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From: mario@cs.man.ac.uk (Mario Wolczko)
Newsgroups: comp.object
Subject: Re: A Hard Problem for Static Type Systems
Message-ID: <2488@m1.cs.man.ac.uk>
Date: 4 May 91 15:39:18 GMT
References: <554@eiffel.UUCP> <1991Apr26.203642.17387@leland.Stanford.EDU> <556@eiffel.UUCP> <52166@nigel.ee.udel.edu> <1991May1.143831.2065@maths.nott.ac.uk> <1991May3.184332.28319@visix.com>
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Reply-To: mario@cs.man.ac.uk (Mario Wolczko)
Organization: Department of Computer Science, University of Manchester
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In article <1991May3.184332.28319@visix.com>, adam@visix.com writes:
> |> That is why it
> |> is easy to describe *situations* in which dynamic typing is desirable,
> |> but we have not seen a completely specified *problem* for which it is
>        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> |> needed.]
> 
> Yes, a completely specified problem is, by definition, one in which
> you know all the objects and operations, ergo there is no way to
> completely specify a problem that requires dynamic typing.

Indeed.  One of the main ideas behind inheritance is that you leave
some things open so that classes may be reused in unanticipated ways,
ie you are building components to assist in the solution of problems
you do not even know about yet!

Mario Wolczko

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