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From: donh@syd.csa.com.au (Don Harrison)
Subject: Re: Replacing Multiple Inheritance with Java's Interfaces
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Date: Wed, 9 Apr 1997 03:07:42 GMT
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Xref: glinda.oz.cs.cmu.edu comp.lang.java.tech:9928 comp.lang.eiffel:19428 comp.lang.dylan:8023

Frank Mitchell wrote:

:You're right, the ways to manage this in traditional OO -- principally the 
:Visitor pattern from the Gang of Four -- make this sort of thing tricky.  
:Many times, though, you can find some simplifying condition: ..

In the case of Eiffel, another specific case allows an elegant solution.
In the special case where, for each value of a parameter, there is only one 
corresponding value for each of the other parameters, you can use covariance.

If a something more general is required, you need to use one of the techniques
for emulating multiple dispatching.


Don.
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Don Harrison             donh@syd.csa.com.au


