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From: "Pat Rogers" <progers@NOclasswideSPAM.com>
Subject: Re: Engineering types hierarchy
Date: 1999/09/09
Message-ID: <rtfqqid31iv76@corp.supernews.com>#1/1
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References: world <37d7ba7d@news1.prserv.net> <37d7d0ef@news1.prserv.net>
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Newsgroups: comp.lang.ada
Date: 1999-09-09T00:00:00+00:00
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Matthew Heaney <matthew_heaney@acm.org> wrote in message
news:37d7d0ef@news1.prserv.net...
> In article <37d7ba7d@news1.prserv.net> , "Matthew Heaney"
> <matthew_heaney@acm.org> wrote:
>
> I forget a couple more references.
>
> 1) I think there's an example in D.W. Jones' book, Ada In Action.  I
don't
> have a URL for the book handy, but why don't you email D.W. and ask
him for
> the URL?  (And be sure to post it here.)
>
> Do-While Jones <do_while@RIDGECREST.CA.US>
>
>
> 2) The package Dimensioned_Units appears in section 9.3.8 of the Ada83
> Rationale.  You can get that book on the web in the usual places,
including
> the AdaIC and the adahome.
>
> <http://www.adaic.org/>
> <htpp:/www.adahome.com/>

Just to be complete, the version in the Rationale had to come from the
one in Paul Hilfinger's dissertation, published in 1982, and his work
with the Ada 83 design team.  Hilfinger cites a prior version by  John
Nestor in the Red language proposal.

I wrote an article about it in Ada Letters, "Dimensional Analysis In
Ada", Vol. 8 No. 5, Sept/Oct 1988, pp. 92-100, back when people often
wrote article for Ada Letters showing the neat things the language could
express*.  Hilfinger's discussion is much more interesting, as he
examines how to define user-defined assuagement by 'overloading' ":="
and then apply it to the dimensioned units abstraction.

* The other thing people did with Ada in the 1980's was to come up with
design methods.  If you didn't have a design method named after you, or
associated with you, you weren't really trying.  :-)

--
Pat Rogers                            Training and Consulting in:
http://www.classwide.com      Deadline Schedulability Analysis
progers@classwide.com       Software Fault Tolerance
(281)648-3165                        Real-Time/OO Languages