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From: lomow@calgary.UUCP
Newsgroups: comp.lang.smalltalk,comp.lang.c++,comp.lang.lisp
Subject: Re: language issues (was Re: teaching object-oriented simulation & modelling)
Message-ID: <978@vaxb.calgary.UUCP>
Date: Fri, 19-Jun-87 11:51:26 EDT
Article-I.D.: vaxb.978
Posted: Fri Jun 19 11:51:26 1987
Date-Received: Sun, 21-Jun-87 05:00:13 EDT
References: <7116@linus.UUCP> <1995@sphinx.uchicago.edu>
Organization: U. of Calgary, Calgary, Ab.
Lines: 60
Keywords: availability, speed, portability, graphics
Xref: utgpu comp.lang.smalltalk:143 comp.lang.c++:294 comp.lang.lisp:267
Summary: DEMOS, Discrete-Event Simulation, Simula

In article <1995@sphinx.uchicago.edu>, code@sphinx.uchicago.edu (paul robinson wilson) writes:
> 
>   2) Where should I look for a good intro to issues in the design of
>      object-oriented languages, especially simulation languages?
>      (This might include comparing existing languages like C++ and
>      Objective C, with an idea to the relevant tradeoffs.)
> 

The best simulation package (object-oriented or otherwise) I
have seen is DEMOS; it was written by and is wholely owned by
Graham Birtwistle [Dept. of Computer Science, University of
Calgary, Calgary, Alberta, Canada].

DEMOS is a general-purpose, object-oriented, discrete-event
simulation package written in Simula. It provides an excellent
set of modelling concepts and simulation tools (some of which
have been incorporated into the Smalltalk simulation package).

My opinion is supported by Kreutzer who writes in his 1986
survey text of simulation languages

    [Kreutzer, W., 1986, System Simulation Programming Styles and
     Languages, Addison-Wesley International Computer Science
     Series, p.176]

that

    DEMOS is a very flexible and powerful modelling framework,
    ... In the author's opinion, it is currently the best tool
    available for any kind of discrete-event simulation. It can
    also be customised to give more support for specialized
    scenarios.

The design rationale for DEMOS is described in the following
sources:

    Birtwistle, G.M., 1979, DEMOS - A System for Discrete Event
    Modelling On Simula, MacMillan.

    Birtwistle, G.M., Lomow, G.A., Unger, B.W., Luker, P.,
    1984a, Process Style Packages For Discrete Event Modelling:
    Data Structures and Packages in Simula, Transactions of the
    Society for Computer Simulation, 1, 1, May, 61-82.

    Birtwistle, G.M., Lomow, G.A., Unger, B.W., Luker, P.,
    1984b, Process Style Packages For Discrete Event Modelling:
    Using Simula's Class Simulation, Transactions of the Society
    for Computer Simulation, 1, 2, 175-195.

    Birtwistle, G.M., Lomow, G.A., Unger, B.W., Luker, P., 1985,
    Process Style Packages For Discrete Event Modelling:
    Experience with the Transaction, Activity, and Event
    Approaches, Transactions of the Society for Computer
    Simulation, 2, 1, 27-56.

-- 
Greg Lomow
	lomow@cpsc.calgary.cdn
      or
	....![ubc-vision,ihnp4]!alberta!calgary!lomow