A meta-method example in the mop page seems incorrect

[titsuki]

I received an error message, when I ran the following example code.

• Example code

    #| THIS IS A CLASS FOR SHOUTING THINGS
    class MY-CLASSES-ARE-ALL-CAPS {
        method WHY { "I DON'T KNOW" }
    }
    my $c = MY-CLASSES-ARE-ALL-CAPS.new;

(From https://docs.perl6.org/language/mop#Metamethods)

• Error message

Method '_add_leading' not found for invocant of class 'Str'

However, I'm not sure what the better one is.

[jonathanstowe]

I'm not sure whether the assertion in that whole section is true. The error is precisely because the explicitly defined WHY method is being called in the SET_LEADING_DOCS method which in turn expects the WHY to return a Pod::Block::Declarator object (which has the _add_leading method.)

I would say that it's remove the assertion about the quotes and the example completely. Unless anyone feels it is a bug that the behaviour doesn't match the doc of course.

[jonathanstowe]

The example will run if it is rewritten so that the over-ride WHY returns the right kind of this:

#| THIS IS A CLASS FOR SHOUTING THINGS
class MY-CLASSES-ARE-ALL-CAPS {
    multi method WHY { Pod::Block::Declarator.new(leading => ["I DON'T KNOW"]) }
}
my $c = MY-CLASSES-ARE-ALL-CAPS.new;
say $c.WHY;    
say $c."WHY"(); 

However it doesn't do what the text says because the over-ridden version will always get called.

I think that it definitely is remove the last sentence of the text and the example. Unless anyone chimes in quickly I'll just do it.