Is it possible to describe @ISA in the specification?

[yuki-kimoto]

Is it possible to describe @ISA in the Section 4: Classes?

https://github.com/Ovid/Cor/blob/master/rfc/classes.md#422-inheritance

In the following FAQ, I heard the class specified by :isa is added @ISA. the roles specified by :does is not added to @ISA.

#72

Or @ISA is not used?

[Ovid]

@ISA should not be used. Corinna is single inheritance. There would be no need for an array of parent classes. Code outside of Corinna should, if it really needs type information, be relying on either if ( $object->isa('Foo') ) { ... } or the MOP.

Even in current Perl, roles would never be added to @ISA because their behavior is flattened into the class. They're not parent classes.

[yuki-kimoto]

Thanks. I understood now. @ISA is not used in Corinna.

[yuki-kimoto]

I have another question.

If @ISA is not used, how does $self->next::method() work?

I think $self->next::method() searches the method from parent classes(@ISA) by the mro order.

[Ovid]

You would have to ask @leonerd that. He's the one implementing it.

[yuki-kimoto]

OK. I will ask @leonerd in this topic.

[leonerd]

I wouldn't say it doesn't use @ISA under the hood, at all. Just you shouldn't interact with it as a regular Perl developer.

Internally the usual inheritance mechanisms are still at work as normal.

[yuki-kimoto]

Thanks!

Internally the usual inheritance mechanisms are still at work as normal.

OK. I wanted to know this.

[leonerd]

FYI, latest implementation of the feature-class branch now unit-tests that reading @ISA still gives the expected results, and forbids any caller from mutating the @ISA array of a true class, so as not to confuse everything.

[yuki-kimoto]

Thanks. I realize that @ISA mechanism to search methods in the super class is used in use feature 'class'.