Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!uunet!mcsun!unido!laura!owl!huba
From: huba@ls5.informatik.uni-dortmund.de (Hubert Baumeister)
Newsgroups: comp.lang.smalltalk
Subject: Re: PP Smalltalk R4 Query, Bug?
Keywords: help
Message-ID: <3086@laura.UUCP>
Date: 8 Mar 91 15:22:18 GMT
References: <4931@goanna.cs.rmit.oz.au> <1991Mar8.140425.10863@m.cs.uiuc.edu>
Sender: news@laura.UUCP
Reply-To: huba@ls5.informatik.uni-dortmund.de (Hubert Baumeister)
Organization: University of Dortmund, Germany
Lines: 32

In article <1991Mar8.140425.10863@m.cs.uiuc.edu>, johnson@cs.uiuc.EDU (Ralph Johnson) writes:
...
|> These expressions have always been different, because
|> the add: messages for collections always returns the
|> argument, not the receiver.  Lot of people think that
|> this is a design bug, but there *is* a reason for it.
|> 
|> The reason is because of cascaded messaged.
|> 	aCollection add: thing1;
|> 		    add: thing2;
|> 		    add: thing3
|> will only work if add: returns the receiver.
|> 

Ralph, I do not understand  your example. These cascaded messages work 
independend of the result of the add: message. On the other hand if you used
the expression
	((aCollection add: thing1)
		    add: thing2)
		    add: thing3
then this would require that add: returns the receiver. To overcome the problem
that add: returns the argument, one can allways use yourself to get the 
collection back like in:
	aCollection := Collection new add: thing1;
		    add: thing2;
		    add: thing3; yourself.


|> Ralph Johnson -- University of Illinois at Urbana-Champaign

Hubert Baumeister
(huba@ls5.informatik.uni-dortmund.de)