Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!pt.cs.cmu.edu!andrew.cmu.edu!sa1z+
From: sa1z+@andrew.cmu.edu (Sudheer Apte)
Newsgroups: comp.lang.smalltalk
Subject: Re: Smalltalk Types
Message-ID: <620840564.543.sa1z.unix5.andrew.cmu.edu@andrew.cmu.edu>
Date: 3 Sep 89 15:42:44 GMT
Organization: Civil Engineering, Carnegie Mellon, Pittsburgh, PA
Lines: 17

Hi,

In article <7776@charlie.OZ>:
>Anyway, if you want to think about types then class is the analogy.

I disagree. I think protocol is the analogy. In fact, a typical non-OO
language has only a few pre-defined protocols, and these are only vaguely
defined as "types."  Some languages allow you to create new types.  What
Smalltalk allows you to do is to create new "types" (protocols) *without*
regard to implementing them (writing the methods). This, IMHO, is what
makes Smalltalk code reusable-- the second programmer gets a
set of types with a high degree of specialized functionality.

Thanks,
	Sudheer.
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