--- chromatic <[EMAIL PROTECTED]> wrote:
> On Thursday, July 24, 2003, at 11:17 AM, Austin Hastings wrote:
>
> >> No, I think Java interfaces are a kluge to get around copying a
> >> broken type system and the lack of multiple inheritance.
> >
> > Multiple Inheritance != Protocols | Interfaces
>
> I quite agree, but I've done enough Java to know that if they could
> have "solved" it with MI, they would have.
>
> > Protocols/Interfaces is a way of saying "My structure is none of
> your
> > damn business, but I comply with the rules you've set."
>
> Yes, exactly.
>
> > I disagree, and I hope you've simply swapped terms around.
> >
> > I think you want to declare "I comply with ruleset X" at the callee
> > object level. That enables the compiler to (1) check that you're
> not
> > lying; and (2) optimize based on (1).
>
> At least one of us is using "caller/callee" in the X11 sense. What I
> mean and what I think you mean is:
>
> method foo ( Thingie $t ) { ... }
>
> $object->foo( $behaves_like_thingie );
>
> foo() says, "Give me something that I can treat like a Thingie. I
> don't care HOW it does it, I just want it to do something sane."
To me, $object.Class is the callee (includes "method foo"). The code
that contains C<$object->foo($behaves_like_thingie);> is the caller.
> If we're just confused over a bit of terminology, we're in violent
> agreement on the idea, which is much more important.
Yeah.
So what do we get?
# Multiple Inheritance:
class Combo is all(SuperClass1, SuperClass2, ...) {...}
class Comb2 is Super1 is Super2 {...}
# Protocol:
# More than just an interface, because Perl6 is okay with
# loose encapsulation
protocol TCPIP {
has $.variable; # Protocol requires this variable
has $.var2 is Array of Int; # Ditto
method Int m1(Int, Str) {...} # Method required
}
Going one step farther, there's a function called "protocol" and maybe
one called "class" that handle this sort of thing. Also, C<is> means
C<implements> when given a protocol, and C<implements> extracts a
default protocol when given a class.
class Scalar implements Str
implements Int
implements Ref
{...} # All you need to know.
class MyArray is class(Array) # Convert PCL to Class
Perverse behavior:
# Converts protocol "TCPIP", above, to anon class, inherits.
class Perv is class(TCPIP) {...}
# Converts Super2 to Protocol, implements it.
class Perv2 is Super1 implements Super2 {...}
class Perv2 is Super1 is protocol(Super2) {...}
# Alternatively, select any of:
# {private, protected, public}_methods (or "methods" => public)
# {private, protected, public}_data ("data" => public)
# inheritance
class Perv2 is Super1 implements Super2, qw(methods inheritance) {...}
class Perv2 is Super1 is protocol(Super2, qw(methods inheritance))
{...}
=Austin
