Re: Leading zeros with Int_IO.Put()? Or another package?

["Norman H. Cohen" <ncohen@watson.ibm.com>]

J.D. Baldwin wrote:
 

> So I added relevant lines of code to CAL.ADB:
> 
>                   if (MINUTE <= 9) then
>                      Int_IO.Put(0, 0);
>                   end if;
>                   Int_IO.Put(MINUTE,0);
> 
> . . . and so forth, for each relevant value.
> 
> My question:  is there a better way to pad out integers with leading
> zeros?  What if I wanted to pad to a width of three or four or sixteen,
> all with zeros?  Is there a standard way to achieve this in Ada?

Using the GNAT-specific 'Img attribute and the standard package
Ada.Strings.Fixed:

   Ada.Strings.Fixed.Move
      (Source  => Minute'Img,
       Target  => Buffer, 
       Justify => Right, 
       Pad     => '0');
   Ada.Text_IO.Put (Buffer);

(where Buffer is a string of the appropriate length, in this case 2). 
Using the standard 'Image attribute (which annoyingly places a space in
front of nonnegative numerals) instead of 'Img to retain portability to
other compilers:

   declare
      Image  : constant String := Minute'Image;
      Buffer : String (1 .. Field_Length);  -- 2 in the case of minutes
   begin
      Ada.Strings.Fixed.Move
         (Source  => Image (2 .. Image'Length),
          Target  => Buffer, 
          Justify => Right, 
          Pad     => '0');
      Ada.Text_IO.Put (Buffer);
   end;

-- 
Norman H. Cohen
mailto:ncohen@watson.ibm.com
http://www.research.ibm.com/people/n/ncohen