Re: function Is_Open (File : File_Type) return Boolean; :Text_io

[AdaMagica <christ-usch.grein@t-online.de>]

Am Mittwoch, 28. Oktober 2015 22:02:17 UTC+1 schrieb Dmitry A. Kazakov:
> > In Ada, we can write:
> > 
> >     type Gizmo_Count is range 0 .. 2**10;
> >     Num_Gizmos: Gizmo_Count := 0;
> > 
> > IMHO, documenting the 0..1024 requirement in executable code is much
> > better than using a comment:
> 
> How is that documenting? It is a direct instruction to the compiler.
> Documentation is addressed to the human reader.
> 
> The advantage of Ada over C is that where in Ada you can instruct, in C the
> only way is to document.

IMHO, this is again a case of Dmitry's special nomenclature:
Documentation is not what is evaluable by the compiler; documentation is in comments or in separate documents (like design docs).

I think the Ada community has a different bias: Expressing requirements, i.e. documentation, in code is preferable. Thus we use Natural rather than Integer  for counting, use constraints like above in Gizmo. And we call this *documenting*. This is both, an instruction for the compiler *and* information addressed to the reader.

My two EURO cents.