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From: susser@Apple.COM (Joshua Susser)
Newsgroups: comp.lang.smalltalk
Subject: Re: Using methods in the superclass' superclass
Message-ID: <53313@apple.Apple.COM>
Date: 24 May 91 20:49:14 GMT
References: <28319BCD.B2F@deneva.sdd.trw.com>
Organization: Apple Computer Inc. (ATG)
Lines: 33

In article <28319BCD.B2F@deneva.sdd.trw.com> mongoose@spf.trw.com (Julian 
Watkins) writes:
> I am porting some st80 code that was originally done by modifying Analyst
> Spreadsheet classes rather than by subclassing them.

[...discussion of problem omitted...]

Class Object has a number of messages that are overridden, that you still 
want to be able to get to directly.  "new" is a good example of this.  The 
provision for allowing direct access to the functionality of new without 
mucking about in the methods implemented in the intermediate ancestors was 
to create a "basicNew" method that does the same thing.  So even though 
"new" is overridden, you can still always get to "basicNew".

So if you have a message "spam" in Matrix, move the body of the method to 
"basicSpam", and change "spam" to just do "^self basicSpam".  Then your 
subclass can say "super basicSpam" anywhere it needs to bypass the code in 
SpreadsheetHolder.

By the way, what *are* you doing that needs to get directly to methods in
Matrix?  I seem to remember the only behavior SpreadsheetHolder inherits
from Matrix is the various atXXX: and atXXX:put: accesing methods.  I guess
I should have made SpreadheetHolder be a subclass of Object with a Matrix
in an instance variable, and then you wouldn't have to muck about with
all this bypassing and disinheritance.  Sorry, but I had only been
programming in Smalltalk a few weeks when I started the design.  But next
time I'll know...

Joshua Susser, Object Percussionist
Apple Computer, Advanced Technology Group
inet: susser@apple.com | link: susser.j | phone: 408/974-6997

Macintosh Jr. - The power to crush the other kids.