HDTenEightyP/NetNews huggingface dataset:
From: mat@mole-end.matawan.nj.us
Subject: Re: Thoughts on the Progression from SA/SD Models to OO Models
Summary: E/R != Relational Model
Organization: :
Date: Thu, 30 Jul 1992 02:52:33 GMT

> I think a significant aspect of the Information Model as 
> described in Shlaer-Mellor is the fact that it (seems) heavily influenced
> by the dictates and constraints of relational database modelling techniques.
> In my opinion, the relational view of data is not as general or natural as
> the object oriented view. While in some cases a relational model of data
> will be most appropriate, in other cases it surely will not be. I'm a bit
> concerned that the Shlaer-Mellor might force, or at least coerce,
> implementations to adopt the relational modelling of data. 
 
> Any comments?

I think that the E/R models of information and data transcend SA/SD,
Codd's Normal Forms, OO, and other approaches.  My view, held for only
about a year but not seriously challenged by anything, is that they
these models are as fundamental to software engineering as circuit
theory is to electrical engineering, or stochiometry to chemical
engineering.  (Which is not to denigrate SA/SD, nth Codd Normal Form,
OO, or any of the other approaches ...)
-- 
 (This man's opinions are his own.)
 From mole-end				Mark Terribile

 mat@mole-end.matawan.nj.us, Somewhere in Matawan, NJ
Newsgroups: comp.object,comp.lang.eiffel
From: graham@maths.su.oz.au (Graham Matthews)
Subject: Re: Class methods (was: Re: How to design a data structure library)
Organization: Sydney University Computing Service, Sydney, NSW, Australia
Date: Tue, 28 Jul 1992 00:30:19 GMT

(Richard Bielak) writes:
>Bertrand Meyer and others, suggest that methods of a class can be
>broken up into "queries" and "commands". "queries" are functions,
>which do not change the object and "commands" are procedures that do.
>So in class SET we have:
>     is_element (e : T) : BOOLEAN is  -- this is a query
>         ....
>     add_element (e : T) is           -- this is a command
>         ....
>     merge (b : SET) is               -- adds elements of 'b' into current
>         ....                         -- this is a command
>The question is then what is "union"? 
>I want to use it to create new sets - as in a := x.union (c,d). It is
>not clearly a command - it doesn't modify its object, but it doesn't
>feel like a query either.
>I'm proposing that it should be a "creation" method - not a query or
>command, so that you can write:
>     !!c.union (a,b)
>which says "create a set which is a union of 'a' and 'b'". 
>This statement clearly shows that a new object is created - this is
>not immediatly clear if you write c := a.union (a,b) or even 
>c := a.unionWith(b).
>...richie

Are you really serious about this notation Richie? This means that
I would have to write integer addition as

	!!c.+(6,7);

After all it creates a new integer!

graham
--
Graham Matthews                 And it's true we are immune
Pure Math, Uni.Sydney, Oz       When fact is fiction and T.V. is reality
graham@maths.su.oz.au
From: liberte@cs.uiuc.edu (Daniel LaLiberte)
Subject: Re: How to design a data structure library.
Organization: University of Illinois, Urbana-Champaign, Dept CS
Date: Wed, 22 Jul 1992 18:33:15 GMT

This is a great question which should probably be stated more
specifically as "How to design an object-oriented data structure
library", though there should be large overlap with non-OO techniques.
(I removed comp.lang.eiffel and added comp.programming.)

In article <1992Jul21.124256.17256@bony1.bony.com> richieb@bony1.bony.com (Richard Bielak) writes:

   I think that cursors should be separate from the data structure they
   are used to traverse. The main reason is to allow multiple iterations
   over the same list. 

I would agree that cursors for iteration should at least be separable
from the objects being iterated over.  However, in some applications,
it may be sufficient, and probably more efficient, to mixin the
cursors with the objects being iterated over.  How to define a class
such that it may be either mixed in or used separately sounds like
an interesting problem.  The functionality is very similar in both cases
so there should be some way to share common features.

Related to this problem of multiple simultaneous uses of a feature
(the multiple iterators, not the mixin vs. separable uses of a class),
I have been working with iterators over DAGs.  To avoid traversing a
subdag more than once, I mark nodes as having been visited.  The
visited status needs to be consistently cleared either before or after
the traversal, though before seemed better but I forget why.  

This traversal scheme does not allow multiple simultaneous traversals
even if the cursor (which I also dont use) is external to the DAG
nodes.  I havent needed this feature (yet!), but I wonder about the
alternatives.  One alternative would be to pretraverse the structure
building a linear list of nodes to traverse.  This requires extra
temporary space but could probably be faster than my current scheme if
you hashed the elements of the constructed linear list to avoid linear
searches.

Dan LaLiberte
liberte@cs.uiuc.edu
(Join the League for Programming Freedom: league@prep.ai.mit.edu)
Newsgroups: comp.object,comp.lang.eiffel
From: graham@maths.su.oz.au (Graham Matthews)
Subject: Re: Class methods (was: Re: How to design a data structure library)
Organization: Sydney University Computing Service, Sydney, NSW, Australia
Date: Mon, 27 Jul 1992 23:08:49 GMT

(Geoffrey Clemm) writes:
>I believe you missed the central point of Richie's article, namely that
>Eiffel 3.0 has a clean way of handling this situation, to quote:
>In article <1992Jul23.123609.11699@bony1.bony.com> richieb@bony1.bony.com (Richard Bielak) writes:
>> Given this, the above call to "union" would be written like this
>> (using Eiffel 3 syntax):
>>     !!c.union (a,b);
>> Which I think is better. 
>With which I completely agree.  This avoids the unpleasant assymetry
>of c:=a.union(b).

Personally I think this is just awful. I want to write

	c := a + b;		OR
	c := a union b;

Any other notation is completely non-suggestive.

graham
--
Graham Matthews                 And it's true we are immune
Pure Math, Uni.Sydney, Oz       When fact is fiction and T.V. is reality
graham@maths.su.oz.au
Newsgroups: comp.object
From: j_ohearn@dsg4.dse.beckman.com
Newsgroups: comp.object
Subject: Re: Help: OOA and OOD Methodologies
Date: 30 Jul 92 15:29:00 GMT
Article-I.D.: dn73.j_ohearn.712510140
Distribution: world

Looks like I have stumbled on to something.  The synthesis of Rumbaugh and
Booch has been given serious consideration by many of us trying to select
an OO methodology.  For those of you trying to make a decision, you should
take a hard look at these two methodologies.  I strongly feel that Rumbaugh
should be the overall methodology of choice and should be supplemented
with Booch during the design phase.  During implementation, I would also
refer to Booch for assistance.

One contact I have made since yesterday tells me that he is working on a
paper which discusses the methodology synthesis of Rumbaugh and Booch.
I do not know about the rest of you, but I am eager to get a copy of that
paper when it is done.

Some engineers from my group attended Object World in San Francisco last
week.  One of those engineers (our new library assets manager) had the
enviable opportunity to attend Dr. David Taylor's seminars (the author of
"Object-Oriented Technology:  A Manager's Guide").  From what I understand,
he is VERY inspirational.  He is now an independent consultant and works to
help companies adopt OO technology.

Good hunting everyone!

Thanks for listening.  (Things are REALLY getting exciting!)

Jim O'Hearn, Software Engineer
Beckman Instruments, Inc.; Diagnostics Systems Group
j_ohearn@dsg4.dse.beckman.com

Character, not color, is what matters.
Newsgroups: comp.object
From: axel@cs.tu-berlin.de (Axel Mahler)
Subject: Re: Is GC needed?
Organization: /home/stone/axel/.organization
	<1992Jul10.165626.7864@visix.com> <4567@balrog.ctron.com>
Date: Fri, 24 Jul 1992 14:46:32 GMT

In article <4567@balrog.ctron.com> smith@ctron.com (Larry Smith) writes:
   In article <1992Jul10.165626.7864@visix.com>, adam@visix.com writes:

   >Have a little imagination, leave room for other paradigms.  I am less
   >fortunate than most people in that I don't know the perfect solution,
   >but I do think about it and if I come up with anything y'all'll be
   >the first to know :-).

   Okay, I'll bite.  What *is* one alternative to GC besides malloc/free???

Have there been any attempts to employ multi-processor shared-memory
computer architectures for solving the GC problem ? Why not have a 
dedicated GC processor that frees the application from worrying about
memory management ? I've not given the idea a great deal of thought, so
it might actually be stupid or unfeasible. Comments ?

Axel.
--
===============================================================================
Axel Mahler, Tech.Univ. Berlin
E-Mail: axel@cs.tu-berlin.de (axel@db0tui62.bitnet)
Voice: +49-30-314-73487
Newsgroups: comp.object
Newsgroups: comp.object

I am interested in learning more about systems design using object oriented
techniques.  When I speak of systems design I mean from systems requirements
to systems partitioning to hardware requirements and software requirements
and finally software design based on the requirements.

Is anyone aware of books/papers etc on this topic?  If so, I would like to 
get the titles.

The type of systems I deal with involve both hardware and software, 
are very interactive oriented, have to respond to a number of real 
time stimuli, and may have multiprocessing. 

As background, I am aware of a very good systems design book based on 
SD/SA called:

"Strategies for Real-Time System Specification" by Derek J Hatley and
						Imtiaz A Pirbhai


I am looking for something similar based on object oriented methods.
Newsgroups: comp.object
From: liang@seas.gwu.edu (Liang Liu)
Subject: Looking for C++ public domain software.
Organization: George Washington University
Date: Fri, 31 Jul 1992 20:22:27 GMT


Hi all,


I am looking for some C++ files providing some tools
for user interface with MS Windows.


Thanks for you help.
Liang

liang@seas.gwu.edu
Newsgroups: comp.object
From: overlord@leland.stanford.edu (Marcos Polanco)
Subject: Re: NeXT Computer and Object Design Announce Joint Development Agreement
Organization: DSO, Stanford University
Date: Mon, 27 Jul 92 07:19:34 GMT

In article <92207.104907MKK2@psuvm.psu.edu> <MKK2@psuvm.psu.edu> writes:
>   As you can see from the Subject: line, and other posts, NeXT and  
Object
> Design have agreed to add OD's OODB concepts to NeXTSTEP.
> 
> 
> 
> Is anybody willing to describe Object Design's database products to the
> rest of us?  What's there?  Is it just the usual objects with  
persistence
> added, or is there a real underlying database model?

If you want to know about the ObjectStore, I will direct you to 
the October 1991 issue of the Communications of the ACM. They have the  
whole architectural description there.

-Marcos
-overlord@leland.stanford.edu
Newsgroups: comp.object
From: dent@DIALix.oz.au (Andrew Dent)
Subject: BERARD SOFTWARE WARNING
Organization: DIALix Services, Perth, Western Australia
Date: Mon, 27 Jul 92 15:14:08 GMT
Summary: Beware international shipping costs
Keywords: BERARD  ANGRY CUSTOMER


To potential customers of Berard Software Engineering. If you are outside
continental USA be VERY CAREFUL to contact the company and obtain shipping
prices for any products.

I recently ordered a fifty dollar book and was charged NINETY dollars for
shipping, sent 12 days after my order and taking 5 days to arrive!

In comparison, most software I've ordered from the USA costs between fifteen
and fifty dollars shipping for delivery in two - three weeks!!!

Please note this NOT a comment on the quality of the book (which appears very
interesting) but IS a comment on the poor service of Berard Software  
Engineering!

Andy Dent (A.D. Software - Mac & VAX programming)
94 Bermuda Dve, BALLAJURA  Western Australia  6066
Phone/Fax: 09 249 2719 (local)  +619 249 2719 (International)
       Internet: dent@DIALix.oz.au    Compuserve: 100033,3241
From: achaplin@axion.bt.co.uk (Anthony Chaplin)
Newsgroups: comp.object
Subject: Examples of OO
Date: 23 Jul 92 10:25:35 GMT
Reply-To: achaplin@axion.bt.co.uk (Anthony Chaplin)
Organization: British Telecom Research Labs


Help! Examples of Coad and Yourdon's OOA/OOD wanted

I've started work on 'Metrics for OOA and OOD' and for various reasons chose Coad and Yourdon's notation. The project is for an MSc and not knowing too much about either metrics or OO consider myself in virgin territory. 

Having derived several metrics I now need some examples of OOA/OOD to apply these metrics too. Unfortunately due to time constraints I have very little time to produce my own examples and the ones I have seen (mostly from Coad and Yourdon's book) have seemed incomplete ??

So if anyone has any old unwanted OOA/OODs which are looking for a good home I'd be pleased to take them off your hands. Size wise anything will do especially designs will multiply subjects, and it doesn't matter if the OOA/OOD is a first draft or not, the only limitation is that the design must use Coad and Yourdon's notation

Cheers

Anthony Chaplin,
B81 G61,
British Telecom Research Labs,
Martlesham Heath,
Ipswich,
IP5 7RE

e-mail : achaplin@axion.bt.co.uk
Tel. (0473) 648135     Fax. (0473) 644605
Newsgroups: comp.object,comp.lang.eiffel
From: richieb@bony1.bony.com (Richard Bielak)
Subject: Re: Class methods (was: Re: How to design a data structure library)
Organization: multi-cellular
Date: Tue, 28 Jul 92 20:18:20 GMT

In article <graham.712283419@galois> graham@maths.su.oz.au (Graham Matthews) writes:

[...]

>
>Are you really serious about this notation Richie? This means that
>I would have to write integer addition as
>
>	!!c.+(6,7);
>
>After all it creates a new integer!
>

It's not the notation that I'm arguing for. 

!!c.+(6,7) is certainly awful syntax. But, (as Jim McKim suggested in
private e-mail) couldn't the compiler do the translation from c := 6 +
7; to the above monstrocity.

My point is that certain methods, "+" for example, should be class
(i.e. creation) methods.

However, once you get away from numbers, with their historical
notation, things make more sense. How about a "concat" method on
strings. We'd have:

           !!s.concat("foo", junk);



...richie

-- 
* Richie Bielak   (212)-815-3072   | "Your brain is a liquid-cooled parallel  *
* Internet:       richieb@bony.com | super-computer". He pointed to his nose, *
* Bang {uupsi,uunet}!bony1!richieb | "This is the fan."                       *
*    - Strictly my opinions -      |                     - David Chudnovsky - *
Newsgroups: comp.object
From: dbarring@dw3f.ess.harris.com (Dwayne Barrington)
Subject: Nathan Goodman on Object DBMS
Reply-To: dbarring@dw3f.ess.harris.com (Dwayne Barrington)
Organization: Harris GISD
Date: Fri, 24 Jul 1992 17:02:46 GMT

Has anyone in this newsgroup attended the Digital Consulting seminar
"Nathan Goodman on 
Object DBMS".  If so, could you let me know what you thought about it?

Thanks in advance

Dewayne Barrington
Newsgroups: comp.object,comp.lang.c++,comp.std.c++
From: maxtal@extro.ucc.su.OZ.AU (John MAX Skaller)
Subject: Re: Re^2: run-time type checking (was: Re: Covariant Types in Derived Classes)
Organization: MAXTAL P/L C/- University Computing Centre, Sydney
Date: Tue, 21 Jul 1992 15:34:05 GMT

In article <14feqsINNt9d@early-bird.think.com> barmar@think.com (Barry Margolin) writes:
>In article <694@data.rain.com> kend@data.rain.com (Ken Dickey) writes:
>>shang@corp.mot.com (David (Lujun) Shang) writes:
>>>Then, once you put an object into a heterogeneous collection, the
>>> object will lose its specific characteristics forever.
>>An object cannot be a member of more than 1 set ???  8^)
>
>Shang didn't really describe it well.  The collection is presumably a set
>of pointers or references, and it's those pointers/references that lose
>their more specific characteristics; static type checking limits you to
>treating them as objects of the class defined by the collection.  The
>original objects to which they refer still retain all their
>characteristics, though.  In particular, virtual function calls will use
>the overriding definitions in derived classes.  But members that are only
>declared and defined in derived classes cannot be accessed through the
>collection.
>
>If an object is referenced by more than one set, each set will define which
>aspects of the object can be accessed.

	A mechanism facilitated by multiply inheriting from various
abstract bases: one for each set you want the object to be in.

>-- 
>Barry Margolin
>System Manager, Thinking Machines Corp.
>
>barmar@think.com          {uunet,harvard}!think!barmar


-- 
;----------------------------------------------------------------------
        JOHN (MAX) SKALLER,         maxtal@extro.ucc.su.oz.au
	Maxtal Pty Ltd, 6 MacKay St ASHFIELD, NSW 2131, AUSTRALIA
;--------------- SCIENTIFIC AND ENGINEERING SOFTWARE ------------------
From: rcsjp@cgl.rmit.oz.au (Jason Pouflis)
Newsgroups: comp.object
Subject: Re: Announcing: the OO Hall of Fame
Date: 27 Jul 92 08:59:08 GMT
Organization: Royal Melbourne Institute of Technology

metz@iam.unibe.ch (Igor Metz) writes:
>Whenever I read an article or book I wonder how the author might look
>like.  Long hair? Blue eyes? Contact lenses?
>That's why I decided to set up a "OO Hall of Fame" gallery. This
>gallery is a directory on our anonymous ftp server which contains
>scanned images stored as TIFF files. (I hope that there will be know

AARGH! Not comp.object.people.gif
(almost as bad as comp.lang.c++.hamster.duct-tape):)
Newsgroups: comp.object
From: richieb@bony1.bony.com (Richard Bielak)
Subject: Re: OOA: Should "Classification" be performed in OOD phase?
Keywords: Class based vs Classless implementations.
Organization: Lost in NYC
Date: Mon, 27 Jul 92 17:22:03 GMT

In article <2640@abcom.ATT.COM> brr@abcom.ATT.COM (Rao) writes:

[...]

>
>Question: When does OOA end and OOD begin?
>
>Another Question: In what phase do we decide if objects should be 
>	"Classified"? During OOA or OOD?
>

Why should OOA end and OOD begin? 

These two processes are the same - you look for objects and classes.
Both should continue throughout the project. 

The beauty of OO aproach is that you doing the same thing during
analysis, design and implementation. You can do them all at the same
time as you are always working with objects and classes.


...richie






-- 
* Richie Bielak   (212)-815-3072   | "Your brain is a liquid-cooled parallel  *
* Internet:       richieb@bony.com | super-computer". He pointed to his nose, *
* Bang {uupsi,uunet}!bony1!richieb | "This is the fan."                       *
*    - Strictly my opinions -      |                     - David Chudnovsky - *
Xref: sparky comp.object:3080 comp.lang.eiffel:1031
From: hasan@ut-emx.uucp (David A. Hasan)
Newsgroups: comp.object,comp.lang.eiffel
Subject: Re: Class methods (was: Re: How to design a data structure library)
Date: 31 Jul 92 15:54:55 GMT
Followup-To: comp.object
Organization: UTexas Center for Space Research

In article <92210.125846MKK2@psuvm.psu.edu> MKK2@psuvm.psu.edu writes:

>[...] c := a + b translates into English  for me
>as something like "start with a, perform the union operation on it with
                    ^^^^^^^^^^^^
>b as an argument, return the union as a result, and assign it to c."


Undoubtedly, this is the kernel of the discussion.  Does the 
statement
            c := a + b
universally translate into "start with a..."?  (I.e., does
everyone agree that the "+" operator in fact "starts" with
its left operand?  I don't think so.  The "+" operator is
suggestive of an commutative operation in which there is
no preference for either argument as the starting point.
This is the heart of the "symmetry" complaint which many feel
makes the OO notation cumbersome for such situations.


>While your crystal clear traditional syntax is nice, I feel fine with
>
>   c = [a union:b];


As long as it is accepted that the meaning of the operation
is "start with a..." then the differences here are nil, but
the heart of this discussion is whether or not it is
reasonable for the notation to impose this asymmetry.  The
"+" notation was in fact suggested precisely because it 
does not require the notion of "starting with a...", and 
to that extent, the "[a union: b]" notation is not an
acceptable alternative.

Of course, we've got to keep all this in perspective.  It
really IS a syntax/notation issue...isn't it? 
-- 
 |   David A. Hasan
 |   hasan@emx.utexas.edu 
Newsgroups: comp.object
From: jpope@axion.bt.co.uk (john pope)
Newsgroups: comp.object
Subject: Re: Benefits of automation - MIT report?
Date: 27 Jul 92 14:42:22 GMT
Reply-To: jpope@zaphod.axion.bt.co.uk
Organization: British Telecom Labs

From article <1560@ictser.UUCP>, by tusveld@ictser.UUCP (Fred Tusveld):
> 
> Hello,
> 
> I was wondering if anyone in this newsgroup is aware of a MIT report that presents results of an investigation into the net benefits of investing in software.
> In a Dutch magazine (Elsevier Weekblad, july 20th) there is an article that surveys corporate experiences of automation. It contains a reference to a recent MIT report, that claims "that every dollar invested in automation is better spent into any other category of investment."
> 
> 
> Thanks in advance.
> 
> 
> 
> Fred Tusveld
> ICT Automatisering Deventer BV - Aerospace Department
> tel. +31 5700 33888
> fax. +31 5700 21362
> Keulenstraat 7
> P.O. Box 701
> 7400 AS Deventer
> The Netherlands
> email :
> tusveld@ict.nl

There's a book based upon the MIT90s project - and I can't for the life of
me remember the title but I have it on loan at the moment - which details
all the sub projects in the programme. Well worth a read. It may
well be called:

Management in the 90s.

I'll check and report back tomorrow......if someone prods me!!! (I'm in that
I'm going on holiday in 4 days time and I have at least 15 days of work to
do mood!)

John


jpope@axion.bt.co.uk 	Software Technology, Requirements, G24 SSTF
UK +44 473 646651	BT Labs,Martlesham Heath, IPSWICH IP5 7RE, UK 
		
Newsgroups: comp.object
From: mat@mole-end.matawan.nj.us
Subject: Re: Benefits of automation - MIT report?
Summary: Yes, but which?
Organization: :
Date: Thu, 30 Jul 1992 02:31:36 GMT

In article <1560@ictser.UUCP>, tusveld@ictser.UUCP (Fred Tusveld) writes:
 
> ... is aware of [an] MIT report that presents results of an investigation
> into the net benefits of investing in software.

> In [Elsevier Weekblad, july 20th] an article [surveys] corporate experiences
> of automation.  It [refers to] [an] MIT report [claiming] "that every dollar
> invested in automation is better spent into any other ... investment."

Yes, but what report?  DO tell!

 -----------------------------------------------------------------------------
	It has long been known that one horse can run faster than another
	--but _which_ one?  Differences are crucial.
				--RAH, TEFL/The Notebooks of Lazarus Long.
-- 
 (This man's opinions are his own.)
 From mole-end				Mark Terribile

 mat@mole-end.matawan.nj.us, Somewhere in Matawan, NJ