Re: Design Decisions and Hurd/L4 work (was: Re: Improving Hurd)

[Jan Atle Ramsli]

"Thomas Bushnell, BSG" wrote:
> 
> Jan Atle Ramsli <trollet@skynet.be> writes:
> 
> > >>There are--horror of horrors--data type problems that abstract data
> > >>types are unable to adequately describe, and this is precisely what
> > >>led to their demise as a fundamental organizing principle about ten
> > >>years ago.
> >
> > Which the means that the _have_ been replaced by something else?
> > This is so confusing that I will have to abandon it if I will not be
> > able to understand it.
> 
> They have not been *replaced*---in some cases, they are still
> appropriate.  But they are not the solution to all problems.

You 1.000.000 windows made me remember what concept replaced the ADT.
It wasn't 10 years ago, though.
I was supposed to have know this, I'm sorry.

What's so special about 1.000.000 anyway, why not 1.000.001 - and here
it comes:

You just set a _class_invariant_ to 999.999 if you can't handle
1.000.000 - but of course then I bit myself in the neck. An ADT does not
have a 'class invariant' -

an 
Abstract Class
does.

Atle