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From: Ludovic Brenta <ludovic@ludovic-brenta.org>
Newsgroups: comp.lang.ada
Subject: Re: Preventing type extensions
Date: Fri, 24 Sep 2010 08:09:04 -0700 (PDT)
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Date: 2010-09-24T08:09:04-07:00
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Simon Wright wrote on comp.lang.ada:
> Ludovic Brenta <ludo...@ludovic-brenta.org> writes:
>> I believe that, if Smalltalk had class-wide types, it would be able to
>> prevent "the yo-yo problem" just like Ada does.
>
> Not sure that the designers of Smalltalk would have described this as a
> 'problem'!

No, only users of the language called it that. Also, this "problem"
became prevalent only in the field, with deep inheritance hierarchies
and large systems, after the language was designed.

Objective-C, Java and, apparently, Object Pascal replicated this same
"problem". In these languages, you have no choice but to redispatch
every time.

--
Ludovic Brenta.