rnd at onego.ru
Tue May 22 10:48:21 CEST 2001
On Tue, 22 May 2001, Oleg Broytmann wrote:
> On Tue, 22 May 2001, Roman Suzi wrote:
> > I was always very irritated when somebody proposed something like
> > class Line(Point):
> > ...
> > just because line could be made of two points.
> Of course. Now THIS is bad design. Line IS NOT a point, hence, no
> inheritance should occur. Line CONSISTS of two point, so
> class Line:
> def __init__(self, p1, p2):
> self.p1 = p1
> self.p2 = p2
> But grey mouse DOES NOT "contains" grey color. The mouse IS really grey
> thing, hence I used inheritance.
It could be _said_ of everything:
Thing IS HavingSomethingThing
Thing HAS Something
(Note, that the later is much shorter and clearer!)
So, your example doesn't make strong agrument.
I could agree that though, that
class Janus(Face1, Face2)
> This is difference between "thing IS a thing of the class" and "thing
> CONTAINS things".
> Oleg Broytmann http://phd.pp.ru/ phd at phd.pp.ru
> Programmers don't die, they just GOSUB without RETURN.
Sincerely yours, Roman A.Suzi
- Petrozavodsk - Karelia - Russia - mailto:rnd at onego.ru -
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