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

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

I wrote:

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

[example presuming that X'Img = "99" when X=99 deleted]

> 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 := Integer'Image(Minute);  
                                       -- Pascal Obry's correction
>       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;

Keith Thompson informed me in private correspondence that, like the
standard 'Image attribute, the GNAT-only 'Img attribute puts in that
annoying leading space, and upon trying it I find he's right.  That's
the risk of relying on vague recollections of descriptions of 'Img by
GNAT team members rather than testing its behavior.  (The ideal
approach, of course, is to consult the documentation, but no version of
gnatinfo.txt that I have mentions 'Img.)

Anyway, the bottom line is that you have to deal with the annoying space
anyway, so you might as well use the standard 'Image attribute.

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