ro', required=>1); |
279 | |
280 | sub ACCEPT_CONTEXT { |
281 | my ($self, $c, @args) = @_; |
282 | return bless { args=>\@args }, $self->type; |
283 | } |
284 | |
285 | MyApp::Model::Foo->meta->make_immutable; |
286 | MyApp::Model::Foo->config( type => 'Type1' ); |
287 | |
288 | And in a controller: |
289 | |
290 | my $type = $c->model('FooFactory', 1,2,3,4): # $type->isa('Type1') |
291 | |
f4d7cf1e |
292 | B<NOTE:> If you define a ACCEPT_CONTEXT method it MUST check to see if the |
293 | second argument is blessed (is a context) or not (is an application class name) and |
294 | it MUST return something valid for the case when the scope is application. This is |
295 | required because a component maybe be called from the application scope even if it |
296 | requires a context and you must prevent errors from being issued if this happens. |
297 | Remeber not all components that ACCEPT_CONTEXT actually need or use context information |
298 | (and there is a school of thought that suggestions doing so is a design error anyway...) |
299 | |
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300 | =head1 SEE ALSO |
301 | |
e7f1cf73 |
302 | L<Catalyst>, L<Catalyst::Model>, L<Catalyst::View>, L<Catalyst::Controller>. |
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303 | |
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304 | =head1 AUTHORS |
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305 | |
2f381252 |
306 | Catalyst Contributors, see Catalyst.pm |
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307 | |
308 | =head1 COPYRIGHT |
309 | |
536bee89 |
310 | This library is free software. You can redistribute it and/or modify it under |
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311 | the same terms as Perl itself. |
312 | |
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313 | =cut |