Re: Best Ada comp/env for Sun

[mfeldman@seas.gwu.edu (Michael Feldman)]

In article <D585E5.12z@rucs.faculty.cs.runet.edu>,
Michael A. Packer <pac@rucs.faculty.cs.runet.edu> wrote:
>We are in the process of switching from pascal to Ada and I need to
>find a compiler to use.  Can anyone recommend which compiler is best
>and most complete to use on Sun machines running SunOS 4.1.4?
>
Depends on what you think you need. 

People new to Ada have trouble believing that there are no dialects,
but it is true. Ada _compilers_ all accept exactly the same language, 
certainly for any program to be written by a first-
year student, and all the first-year texts have completely portable
examples and software distributions.

So the choice of a compiler has nothing to do with the language itself,
but rather with the environmental stuff. Some of the commercial compilers
have nice X-based environments, but then the students need X terminals to 
use them.  Otherwise, you're talking about vt100 emulation.

Our students use vi as their editor. This lets them run from any seat
in the university, whether PC, Mac, or workstation, using terminal
emulation. There are also some serial network plugs in the dorms,
so students with PCs or Macs can run from there. Students who live
off campus dial in.

We've also concluded that Unix is a great "leveler", as the kids who
"learned it all" in high school find they are not as learned as they
thought.:-)

We have used Ada/Ed for our CS1 course for the last 4 years, and found it
to be just great at that level. It's easy to install (builds wih GCC)
and simple. We have a few scripts that encapsulate a number of options
to make it easier for newbies. The messages are friendly, and, CS1-level
programs, compilation is faster than is the case with commercial compilers.
Runtime tracing is, at the level of intro programs, almost trivial to
set up, with no need to learn a debugger.

For more advanced students, you can install GNAT, the Ada 95 compiler 
from NYU. This fits in nicely with your GCC installation. We are using
it with some more advanced classes. It's a great piece of work and it's
free; I would not recommend it for freshmen because the runtime tracing
requires them to learn how to use gdb. No environment either, but if
students have access to X terminals they (or you) can set up their own
set of windows (editor, listing, output, etc.).

Ada/Ed and GNAT can be ftp-ed from cs.nyu.edu; details on request.

Alsys (now Thomson Software) provides a very nice Ada 83 compiler with full
X environment. It's mature and stable, and costs perhaps $1000. through the
LEAP program. You can install it on your server and run it on workstations
without floating-license grief.

Rational's SEED program provides the APEX environment free to universities, 
which is very nice for advanced work, but is too resource-hungry for
large intro classes. The baseline VADS (formerly Verdix) compiler
is not available for SunOS through SEED, because of an arrangement
with Sun that prohibits it.

If you have the disk space and a bit of system manager resources to do so,
I recommend bringing in as many as you can, then letting the faculty and
students explore. Comparing Ada compilers is fun for many folks, especially
because - for nearly all student programs - the language is identical so
you can compare the other stuff at will.

More by e-mail if you wish.

Mike Feldman
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Michael B. Feldman -  chair, SIGAda Education Working Group
Professor, Dept. of Electrical Engineering and Computer Science
The George Washington University -  Washington, DC 20052 USA
202-994-5919 (voice) - 202-994-0227 (fax) - mfeldman@seas.gwu.edu (Internet)
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One, two, three ways an underdog: Ada fan, Mac fan, Old Liberal Democrat
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Ada on the WWW: http://lglwww.epfl.ch/Ada/ or http://info.acm.org/sigada/
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