Objective-C Issues

self-isa

People ( From: lines )
 Chris Petrilli 
 Dennis Glatting 
Subjects ( 2 mails )
 Re: object.m, self->isa
 Re: object.m, self->isa 
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Date: Mon, 8 Feb 93 20:20:05 -0800
From: Dennis Glatting 
To: "Geoffrey S. Knauth" 
Subject: Re: object.m, self->isa
Cc: gnu-objc@prep.ai.mit.edu
Reply-To: dennis_glatting@trirex.com


> While I also look at this, could someone please comment on
> whether this is a correct fix? 

> 


self-isa is (was?) a valid decl.  It is still a valid decl under  
NeXTSTEP 3.0 too.


-dpg

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To: dennis_glatting@trirex.com
Cc: gnu-objc@prep.ai.mit.edu
Subject: Re: object.m, self->isa 
In-Reply-To: (Your message of Mon, 08 Feb 93 20:20:05 PST.)
             <9302090420.AA00577@seattle.trirex.com> 
Date: Tue, 09 Feb 93 06:48:29 -0600
From: Chris Petrilli 


>>>>> On Mon, 8 Feb 93 20:20:05 -0800, Dennis Glatting  said:

Dennis> self-isa is (was?) a valid decl.  It is still a valid decl under  
Dennis> NeXTSTEP 3.0 too.

While it might be valid it is EXTREEMLY bad programming style to use
it.  For it to be valid, you MUST declare the object typed rather than
"dynamically typed" as with "id".  For example:

        Object *myObject;

        printf ("%s\n", myObject->isA);

Is valid, but it is not guaranteed to always work.  It's my opinion
that if you HAVE to use this to make it work, then your machine or
compiler is broken.  Since I use Alphas daily, I can testify that it's
the machine that's broken in my opinion.  Anyway, when I get some
spare time I'm going to work on getting the GCC compiler to work
better on the boxes... if I have to use them, I should at least have a
decent compiler.

Chris

Statistics
 filename:           self-isa
 number of mails:    2
 number of writers:  2
 line count:         54
 word count:         249
 character count:    1659

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