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From: pkr@media03.UUCP (Peter Kriens)
Newsgroups: comp.lang.smalltalk
Subject: Re: Access methods - New feature ?
Keywords: Access methods, Smalltalk-80
Message-ID: <2270@media03.UUCP>
Date: 22 Apr 91 08:17:36 GMT
References: <1991Apr21.221149.8057@vuse.vanderbilt.edu> <1991Apr22.003659.18658@ux1.cso.uiuc.edu>
Reply-To: pkr@media03.UUCP (Peter Kriens)
Organization: aQute, Netherlands
Lines: 26

Dan Walkowski writes:
> If access methods were automatically generated for every private variable,
> then this breaks down; every object can diddle with the state of every other.
> Yes, frequently you need to write several access methods for several private
> variables of an object, but if you are finding that you need to make ALL of
> your instance variables public, then perhaps you need to rethink your design.

I basically agree with this statement, but I have found that it is much more
tru in technical software then information technology. The last moths{ I have
been trying several times to build a program that uses a SQL database as
backend and a smalltalk front end. The problem is that in those environments
you basically need access to most instance variables.(the origininal database
fields). 

Eiffel has a very nice solution for this. It allows an instance variable
to be exported in the header (Smalltalk could also do that in the
class definition, you could for example place a colon behinde the 
definition of the instance variable). So in Eiffel you can easely access those often
used instance variables. The good thing is that if you decide later on
to replace the instance access with a procedure, because the implementation
changes, nobody notices because the syntax stays the same. Sounds like
a feature I could love in Smalltalk. Unfortunately you cannot access the
compiler in Digitalk smalltalk, otherwise it could be done.

Peter Kriens
pkr@media01