Re: Help me to chose between ADA 95 and C++

[Ray Blaak <blaak@infomatch.com>]

Chris Powell <chris.powell@rrds.co.uk> writes:
> Did the coding standard for the safety-critical software developed allow
> full use of Ada 95 constructs? My experience of safety-critical software
> is that while Ada is usually the chosen language, most of the Ada
> language features are disallowed. I worked on one project where
> constrained types were not allowed (because they are more likely to
> raise exceptions than unconstrained types), no packages (because data
> hiding limited testability) and certainly nothing as difficult to test
> as inheritance/polymorphism could be used.

Oh Lord. Packages not allowed? In a safety-critical system? Packages are the
one of the fundamental building blocks of Ada to piece systems together with.

Controlling the namespace effectively prevents all sorts of errors, and is the
necessary for having a reasonable design. Anything else is chaos -- a
collection of library level procedures, I suppose, with what cohesiveness?

The testing argument is bogus -- design your packages with testing in mind, and
export the necessary services to allow coverage.

I would hate to maintain that system, or to work for that company in the first
place.

I have also worked in situations with some language features were not allowed
(i.e. access types), and have usually found that the work-arounds to overcome
the missing feature usually tended to be more error-prone and confusing than
using the feature directly.


-- 
Cheers,                                        The Rhythm is around me,
                                               The Rhythm has control.
Ray Blaak                                      The Rhythm is inside me,
blaak@infomatch.com                            The Rhythm has my soul.