role Metamodel::ParametricRoleGroupHOW

:for code :solo class Metamodel::ParametricRoleGroupHOW does Metamodel::Naming does Metamodel::Documenting does Metamodel::Stashing does Metamodel::TypePretense does Metamodel::RolePunning does Metamodel::BoolificationProtocol {}

Warning: this role is part of the Rakudo implementation, and is not a part of the language specification.

A ParametricRoleGroupHOW groups a set of ParametricRoleHOW, every one of them representing a single role declaration with their own parameter sets.

(role Zape[::T] {}).HOW.say; # OUTPUT: «Perl6::Metamodel::ParametricRoleHOW.new␤»
Zape.HOW.say ; # OUTPUT: «Perl6::Metamodel::ParametricRoleGroupHOW.new␤»

ParametricRoleHOWs need to be added to this kind of group:

my \zape := Metamodel::ParametricRoleGroupHOW.new_type( name => "zape");
my \zipi := Metamodel::ParametricRoleHOW.new_type( name => "zipi", group => zape);
say zipi.HOW; # OUTPUT: «Perl6::Metamodel::ParametricRoleHOW.new␤»

Role groups pretend to be of types Mu, Any, and Cool, and delegate methods to Any.

Note: As with most of the Metamodel classes, this one is mainly for illustration purposes and is not intended for the end user to instantiate.