Course of Raku / Objects, I/O, and exceptions / Classes and objects / The metaobject protocol 🆕 / Exercises / Add a method

Solution: Add a method

Here is a possible solution to the task.

Code

class Dog {
    has $.name;
}

Dog.^add_method('speak', method { $.name ~ ' says woof' });

say Dog.new(name => 'Rex').speak;

🦋 You can find the source code in the file add-a-method.raku.

Output

Rex says woof

Comments

.^add_method attaches a new method to the class’s metaobject at runtime, given as an anonymous method { … }.
The added method is a real method of the class, so inside it $.name reaches the object’s name attribute, just as a method written in the class body would. After the call, every Dog responds to .speak.

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