Heritage

[David Baelde <david.baelde@gmail.com>]

Hi list,

We're getting crazy with some design problem. We need to design a
buffer object and be able to extend it with some features
(lexing,color highlighting... yes we're working on an editor). Here's
the problem.

I'd like to have a class (or function) for every extension. For
example be able to write
new parsed (new lexed (new basic)). I.e. I would need the class:

class lexed buf =
object inherit buf method get_token = ... end

It doesn't work cause inheritance is only from classes, not objects.
But I want buf to be of any class (any super-class of buffer actually)
but I don't want to coerce buf to type buffer, cause I want to keep
extra methods if any were added.

I'd like to know if there's any simple example of why
object-inheritance is forbidden, and if any of you have an idea for
that problem..

Thanks.
-- 
David