Re: Design by contract and control inversion

["Yannick Duchêne (Hibou57)" <yannick_duchene@yahoo.fr>]

Le Fri, 02 Nov 2012 09:59:53 +0100, Yannick Duchêne (Hibou57)  
<yannick_duchene@yahoo.fr> a écrit:
> […]
>      package ABC.Sets.Base is
>
> […]
>      package ABC.Sets.Functional is
>

Out of the primary topic, but a tiny tip I forgot while posting the  
excerpts (as it may be worth to people discovering Ada).

Replace the beginning of `ABC.Sets.Base`, with the following:


     package ABC.Sets.Base is

        package Formals is
           subtype Element_Type is Base.Element_Type;
           subtype Cardinal_Type is Base.Cardinal_Type;
        end Formals;


Then replace the beginning of `ABC.Sets.Functional` with the following:


     package ABC.Sets.Functional is

        package Formals is
           package Base renames Functional.Base;
        end Formals;


That's a useful tip, which will allow you to access the formal parameters  
of an instance of a generic package, whenever needed. Otherwise, as an  
example, `Base.Cardinal_Type` won't be visible from outside of its  
hierarchy, if ever you needed to refer to it this way. Instead of  
`Base.Cardinal_Type` you will then do `Base.Formals.Cardinal_Type`, and  
will be OK. This question used to be discussed about two years ago on this  
Usenet.


-- 
“Syntactic sugar causes cancer of the semi-colons.” [1]
“Structured Programming supports the law of the excluded muddle.” [1]
[1]: Epigrams on Programming — Alan J. — P. Yale University