More about Ada as a programming language

More about Ada as a programming language

[����RM��]

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Sorry about last message on "ADA", I actually meant about the Ada
programming language. Thanks anyway, but could anyone please tell me a
little more about Ada programming? 

^   ^
O   O
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     ... ...����RM��

Re: More about Ada as a programming language

[John Herro]

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����RM��@everywhere.com writes:
> ... could anyone please tell me a
> little more about Ada programming? 
     I assume you saw my last message (saying that Ada catches errors at
compile time that other languages catch only at run time, or not at all,
and saying how enthusiastic I am about Ada).
     It's hard to know where to begin to tell you "a little more" about a
language as large as Ada, but I'll pick a couple of points.  Ada's
handling of access types ("pointers" in other languages) makes it
impossible to create dangling references, unless you deliberately use
Unchecked_Deallocation or Unchecked_Access in your program.  In contrast,
I've seen many, many problems with C and C++ programs due to dangling
references.
     In Ada, it IS possible to attempt to dereference a null pointer, that
is, to try to access "the object pointed to" when there's no such object. 
But in Ada this error raises an exception which you can trap and handle. 
If you don't trap and handle it, the Ada program ends gracefully with a
"Constraint_Error" message, and, with many Ada compilers, it can tell you
on what line of your program the error occurred.  In other languages,
attempting to dereference a null pointer crashes the program and causes a
General Protection Fault on a PC, an Access Violation on a VAX, etc.
     Ada's Named Parameter Association improves the readability of a call,
because in the call you can see the names of the formal parameters ("dummy
arguments") of the subprogram.  In other languages, you have to turn to
the subprogram to find the names of the formal parameters.
     Ada's packages enable you to contain the effects of certain program
changes to a small portion of the entire program, improving
maintainability.  Trying to explain here how that works would take much
too long.
     Ada has many, many other advantages; I cited just a few here.  Permit
me to post one more reference to my shareware Ada Tutor program, available
for download at the WWW and FTP sites below my signature, and to mention
once again the free on-line Ada tutorials at
http://lglwww.epfl.ch/Ada/Tutorials/Lovelace/lovelace.html and at
http://www.scism.sbu.ac.uk/law/lawhp.html.
     You'll like Ada, and you'll find the people at comp.lang.ada eager to
help you.
- John Herro
Software Innovations Technology
http://members.aol.com/AdaTutor
ftp://members.aol.com/AdaTutor
MUSIC is easier to read when written in C.
SOFTWARE is easier to read when written in Ada!

Re: More about Ada as a programming language

[����RM��]

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On 5 May 1996 07:19:04 -0400, johnherro@aol.com (John Herro) wrote:

>If you don't trap and handle it, the Ada program ends gracefully with a
>"Constraint_Error" message, and, with many Ada compilers, it can tell you
>on what line of your program the error occurred.  In other languages,
>attempting to dereference a null pointer crashes the program and causes a
>General Protection Fault on a PC, an Access Violation on a VAX, etc.
>     Ada's Named Parameter Association improves the readability of a call,
>because in the call you can see the names of the formal parameters ("dummy
>arguments") of the subprogram.  In other languages, you have to turn to
>the subprogram to find the names of the formal parameters.
>     Ada's packages enable you to contain the effects of certain program
>changes to a small portion of the entire program, improving
>maintainability.  Trying to explain here how that works would take much
>too long.
>     Ada has many, many other advantages; I cited just a few here.  Permit
>me to post one more reference to my shareware Ada Tutor program, available
>for download at the WWW and FTP sites below my signature, and to mention
>once again the free on-line Ada tutorials at
>http://lglwww.epfl.ch/Ada/Tutorials/Lovelace/lovelace.html and at
>http://www.scism.sbu.ac.uk/law/lawhp.html.
>     You'll like Ada, and you'll find the people at comp.lang.ada eager to
>help you.
>- John Herro
>Software Innovations Technology
>http://members.aol.com/AdaTutor
>ftp://members.aol.com/AdaTutor
>MUSIC is easier to read when written in C.
>SOFTWARE is easier to read when written in Ada!

Thanks, I checked out one of the tutorial site, I agree Ada's source
is easier to read than in C. But what platform will Ada program run
on? Does it do multimedia, graphics, etc? 

^   ^
O   O
  < 
\___/ 
     ... ...����RM��

Re: More about Ada as a programming language

[John Herro]

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I wrote:
>> MUSIC is easier to read when written in C.
>> SOFTWARE is easier to read when written in Ada!

����RM��@everywhere.com (����RM��) writes:
> I agree Ada's source is easier to read than in
> C. But what platform will Ada program run
> on? Does it do multimedia, graphics, etc?
     It depends on the Ada compiler.  Ada compilers are available for a
very wide variety of platforms.  Most of my experience is with a PC, but
I've used VAX Ada and Ada on Unix machines.
     The compiler I'm using at the moment, Open Ada for DOS, doesn't
directly do graphics and multimedia.  It does, however, let you call the
DOS interrupts and interface to assembly language.
     Thomson Software Products (800-833-0085, http://www.thomsoft.com)
sells ActivAda for the PC, starting at $95, which works with Windows 3.1,
NT, and 95, and supports 32-bit DLLs.  (I have no financial interest in
Thomson.)
     The Ada language standard was revised in 1983 and again in 1995.  The
compilers mentioned above are Ada 83 compilers, but Thomson is working on
an Ada 95 version of ActivAda.
     The PRINT.ME file in my Ada Tutor program includes a list of Ada
compilers for DOS and Windows only.  You can find a *complete* list of
validated Ada 83 compilers at
ftp://sw-eng.falls-church.va.us/public/AdaIC/compilers/83val/val-comp.txt,
and a complete list of validated Ada 95 compilers at
ftp://sw-eng.falls-church.va.us/public/AdaIC/compilers/95val/95vcl.txt.  A
"validated" Ada compiler is a compiler that has been tested to meet the
Ada language standard exactly, so you know that it's not a subset or
superset of standard Ada.  This, among other things, tends to make Ada
programs more portable than programs in other languages.
     I hope this helps.
- John Herro
Software Innovations Technology
http://members.aol.com/AdaTutor
ftp://members.aol.com/AdaTutor

Re: More about Ada as a programming language

[Todd Coniam]

In article <31919b09.38647862@news.saipan.com>, ����RM��@everywhere.com 
says...
>
>Thanks, I checked out one of the tutorial site, I agree Ada's source
>is easier to read than in C. But what platform will Ada program run
>on? Does it do multimedia, graphics, etc? 
>
>^   ^
>O   O
>  < 
>\___/ 
>     ... ...����RM��

-- 

What platform do you want Ada on?  Currently, (and I know this is not 
complete) you may run Ada on:  MS-DOS, OS/2, Mac, MS-Win 3.1, MS-Win95, 
MS-Win NT, Sun SunOS 4.x & Solaris 2.x, DEC, SGI, HP, VAX/VMS, Harris 
Nighthawk, TI DSP's, etc...

Ada, like most general purpose languages, is capable of doing almost anything 
you want.  What are you interested in doing?

-------------------------------------------------------------------------
Todd Coniam       | Member: Team Ada
tconiam@ionet.net | Ada 95 - The international standard in OO languages
-------------------------------------------------------------------------
Check: http://lglwww.epfl.ch/Ada/     Free compiler: http://www.gnat.com/

Re: More about Ada as a programming language

[Todd Coniam]

In article <318bd23f.2688720@news.saipan.com>, ����RM��@everywhere.com 
says...
>
>Sorry about last message on "ADA", I actually meant about the Ada
>programming language. Thanks anyway, but could anyone please tell me a
>little more about Ada programming? 
>
>^   ^
>O   O
>  < 
>\___/ 
>     ... ...����RM��

-- 

Your best bet is to get one of the free tutorials listed at:

     http://lglwww.epfl.ch/Ada/Tutorials/Tutorials.html

They are all quite good.  They do not cover the entire language, however.

Feel free to ask specific questions about Ada.  Everyone is glad to help.
-------------------------------------------------------------------------
Todd Coniam       | Member: Team Ada
tconiam@ionet.net | Ada 95 - The international standard in OO languages
-------------------------------------------------------------------------
Check: http://lglwww.epfl.ch/Ada/     Free compiler: http://www.gnat.com/

Re: More about Ada as a programming language

[tmoran]

In <31919b09.38647862@news.saipan.com> G]_KRMdq asked:
> what platform will Ada program run on? Does it do multimedia, graphics, etc?
  You can, of course, read from CDROMs, draw graphics, input/output
with sound cards, etc, just as well with Ada as anything else.  A few
years ago I did a videotape editor on a PC, using RR's compiler.  It
used TV frame capture and sound cards, as well as a true GUI (user
interacted with two TV monitors, remote controls, and yellow note pads
shown on the computer's screen or on a TV set).  Ada is particularly
good at timing (you can program in terms of seconds, rather than
'clock ticks').  You can use separate Ada tasks to concentrate on
video, sound, VCR control, etc, rather than juggling complex sets of
call-back routines.  I ported the 'edit' part of that system to the
Macintosh using Meridian's Ada compiler.