Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!elroy.jpl.nasa.gov!jarthur!petunia!kestrel.edu!gyro
From: gyro@kestrel.edu (Scott Layson)
Newsgroups: comp.object
Subject: Re: Closures in C++
Keywords: lambda
Message-ID: <1991Mar25.180147.5735@kestrel.edu>
Date: 25 Mar 91 18:01:47 GMT
References: <4684@m5.COM> <1991Mar24.020701.27641@kestrel.edu> <4687@osc.COM>
Reply-To: Gyro@Reasoning.COM
Distribution: comp
Organization: Kestrel Institute, Palo Alto, CA
Lines: 24

In article <4687@osc.COM> jgk@osc.COM (Joe Keane) writes:
>In article <1991Mar24.020701.27641@kestrel.edu> gyro@kestrel.edu (Scott
>Layson) writes:
>>Therefore an instance, to me, is not exactly the same thing as a
>>closure, but they are very closely related: a closure can do only one
>>thing, while an instance can do any of several things depending on
>>which operation is invoked on it.
>
>But when someone says `an object is a closure', it's understood that the
>operation to be performed on the object is the first argument to the closure.
>So there's really no difference at all if you take this view.

That's true.  But I don't take that view.  I prefer to think of
operation dispatch as happening outside the object rather than inside
it.

Why?  Only because some, though certainly not all, object-oriented
languages take the same view (C++, for instance [sorry]).

I will grant that this is solely a matter of convention, but it's a
convention that is often useful and therefore I adhere to it.

-- Scott Layson Burson
Gyro@Reasoning.COM