Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!uupsi!sunic!news.funet.fi!tukki.jyu.fi!sakkinen
From: sakkinen@jyu.fi (Markku Sakkinen)
Newsgroups: comp.object
Subject: Re: Objects and Interactions: Separate Definitions
Message-ID: <1991May21.092050.23924@jyu.fi>
Date: 21 May 91 09:20:50 GMT
References: <3999@motcsd.csd.mot.com>
Reply-To: sakkinen@jytko.jyu.fi (Markku Sakkinen)
Distribution: comp
Organization: University of Jyvaskyla, Finland
Lines: 26

In article <3999@motcsd.csd.mot.com> lance@motcsd.csd.mot.com (lance.norskog) writes:
> ...
>An alternative is to have a separate
>set of declarations which define interactions between objects.  These
>interaction definitions are where you code up classic algorithms.
> ...
>Separating objects and their interactions shears class definitions 
>of descriptions of their dealings with other specific objects, and 
>leaves them only with a small, simple set of messages and responses.
>My theory is that this will encourage defining small, simple,
>reusable objects.  
> ...

Your thoughts look a lot similar to those of Richard Helm,
Ian Holland and Dipayan Gangopadhyay in their OOPSLA/ECOOP'90 paper
"Contracts: Specifying Behavioral Compositions in Object-Oriented
Systems".  These ideas looked really worth pursuing further,
and that's what at least Ian is currently doing.

Markku Sakkinen
Department of Computer Science and Information Systems
University of Jyvaskyla (a's with umlauts)
PL 35
SF-40351 Jyvaskyla (umlauts again)
Finland
          SAKKINEN@FINJYU.bitnet (alternative network address)