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[Caml-list] classes, objects, and class variables
-
Jacques Garrigue
- james woodyatt
- Gerd Stolpmann
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| Date: | -- (:) |
| From: | james woodyatt <jhw@w...> |
| Subject: | Re: [Caml-list] classes, objects, and class variables |
[just now catching up with my caml mail; i left it accumulating unread
for a couple months]
On 20 Nov 2003, at 05:07, Jacques Garrigue wrote:
>
> But in this process, I came along with the rather strange behaviour of
> class variables. Class variables are defined by a let before any
> parameters, for instance
> class c = let a = init () in fun ... -> object ... end
> Their current semantics is to be evaluated repeatedly, once for c,
> but again for all classes inheriting from c. The problem is that this
> is costly for the implementation, doesn't fit well with the
> possibility to create dynamically an arbitrary number of classes
> inheriting from, and that I don't see what it's intended for.
>
> So I'm planning to revert to the more intuitive semantics: evaluation
> when creating c, but never again.
>
> Does that bother anybody?
The behavior you want to change is a behavior I noticed and it bothered
me when I noticed it. I just chalked it up to yet another weird thing
about classes. In order to get the behavior I wanted, I just lifted
all my class variables out of the class definitions and used module
signatures to hide them.
You want to make this change? I'm supportive. Please do.
One request I would make: please retain the functional object semantics
and the {< ... >} syntax. I used that feature with state monads and I
like it a lot.
--
j h woodyatt <jhw@wetware.com>
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