Re: Functions vs constants

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Fri, 25 Jul 2014 14:31:06 -0500, Randy Brukardt wrote:

> "Georg Bauhaus" <bauhaus@futureapps.invalid> wrote in message 
> news:lqsueh$q0v$1@dont-email.me...
>> On 25/07/14 06:56, Randy Brukardt wrote:
> ...
>>> In what sense is Put for a
>>> String overriding Put for a Float? Dmitry covered this ground pretty well 
>>> in his response.
>>
>> His answer includes, actually, that for Put you need non-Ada only
>> if the file argument should be included in dispatching. Any Float
>> or String arguments could be passed to an overridden version of Put
>> determined statically.
> 
> Huh? "overriding" only works for related types. In what universe are Float 
> and String related? They have almost no common operations. "overloading" 
> (which you don't want to use) works for any types, including unrelated ones.

One thing missing in Ada is ad-hoc supertypes. That is when you could
create a common parent for existing types.

E.g. Ada.Text_IO would create an interface Printable and then pronounce it
a supertype of Integer, Float, String etc. After that Put will become a
primitive operation of Printable and thus overridden rather than
overloaded.

This is also the way of having containers of Float and String without
having a premeditated common parent type.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de