Members of TCSIGAda and persons interested in Software Engineering
You are are invited to attend the  January TCSIGAda meeting, where the
topic is

   Reusability: When Objects are not good enough

A .htm version of this announcment is attached, please feel free to
print it, post it,
forward it, as appropriate.

Today's pardigm is objects, however objects are not a cure-all.
We'll look at "types" as a Software Engineering Principle, and discuss
"good typing" is better in many ways for reusability and maintainability
than objects.
Come prepared with your questions and be ready for discussion.
  Cheers, ..Paul S.


When Objects are not good enough, or
Why are there 7 kinds of types plus type composition in Ada?

7:00 p.m., Thursday, Jan 18, 2001
Founder's Hall Auditorium
on Metro State University's St. Paul Campus
700 E. 7th St.,St. Paul, MN 55106

This meeting is Co-hosted by the Information
and Computer Sciences Department at
Metropolitan State University and TCSIGAda.

Today's computer programs are very large.
We can no longer afford to write each subprogram group separately.
Objects are today's cure-all for reusability.
However, objects have a number of disadvantages, including
hiding information from both the programmer and the compiler.
Indeed, solid types, composed in a type-rich language such as Ada,
are superiour to objects in their understandability, efficiency,
and correctness.
In this meeting, Paul will discuss the kinds of things which
need to be parameterized for resuability, and how objects,
as defined by programming languages such as Java and C++ fall short.
He will describe how one can use a language which is rich in:
  primitive types
  type (not object) sub and superinheritance
  type=disc>type composition
to provide ways to create reusable code in such a manner
that we need only small, or no, amounts of testing.

About the Speaker:
  Paul Stachour has been interested in reusability since he found
himself rewriting and retesting stack packages in 1970.
He is concerned about the lack of separation of interface and
implementation in many languages, and how that prevents reusablity.
He has observed that languages that do not enable one to
manipulate types do not not seem to scale,
while those that do so statically "inside the language"
makes reusability easy and reliable.
Paul has been interested in what makes software "quality software" ever
In particular, he is interested in what languages, features, tools, and
processes prevent defects. Paul is the current president of TCSIGAda.

Bus Route:  9, 10, 12, 15 (St. Paul).
  These buses may have any terminal letter.
Driving from east on I-94 in St. Paul: Take the Mounds Boulevard
  (left lane) exit, straight ahead on Sixth Street one block to
  Maria Avenue; turn left on Maria Avenue; parking lot is on the right.
Driving from east on I-94 in St. Paul: Take the Mounds Boulevard exit;
  turn right at Sixth Street to Maria Avenue; turn left on Maria Avenue;

  parking lot is on the right.
There is limited street parking (free), recommend that you park in the
  Metro State lot ($1.50).
The Auditorium is located in Founders Hall.  As you leave the parking
  you will be facing a quadrangle with buildings on three sides.
  Hall is on the left (or south) side of the quadrangle.  Enter the
  doors and turn right.  Go through the open area and through a set of
  The auditorium will be directly in front of you.

For information about TCACMSIGAda, call (952)-884-5977
or visit <em></em>

At each TCSIGAda meeting, we give away a free Ada CROM,
a copy of the tutorial comparing Ada and Java concurrency,
or some other item.  At the January meeting, we will give away
a CDROM containing a compiler that allows you to mix Ada, Java,
and C code.
These will be given  to two individuals who have registered
by EMail to our publicity chair Mark Glewwe.
So, send him an EMail at "[log in to unmask]" today.

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