Language 'standards' for LispOS

Chris Bitmead uid
Tue, 20 May 1997 09:38:49 +1000

>As far as I've read, the definition takes care never to require that
>e.g. CONSes or STRINGs are only of one class, but there can be lots
>of subclasses of the official CONS and STRING classes, and we might
>even perform a CHANGE-CLASS e.g. to a CONS-IMMUTABLE subclass of CONS
>in such situations. This, plus appropriately immutability-conscious
>standard functions, should already cover quite a lot (I'm not saying
>we shouldn't have more control of those things).

But a sub-class should be able to do everything the base class
can. i.e. it should conform to the same interface. So if the base
class has methods for mutability, then the subclass should too. What
you really need is a super-class.