Xref: utzoo comp.object:570 comp.lang.c++:5762
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!usc!aero!abbott
From: abbott@aerospace.aero.org (Russell J. Abbott)
Newsgroups: comp.object,comp.lang.c++
Subject: (Very) Dymanic Typing (Was: Dumb question)
Message-ID: <62298@aerospace.AERO.ORG>
Date: 1 Dec 89 16:30:44 GMT
References: <61737@aerospace.AERO.ORG> <9938@june.cs.washington.edu> <2122@tukki.jyu.fi> <2159@tukki.jyu.fi> <9191@microsoft.UUCP> <32106@watmath.waterloo.edu>
Reply-To: abbott@aero.UUCP (Russell J. Abbott)
Organization: The Aerospace Corporation, El Segundo, CA
Lines: 22

In article <32106@watmath.waterloo.edu> gjditchfield@watmsg.waterloo.edu (Glen Ditchfield) writes:
>  ...   In practice, in C++, wouldn't it be simpler to pass a comparison
>function as an argument to the sort() function?

Can you really do that in C++?  What would the declarations look like?
That would be even more flexible than the generic sort that I asked
about originally.

In Smalltalk one can ask an object to "perform" a "message."  (I gather
that in C++ terminology a "message" is a call, along with its
argument(s), to a "member" function.  Again, pardon my lack of
familiarity with C++.)  Smalltalk's "perform" is similar to "eval" in
Lisp in that the thing to be perform'ed or eval'ed is unknown at program
entry/compilation time.  In such a situation there is *no* type
information at all available to the compiler/language processor.  So how
does a statically typed language like C++ deal with that?  And if it
does deal with it: (a) is the static type checking that it does worth
bothing with since there seems to be nothing that can be statically
checked and (b) doesn't there have to be dynamic type checking of the
same order of complexity as goes on in Smalltalk anyway?
-- 
-- Russ abbott@itro3.aero.org


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