Re: What's wrong with my code?

[stefan-lucks@see-the.signature]

On Mon, 28 Apr 2008, amal.alphonse@gmail.com wrote:

> Sorry if I'm posting in the wrong forum.

You are perfectly right here. 

> with Ada.Text_IO, Ada.Integer_Text_IO;
> with SelectionP;
> procedure SelectionPUser is

Replace the following line

>    package IntSelectionP is new SelectionP(Integer, Ada.Text_IO.Put);

by

   procedure Put_Int(I: Integer) is
   begin
      Ada.Integer_Text_IO.Put(I);
   end Put_Int;

   package Int_SelectionP is new X(Integer, Put_Int);

The specification of Put in Ada.Integer_Text_IO is 
   
         procedure Put(Item  : in Num;	
                       Width : in Field := Default_Width;
                       Base  : in Number_Base := Default_Base);

Thanks to the default parameters, you can just write 
"Ada.Integer_Text_IO.Put(I);" to *call* this procedure Put. But using the 
same Put as a generic parameter appears to be different ...

> begin
>    Ada.Text_IO.New_Line;
> end SelectionPUser;

>    procedure Print (A: in out My_Array) is

Nitpick: this should be 
     procedure Print(A in My_Array) is 
to conform with the specification. 

Additional point: Most Ada programmers depreciate identifiers like 
IntSelectionP, SelectionP, ... but prefer to use underscores: 
Int_Selection_P, Selection_P. This improves readability and copes well 
with the case-insensitivity of Ada identifiers. (E.g., for ada Selections 
and SelectionS are the same, but Selections and Selection_S are different. 
I currently can't find a better example, but I hope you get the idea.)

> Also, is my code correct if my purpose is to use the package to create
> arrays of different elements (integer, character, etc) and use the
> procedures Find_Min and Sort and Print on them?

I guess you are going to compare your elements? Then you'll want to 
specify another generic parameter (in addition to the type Element and the 
procedure Element_Put), such as

  function "<"(Left, Right: Element) return Boolean;





-- 
------ Stefan Lucks   --  Bauhaus-University Weimar  --   Germany  ------
               Stefan dot Lucks at uni minus weimar dot de
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