> -----Original Message-----
> From: Jonathan Scott Duff [mailto:[EMAIL PROTECTED]
> Sent: Friday, December 12, 2003 11:13 AM
> To: Luke Palmer
> Cc: Language List
> Subject: Re: Vocabulary
>
>
> On Fri, Dec 12, 2003 at 04:23:02AM -0700, Luke Palmer wrote:
> > So I'm seeing a lot of inconsistent OO-vocabulary around here, and it
> > makes things pretty hard to understand.
> >
> > So here's how Perl 6 is using said inconsistent terms, AFAIK:
> >
> > - attribute
> > A concrete data member of a class. Used with C<has>.
> >
> > - property
> > An out-of-band sticky note to be placed on a single object.
> > Used with C<but>.
>
> I think an important aspect of properties that you left out here is
> that they are run-time.
>
> > - trait
> > A compile time sticky note to be placed on a wide variety
> of things.
> > Used with C<is>.
> >
> > - role
> > A collection of methods to be incorporated into a class sans
> > inheritance (and maybe some other stuff, too). Used
> with C<does>.
>
> s/class/object/
>
> Roles are like sticky behavior (as I understand them) just as properties
> are sticky state. And I assume that roles are run-time so that you can
> have your objects obtain new behavior (fullfill new roles) as needed
> without having to use eval all the time.
>
This seems needlessly restrictive. If we're defining roles as having mixin
capabilities, we should be able to use them in classes. Laziness.
role Work {...};
role Management {...};
class Employee {...};
class Worker is Employee does Work;
class Manager is Employee does Management;
role PHB does Manager[does no Work];
> I think I'm getting it but I'm not sure. Does something like this
> work?
>
> my role Teach { ... }
> my role Operate { ... }
> my role Learn { ... }
>
> my Person $frank;
> { temp $frank_the_teacher = $frank does Teach; ... }
> { temp $frank_the_doctor = $frank does Operate; ... }
> { temp $frank_the_student = $frank does Learn; ... }
>
> I.e., we can use dynamic scoping to control how long an object
> fulfills a particular role? Maybe it could also be written like so:
>
> my Person $frank;
> { my role Teach { ... }; $frank does Teach; ... }
> { my role Operate { ... }; $frank does Operate; ... }
> { my role Learn { ... } $frank does Learn; ... }
>
> so that when the role goes out of scope, the object no longer
> possesses the abilities of that role.
>
> I confuse myself everytime I think about this stuff.
That's brilliant, if twisted. The object persists, but the behaviors expire.
There's a paradigm there, man. Write a book.
(It's double-e Eevil, too, but that's Damian's problem. :-)
=Austin
