>From: Alan Lovejoy <sourcery at pacbell.net>
>Reply-To: squeak at cs.uiuc.edu
<big snip>
>8. Given the above, I would avoid being dogmatic on this
>issue.  I think the fact that so many good Smalltalk programmers
>still access instance variables directly, and that code that commits
>this "sin" has lasted unchanged for so long, should cause one to
>at least question whether or not it's all that sinful.
<snip>

Thanks for the brain dump Alan!  :-)

I understand the pragmatics of this issue well, but I feel compelled to make 
a counterpoint about the above.  Code that accesses ivars directly can be 
brittle.  In particular, code which uses both direct access and accessor 
methods on the same ivars can behave in unpredictable ways.  Sometimes such 
code survives for a very long time because it is brittle and hard to 
understand, and no one wants to touch it for fear of breaking it.

I tend to defer writing code which accesses ivars directly until performance 
tuning time.  I wish I never had to write such code because it hurt the 
maintainability and extensibility of my design, but I live in the real world 
(oh Bah!).

Thanks again!

-Carl


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