Wolfgang Weck wrote:
>Tough words! :-)
We are still friends I hope ;-)
> The one and only reason for having the model handling the bounding boxes is
> the wish to handle alien figures in a reasonable way.
Good point. Like I said in an earlier mail to you, I am using Graph
as a starting point and I am enjoying the fact that you have designed it
in a competent way. I do not even understand all the details like
operations, and as I now learned also those aliens. Extending
source code without understanding it is called "grey box design"
I believe ;-)
[snip]
> In that way, the above code pattern reliefes a client programmer from some
> debugging. Even more: it is better documenting. By having the browser to list
> an abstract method (and a final, non-extensible one), the framework designer
> communicates quite clearly that there is a slot that must be filled by the
> extension (and one which has been filled already is not to be touched
> anymore). Compare this to situations with implemented but extensible
> procedures. I never know what to do, overwrite it, and if I do, to call super
> or not to call super? I am now talking of the more general pattern, not the
> relatively well-known externalize / internalize situation.
Thank you for the example. I will perhaps use supercalls
for the time being, and switch to your solution later when my package
is debugged, and when I fully understand ramifications of your design
pattern.
BTW, the traffic in this list is encouraging. Reportedly, Professor Wirth
said recently that his spin-off company was "not very successful", what
sort of casts a shadow of doubt whether using BB is a good idea
to begin with. It is encouraging to me that the mailing list is alive and well.
Thank you again for the response.
Wojtek
Received on Mon Feb 15 1999 - 22:21:59 UTC