Re: Built-in types (was Re: How can I avoid Using a Semaphore?

[Robert Dewar <robert_dewar@my-deja.com>]

In article <94fv9d$cjt$1@nnrp1.deja.com>,
  mark_lundquist@my-deja.com wrote:
> In article <94f1a8$k9r$1@nnrp1.deja.com>,
>   Robert Dewar <robert_dewar@my-deja.com> wrote:
> >
> > Carefully written Ada programs should
> > not use the built-in types in any case.
> >
>
> That seems a little broad...
>
> When a careful Ada programmer writes 'Integer', he's saying
> that he understands the things about Integer that are
> implementation-defined and that those things are "don't
> cares" for him in this instance.  It's not careless to say
> that and mean it.

It is never actively *useful* to be able to do this, since
you certainly have *some* requirements on any type you supply,
and you may as well make them explicit.

The trouble is that 90% of programmers writing Integer
explicitly do NOT know what they are saying, and make a mess.
That is why most coding standards wisely suggest not using
type Integer. There are some exceptions, e.g. as the subscript
of the standard type String, and you cannot get away from this
built in type, because of library usage.

P.S. Jean Ichbiah feels it was a bad mistake to have had the
type Standard.String depend on Integer in this way, but it was
too late to change.


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