Re: GNAT verses A# for soft-realtime system

["Chip Orange" <Chip.Orange@psc.state.fl.us>]

"Rob Veenker" <veenker@xs4all.nl> wrote in message 
news:461a279f$0$79139$e4fe514c@news.xs4all.nl...
> Chip and Allie Orange wrote:
>
>>
>> "Jeffrey R. Carter" <jrcarter@acm.org> wrote in message
>> news:2IWRh.39480$_c5.25338@attbi_s22...
>>> Chip and Allie Orange wrote:
>>>>
>>>> I can purchase a Windows-based PC robot for $5k, and I'd like to learn
>>>> to program it to do autonomous functions (including realtime image
>>>> analysis).
>>>>
>>>> I have a choice of GNAT or A# for my programming environment.
>>>
>>> A# is a version of GNAT that targets .net.
>>>
>>> If you're willing to pay $5k for your robot, you might be willing to pay
>>> 10% or less of that for a supported compiler. AdaCore doesn't provide
>>> anything in that price range, but both Aonix and RR SW do.
>>>
>>> Whether you go with a supported compiler, or with a free version of GNAT
>>> (including A#), you have a couple of decisions to make. One is which
>>> version of Ada you want to use. Only GNAT GPL implements most of the 
>>> most
>>> recent version; A# and the commercial compilers implement Ada 95.
>>>
>>> The other is the target platform you want to use. Apparently you have a
>>> Windows target but could also use .net on top of that. Using .net would
>>> constrain you to A#.
>>>
>>> These are not decisions we can make for you. GNAT GPL has some errors in
>>> the new features, but if you're interested in learning the new version 
>>> of
>>> Ada, that might be the way you want to go. If you'd rather have support
>>> and Ada 95 is acceptable, a commercial compiler would probably be your
>>> choice. If you'd like to use existing .net SW, A# would be the way to 
>>> go.
>>>
>>
>>
>> Thanks Jeff.
>>
>> I am constrained by an NDA from saying why .net offers me some 
>> advantages,
>> but it does.
>>
>> You've helped answer one of my questions, in that I now understand A# is
>> Ada95, while GNAT/GPL is Ada2005.  I was interested in Ada2005, as long 
>> as
>> I'm bothering to throw my time and money into this.
>>
>> My question was also, does .net have something about it that makes it a
>> poor
>> environment for soft real-time systems?  Especially, does it produce code
>> that's noticeably slow, or that garbage collects in some way that would
>> make it less than desirable for real-time systems with very limited CPU
>> resources?
>>
>> Do the additional features of 2005 target real-time systems?
>>
>> Finally, are the products from compiler vendors (Aionix and RR) that much
>> better than GNAT/GPL?
>>
>> Thanks again.
>>
>> Chip
>
> You may want to take a look at
> http://www.adacore.com/wp-content/files/attachments/adacore_news_1106_web.pdf
>


Thank you Rob.  This obviously makes GNAT/Pro attractive to me, but as a 
hobbyist, is there a version that I could reasonably afford?  Or, will these 
features planned for GNAT/Pro also be available in GNAT/GPL?

I'm not quite clear on pricing, or if there are differences in the feature 
set of the two versions of GNAT?  I believe GNAT/Pro buys you support, but 
I'm not sure if it buys you a different compiler or not?

Thanks again,

Chip