Re: Ada OO Mechanism

[Richard D Riehle <laoXhai@ix.netcom.com>]

In article <t7iu9hrqpw.fsf@calumny.jyacc.com>,
	Hyman Rosen <hymie@prolifics.com> wrote:

>Once again, I will ask for an example demonstrating this, where
>something is more complicated to use in C++ generics than in Ada.
>This will make you the fourth person I have asked for this type
>of example, the others being Richard D. Riehle, Samuel Mize, and
>Robert Dewar. None of the others have chosen to post such an
>example.

 I have a wonderful little proof that this is the case but this
 margin is too narrow for me to write it in its entirety. To
 paraphrase G.B. Shaw, "One an lay all the language advocates
 in the world end to end and still not reach a conclusion."  

 There are certainly benefits to the C++ approach for generic
 programming, which is how Dr. Stroustrup refers to templates
 in his own book and how Ada refers to the same subject.  There
 are also benefits to the Ada approach.  There were inadequacies
 with the Ada model for generics before the addition of the 

            "with package ..."

 construct.  There were serious problems with C++ prior to adding
 the typename reserved word.  Both languages are evolving.  I prefer
 the Ada model for most designs.  However, the syntax of C++ is a
 little more straightforward.  The Ada syntax is designed to enforce
 a stricter set of type checking rules.  C++ can also, in most but not
 all, cases do strict type checking.  There are published examples of
 this.  One of my favorite columns is in a magazine, C++ Report, called
 "Obfuscated C++."  The monthly examples illustrate the central idea. 

 Take any of the examples from that column and try to create equally 
 obfuscated Ada.  In fact, try to create an "obfuscated" Ada program.
 Pretty difficult (not impossible).  

 I am not going to engage in dueling source code where anything I
 can play on my banjo you can play your guitar and Robert can play
 on his pipe organ.  On the other hand, Tocatta and Fuge in D Minor
 is a bit of a stretch for my banjo and Foggy Mountain Breakdown
 sounds a little strange on the pipe organ.  

 C++ is a great language for graphics and other stuff that is not
 safety-critical.  It would seem to me, strange, to select it as 
 the language for flight avionics, air traffic control, or other 
 projects where human life is at stake.  I know people do this, but
 knowing a little bit about both Ada and C++, I find it scary when
 someone decides to use C++ in this situation.  On the other hand,
 for high-speed graphics where safety is not a factor, C++ might ]
 often be a better choice than Ada.  Some instruments just do better
 for certain kinds of music.

 Richard Riehle
 richard@adaworks.com
 http://www.adaworks.com