Re: "C" vrs ADA

[eric@sarin.UUCP (Eric Beser sys admin)]

In article <2231@cbmvax.UUCP>, daveh@cbmvax.UUCP (Dave Haynie) writes:

> The biggest problems with Ada is the massive size of its compiler and the
> verbosity of it's language.  I guess if you really like Pascal or Modula2,
> you might adjust, but if you're used to C, it might take some getting used
> to.  

      I am the Ada Technology Coordinator for a major corporation. Part of my
responsibility is to evaluate and select compilers, evaluate Ada runtime
environments, and to guide our Ada insertion effort. Mr. Haynie having
just written this "Ada Bashing" deserves a proper response. His response
was filled with old information, no longer valid today. My suggesting is
that you take an open mind to the Ada vs C issue, because it is not
as Mr. Haynie suggests.


   Working in an industrial environment, and having used Ada, I do not see
how the "size" of a compiler matters in producing code that is efficient,
that is easily maintainable, and documentable. If you are used to C, you
may have trouble adjusting to the strong typing of the language. Ada is
a verbose language (if rich can be stated in any other words). But it is that
richness that makes the language so useful.

> 
> As for where it's used, mainly DOD I'd guess.  It certainly isn't used much,
> if any, in commercial or industrial sectors.  C's the language for most of
> these, though your Fortran experience could come in handy in some heavy
> duty scientific fields (most machines have Fortran compilers that code better
> than existing C compilers, but since there's more work being done on C, I
> wouldn't be surprised if this is changing).  Ada is certainly general purpose
> enough to be used elsewhere if you have access to a compiler for it, and it
> generally has alot of things built into it that you have to add to C language
> (like tasks, exceptions, etc.).

  I get irked when I hear this. This may have been true a year ago, but no
longer. Many customers (non DOD or NATO) are requesting Ada because of the
software engineering that it dictates. Ada is not just a computer language,
it is a software engineering methodology. Many customers who originally
requested C are now asking for Ada. The compilers today are becoming efficient.
There are some imperfections however, and all is not rosy. But there are
compilers for the 68020 that produce well optimized code. There are compilers
for the 1750A military processor that produced adequate code, although 
not as well optimized. Toolsets are now usable. In fact, you can buy a 
validate Ada compiler for the IBM PC-XT (Meridian) that does not require
extra memory, is somewhat expensive (700.00), but not the $3000.00 that
the leading pc vendor charges.


Let me give an example from actual experience.

  I am part of a large Ada project that is building a tool for use by our
engineers (industrial, commercial, as well as DOD contracts). After coding
this tool, we determined that some inefficiencies dictated a design change.
This design change proliferated itself through the entire system. The coding
for this change took about a man-month, but the debug and reintegration
phase took only two days. The system ran as before, must more efficient
due to the design change. Had the code been written in C, this would not
have happened. Many of the errors that were interjected by the engineers
were due to spelling, wrong variable selection, or unhandled boundary
conditions. These errors would not have come out during C compilation.
They would have manifested themselves in various (or nefarious) bugs. These
interjected errors were found (80% approx) during compilation of the code.
An additional 15% were found on first startup of the system by constraint
and unhandled exceptions. The remainder were found on integration.

My suggestion is that you learn software engineering, object oriented
design, and the use of software tools. Then learn Ada. You will find
that the C will come in handy when you have to try to understand what
some engineer did so to do an Ada redesign.

Eric Beser
EBESER@ADA20   - arpa
{mimsy}!aplcen!cp1!sarin!eric - usenet