Re: Suggestion for Ada 200x - Interface inheritance

["Steve" <nospam_steved94@attbi.com>]

Thanks.  I looked at AI-251.  It looks like it is covered..

Here's another one:
  Ada currently permits giving the names of operands to functions and
procedures from the caller:

Example:
  function Add( left, right : Natural ) return Natural;

  May be called using:

  result := Add( left => 2, right => 3 );

Use of the names is optional, but if they are present they must match.

What do you think of the idea of also optionally giving the mode of the
parameter, which if present must match the function or procedure
declaration.  That is, extending the above example:

  result := Add( in left => 2, in right => 3 );

Why?  Readability.  When reading code it is sometimes unclear from the
caller whether or not a procedure modifies its parameters.  Adding this
feature would permit specifying this explicitly.  I realize I haven't chosen
the best example since functions only permit "in" parameters, but you
probably get the idea.

It really enhances readability with certain procedure calls such as:

Copy( out buf_1 => a, in buf_2 => b );

Of course bettern naming conventions would help readability in this example.

I could even imagine a pragma that requiring such qualification to enforce
coding conventions.

Steve
(The Duck)

"Wojtek Narczynski" <wojtek@power.com.pl> wrote in message
news:5ad0dd8a.0305240435.337d9373@posting.google.com...
> "Steve" <nospam_steved94@attbi.com> wrote in message
news:<0Pxza.699607$OV.652508@rwcrnsc54>...
[snip]
>
> I find your syntax cleaner than the AI proposal:
>
> http://www.ada-auth.org/cgi-bin/cvsweb.cgi/AIs/AI-00251.TXT?rev=1.12
>
> This AI has a funny title: "Abstract Interfaces to provide Multiple
> Inheritance". Two misconceptions: 1. Interfaces cannot be concrete, 2.
> Interfaces do not provide multiple inheritance. They are just a
> different solution to to the problem.
[snip]
>
> Regards,
> Wojtek