Re: using `use' : what is the best practice ?

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

Le Tue, 07 Jun 2011 19:33:29 +0200, Pascal Obry <pascal@obry.net> a écrit:
> in this case... Look at this code:
>
>     with Ada.Strings.Unbounded;
>     procedure Whatever is
>        S : Ada.Strings.Unbounded.Unbounded_String;
>     begin
>        Ada.Strings.Unbounded.Append (S, "toto");
>     end Whatever;
>
> Far better with:
>
>     with Ada.Strings.Unbounded;
>     procedure Whatever is
>        use Ada.Strings.Unbounded;
>        S : Unbounded_String;
>     begin
>        Append (S, "toto");
>     end Whatever;

You could also use package renaming, to access the leaf of a whole branch  
via a single short name. By the way, subprogram renaming is an option too  
in some cases (when a subprogram's invocation is very often encountered in  
some package body).

> Because Ada.Strings.Unbounded (and all Ada runtime packages) has been  
> designed to be used with a use clause.
>
> Now I do prefer:
>
>     package Circle is
>        type Object is...
>
> And use it as:
>
>     with Circle;
>
>     O : Circle.Object;

Good convention indeed. To talk about concrete matters, the name Instance  
may also be an option to have in mind along with the name Object (Instance  
may be more neutral, depending on one's feeling)

-- 
“Syntactic sugar causes cancer of the semi-colons.”  [Epigrams on  
Programming — Alan J. — P. Yale University]
“Structured Programming supports the law of the excluded muddle.” [Idem]
“c++; /* this makes c bigger but returns the old value */” [Anonymous]