Re: Enumerations and Arrays Unnecessary!???

["Nick Roberts" <Nick.Roberts@dial.pipex.com>]

Robert Dewar <dewar@merv.cs.nyu.edu> wrote in article
<dewar.866335292@merv>...
> YOu mean that you don't see that Character is obviously a class, and
> specific characters like 'C' '+' '+' are simply objects of that class
> to which messages should be sent as required.

Conceptually, this is a perfectly reasonable idea. But imagine implementing
characters this way in Ada (where each character would be a tagged type).
Uh oh! Better still, imagine (as we are not allowed arrays either)
implementing strings as linked lists (or whatever) of these tagged types.
[Of course, this is roughly how languages such as (traditional) Prolog _do_
implement strings!]

Class CHARACTER would have obvious subclasses, such as LETTER and DIGIT,
with their own specialised constants and methods (such as FIRST, LAST,
NEXT, and VALUE). This approach is really not so silly, if it could be
implemented efficiently (in a language other than Ada).

I think this is an interesting question: could it be implemented
efficiently? In my ignorance, how does Smalltalk implement characters? And
other O. O. languages?

Nick.