Re: Interfacing Ada with C

[Ada novice <posts@gmx.us>]

On Aug 6, 11:51 am, "Dmitry A. Kazakov" <mail...@dmitry-kazakov.de>
wrote:
>
> Because it does not tell anything about My_Float. When you declare a
> subtype you should have a reason for it. The only reason is putting a
> constraint on it. (Another might be type renaming, but that is an Ada
> kludge)
>
> > What about "type My_Float is digits 18" as Jacob Sparre Andersen said
> > in an earlier message?
>
> If you wanted a type of defined accuracy.
>
> It depends on what you want to achieve:
>
> 1. Constraining -> Subtype
>
> 2. Requiring certain accuracy/precision -> Type
>
> 3. Interfacing -> A type from some library package like Interfaces.C
>
> 4. Separation of domains (e.g. measurement units etc) -> Type
>
> 5. Type extension, reimplementation -> type T is private; and in the
> private part: type T is new Float;
>
> > But sjw in an earlier message
> > mentions that the "internals of the matrix operations only use 64
> > bits. So in any case then asking for more than Long-Float precision is
> > not "relevant".
>
> That would be the case 3.
>

Thanks for the explanations.

YC