$self access within methods

[leonerd]

How should method bodies find the $self instance?

In Object::Pad, every method has a $self lexical injected early on parsing meaning it always has pad index 1. Early at runtime of every method body, this instance is shifted from the incoming argument list, sanity-checked, then stored into that pad slot.

[yuki-kimoto]

$self is got from the first argument of subroutine.

sub ($self, $arg) { $self->{x} }

method ($arg) { $self->{x} }

[Ovid]

Part of the spec (maybe, I need to double-check) is that $class is also available. That way, we don't need to check __PACKAGE__ (which is wrong if you have a subclass) or ref $self (which is an ugly artifact).

[leonerd]

The current implementation stores $self in lexical pad slot 1, identically to Object::Pad. This seems sufficient.
(I'd now close this Discussion issue if I could find the button for that...)