Re: A couple of questions

["Ed Falis" <falis@verizon.net>]

On Sat, 1 May 2004 15:12:33 +0000 (UTC), Yeric <NOSPAM@NOSPAM.com> wrote:

> Thank you for your insight.

I'll take a crack at some of these - I'm sure there will be some errors.


> How well does ADA interface with other languages ?

Ada is one of the few languages whose design attended to issues of  
interfacing to other languages.  It does well, particularly with C,  
Fortran, assember, and reasonably well with a lot of others.  There are  
specific capabilities to force calling conventions to match those of other  
languages, and there are specific packages that provide definitions of  
common base types from other languages (eg Interfaces.C,  
Interfaces.Fortran ...).

> I know it has capabilities to interface with ADO through COM, what about
> .NET, Can ADA do this now, are there any plans for the future ?

I believe Martin Carlisle at the USAF Academy and his team have made a  
port of GNAT to .NET.

>
> I also read that ADA is reviewd every 10 years, so does this mean the
> language is going to change/enhance in any way for 2005 ?

There are a number of revision issues being considered at this time, for  
enhancement to the standard in roughly 2005.

>
> One thing that makes me feel a bit uneasy about adopting ADA is that  
> there
> seems to be very little activity on web pages for it, and the ADA FAQ is
> dated 1997, even some projects that are good now have not changed in  
> over a
> year.

Don't know what to tell you.  libre.act-europe.fr is updated on a pretty  
regular basis.

> How would ADA handle incorrect data types being input apart from  
> exception
> handling or lots of messy if then statements ?

Usually by exception handling, though there is a typename'Valid (x)  
attribute available that can be used on input of broader type than  
"typename" to explicitly test.

>
> I would very much like to know any thoughts advantages/disadvantes of ADA
> compared to another language, but I dare not mention the other languages
> name to avoid being called a TROLL or starting a debate of this language  
> is
> better than that, like a similar post I noted about OO operating systems.

Well, you are on comp.lang.ada, so the likelihood of a flameware is less  
(the other posting went to a variety of language newsgroups, so invited it  
a bit more).  It's difficult to state advantages in the abstract.

I've done more than dabbling in quite a few languages, including Java,  
Eiffel, C++, Lisp, ...  The things I most appreciate about Ada are its  
flexibility, its clean syntax, well-defined semantics, and its portability  
(oh yeah, and its helpful compilers).  A nice combination.  Other  
languages I've used are IMO superior in certain areas, but don't bring  
that particular balance that I prefer.

> It is interesting to see that ADA supports range checking, but how about
> data type checking, does range checking preclude the need for exception
> handling  for a number too large being entered ?

Certain type checking can be done at compile time; other checking requires  
run-time checks.  In the latter case, exceptions are the standard way of  
flagging a violation.

>
> I guess design by contract could be handled using lots of if then  
> statements
> and carefully crafted exception handling statements ?

Several compilers provide the implementation-defined pragma Assert, that  
can be used to plant assertions in the code - It provides a lot of DBC,  
though it is not as powerful as what is found in Eiffel.  I believe this  
pragma is being added to the next revision of Ada.  Again, the mechanism  
used to enforce the assertion is an exception.

>
> Can ADA interface with OpenGL ? have any games been written in ADA/would  
> ADA
> be suited for games programming ?

I don't know about games.  The mailing list oglada@niestu.com is all about  
OpenGL bindings and use.

>
> Are there any GUI designers available for ADA like in VB? even if this is
> just designing them and compiling as a resource or exporting as ADA code  
> ?

glade is available for use with GTKAda. ObjectAda has a GUI builder for  
Windows.  There are others, I'm sure.

>
> I have seen a couple of Commercial products for ADA Gnat Pro and GPS, but
> there are no published prices for this software.

Contact sales@gnat.com or sales@act-europe.fr.  These products are mainly  
oriented towards project customers and consultative support (disclaimer: I  
work for AdaCore).  ObjectAda from Aonix has a relatively inexpensive  
version available. RR Software almost certainly does as well.  But most  
hobbiests will use public distributions of GNAT.


> I have bookmarked ADApower.com, any other web sites that may be of  
> interest
> ?

www.adaworld.com, libre.act-europe.fr

- Ed