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Date: 7 Dec 92 19:40:59 GMT
From: mcsun!sunic!news.lth.se!dag@uunet.uu.net  (Dag Bruck)
Subject: Re: C++ vs. Ada -- Is Ada loosing?
Message-ID: <1992Dec7.194059.9171@lth.se>
List-Id: <comp.lang.ada>

In <comp.lang.ada> srheintze@happy.colorado.edu writes:
>
>HOWEVER, please read "A dynamic Vector is harder than it looks" from the June
>1992 is issue of JOOP (Journal of Object Oriented Programming) - vol 5 no 4. 
>*THIS ARTICLE IS SCARY*  Basically Tom Cargill pointed out a bug that nearly
>all C++ textbooks have made when they implement a dynamically sized array. 
>This includes the textbook written by the implementor of the AT&T Cfront
>compiler (will I get in trouble if I mention his name?).  If the language is s
o
>convoluted that even the experts (including the compiler writers) cannot get
>their simple textbook examples correct, then I conclude there is something
>drastically wrong with the language.

I agree that Tom Cargill wrote an interesting article, but I think the
conclusion is exactly what Cargill writes: a dynamic vector class is
harder than it looks.

People sometimes fall into the trap of thinking that hard problems are
easier to solve with a "stricter" programming language.  This is often
not the case.  It is particularly difficult to realize a library that
is natural to use, and at the same time efficient with regard to space
and time.  A matrix library is a good example:

	- a trivial matrix library is not hard to write

	- it becomes much harder if you want to implement a full
	  set of natural operations, e.g., slices

	- it becomes harder if you want to provide automatic
	  memory management

	- it becomes *much* harder if you want to provide "optimal"
	  memory management that immediately reuses space for used
	  temporaries.

[Optimal space utilization is for example to use only one temporary
variable to calculate the matrix expression "X := A+B+C".]

Dag Bruck