HaloO,
John M. Dlugosz wrote:
I hope you have a few minutes to look it over.
I started to think it through. There are two quick remarks.
In
module M
{
class C { ... }
class D
{
# lexical region where C refers to M::C
method m1 () { my C $x; my Int $y; ... }
class C { ... }
# lexical region where C refers to D::C
method m2 () { my C $x; ... }
}
}
I would make the use of C in m1 of D an error because otherwise
the scope D is split into two at the point where D::C is defined.
In other words D::C is not the innermost definition everywhere in
D. This is a serious source of subtle errors. If this is what you
want than write M::C in m1. Scopes should be one-dimensional along
the lines of inner versus outer. An additional dimension before
versus after should be used only for error checking. That is in m1
C is parsed provisionally as M::C and this fails when D::C is seen
later.
Second, I don't like the concept of a virtual method that returns
a type. That horribly mixes type level and value level. From the
namespace POV we have M::D::foo and P::E::foo bound to the same
implementation. In both cases C is OUTER::C. The "magic" should
happen when an invocation of foo is created. That is the moment when
the scope of OUTER::C can be bound by 'my C $b' through $x and $y
respectively.
Regards, TSa.
--
"The unavoidable price of reliability is simplicity"
-- C.A.R. Hoare
