Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!NORUNIX.BITNET!knut-skog%rglab.uit.uninett
From: knut-skog%rglab.uit.uninett@NORUNIX.BITNET (Knut Skog)
Newsgroups: comp.windows.news
Subject: Class vars or Instance vars
Message-ID: <93*knut-skog@rglab.uit.uninett>
Date: 7 Mar 89 05:08:46 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 25

After a close inspection of the elegant implementation
of classes and message-pasing by the rutines in class.ps
I am unable to see the reason for the distinction made
between instance- and class-vars in the definition of
the LiteWindow class .

I would have put several of the class vars (f.i. FrameLabel,
PaintClient, etc) as instance vars. In effect that is what
happens when  a { /FrameLabel (<somelabel>) def} is sent
to  some window instance. The definition is added to the
instance and since the instance is currentdict when the message
is executed, this definition overrules definitions in its parent class
as long as the keys are the same. (Using store insted of def
would be rather bad style of programming)

Installing attributes of this type as class-vars reduces
generality.

Despite the "lite/play" nature of this class I wonder if someone
close to its design will comment on this issue. Have I missed
out some esential part of the nature  of instance and class properties?

Much obliged.

Knut