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From: =?utf-8?Q?Yannick_Duch=C3=AAne_=28Hibou57?=
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Newsgroups: comp.lang.ada
Subject: Re: Using Red-Black Trees
Date: Wed, 17 Nov 2010 23:59:13 +0100
Organization: Ada @ Home
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Date: 2010-11-17T23:59:13+01:00
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Le Wed, 17 Nov 2010 06:10:22 +0100, Adam Beneschan <adam@irvine.com> a  =

=C3=A9crit:
> (And to *really* dream, an
> implementation could provide an operation in a child package to allow
> the caller to select from a set of optimization options and then
> provide alternate implementations.  No, I'm not volunteering to do the=

> work :) )
>
>                                  -- Adam
How do you get, with Ada, something similar to what you have with SML, I=
  =

mean multiple structures all implementing a same signature ?  =

Unfortunately, with Ada, there is no way to do it without tagged/interfa=
ce  =

types (if a package interface specifies operations, then it must a packa=
ge  =

body which implements, =E2=80=A6 in one way only). Would be nice to be a=
ble with  =

Ada to have this SML feature: =E2=80=9Cfor that package specification, u=
se that or  =

this implementation.=E2=80=9D

I don't see a way to do that using child packages, as the implementation=
  =

of an operation specified in a package interface cannot be deferred to a=
  =

(or multiple) child package. Child package can only extent.

-- =

Si les chats miaulent et font autant de vocalises bizarres, c=E2=80=99es=
t pas pour  =

les chiens.

=E2=80=9CI am fluent in ASCII=E2=80=9D [Warren 2010]