Re: Differences between Ada 83 and other revisions

[Niklas Holsti <niklas.holsti@tidorum.invalid>]

On 14-02-13 23:25 , yoursurrogategod@gmail.com wrote:
> On Thursday, February 13, 2014 2:44:47 PM UTC-5, Niklas Holsti wrote:

>> However, Ada 95 and later Ada standards extend the language beyond Ada
>> 83 in many ways. Some extensions include new kinds of run-time checks
>> for new kinds of run-time errors, which cannot be detected at compile
>> time. Ada 83 had a smaller set of run-time checks and errors, so it can
>> be argued that programs using the Ada 95 and later extensions have an
>> increased risk of failing at run-time even if their compilation succeeds.
>>
>> I don't know if this argument is valid; I don't see an increased risk of
>> run-time failure in my own programming. But I use the new features
>> rather conservatively and sparingly. Moreover, some of the new features
>> make it easier to avoid some Ada 83 -level run-time errors -- for
>> example, controlled types help to avoid errors in memory allocation and
>> deallocation.
>>
> 
> So it would be safe to say that the newer versions of Ada have not
> enabled the creation of less reliable code.

I would say so. You may find other people who disapprove of certain
language details (such as allowing "out" and "in out" parameters for
functions), due to reliability concerns.

> And that the newer versions are overall qualitatively better (hence
> them being used in things such as Thaly's Bullet and more than a
> few aerospace projects.

"Better" is application-specific and perhaps subjective. Certainly the
newer Ada standards are more powerful, but you may not be able to, or
want to, use all the new powerful features in certain applications. For
example, I am currently working in Ada 95, and without the Ada
run-time-system, because this is what the customer has defined as the
HW/SW platform for the application (satellite SW).

-- 
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
      .      @       .