Re: Ada Annoyances

[Norman Worth <nworth@comcastNOSPAM.net>]

Randy Brukardt wrote:
> <raph.amiard@gmail.com> wrote in message
> news:be1619b4-2220-4287-8e67-1af32377d3f7@googlegroups.com...
> ...
>> Ada forcing tagged types on you to use certain features *is* a problem, if
>> only
>> because certain Ada users are forbidden to use tagged types altogether and
>> thus
>> are prevented to use a lot of useful features.
>
> Stupid language usage rules are not the problem of the language design,
> they're a management problem. I can understand banning T'Class (thus banning
> dynamic dispatching) and banning controlled types (thus banning hidden calls
> that can be harder to analyze), but not banning tagged types themselves.
> Indeed, (almost) all new types should be tagged - as Tucker said often
> during the Ada 9x development, "Tagged types work right"; for the most part,
> regular record types don't "work right" for various things and that can't be
> fixed because compatibility concerns. (Although Ada 2012 did bite the bullet
> about equality; that may be a significant reason why there is only one Ada
> 2012 compiler to date.)
>
>                                                Randy.
>
>
Programmers should stop trying to write C++ in Ada.  For the most part, 
it doesn't work.  Where it is forced, it is ugly and unreliable.

You should not use tagged types where they are not needed.  It messes up 
the code.  In general, if you are not going to have derived types, the 
base type should not be tagged.  It's easy enough to change if you 
change your mind, but that means you didn't think things out fully.

Tagged types really do work, for the most part.  And Ada compilers are 
very smart about when they can use static calls and when dispatching is 
really needed.

Using a tagged type for Ada.Controlled was a natural way of implementing it.