Re: CLOS

[Ken Kahn <Kahn.pa@Xerox.COM>]

>   However, it has been proposed to add a feature by which the
programmer
>   can declare that nothing will be added or changed at run time, and
then
>   to compile the entire program as a unit.  In that case, the compiler
>   knows the complete set of methods for a generic function and the
>   complete set of subclasses of a class, and optimizations such as the
>   ones you suggest would then become permissible.  I imagine that by
the
>   time the CLOS specification is finished and approved, there will be
a
>   feature like this in it.  Currently, it's not in the document
because
>   the people working out a detailed proposal haven't finished yet.

I had always imagined that one could defined metaclasses which compiled
slot access as an array access.  These metaclasses would not allow
subclassing for its instances.  Or they would recompile or etc. Probably
something like this could be done by defining a new generic function
class which compiled method lookup specially and refused to add new
methods.

The point is to leave it up to the meta object protocol and not treat
the entire program as a unit.  Some parts of a program could use such
metaclasses and other parts remain unoptimized.


References
	Moon@STONY-BROOK.SCRC.Symbolics.COM's message of Fri, 14 Aug 87
13:35:00 EDT -- CLOS