Re: The old "Object.Method" syntax debate

["David C. Hoos" <david.c.hoos.sr@ada95.com>]

"Preben Randhol" <randhol+abuse@pvv.org> wrote in message
news:slrnbcnb56.996.randhol+abuse@kiuk0152.chembio.ntnu.no...
> Robert A Duff wrote:
> > Jacob Sparre Andersen <sparre@crs4.it> writes:
> >
> >> Will the change mean that currently legal programs will have to be
> >> rewritten?
> >
> > No.  The ARG is very concerned about compatibility, and would never make
> > a change that would cause everybody to have to rewrite their Ada
> > programs.
>
> But how is it done?
>
> I mean how can the compiler know that a procedure say:
>
>    procedure Marry (Person : Man; Person2 : Woman);
>
> should be able to call like this:
>
>    type Him : Man;
>    type Her : Woman;
>
>
>    Him.Marry (Her);
>    --  or
>    Her.Marry (Him);
>
> If I have understood the change suggested.
>
> Would it not make the language ambigous?

It would not make the language ambiguous.  Since Him and Her
are objects of different types, each type would need its own
version of the Marry procedure, unless they were both derived
from a common ancestor type which had a class-wide Marry
procedure.

The two calls to such a class-wide procedure would not be
ambiguous, any more than overloaded subprograms are
ambiguous.  The different subprogram profiles disambiguate
the calls.

> -- 
> Preben Randhol                    http://www.pvv.org/~randhol/
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