如何发现Perl 6类型的所有角色? [英] How can I discover all the roles a Perl 6 type does?

问题描述

使用.does，我可以检查某个类型是否具有我已经知道的角色.我想获取角色列表.继承具有.^mro，但对于元模型中的角色，我没有看到类似的内容.

With .does I can check if a type has the role I already know. I'd like to get the list of roles. Inheritance has .^mro but I didn't see anything like that for roles in the meta model stuff.

此外，给定一个类型"，如何确定它是定义为类还是角色?

Along with that, given a "type", how can I tell if it was defined as a class or a role?

推荐答案

.^roles

say Rat.^roles; # ((Rational[Int,Int]) (Real) (Numeric))

默认情况下，它包括每个角色，包括其他角色带来的角色.要只获得第一级，请使用:!transitive

By default it includes every role, including roles brought in by other roles. To only get the first level use :!transitive

Rat.^roles(:!transitive); # ((Rational[Int,Int]))

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