Metamodel::MultipleInheritance Reference

Metaobject that supports multiple inheritance

What it is #

Position in the hierarchy #

Routines #

Signatures are reproduced from the documentation, including their declared return types. A routine listed here is part of the type's published interface; whether Raku++ implements it is a separate question, answered by the examples below.

method add_parent #

method add_parent($obj, $parent, :$hides)

Adds $parent as a parent type. If $hides is set to a true value, the parent type is added as a hidden parent. $parent must be a fully composed typed. Otherwise an exception of type X::Inheritance::NotComposed is thrown.

method ^parents #

method ^parents($obj, :$all, :$tree)

Returns the list of parent classes. By default it stops at Cool, Any or Mu, which you can suppress by supplying the :all adverb. With :tree, a nested list is returned.

method hides #

method hides($obj)

Returns a list of all hidden parent classes.

method hidden #

method hidden($obj)

Returns a true value if (and only if) the class is marked with the trait is hidden.

method set_hidden #

method set_hidden($obj)

Marks the type as hidden.

Examples, run three ways #

Every example below comes from the official documentation, together with the output that documentation asserts. Each was then executed by Rakudo and by Raku++ when this page was built. Where the three agree, one result is shown; where they do not, all three are — because which of them is wrong is exactly the information worth having.

1 all-differ · 2 no-output

role Metamodel::MultipleInheritance {}

class D { };
class C1 is D { };
class C2 is D { };
class B is C1 is C2 { };
class A is B { };

say A.^parents(:all).raku;
# OUTPUT: «(B, C1, C2, D, Any, Mu)␤»
say A.^parents(:all, :tree).raku;
# OUTPUT: «[B, ([C1, [D, [Any, [Mu]]]], [C2, [D, [Any, [Mu]]]])]␤»

(B, C1, C2, D, Any, Mu)
[B, ([C1, [D, [Any, [Mu]]]], [C2, [D, [Any, [Mu]]]])]

(Mu,)
(Mu,)