+
+(define-layered-method (setf attribute-value) ((value standard-object) object (attribute has-a))
+ (let ((val (slot-value value (find-if (curry #'primary-key-p value) (list-keys value)))))
+ (setf (attribute-value object attribute) val)))
+
+
+
+(define-layered-function find-all-foreign-objects (o a))
+
+(define-layered-method find-all-foreign-objects (object (attribute has-a))
+ (select (meta-model:find-join-class object (slot-name attribute)) :flatp t))