🚀 go-pugleaf

> When I learned about object oriented programming one of the views that
> was taught was that the set of methods of a class should preserve a
> set of invariants related to the class. I.e. the object state before
> and after a (official or exported) method is run should satisfy a set
> of constraints, which of course could be violated while running the
> method.

This is a good idea, but it's not clear that it should apply to
accessors (or readers or writers).  (1) It's reasonable to do all
slot access via accessors and never use SLOT-VALUE and (2) it's
often necessary to make several state changes before you're back in
a consistent state.

Obviously, there are some, even many, accessors that could be asked
to maintain the invariant, but I don't think it can work as a general
rule for all public accessors.  This sort of thing works better in
languages wiht "instance variables", I suspect.

-- jd