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

[koehnema@enuxhb.eas.asu.edu (Harry Koehnemann)]

In article <1993Mar13.031104.21673@telesoft.com> kst@telesoft.com (Keith Thompson @pulsar) writes:
>
>Once I had made that connection, I didn't have any problem understanding
>what access types are and how they work; most of what I had learned about
>Pascal pointer types applied almost directly to Ada access types.

And look how the word "access" has completely removed "pointer" or
"reference" from existence in the CS world :).  But really, why take a
very well understood concept and name it something completely off the
wall.  Didn't Ada desire to facilitate understanding, rather than get
in it's way?

>My point is that these minor differences in terminology (pointers vs.
>access types, classes vs. tagged types, functions returning void vs.
>procedures) really don't matter.  It should take literally no more than
>a few seconds to make the connection between similar features in
>different languages, once the correlation is pointed out.

This of course is not true.  The mapping between a Pascal "pointer"
variable and an Ada "access" variable is well understood.  Only minor
semantic differences exist between the two.  However, no such mapping
exists between a Smalltalk/Eiffel/C++ "class" and an Ada "tagged type/
package/generic/task" (objects with separate threads of control).

I'll contend that translating an OO design into the Ada paradigm is not
a straight forward activity for someone raised on these other languages
(if it is a straight forward activity at all).  It is certainly not as
trivial as making the transition from pointers to access types (if you
can call "access" = "pointer" a transition).

>The Ada 9X reference manual should probably have a note pointing out
>the correlation between tagged types and the various class constructs
>of C++ and other object-oriented languages.

This is not as simple as it might seem and if anything would probably
do more harm than good.  If you're going to use a new paradigm, learn
it, understand it, and *then* build smoething in it.  Don't take the
cheesy way out and use some mechanical translation algorithm without
understanding what's being created.  I can already see the subject
line: "Wanted C++ to Ada9X translator".  I'd love to see that Ada code.

>-- 
>Keith Thompson (The_Other_Keith)  kst@telesoft.com
>TeleSoft^H^H^H^H^H^H^H^H Alsys, Inc.
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Now that's funny.
--
Harry Koehnemann			Arizona State University
koehnema@enuxha.eas.asu.edu		Computer Science Department