Re: user-defined type conversion

[18k11tm001@sneakemail.com (Russ)]

"David C. Hoos, Sr." <david.c.hoos.sr@ada95.com> wrote in message news:<mailman.1021892102.6644.comp.lang.ada@ada.eu.org>...
> ----- Original Message ----- 
> From: "Russ" <18k11tm001@sneakemail.com>
> Newsgroups: comp.lang.ada
> To: <comp.lang.ada@ada.eu.org>
> Sent: May 19, 2002 10:25 PM
> Subject: Re: user-defined type conversion
> 
> 
> <snip>
> > Yes, I meant "arg" rather than "feet", and I don't think it's an
> > infinite resursion. The "inches" function takes a "feet" argument,
> > whereas the call of "inches" within it takes a "float" argument.
> > That's two different functions.
> >
> As has been pointed out, the call of "inches" within takes an argument of
> _any numeric type_, not just float, and it is this which makes the call
> ambiguous.
>  
> > I still don't see why I shouldn't be able to make my own type/unit
> > conversion that has the same simple syntax as the built-in type
> > conversions. Until I do, I consider it a minor deficiency of the
> > language.
> Do you understand now?

Yes, I understand now. But I think Ada should have been designed to
first check for a user-defined type conversion before using a
compiler-generated conversion. That would solve the ambiguity problem
and allow users to create their own type/unit conversions with the
same syntax as built-in type conversions. That, in turn, would allow
developers to create simple and elegant type/unit system for each
particular application.