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From: "Pascal Obry" <p.obry@der.edf.fr>
Subject: Re: Language question : function'Access / function'unchecked_Access
Date: 1998/11/25
Message-ID: <73gka5$fco$1@cf01.edf.fr>#1/1
X-Deja-AN: 415476154
References: <ek1BDX5F#GA.291@nih2naac.prod2.compuserve.com>
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Organization: EDF
Newsgroups: comp.lang.ada
Date: 1998-11-25T00:00:00+00:00
List-Id: <comp.lang.ada>

Didier,

You can't do that, the compiler is right !

There is many solutions. Two of them have been described by Matthew Heaney.

The other solution is to put you Match function in a separate package. This
way you don't
have the problem of "Accessiblility Level".

Pascal.

Didier DOUSSAUD a �crit dans le message ...
>I write a list package and need a Seach function that return the "Index" of
>the object that match some condition.
>
>(the condition is coded in a function that have for parameter the item of
>the list and return the boolean result of the test )
>
>Impossible to call the Search function ????
>
>Look the following sample may be more explicit than my poor english...
>
>Thanks
>Didier
>d_doussaud@csi.com
>
>--------------------------------------------------------------------
>package P_List is
>  type Item is null record;
>  type List is null record;
>  type Index is null record;
>
>  type Search_Function is access function ( I : Item ) return Boolean;
>
>  function Search( L : List; Funct : Search_Function ) return Index;
>end P_List;
>-----------------------------------------------------------------------
>with P_List; use P_List;
>procedure Test_Callback is
>  L : List;
>  I : Index;
>  function Match( I : Item ) return Boolean is
>  begin
>    return True;
>  end;
>begin
>
>  -- this line :
>  I := Search( L, Match );
>  -- generate the ERROR :
>  --    The Accessibility Level of The Subprogram Denoted By The The Prefix
>  --    Shall not Be Statically Deeper Than That of The Expected type
>  -- I can understand this
>
>  -- but this line :
>  I := Search( L, Match'Unchecked_Access );
>  -- generate the ERROR :
>  --    The prefix of Unchecked_Access, which is function name, has no
>  --    interpretation as A Parameterless function Call
>  -- ????
>
>  -- is it possible to do what I want in ADA ?
>end;


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