[Date Prev] [Date Next] [Thread Prev] [Thread Next] Date Index Thread Index Search archive:
Date:Mon Jun 7 12:40:00 2001 
Subject:Re: Closures and OOP (Was Re: filenames, argument list separators + gsl extension) 
From:Jonathan L Cunningham 
Volume-ID:1010607.02 

On Thu, 31 May 2001 11:47:06 +0000 (UTC),
Aaron.Sloman.XX@cs.bham.ac.uk (Aaron Sloman See text for reply
address) wrote:

>[To reply replace "Aaron.Sloman.XX" with "A.Sloman"]
>
>Jonathan.Cunningham@tesco.net (Jonathan L Cunningham) wrote
>an interesting message about closures and objectclass instances
(snip)
>I liked your tutorial on closures and objectclass. I have temporarily
>saved it in
>
>    http://www.cs.bham.ac.uk/~axs/misc/closures.and.classes.txt

Fine - if it seems useful/interesting to anyone I'm glad.

>A few small points.
>
(snip)
>This could be handled by using class_apply. From REF KEYS:
>
(snip)
>This means that instances can be treated as if they were procedures,

I'd forgotten about class_apply - thanks for the reminder.

>Every pop11 entity has a class represented by its datakey
(snip)
>which holds generic information about entities in that class,

Yes. John Gibson was, ISTM, gradually evolving the innards of
poplog into being an object-based language. This is not the
same as an object-oriented language. I wonder if this is
still the terminology used for this distinction? Jargon
seems to change faster than the underlying concepts.

The distinction I'm talking about mostly boils down to
that object-oriented languages support inheritance, whereas
object-based ones don't, as I understand it. It was the
failure to support inheritance in various Microsoft
distributed object models that was the biggest technical
criticism of them. Not that it stops them being used ...

>This is not to be confused with objectclass classes. See

which, of course, does support inheritance, and is
properly object-oriented.

>> In Java, I needn't have declared
>> the class "midclosure" -- I could have used an anonymous
>> class. And so on.
>
>I don't know how anonymous classes work in Java, but I guess there are
>at least three reasons for using anonymous classes:

Chris Dollin replied to this, so I'll continue in a follow-up
to his post.

Jonathan


-- 
Jonathan L Cunningham