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From: jans@mako.UUCP (Jan Steinman)
Newsgroups: net.lang,net.lang.st80
Subject: Re: What is Object-Oriented
Message-ID: <612@mako.UUCP>
Date: Fri, 1-Mar-85 16:35:06 EST
Article-I.D.: mako.612
Posted: Fri Mar  1 16:35:06 1985
Date-Received: Mon, 4-Mar-85 07:06:13 EST
References: <3013@umcp-cs.UUCP> <117@tove.UUCP> <1631@pur-phy.UUCP> <1095@opus.UUCP> <316@gumby.UUCP>
Reply-To: jans@mako.UUCP (Jan Steinman)
Organization: Tektronix, Wilsonville OR
Lines: 18
Xref: watmath net.lang:1489 net.lang.st80:209
Summary: 

Dick Dunn writes:
> ... some of those objects bodily grab others (the arguments) and cart them
> off to parts unknown, slaves in bondage to their nefarious purposes.

Hold on there, Dick.  I don't think you really understand what's going on in
Smalltalk.  An object is in control of it's own private memory (known as
"instance variables") and doesn't get abused by other objects unless it agrees
to (implements a selector for) such abuse.

Also, (excepting UCB's latest implementation) only object *references* are
passed around as arguments.  An object can ask another object "what is your
value", "change your value to X", or even "destroy thyself", but the object
doesn't do damned thing (except report that it's confused by the request)
unless an appropriate response exists in it's protocol, or the protocol of
it's superclass chain.
-- 
:::::: Jan Steinman		Box 1000, MS 61-161	(w)503/685-2843 ::::::
:::::: tektronix!tekecs!jans	Wilsonville, OR 97070	(h)503/657-7703 ::::::