role Metamodel::MethodContainer

Metaobject that supports storing and introspecting methods

role Metamodel::MethodContainer {}

roles, classes, grammars and enums can contain methods. This role implements the API around storing and introspecting them.

say .name for Int.^methods(:all);
 
# don't do that, because it changes type Int globally. 
# just for demonstration purposes. 
Int.^add_method('double'method ($x:{ 2 * $x });
say 21.double# OUTPUT: «42␤»

Methods

method add_method

method add_method(Metamodel::MethodContainer: $obj$name$code)

Adds a method to the metaclass, to be called with name $name. This should only be done before a type is composed.

method methods

method methods(Metamodel::MethodContainer: $obj:$all:$local)

Returns a list of public methods available on the class (which includes methods from superclasses and roles). By default this stops at the classes Cool, Any or Mu; to really get all methods, use the :all adverb. If :local is set, only methods declared directly in the class are returned.

class A {
    method x() { };
}
 
say A.^methods();                   # x 
say A.^methods(:all);               # x infinite defined ...

The returned list contains objects of type Method, which you can use to introspect their signatures and call them.

Some introspection method-look-alikes like WHAT will not show up, although they are present in any Perl 6 object. They are handled at the grammar level and will likely remain so for bootstrap reasons.

method method_table

method method_table(Metamodel::MethodContainer:D: $obj --> Hash:D)

Returns a hash where the keys are method names, and the values are methods. Note that the keys are the names by which the methods can be called, not necessarily the names by which the methods know themselves.

method lookup

method lookup(Metamodel::MethodContainer: $obj$name --> Method)

Returns the first matching method object of the provided $name or (Mu) if no method object was found. The search for a matching method object is done by following the mro of $obj. Note that lookup is supposed to be used for introspection, if you're after something which can be invoked you probably want to use find_method instead.

say 2.5.^lookup("sqrt").perl:      # OUTPUT: «method sqrt (Rat $: *%_) ...␤» 
say Str.^lookup("BUILD").perl;     # OUTPUT: «submethod BUILD (Str $: :$value = "", *%_ --> Nil) ...␤» 
say Int.^lookup("does-not-exist"); # OUTPUT: «(Mu)␤»

The difference between find_method and lookup are that find_method will use a default candidate for parametric roles, whereas lookup throws an exception in this case, and that find_method honors FALLBACK methods, which lookup does not.

Type Graph

Type relations for Metamodel::MethodContainer
perl6-type-graph Metamodel::MethodContainer Metamodel::MethodContainer Mu Mu Any Any Any->Mu Metamodel::Naming Metamodel::Naming Metamodel::Documenting Metamodel::Documenting Metamodel::Versioning Metamodel::Versioning Metamodel::PrivateMethodContainer Metamodel::PrivateMethodContainer Metamodel::MultiMethodContainer Metamodel::MultiMethodContainer Metamodel::AttributeContainer Metamodel::AttributeContainer Metamodel::RoleContainer Metamodel::RoleContainer Metamodel::MultipleInheritance Metamodel::MultipleInheritance Metamodel::Stashing Metamodel::Stashing Metamodel::TypePretense Metamodel::TypePretense Metamodel::RolePunning Metamodel::RolePunning Metamodel::ParametricRoleHOW Metamodel::ParametricRoleHOW Metamodel::ParametricRoleHOW->Metamodel::MethodContainer Metamodel::ParametricRoleHOW->Any Metamodel::ParametricRoleHOW->Metamodel::Naming Metamodel::ParametricRoleHOW->Metamodel::Documenting Metamodel::ParametricRoleHOW->Metamodel::Versioning Metamodel::ParametricRoleHOW->Metamodel::PrivateMethodContainer Metamodel::ParametricRoleHOW->Metamodel::MultiMethodContainer Metamodel::ParametricRoleHOW->Metamodel::AttributeContainer Metamodel::ParametricRoleHOW->Metamodel::RoleContainer Metamodel::ParametricRoleHOW->Metamodel::MultipleInheritance Metamodel::ParametricRoleHOW->Metamodel::Stashing Metamodel::ParametricRoleHOW->Metamodel::TypePretense Metamodel::ParametricRoleHOW->Metamodel::RolePunning Metamodel::BaseType Metamodel::BaseType Metamodel::MROBasedMethodDispatch Metamodel::MROBasedMethodDispatch Metamodel::MROBasedTypeChecking Metamodel::MROBasedTypeChecking Metamodel::BUILDPLAN Metamodel::BUILDPLAN Metamodel::BoolificationProtocol Metamodel::BoolificationProtocol Metamodel::EnumHOW Metamodel::EnumHOW Metamodel::EnumHOW->Metamodel::MethodContainer Metamodel::EnumHOW->Any Metamodel::EnumHOW->Metamodel::Naming Metamodel::EnumHOW->Metamodel::MultiMethodContainer Metamodel::EnumHOW->Metamodel::AttributeContainer Metamodel::EnumHOW->Metamodel::RoleContainer Metamodel::EnumHOW->Metamodel::Stashing Metamodel::EnumHOW->Metamodel::BaseType Metamodel::EnumHOW->Metamodel::MROBasedMethodDispatch Metamodel::EnumHOW->Metamodel::MROBasedTypeChecking Metamodel::EnumHOW->Metamodel::BUILDPLAN Metamodel::EnumHOW->Metamodel::BoolificationProtocol Metamodel::ConcreteRoleHOW Metamodel::ConcreteRoleHOW Metamodel::ConcreteRoleHOW->Metamodel::MethodContainer Metamodel::ConcreteRoleHOW->Any Metamodel::ConcreteRoleHOW->Metamodel::Naming Metamodel::ConcreteRoleHOW->Metamodel::Versioning Metamodel::ConcreteRoleHOW->Metamodel::PrivateMethodContainer Metamodel::ConcreteRoleHOW->Metamodel::MultiMethodContainer Metamodel::ConcreteRoleHOW->Metamodel::AttributeContainer Metamodel::ConcreteRoleHOW->Metamodel::RoleContainer Metamodel::ConcreteRoleHOW->Metamodel::MultipleInheritance Metamodel::Finalization Metamodel::Finalization Metamodel::DefaultParent Metamodel::DefaultParent Metamodel::C3MRO Metamodel::C3MRO Metamodel::Trusting Metamodel::Trusting Metamodel::Mixins Metamodel::Mixins Metamodel::ClassHOW Metamodel::ClassHOW Metamodel::ClassHOW->Metamodel::MethodContainer Metamodel::ClassHOW->Any Metamodel::ClassHOW->Metamodel::Naming Metamodel::ClassHOW->Metamodel::Documenting Metamodel::ClassHOW->Metamodel::Versioning Metamodel::ClassHOW->Metamodel::PrivateMethodContainer Metamodel::ClassHOW->Metamodel::MultiMethodContainer Metamodel::ClassHOW->Metamodel::AttributeContainer Metamodel::ClassHOW->Metamodel::RoleContainer Metamodel::ClassHOW->Metamodel::MultipleInheritance Metamodel::ClassHOW->Metamodel::Stashing Metamodel::ClassHOW->Metamodel::MROBasedMethodDispatch Metamodel::ClassHOW->Metamodel::MROBasedTypeChecking Metamodel::ClassHOW->Metamodel::BUILDPLAN Metamodel::ClassHOW->Metamodel::BoolificationProtocol Metamodel::ClassHOW->Metamodel::Finalization Metamodel::ClassHOW->Metamodel::DefaultParent Metamodel::ClassHOW->Metamodel::C3MRO Metamodel::ClassHOW->Metamodel::Trusting Metamodel::ClassHOW->Metamodel::Mixins

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