Re: Ichibah [sic] flames, and flames out over, Ada 9X

Re: Ichibah [sic] flames, and flames out over, Ada 9X

[cis.ohio-state.edu!pacific.mps.ohio-state.edu!linac!uwm.edu!wupost!howlan]

>I was under the impression that the letter was sent to a private (semi-
>private?) mailing list.  Dissemination beyond that list should be at
>the discretion of the author, IMHO.

Fine, any one have Ichbiah's (sorry about the initial type) email address
so someone can ask him to post his message?

Greg Aharonian
Source Translation & Optimization
-- 
**************************************************************************
Greg Aharonian
Source Translation & Optimiztion
P.O. Box 404, Belmont, MA 02178

Re: Ichibah flames, and flames out over, Ada 9X

[John Goodsen]

stt@spock.camb.inmet.com (Tucker Taft) writes:

>srctran@world.std.com (Gregory Aharonian) writes:
>> . . .From this point of view, the original posting's
>>call for more features in Ada9X that allows better competition with C++
>>(and Smalltalk) should be heeded.
>
>There are many ways to skin a cat.  In many cases, imitation is not
>the most effective strategy.  Why choose Ada 9X if it makes the same
>mistakes that C++ does?  

Which is hardly what I was proposing.  Are you saying that classes
are a mistake in C++ ?  I would hope that the real message of 
the original posting was received as:

  Object Oriented Analysis and Design approaches (most of them
  and certainly the mainstream) use class based approaches.  
  When a software engineer performs OOA and/or OOD, it is going
  to be quite natural to look for an implementation language
  which *has class*.  If you don't make it easy for someone on
  the language search to see that Ada supports the concept of
  "class", then the acceptance of the language for OO development
  will not meet it's true potential.

I have heard the arguments on why tagged types are *better* than
classes, and for the most part agree with them.  This is not a
technical issue.  It's a market acceptance issue.  If the solution
is to change the syntax from "tagged type" to "class" and leave
it at that, then it doesn't sound like too much of a problem and
I will predict that the commercial payoff will be worth the minor
syntactical change.  

I know what you're thinking:  "But, if we change 'tagged type'
syntax to 'class' syntax, it won't be a class in the same
terms as other languages!"  Great!  If you want to introduce the
world to a better object oriented programming mechanism, then
at least speak to the world in their language.  The language
that people will understand is "class", not "tagged type".

A class in CLOS, smalltalk and C++ are not identical already.
The argument that if Ada uses the word "class" then it has
to be exactly like C++'s implementation of a class doesn't
hold water.  Don't let a C++ vs. Ada bias affect this "CLASS"
syntax issue.  It will seriously hinder new market acceptance of
Ada as an OOP language.

>
>We should learn from the strengths and
>weaknesses of other languages, and advance the state of the art, 
>not solidify it around a 1985-vintage design.
>

So is it safe to assume that 9x tagged types are considered
as "advancing the state of the art" by the Ada 9X project or
wasn't the syntax terminology introduced to remain consistent
with the Ada 83 "state of the art".

A serious question, really :-)

-- 
John Goodsen
Software Process & Environments
EVB Software Engineering
jgg@evb.com

Re: Ichibah [sic] flames, and flames out over, Ada 9X

[Magnus Kempe]

In article <1993Mar10.201515.6295@evb.com>, jgg@evb.com (John Goodsen) writes:
: If you don't make it easy for someone on the language search to see
: that Ada supports the concept of "class", then the acceptance of the
: language for OO development will not meet it's true potential.

In Ada 9X, you will be able to declare e.g. class-wide objects and
access types, such as:

	type Stack_Ref is
	  access Stack'class;
	
	A : Stack'class;

Is it easy enough to see that Ada 9X has "class" ?


: If the solution is to change the syntax from "tagged type" to
: "class" and leave it at that, then it doesn't sound like too
: much of a problem...

Contrary to OOP languages where objects per se are polymorphic,
Ada objects are monomorphic since Ada has by-value semantics.
Ada 9X programmers will _also_ be able to manage by-reference
semantics to have polymorphic references to objects, which is
what other OOP languages really provide.  Generally, a class
declaration in an OOPL implies that instances may belong to
the class itself or to a subclass, and that they are polymorphic;
in consequence, OOPLs rarely perform any significant amount of
strong, static type checking.

You don't want to throw away Ada's strong type system and static
checking, do you?

Anyway, I doubt that the adoption of Ada 9X will rest on the ability
of C++ programmers to grasp that "tagged" is somehow an equivalent of
their "class".  I don't think they will, since most C++ programmers
that I know enjoy C++ "because it's compatible with C".  Ada is
incompatible with C-oriented minds.  And that's a Good Thing.

If you want to learn of the many problems with C++, go read
  "C++?? A Critique of C++", Ian Joyner (e-mail: ian@syacus.acus.oz.au)
  "A Critique of the Inheritance Principle of C++", Markku Sakkinen,
  in Computing Systems, Vol. 5, No. 1, Winter 1992
  "The Darker Side of C++ Revisited", Markku Sakkinen,
  in Structured Programming (1992) 13: pp. 155-177.
(Warning: Referenceless flames and other hate-mail ignored on principle :-)

-- 
Magnus Kempe                "No nation was ever drunk when wine was cheap."
magnus@lglsun.epfl.ch                                   -- Thomas Jefferson

Re: Ichibah [sic] flames, and flames out over, Ada 9X

[Bob Kitzberger]

msbuck@tacom-emh1.army.mil (M. Scott Buck) writes:

>Does anyone have a copy of the letter from Mr. Ichibah [sic] so that the
>news group can review the specifics?

I was under the impression that the letter was sent to a private (semi-
private?) mailing list.  Dissemination beyond that list should be at
the discretion of the author, IMHO.

	.Bob.
----------------
Bob Kitzberger          VisiCom Laboratories, Inc.
rlk@visicom.com         10052 Mesa Ridge Court, San Diego CA 92121 USA
                        +1 619 457 2111    FAX +1 619 457 0888

Re: Ichibah [sic] flames, and flames out over, Ada 9X

[M. Scot t Buck]

Does anyone have a copy of the letter from Mr. Ichibah [sic] so that the
news group can review the specifics?

Scott

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Re: Ichibah [sic] flames, and flames out over, Ada 9X

[enterpoop.mit.edu!linus!think.com!rpi!ghost.dsi.unimi.it!univ-lyon1.fr!sc]

In article <1993Feb17.065421.12021@sei.cmu.edu>,
wellerd@ajpo.sei.cmu.edu (David Weller) writes:
: 
: I believe [Ichbiah] also used it as a platform to make a final
: protest against the "with private" clause for tagged types.
: ...
: He was rather insistent on creating a class-based language, rather
: than the tagged types that we have now.

Both statements are erroneous.

The disagreement around tagged types was about _syntax_ (esthetics).
Not about semantics.

-- 
Magnus Kempe                "No nation was ever drunk when wine was cheap."
magnus@lglsun.epfl.ch                                   -- Thomas Jefferson