1Object::Pad::MOP::ClassU(s3e)r Contributed Perl DocumentaOtbijoenct::Pad::MOP::Class(3)
2
6 "Object::Pad::MOP::Class" - meta-object representation of a
7 "Object::Pad" class
8
10 Instances of this class represent a class or role implemented by
11 Object::Pad. Accessors provide information about the class or role, and
12 methods that can alter the class, typically by adding new elements to
13 it, allow a program to extend existing classes.
14 Where possible, this API is designed to be compatible with MOP::Class.
16 This API should be considered experimental even within the overall
18 context in which "Object::Pad" is expermental.
19
21 for_class
22 $metaclass = Object::Pad::MOP::Class->for_class( $class )
23 Since version 0.38.
25 Returns the metaclass instance associated with the given class name.
27 for_caller
29 $metaclass = Object::Pad::MOP::Class->for_caller;
30 Since version 0.38.
32 A convenient shortcut for obtaining the metaclass instance of the
34 calling package scope. Often handy during "BEGIN" blocks of the class
35 itself to perform adjustments or additions.
36 class Some::Class::Here 1.234 {
38 BEGIN {
39 my $meta = Object::Pad::MOP::Class->for_caller;
40 ...
41 }
42 }
43 begin_class
45 BEGIN {
46 my $metaclass = Object::Pad::MOP::Class->begin_class( $name, %args )
47 ...
48 }
49 Since version 0.46.
51 Creates a new class of the given name and yields the metaclass for it.
53 This must be done during "BEGIN" time, as it creates a deferred code
54 block at "UNITCHECK" time of its surrounding scope, which is used to
55 finalise the constructed class.
56 Takes the following additional named arguments:
58 extends => STRING
60 An optional name of a superclass that this class will extend.
61 begin_role
63 Since version 0.46.
64 As "begin_class" but creates a role instead of a class.
66
68 is_class
69 is_role
70 $bool = $metaclass->is_class
71 $bool = $metaclass->is_role
72 Exactly one of these methods will return true, depending on whether
74 this metaclass instance represents a true "class", or a "role".
75 name
77 $name = $metaclass->name
78 Returns the name of the class, as a plain string.
80 superclasses
82 @classes = $metaclass->superclasses
83 Returns a list of superclasses, as Object::Pad::MOP::Class instances.
85 Because "Object::Pad" does not support multiple superclasses, this list
87 will contain at most one item.
88 roles
90 @roles = $metaclass->roles
91 Returns a list of roles implemented by this class, as
93 Object::Pad::MOP::Class instances.
94 compose_role
96 $metaclass->compose_role( $rolename )
97 $metaclass->compose_role( $rolemeta )
98 Adds a new role to the list of those implemented by the class.
100 The new role can be specified either as a plain string giving its name,
102 or as an "Object::Pad::MOP::Class" meta instance directly.
103 add_BUILD
105 $metaclass->add_BUILD( $code )
106 Adds a new "BUILD" block to the class, as a CODE reference.
108 add_method
110 $metamethod = $metaclass->add_method( $name, $code )
111 Adds a new named method to the class under the given name, as CODE
113 reference.
114 Returns an instance of Object::Pad::MOP::Method to represent it.
116 get_own_method
118 $metamethod = $metaclass->get_own_method( $name )
119 Returns an instance of Object::Pad::MOP::Method to represent the method
121 of the given name, if one exists. If not an exception is thrown.
122 This can only see directly-applied methods; that is, methods created by
124 the "method" keyword on the class itself, or added via "add_method".
125 This will not see other names in the package stash, even if they
126 contain a "CODE" slot, nor will it see methods inherited from a
127 superclass.
128 add_slot
130 $metaslot = $metaclass->add_slot( $name, %args )
131 Adds a new slot to the class, using the given name (which must begin
133 with the sigil character "$", "@" or "%").
134 Recognises the following additional named arguments:
136 default => SCALAR
138 Since version 0.43.
139 Provides a default value for the slot; similar to using the syntax
141 has $slot = SCALAR;
143 This value may be "undef", to set the value as being optional if it
145 additionally has a parameter name.
146 param => STRING
148 Since version 0.43.
149 Provides a parameter name for the slot; similar to setting it using
151 the ":param" attribute. This parameter will be required unless a
152 default value is set (such value may still be "undef").
153 reader => STRING
155 writer => STRING
156 mutator => STRING
157 Since version 0.46.
158 Provides method names for generated reader, writer or lvalue-
160 mutator accessor methods, similar to setting them via the
161 ":reader", ":writer" or ":mutator" attributes.
162 weak => BOOL
164 Since version 0.46.
165 If true, reference values assigned into the slot by the constructor
167 or accessor methods will be weakened, similar to setting the
168 ":weak" attribute.
169 Returns an instance of Object::Pad::MOP::Slot to represent it.
171 get_slot
173 $metaslot = $metaclass->get_slot( $name )
174 Returns an instance of Object::Pad::MOP::Slot to represent the slot of
176 the given name, if one exists. If not an exception is thrown.
177 slots
179 @metaslots = $metaclass->slots
180 Since version 0.42.
182 Returns a list of Object::Pad::MOP::Slot instances to represent all the
184 slots of the class. This list may be empty.
185
187 Paul Evans <leonerd@leonerd.org.uk>
188perl v5.34.0 2021-10-08 Object::Pad::MOP::Class(3)