[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Fwd: Returned mail: User unknown

Excerpts from mail: 30-Oct-90 mop questions davis@ilog.ilog.fr (3091)

> For instance, in section 3.5 there is a
> discussion of the difference between making SLOT-VALUE generic and
> using SLOT-VALUE-USING-CLASS.  However, there is no explanation of why
> the CLOS MOP chose the latter approach, or of other alternatives for
> the slot access protocol.

Gregor and Jim have answered many of the direct questions.  I thought I
would take a crack at this one.  In Jim's answer, he talks about the
PERSISTENT-OBJECT example, how the metaclass can be distributed over
many disparate parts of the class space not connected bhas a different
distribution than an inheritance hierarchy.  On the other hand, in many
examples, an inheritance hierarchy provides exactly the right handle for
a change in how SLOT-VALUE should work.  The argument for using
SLOT-VALUE-USING-CLASS is therefore that both options are available
since its arguments are <class-of-object object slot>.