HDTenEightyP/NetNews huggingface dataset:
Newsgroups: comp.object
From: akao@.com (Adam Kao)
Subject: Re: Re: FAQ  Part 1 (of 2) [ polymorphism or latent typing? ]
Organization: Oracle Corporation, Redwood Shores, CA
Date: Sun, 24 Jan 1993 06:47:20 GMT
X-Disclaimer: This message was written by an unauthenticated user
              at Oracle Corporation.  The opinions expressed are those
              of the user and not necessarily those of Oracle.

In article <1993Jan23.055312.23517@netcom.com> objsys@netcom.com (Bob Hathaway) writes:
>In article <KERS.93Jan22095935@cdollin.hpl.hp.com> kers@hplb.hpl.hp.com (Chris Dollin) writes:

>>Not in the natural sciences, perhaps. Different fields of inquiry are
>>characterised by different linguistic perversions, sorry, developments.
>>How else could it be? There are different clusters of people doing the 
>>work, with their own linguistic history, and the subject matter itself
>>suggests its own metaphors.

>Boy did you get this one wrong.  After posting, I looked up the definition
>of polymorphism in the old Webster's...

Chris was responding to your previous statements:

> In the sciences, B is refered to as "polymorphic" or
>  as a "polymorphic object" ...
> So sorry, it doesn't look as though structural and
>  behavioral replacement (or a becomes facility) is the standard usage of the
>  term polymorphism.

You miss Chris' point: the standard usage of the term "polymorphism"
in the natural sciences is not relevant to the question of what
definition to use in the computing sciences.

You further miss the point by referring to Webster's dictionary, which
contains the "common" definition, which is still not relevant to the
question of what definition to use in the computing sciences.

Chris is making a philosophical point, that the technical definition
of a term in one field need not be related to the definition of that
term in other fields, nor to the common usage definition; therefore,
the statements I quoted from you are not relevant to this debate.

Chris' point is one of the fundamental tenets of linguistics, namely,
that we should not expect Computer English and Physics English to be
the same any more than we expect German and English to be the same.

For more information, please look up "idiolect" in any introductory
linguistics textbook.

Please refrain from statements like "boy did you get this one wrong";
they do not help the debate.

>P.S.  Are there any other true object-oriented followers out there?  There
>  seems to be lots of functional ones...

Please also refrain from claiming the true object-oriented follower mantle.

Adam
From: pcg@aber.ac.uk (Piercarlo Grandi)
Newsgroups: comp.object
Subject: Re: Re-use and OO
Date: 21 Jan 93 22:19:10 GMT
	<C0uBAL.2EK@dcs.ed.ac.uk> <1993Jan17.161536.27190@ucl.ac.uk>
Reply-To: pcg@aber.ac.uk (Piercarlo Grandi)
Organization: Prifysgol Cymru, Aberystwyth

gym@dcs.ed.ac.uk (Graham Matthews) writes:

Matthews> If re-use was being supported properly these redundancies
Matthews> would not be in a program and hence the need for such tools
Matthews> would disappear. Comments?

Joly> (1) How do you assess the problem of "names of things"?

Matthews> I am not sure I understand the first question Gordon - can you
Matthews> rephrase it?

On 17 Jan 93 16:15:36 GMT, ucacgcj@ucl.ac.uk (Gordon C Joly) said:

Joly> It I write a stack method and call it "kcats", who would another
Joly> user, or even myself one year later:-), find this method?

But this is a "trivial" problem! All you need is an inventory of things,
with suitable indexes. This is not even too hard to do (even if very few
people do it). At times just having an indexed manual a la Unix man
pages will do. I remember a beautiful system called Calico from the MIT
Prog Tech Lab, which they used to great effect with MDL classes/method
(and with PDP-10 macro code too!).

The really hard problem with names and reuse is, for most languages, how
to work around name conflicts, e.g. how to use two different classes
called 'transport', where say one is about travel and the other is about
network connections.

In most languages the only possible solution is to rename the module,
but this creates longer term problems and reduces reuse actually.
--
Piercarlo Grandi <pcg@aber.ac.uk> c/o Dept of CS
University of Wales, Penglais, Aberystwyth SY23 3BZ, UK
Newsgroups: comp.object,comp.lang.c++,comp.lang.c,comp.lang.clos
From: samantha@shell.portal.com (Samantha Atkins)
Subject: Re: CORBA DII Implementation (CLOS & C) - Anonymous FTP Site
Keywords: CORBA OMG DII
Organization: Portal Communications Company -- 408/973-9111 (voice) 408/973-8091 (data)
Date: Tue, 26 Jan 1993 07:36:46 GMT

I would like to see a News group devoted to the OMG efforts.  If there is
already such a group I would appreciate being advised of it.  These efforts
are quite likely to impact all of us who work with the OO paradigm.  Therefore
I think it is vastly important that we begin to think of what the implications
both pro and con are likely to be.  

Opinions?


Newsgroups: comp.object,comp.software-eng
From: tne@world.std.com (Thomas N Erickson)
Subject: Re: Writing Windows Applications in Ada?
Organization: The World Public Access UNIX, Brookline, MA
Date: Sat, 23 Jan 1993 02:44:10 GMT

tarcea@gdls.CSCTMD.COM (Glenn Tarcea) writes:

>>
>>Unfortunately, it is not possible to validate an Ada compiler under
>>Windows 3.1.
>>

>   Why? I am not so sure I understand why you can't validate an Ada
>compiler Under Windows 3.1. Is it because of the tasking model that
>Ada needs, if so then Windows definitely supports such a model better
>than DOS (Sick!!)! I would be interested in knowing the technical reasons
>why you can't have a validated Ada compiler under Windows 3.1

It is due to the tasking model.  The lack of the ability to do pre-emptive
tasking in Windows 3.1 prevents validation.  You can contact our product
manager, Sharon Aucoin at Alsys (617)270-0030 (aucoin@world.std.com) if
you would like more detailed technical information.




-- 
Tom Erickson
Alsys
tne@world.std.com
Newsgroups: comp.object
From: A.H.Al_ashaab@lut.ac.uk (AH Al_ashaab) 
Subject: relation betweem OOM and IDEFo and EXPRESS language
Reply-To: A.H.Al_ashaab@lut.ac.uk (AH Al_ashaab)
Organization: Loughborough University, UK.
Date: Wed, 27 Jan 93 12:44:31 GMT

Hi
Can any body tell me what is the relation between activity modelling
techniques like IDEF0 IDEF1X NIAM and the Object Oriented Methodologies (OOM)?
and between EXPRESS information modelling language and OOM.

Am I right in my thinking that IDEF0 model is helping in the analysis of
the problem and EXPRESS language captures the constrains on the Entities 
or classes SO BOTH IDEF0 and EXPRESS help in OOA then OOD will be the stage 
before the implementation using OOP to have a clear decompostion of classes
and the relations between the classes

OR Iam wrong and using any OOM is enough to do all our work from the
beginning

thanks


Ahmed AL-ASHAAB
Manuf. Eng Dept., Loughborough Univ of Tech
Loughborough, Leics LE11 3TU, England.
EMail : A.H.Al_ashaab@lut.ac.uk  OR     ahmed@mansun.lut.ac.uk
Tel 0509-263171 Ext. 4247 	Fax. 0509-267725
From: C.D.Turner@newcastle.ac.uk (Chris Turner)
Newsgroups: comp.object
Subject: Re: Testing - Tech Report
Date: 25 Jan 93 10:48:29 GMT
Organization: University of Newcastle upon Tyne, UK, NE1 7RU
X-Newsreader: TIN [version 1.1 PL6]

firstly, I owe everyone my sincerest apologies, it is actually my
fault that everyone has been having difficulty with the ftp site.

I quoted the 'long-name' which apparently only works for e-mail 
whereas I should have quoted the short-name vega.dur.ac.uk.

Also, a number of people are having problems printing it out, there
are two special characters at the start and end of the file (control-D)
which must be removed.

Because the postcript file is so large, it causes memory problems
on some printers, therefore I will place another version in the directory
which is done in segments. 

Again my apologies,

I will post to this newsgroup when the new versions of the file are Ready.

Chris Turner

Department of Computer Science, University of Durham, DH1 3LE England
Tel. +44 91 374 3657 FAX +44 374 3741 E-Mail C.D.Turner@durham.ac.uk
From: rmartin@thor.Rational.COM (Bob Martin)
Subject: Re: Booch question: new class relationship?
Organization: Rational
Date: Fri, 22 Jan 1993 22:05:31 GMT

hartman@ulogic.UUCP (Richard M. Hartman) writes:

>I have a question here.  I have been thinking about class
>relationships and I think I've come up w/ one that is not
>distinguished in the Booch method.

>Comments?  Am I imagining a difference that makes no difference?  Has
>someone brought this difference up before?  Is it represented in some
>OO Design methodology somewhere?

You can mail a letter to prod_info@rational.com asking them for
Booch's latest paper on the notation.  In that paper you will find
what you are looking for. 

The "using" relationships described in his book have been replaced
with:

	Contains by Value
		Which is a black circle, a double line and a black box

                *=========#

	Contains by Reference
		A black circle, double line and a white box

                *=========[]

	Uses
		A white circle, double line and no box.
		
		O=============

Containment by value represents the notion that the storage of the
contained class exists within the storage of the containing class.
The containing class has intrinsic knowledge of the contained class
(ie. knows where to find it).  The contained class is created and
destroyed with the containing class.  The contained class cannot be
polymorphic.

	class ContainingByValue
	{
	  Contained x;
	};

Containment by reference denots that the containing class contains a
pointer or reference to the contained class.  Such containment can be
polymorhpic, but does not dictate that the lifetimes of the contained
and containing objects are the same.

	Class ContainingByReference
	{
	  Contained* x;
	};

Uses is a weak relatioship which means that the using class uses the
used class in its interface somewhere.

	Class Uses
	{
	  void f(const Used& u);
	};

--
Robert Martin       | Design Consulting    | Training courses offered:
R. C. M. Consulting | rmartin@rational.com |  Object Oriented Analysis
2080 Cranbrook Rd.  | Tel: (708) 918-1004  |  Object Oriented Design
Green Oaks, Il 60048| Fax: (708) 918-1023  |  C++
From: kers@hplb.hpl.hp.com (Chris Dollin)
Date: Mon, 25 Jan 1993 10:48:38 GMT
Subject: Re: Re: FAQ  Part 1 (of 2) [ polymorphism or latent typing? ]
Organization: Hewlett-Packard Laboratories, Bristol, UK.
Newsgroups: comp.object

In article ... akao@.com (Adam Kao) writes:

... an excellent forecast of my response to Hathaway's response to my remarks
about how the meaning of ``polymorphic'' in the natural sciences does not 
force a meaning on computer science ...

... thus making it unnecessary to respond myself, except to say, Ta!
--

Kers.       | "A foolish hobgoblin has the consistency of little minds".
Newsgroups: comp.object
From: mack@jasmin.zko.dec.com (Ralph A. Mack)
Subject: Literature on management of iterative/recursive projects?
Reply-To: mack@jasmin.zko.dec.com (Ralph A. Mack)
Organization: Digital Equipment Corporation, Nashua, NH USA
Date: Tue, 26 Jan 1993 18:47:51 GMT


Hello,

I'm looking for any good literature on managing projects using
an iterative/recursive design methodology.  I know there was some
work a few years ago by Don Firesmith, but have lost track of him
since I left the Ada community in '89 to wander in the wilderness of 
C for a few years.  Now that I'm starting to look at using C++ for a 
live project, I need to explore what advances have taken place in the 
art and science of managing O-O projects since then. So:

1.  What books, papers, articles, etc. are well worth reading in this
    space (i.e. that talk seriously about process, not just principles)?

2.  Is Don Firesmith still in the business?  I liked what he'd been doing
    at the time.

3.  Did Ed Berard ever publish his masterwork on OOA, OOD, OOT, OOM, etc.?

					It's good to be back,

					    Ralph
Newsgroups: comp.object
From: papresco@undergrad.math.waterloo.edu (Paul Prescod)
Subject: Opinions
Organization: University of Waterloo
Date: Tue, 26 Jan 1993 17:48:36 GMT

I'm giving an introductory talk on OOP.  I'd like to solicit the views
of some people in Object-World first.  I'd appreciate E-mail to avoid
a flame war:

1.Can a person move to OOP in stages, using a language like C++ or
Modula-3 which are still fully useful without objects?  In other words:
is it okay to take time to move from procedural to OOP, or is the only
way a clean break?

2.What is the *BEST* language for learning OOP?

3.What is your opinion any or all of the following languages, or any
others you can think of:

Smalltalk,
C++,
Ada,
Modula-3,
Self,
Sabre,
CLOS,
TP w/objects,
Objective-C,
Oberon,
Actor,
again, anything else you can think of.

From: kers@hplb.hpl.hp.com (Chris Dollin)
Date: Mon, 25 Jan 1993 11:28:36 GMT
Subject: Re: Re: FAQ  Part 1 (of 2) [ polymorphism or latent typing? ]
Organization: Hewlett-Packard Laboratories, Bristol, UK.
Newsgroups: comp.object

In article ... santas@inf.ethz.ch (Philip Santas) writes:

   In article ... kers@hplb.hpl.hp.com (Chris Dollin) writes:
   >
   > Meyer describes [p73, OOSC] an
   >``entity'' as the object-oriented equivalent of a variable. In Eiffel, 
   >entities of a class hold references to objects.
   >Thus, in at least this one case, polymorphism is a property of *entities*,
   >not *objects*. 

   Any particular reason why the original term ``variable'' is not used?

Presumably because formal parameters, while being entities, are not 
variables -- you can't assign to them. (You can assign to [slots of]
the object they refer to, but not to the entity itself.)
--

Kers.       | "A foolish hobgoblin has the consistency of little minds".
Newsgroups: comp.object
From: mahesh@elcaro1.ColumbiaSC.NCR.COM (Mahesh Zambani)
Subject: Re: What the hell is "IMO" ?
Reply-To: mahesh@elcaro1.columbiaSC.NCR.COM
Organization: NCR Corp., Columbia
Date: Thu, 28 Jan 93 16:45:13 GMT

In article <chandram.728185573@weber>, chandram@ece.scarolina.edu (Rajagopal Chandramohan) writes:
|> Would some kind soul explain what does IMO stand for? I have been
|> trying to guess the meaning from context without luck. Thanks.
|> 
|> Rajagopal

	IMO, IMO stands for "In My Opinion".

--Mahesh
                            ^  ^  ^
-- 

Mahesh Zambani                                mahesh@elcaro1.ColumbiaSC.NCR.COM
NCR MCPD , Columbia,SC 29170                  
_____________________________________________________________________________
From: konnbt@eua.ericsson.se (Niklas Bjornerstedt)
Newsgroups: comp.object
Subject: Re: Strong typing (was: Re: Pros and cons o
Date: 28 Jan 93 07:54:22 GMT
Reply-To: konnbt@eua.ericsson.se
Organization: Enator Functional Systems, Stockholm, Sweden

In article 21849@bnr.ca, tims@bcarh680.bnr.ca (Tim Spurway) writes:
> In article <1993Jan27.082721.3841@nwnexus.WA.COM> markmc@halcyon.com (Mark McWiggins) writes:

> >But give me this any day over my customer calling from Buenos Aires
> >saying "What's this 'method not found' mean?" as in Smalltalk.
> >
> 
> But give me this any day over my customer calling from England saying
> "What's this 'Segmentation fault: core dumped' mean?" as in C++.  :)

I'll second that. I my experience most runtime errors that users of a
Smalltalk system encounter are of the type: UndefinedObject>doesNotUnderstand.
This is very often caused by what you in C++ would call a null-pointer. 
No current type system helps you find null-pointers.

_____________________________

Niklas Bjornerstedt
Enator Functional Systems
Email: konnbt@eua.ericsson.se
Newsgroups: comp.object
From: berczuk@space.mit.edu (Steve Berczuk)
Subject: Re: Booch question: new class relationship?
Organization: MIT Center for Space Research
Date: Thu, 21 Jan 1993 17:09:56 GMT

>> hartman@ulogic.UUCP (Richard M. Hartman) says:
|> However a child window frequently has to know about the parent
|> window.  And may be passed a pointer to it's parent in the constructor,
|> which it stores internally & may make use of in various ways.  BUT
|> this pointer is something that the child window must NOT screw around
|> with in any serious way.  It can't reallocate it, it can't destroy it
|> in it's destructor.  It "has" a parent, but it is not "in control" of
|> it.  This is what I am calling "knows-a".  It is a form of "uses" in
|> the Booch system, but I think that the distinction between this and
|> the OTHER kind of uses (has-a) is both significant and not currently
|> represented in any formal OO Design system that I have seen.
|> 
 my first reaction is to say that this is just a has-a (or "uses"), 
albeit a has-a of a shared reference. 

to take another example, a class Employee might have a "is-supervised
by" relationship with a Manager object that may be implemented as a pointer to a
manager object. (ie, the employee Uses the manager object for some function)
 When the employee is "removed" the Manager most likely isn't and
this protocol should be enforced by the employee destructor..

I think the distinction between "has-a" and "knows-a" is good to keep in mind, but
adding it explicitly to a design methodology could make things ugly, as issues such
as ownership of the object for allocation, destruction, etc can be very
implementation specific (the Manager can be reference counted, say, and the
employee objects DO delete it but it only goes away when there are no employees to
supervise...


-- 
Steve Berczuk			berczuk@mit.edu		
MIT Center for Space Research	(617) 253-3840

Newsgroups: comp.object
From: dave@ait.com
Subject: Distributed transaction processing with a relational database
Reply-To: dave@ait.com
Organization: Artificial Intelligence Technologies, Inc.
Date: Wed, 20 Jan 1993 22:05:50 GMT


We are in the problem analysis phase for a project to move an existing
mainframe transaction processing system using VSAM, to distributed
workstations and a relational database.  The application must handle
about 500,000 existing customers, periodically calling into the
customer service reps. who handle complaints, new products, cancel
products, etc.  These customers need to be billed for their products,
and the product must be transported to the customer.  The total size
of the VSAM files is now about 2-4 gig of data, with some of this
being historical records.  There will be about 100 users of hte
system, with 50-70 fulltime.  Batch processes will also be running
over the data at various times through the cycle.

I am looking for persons out there that have deployed, or are developing
similar applications, and I would like information on how this can be
accomplished most efficiently.  Specifically:

1) What methods/tools did you use if you used OOA or Design?

2) What platform/workstation/servers are prefered for both development
and deployment?

3) What language(s) did you use, C, C++, Cobol, 4GL?  Did you use any CASE
tools?  E.g. What is a _very_ large, deployed system for C++?

4) How about GUIs and their development tools?  Motif, Windows, Forms?
The ideal situation would take advantage of existing PC hardware
running Windows for the infrequent users, and perhaps an Xterm to a
workstation for continous users.

5) Which database tools were used, Sybase, Ingres, Oracle?

6) I am also looking for any literature I can find on _deployed_ systems
similar to this, books, papers, etc.

Thank you for your input,
dave

________________________________________________________________________
Dave Pracht					phone: (914)347-6860
Director of Applications Development		fax: (914)347-3182
Artificial Intelligence Technologies, Inc.	internet: dave@ait.com
Westchester Co. NY
________________________________________________________________________
Newsgroups: comp.object
From: wags@cimage.com (Bill Wagner /10000)
Subject: Metrics on OOD / OOP
Reply-To: wags@cimage.com (Bill Wagner)
Organization: Cimage Corporation
Date: Wed, 27 Jan 93 15:08:15 GMT

I have been asked to propose and defend a plan for moving to Object
Oriented Design and Programming.  I am looking for literature that will
point to its advantages with respect to reusability and time to market for
new development.  Does anyone know of any good references?


-------------
          Bill Wagner                USPS net: Cimage Corporation
Internet: wags@cimage.com                      3885 Research Park Dr.
AT&Tnet:  (313)-761-6523                       Ann Arbor MI 48108
FaxNet:   (313)-761-6551

"One should be able to see that things are hopeless, and yet be 
determined to make them otherwise."  - F. Scott Fitzgerald
From: mack@rathe.cs.umn.edu (Mack Read-Mackenzie)
Newsgroups: comp.object
Subject: POLYMORPHISM: (was RE:FAQ && RE:HELP:Array of different classes)
Date: 22 Jan 93 16:08:56 GMT
Organization: Rathe, Inc.

vinay> The user of this program will choose at the runtime what objects to put
vinay> in the holder. The problem is how do i store this information (i.e the
vinay> contents ) in class HOLDER. I cannot create a single array of objects
vinay> because each object is of different class.

woods> All things, like `pen', `eraser', `pencil' etc.  share the property
woods> that they can be put in the holder.  So, define class HolderTool.
woods> Then define subclasses of this, such as Pencil, Pen and Eraser.  Then
woods> one's holder is simply an array of HolderTool instances. 

This is a classic example in polymorphism in action.  A variety of distinct
yet related objects can be handled by one set of code.  The trick is to extract
what is similar among all of the objects into an abstract base class, from
which each of the unique objects will inherit.  The code which needs to deal
with their commonality will treat each of the unique objects as a member of
the base class.  (Just what John Woods said above).  To the guys arguing over
the FAQ: what is so hard to understand or define about polymorphism anyway?

I don't mean to be rude, but this seems pretty simple...
Newsgroups: comp.object
From: tarcea@gdls.CSCTMD.COM (Glenn Tarcea)
Subject: Re: Writing Windows Applications in Ada?
Organization: Computer Sciences Corp. @ General Dynamics
Date: Fri, 22 Jan 1993 12:51:32 GMT

>
>Unfortunately, it is not possible to validate an Ada compiler under
>Windows 3.1.
>

   Why? I am not so sure I understand why you can't validate an Ada
compiler Under Windows 3.1. Is it because of the tasking model that
Ada needs, if so then Windows definitely supports such a model better
than DOS (Sick!!)! I would be interested in knowing the technical reasons
why you can't have a validated Ada compiler under Windows 3.1

   -- glenn

   vgtarcea@vela.acs.oakland.edu

-- 
================================================================================
              __   __   ___  |   Glenn Tarcea -| Software Tools |-
         //// _  __  ___     |   General Dynamics
        ///  __    ___    __ |