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From: doylep@ecf.toronto.edu (Patrick Doyle)
Subject: Re: Opinions on Ellipse-Circle dilemma?
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Date: Fri, 14 Feb 1997 16:34:08 GMT
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In article <5dvur5$d75@bagan.srce.hr>,
Kazimir Majorinc <kmajor@jagor.srce.hr> wrote:
>Patrick Doyle (doylep@ecf.toronto.edu) wrote:
>
>:     stretch: Ellipse x Real x Real  ->  Ellipse 
>
>:   If Circle is a subclass of Ellipse, it must satisfy this:
>
>:     stretch: Circle x Real x Real  ->  Circle
>
>:   which could not be satisfied any better in a functional language than
>: in an OO language.
>
>:   You may argue that it's a flaw in the language to require such a function
>: to exist.  Well, perhaps you would have a point there.  I don't have a good
>: answer to that one.  :-)
>
>No, it is flaw that language insist on inheritance, and that language
>do not recognize this so simple function should not be inherited.
>Idea that modifiers should be inherited is wrong!!!

  Are you saying that _ANY_ method which modifies its object should not be
inheritable?  I think there are many modifiers which can be inherited perfectly
safely.  What sorts of mdifiers should be ineligible for inheritance?

 -PD

-- 
--
Patrick Doyle
doylep@ecf.utoronto.ca
