[Openmcl-devel] Any plan to support virtual slots?

Chisheng Huang cph at chi-square-works.com
Tue Mar 10 11:46:45 PDT 2009


Hi,

CCL only allows :INSTANCE and :CLASS as valid allocation types for a
slot in DEFCLASS.   I know this is what CLHS specifies but I wonder if
there is any plan for CCL to remove this restriction in the future?

More specifically, 

(defclass alien-metaclass (standard-class)
  ())

(defmethod validate-superclass ((class alien-metaclass) (super standard-class))
  t)

(defclass alien-class ()
  ((alien-slot :accessor alien-slot 
               :initarg :alien-slot
               :allocation :alien))
  (:metaclass alien-metaclass))

> Error: value :ALIEN is not of the expected type (MEMBER (:INSTANCE :CLASS)).
> While executing: #<CCL::STANDARD-KERNEL-METHOD DIRECT-SLOT-DEFINITION-CLASS (CCL::STD-CLASS)>, in process listener(1).
> Type :POP to abort, :R for a list of available restarts.
> Type :? for other options.
1 > 


Best wishes,

-cph



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