Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!rochester!udel!new
From: new@udel.EDU (Darren New)
Newsgroups: comp.lang.smalltalk
Subject: Re: Polymorphism
Message-ID: <14123@louie.udel.EDU>
Date: 27 Apr 89 16:05:06 GMT
References: <1546@cfa.cfa.harvard.EDU> <80500056@p.cs.uiuc.edu> <8418@boulder.Colorado.EDU>
Sender: usenet@udel.EDU
Reply-To: new@udel.EDU (Darren New)
Organization: University of Delaware
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In article <8418@boulder.Colorado.EDU> bouguett@boulder.Colorado.EDU (Athman Bouguettaya) writes:
>Excuse my ignorance but what is a first-class object?  Does the latter
>imply that there are second-class or n-class  objects?

I'm sure that others can give a better definition, but here's
my shot at it: Basically, a first-class object is one that
can be stored in a variable, passed as parameters, etc.
As examples, types and blocks are not first-class
objects in C, whereas classes and blockContexts are first-
class objects in Smalltalk. In C, functions are not first-
class, but pointers to functions are. I think the
non-first-class objects are called second-class, and that
there is nothing "lower" than second class (i.e., no
third-class objects) but I could be mistaken.
	       - Darren